clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
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/*
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* Copyright (C) 2013 Broadcom Corporation
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* Copyright 2013 Linaro Limited
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include "clk-kona.h"
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#include <linux/delay.h>
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2019-04-18 22:20:22 +00:00
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#include <linux/io.h>
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2015-04-16 19:43:48 +00:00
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#include <linux/kernel.h>
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2019-04-18 22:20:22 +00:00
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#include <linux/clk-provider.h>
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clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
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2014-04-21 21:11:42 +00:00
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/*
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* "Policies" affect the frequencies of bus clocks provided by a
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* CCU. (I believe these polices are named "Deep Sleep", "Economy",
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* "Normal", and "Turbo".) A lower policy number has lower power
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* consumption, and policy 2 is the default.
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*/
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#define CCU_POLICY_COUNT 4
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clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
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#define CCU_ACCESS_PASSWORD 0xA5A500
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#define CLK_GATE_DELAY_LOOP 2000
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/* Bitfield operations */
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/* Produces a mask of set bits covering a range of a 32-bit value */
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static inline u32 bitfield_mask(u32 shift, u32 width)
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{
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return ((1 << width) - 1) << shift;
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}
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/* Extract the value of a bitfield found within a given register value */
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static inline u32 bitfield_extract(u32 reg_val, u32 shift, u32 width)
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{
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return (reg_val & bitfield_mask(shift, width)) >> shift;
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}
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/* Replace the value of a bitfield found within a given register value */
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static inline u32 bitfield_replace(u32 reg_val, u32 shift, u32 width, u32 val)
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{
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u32 mask = bitfield_mask(shift, width);
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return (reg_val & ~mask) | (val << shift);
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}
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/* Divider and scaling helpers */
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/* Convert a divider into the scaled divisor value it represents. */
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static inline u64 scaled_div_value(struct bcm_clk_div *div, u32 reg_div)
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{
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2014-04-07 13:22:12 +00:00
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return (u64)reg_div + ((u64)1 << div->u.s.frac_width);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
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}
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/*
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* Build a scaled divider value as close as possible to the
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* given whole part (div_value) and fractional part (expressed
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* in billionths).
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*/
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u64 scaled_div_build(struct bcm_clk_div *div, u32 div_value, u32 billionths)
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{
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u64 combined;
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BUG_ON(!div_value);
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BUG_ON(billionths >= BILLION);
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combined = (u64)div_value * BILLION + billionths;
|
2014-04-07 13:22:12 +00:00
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combined <<= div->u.s.frac_width;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
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|
2015-04-16 19:43:48 +00:00
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return DIV_ROUND_CLOSEST_ULL(combined, BILLION);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
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|
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|
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|
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|
|
|
/* The scaled minimum divisor representable by a divider */
|
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|
|
static inline u64
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scaled_div_min(struct bcm_clk_div *div)
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{
|
|
|
|
|
if (divider_is_fixed(div))
|
2014-04-07 13:22:12 +00:00
|
|
|
return (u64)div->u.fixed;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return scaled_div_value(div, 0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* The scaled maximum divisor representable by a divider */
|
|
|
|
|
u64 scaled_div_max(struct bcm_clk_div *div)
|
|
|
|
|
{
|
|
|
|
|
u32 reg_div;
|
|
|
|
|
|
|
|
|
|
if (divider_is_fixed(div))
|
2014-04-07 13:22:12 +00:00
|
|
|
return (u64)div->u.fixed;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
2014-04-07 13:22:12 +00:00
|
|
|
reg_div = ((u32)1 << div->u.s.width) - 1;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return scaled_div_value(div, reg_div);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Convert a scaled divisor into its divider representation as
|
|
|
|
|
* stored in a divider register field.
|
|
|
|
|
*/
|
|
|
|
|
static inline u32
|
|
|
|
|
divider(struct bcm_clk_div *div, u64 scaled_div)
|
|
|
|
|
{
|
|
|
|
|
BUG_ON(scaled_div < scaled_div_min(div));
|
|
|
|
|
BUG_ON(scaled_div > scaled_div_max(div));
|
|
|
|
|
|
2014-04-07 13:22:12 +00:00
|
|
|
return (u32)(scaled_div - ((u64)1 << div->u.s.frac_width));
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Return a rate scaled for use when dividing by a scaled divisor. */
|
|
|
|
|
static inline u64
|
|
|
|
|
scale_rate(struct bcm_clk_div *div, u32 rate)
|
|
|
|
|
{
|
|
|
|
|
if (divider_is_fixed(div))
|
|
|
|
|
return (u64)rate;
|
|
|
|
|
|
2014-04-07 13:22:12 +00:00
|
|
|
return (u64)rate << div->u.s.frac_width;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* CCU access */
|
|
|
|
|
|
|
|
|
|
/* Read a 32-bit register value from a CCU's address space. */
|
|
|
|
|
static inline u32 __ccu_read(struct ccu_data *ccu, u32 reg_offset)
|
|
|
|
|
{
|
|
|
|
|
return readl(ccu->base + reg_offset);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Write a 32-bit register value into a CCU's address space. */
|
|
|
|
|
static inline void
|
|
|
|
|
__ccu_write(struct ccu_data *ccu, u32 reg_offset, u32 reg_val)
|
|
|
|
|
{
|
|
|
|
|
writel(reg_val, ccu->base + reg_offset);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline unsigned long ccu_lock(struct ccu_data *ccu)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
|
|
|
|
|
spin_lock_irqsave(&ccu->lock, flags);
|
|
|
|
|
|
|
|
|
|
return flags;
|
|
|
|
|
}
|
|
|
|
|
static inline void ccu_unlock(struct ccu_data *ccu, unsigned long flags)
|
|
|
|
|
{
|
|
|
|
|
spin_unlock_irqrestore(&ccu->lock, flags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Enable/disable write access to CCU protected registers. The
|
|
|
|
|
* WR_ACCESS register for all CCUs is at offset 0.
|
|
|
|
|
*/
|
|
|
|
|
static inline void __ccu_write_enable(struct ccu_data *ccu)
|
|
|
|
|
{
|
|
|
|
|
if (ccu->write_enabled) {
|
|
|
|
|
pr_err("%s: access already enabled for %s\n", __func__,
|
|
|
|
|
ccu->name);
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
ccu->write_enabled = true;
|
|
|
|
|
__ccu_write(ccu, 0, CCU_ACCESS_PASSWORD | 1);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void __ccu_write_disable(struct ccu_data *ccu)
|
|
|
|
|
{
|
|
|
|
|
if (!ccu->write_enabled) {
|
|
|
|
|
pr_err("%s: access wasn't enabled for %s\n", __func__,
|
|
|
|
|
ccu->name);
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
__ccu_write(ccu, 0, CCU_ACCESS_PASSWORD);
|
|
|
|
|
ccu->write_enabled = false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Poll a register in a CCU's address space, returning when the
|
|
|
|
|
* specified bit in that register's value is set (or clear). Delay
|
|
|
|
|
* a microsecond after each read of the register. Returns true if
|
|
|
|
|
* successful, or false if we gave up trying.
|
|
|
|
|
*
|
|
|
|
|
* Caller must ensure the CCU lock is held.
|
|
|
|
|
*/
|
|
|
|
|
static inline bool
|
|
|
|
|
__ccu_wait_bit(struct ccu_data *ccu, u32 reg_offset, u32 bit, bool want)
|
|
|
|
|
{
|
|
|
|
|
unsigned int tries;
|
|
|
|
|
u32 bit_mask = 1 << bit;
|
|
|
|
|
|
|
|
|
|
for (tries = 0; tries < CLK_GATE_DELAY_LOOP; tries++) {
|
|
|
|
|
u32 val;
|
|
|
|
|
bool bit_val;
|
|
|
|
|
|
|
|
|
|
val = __ccu_read(ccu, reg_offset);
|
|
|
|
|
bit_val = (val & bit_mask) != 0;
|
|
|
|
|
if (bit_val == want)
|
|
|
|
|
return true;
|
|
|
|
|
udelay(1);
|
|
|
|
|
}
|
2014-04-21 21:11:37 +00:00
|
|
|
pr_warn("%s: %s/0x%04x bit %u was never %s\n", __func__,
|
|
|
|
|
ccu->name, reg_offset, bit, want ? "set" : "clear");
|
|
|
|
|
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2014-04-21 21:11:42 +00:00
|
|
|
/* Policy operations */
|
|
|
|
|
|
|
|
|
|
static bool __ccu_policy_engine_start(struct ccu_data *ccu, bool sync)
|
|
|
|
|
{
|
|
|
|
|
struct bcm_policy_ctl *control = &ccu->policy.control;
|
|
|
|
|
u32 offset;
|
|
|
|
|
u32 go_bit;
|
|
|
|
|
u32 mask;
|
|
|
|
|
bool ret;
|
|
|
|
|
|
|
|
|
|
/* If we don't need to control policy for this CCU, we're done. */
|
|
|
|
|
if (!policy_ctl_exists(control))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
offset = control->offset;
|
|
|
|
|
go_bit = control->go_bit;
|
|
|
|
|
|
|
|
|
|
/* Ensure we're not busy before we start */
|
|
|
|
|
ret = __ccu_wait_bit(ccu, offset, go_bit, false);
|
|
|
|
|
if (!ret) {
|
|
|
|
|
pr_err("%s: ccu %s policy engine wouldn't go idle\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If it's a synchronous request, we'll wait for the voltage
|
|
|
|
|
* and frequency of the active load to stabilize before
|
|
|
|
|
* returning. To do this we select the active load by
|
|
|
|
|
* setting the ATL bit.
|
|
|
|
|
*
|
|
|
|
|
* An asynchronous request instead ramps the voltage in the
|
|
|
|
|
* background, and when that process stabilizes, the target
|
|
|
|
|
* load is copied to the active load and the CCU frequency
|
|
|
|
|
* is switched. We do this by selecting the target load
|
|
|
|
|
* (ATL bit clear) and setting the request auto-copy (AC bit
|
|
|
|
|
* set).
|
|
|
|
|
*
|
|
|
|
|
* Note, we do NOT read-modify-write this register.
|
|
|
|
|
*/
|
|
|
|
|
mask = (u32)1 << go_bit;
|
|
|
|
|
if (sync)
|
|
|
|
|
mask |= 1 << control->atl_bit;
|
|
|
|
|
else
|
|
|
|
|
mask |= 1 << control->ac_bit;
|
|
|
|
|
__ccu_write(ccu, offset, mask);
|
|
|
|
|
|
|
|
|
|
/* Wait for indication that operation is complete. */
|
|
|
|
|
ret = __ccu_wait_bit(ccu, offset, go_bit, false);
|
|
|
|
|
if (!ret)
|
|
|
|
|
pr_err("%s: ccu %s policy engine never started\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool __ccu_policy_engine_stop(struct ccu_data *ccu)
|
|
|
|
|
{
|
|
|
|
|
struct bcm_lvm_en *enable = &ccu->policy.enable;
|
|
|
|
|
u32 offset;
|
|
|
|
|
u32 enable_bit;
|
|
|
|
|
bool ret;
|
|
|
|
|
|
|
|
|
|
/* If we don't need to control policy for this CCU, we're done. */
|
|
|
|
|
if (!policy_lvm_en_exists(enable))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
/* Ensure we're not busy before we start */
|
|
|
|
|
offset = enable->offset;
|
|
|
|
|
enable_bit = enable->bit;
|
|
|
|
|
ret = __ccu_wait_bit(ccu, offset, enable_bit, false);
|
|
|
|
|
if (!ret) {
|
|
|
|
|
pr_err("%s: ccu %s policy engine already stopped\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Now set the bit to stop the engine (NO read-modify-write) */
|
|
|
|
|
__ccu_write(ccu, offset, (u32)1 << enable_bit);
|
|
|
|
|
|
|
|
|
|
/* Wait for indication that it has stopped. */
|
|
|
|
|
ret = __ccu_wait_bit(ccu, offset, enable_bit, false);
|
|
|
|
|
if (!ret)
|
|
|
|
|
pr_err("%s: ccu %s policy engine never stopped\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* A CCU has four operating conditions ("policies"), and some clocks
|
|
|
|
|
* can be disabled or enabled based on which policy is currently in
|
|
|
|
|
* effect. Such clocks have a bit in a "policy mask" register for
|
|
|
|
|
* each policy indicating whether the clock is enabled for that
|
|
|
|
|
* policy or not. The bit position for a clock is the same for all
|
|
|
|
|
* four registers, and the 32-bit registers are at consecutive
|
|
|
|
|
* addresses.
|
|
|
|
|
*/
|
|
|
|
|
static bool policy_init(struct ccu_data *ccu, struct bcm_clk_policy *policy)
|
|
|
|
|
{
|
|
|
|
|
u32 offset;
|
|
|
|
|
u32 mask;
|
|
|
|
|
int i;
|
|
|
|
|
bool ret;
|
|
|
|
|
|
|
|
|
|
if (!policy_exists(policy))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We need to stop the CCU policy engine to allow update
|
|
|
|
|
* of our policy bits.
|
|
|
|
|
*/
|
|
|
|
|
if (!__ccu_policy_engine_stop(ccu)) {
|
|
|
|
|
pr_err("%s: unable to stop CCU %s policy engine\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* For now, if a clock defines its policy bit we just mark
|
|
|
|
|
* it "enabled" for all four policies.
|
|
|
|
|
*/
|
|
|
|
|
offset = policy->offset;
|
|
|
|
|
mask = (u32)1 << policy->bit;
|
|
|
|
|
for (i = 0; i < CCU_POLICY_COUNT; i++) {
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
|
|
|
|
|
reg_val = __ccu_read(ccu, offset);
|
|
|
|
|
reg_val |= mask;
|
|
|
|
|
__ccu_write(ccu, offset, reg_val);
|
|
|
|
|
offset += sizeof(u32);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* We're done updating; fire up the policy engine again. */
|
|
|
|
|
ret = __ccu_policy_engine_start(ccu, true);
|
|
|
|
|
if (!ret)
|
|
|
|
|
pr_err("%s: unable to restart CCU %s policy engine\n",
|
|
|
|
|
__func__, ccu->name);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
/* Gate operations */
|
|
|
|
|
|
|
|
|
|
/* Determine whether a clock is gated. CCU lock must be held. */
|
|
|
|
|
static bool
|
|
|
|
|
__is_clk_gate_enabled(struct ccu_data *ccu, struct bcm_clk_gate *gate)
|
|
|
|
|
{
|
|
|
|
|
u32 bit_mask;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
|
|
|
|
|
/* If there is no gate we can assume it's enabled. */
|
|
|
|
|
if (!gate_exists(gate))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
bit_mask = 1 << gate->status_bit;
|
|
|
|
|
reg_val = __ccu_read(ccu, gate->offset);
|
|
|
|
|
|
|
|
|
|
return (reg_val & bit_mask) != 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Determine whether a clock is gated. */
|
|
|
|
|
static bool
|
|
|
|
|
is_clk_gate_enabled(struct ccu_data *ccu, struct bcm_clk_gate *gate)
|
|
|
|
|
{
|
|
|
|
|
long flags;
|
|
|
|
|
bool ret;
|
|
|
|
|
|
|
|
|
|
/* Avoid taking the lock if we can */
|
|
|
|
|
if (!gate_exists(gate))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
ret = __is_clk_gate_enabled(ccu, gate);
|
|
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Commit our desired gate state to the hardware.
|
|
|
|
|
* Returns true if successful, false otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static bool
|
|
|
|
|
__gate_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate)
|
|
|
|
|
{
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
u32 mask;
|
|
|
|
|
bool enabled = false;
|
|
|
|
|
|
|
|
|
|
BUG_ON(!gate_exists(gate));
|
|
|
|
|
if (!gate_is_sw_controllable(gate))
|
|
|
|
|
return true; /* Nothing we can change */
|
|
|
|
|
|
|
|
|
|
reg_val = __ccu_read(ccu, gate->offset);
|
|
|
|
|
|
|
|
|
|
/* For a hardware/software gate, set which is in control */
|
|
|
|
|
if (gate_is_hw_controllable(gate)) {
|
|
|
|
|
mask = (u32)1 << gate->hw_sw_sel_bit;
|
|
|
|
|
if (gate_is_sw_managed(gate))
|
|
|
|
|
reg_val |= mask;
|
|
|
|
|
else
|
|
|
|
|
reg_val &= ~mask;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If software is in control, enable or disable the gate.
|
|
|
|
|
* If hardware is, clear the enabled bit for good measure.
|
|
|
|
|
* If a software controlled gate can't be disabled, we're
|
|
|
|
|
* required to write a 0 into the enable bit (but the gate
|
|
|
|
|
* will be enabled).
|
|
|
|
|
*/
|
|
|
|
|
mask = (u32)1 << gate->en_bit;
|
|
|
|
|
if (gate_is_sw_managed(gate) && (enabled = gate_is_enabled(gate)) &&
|
|
|
|
|
!gate_is_no_disable(gate))
|
|
|
|
|
reg_val |= mask;
|
|
|
|
|
else
|
|
|
|
|
reg_val &= ~mask;
|
|
|
|
|
|
|
|
|
|
__ccu_write(ccu, gate->offset, reg_val);
|
|
|
|
|
|
|
|
|
|
/* For a hardware controlled gate, we're done */
|
|
|
|
|
if (!gate_is_sw_managed(gate))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
/* Otherwise wait for the gate to be in desired state */
|
|
|
|
|
return __ccu_wait_bit(ccu, gate->offset, gate->status_bit, enabled);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Initialize a gate. Our desired state (hardware/software select,
|
|
|
|
|
* and if software, its enable state) is committed to hardware
|
|
|
|
|
* without the usual checks to see if it's already set up that way.
|
|
|
|
|
* Returns true if successful, false otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static bool gate_init(struct ccu_data *ccu, struct bcm_clk_gate *gate)
|
|
|
|
|
{
|
|
|
|
|
if (!gate_exists(gate))
|
|
|
|
|
return true;
|
|
|
|
|
return __gate_commit(ccu, gate);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Set a gate to enabled or disabled state. Does nothing if the
|
|
|
|
|
* gate is not currently under software control, or if it is already
|
|
|
|
|
* in the requested state. Returns true if successful, false
|
|
|
|
|
* otherwise. CCU lock must be held.
|
|
|
|
|
*/
|
|
|
|
|
static bool
|
|
|
|
|
__clk_gate(struct ccu_data *ccu, struct bcm_clk_gate *gate, bool enable)
|
|
|
|
|
{
|
|
|
|
|
bool ret;
|
|
|
|
|
|
|
|
|
|
if (!gate_exists(gate) || !gate_is_sw_managed(gate))
|
|
|
|
|
return true; /* Nothing to do */
|
|
|
|
|
|
|
|
|
|
if (!enable && gate_is_no_disable(gate)) {
|
|
|
|
|
pr_warn("%s: invalid gate disable request (ignoring)\n",
|
|
|
|
|
__func__);
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (enable == gate_is_enabled(gate))
|
|
|
|
|
return true; /* No change */
|
|
|
|
|
|
|
|
|
|
gate_flip_enabled(gate);
|
|
|
|
|
ret = __gate_commit(ccu, gate);
|
|
|
|
|
if (!ret)
|
|
|
|
|
gate_flip_enabled(gate); /* Revert the change */
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Enable or disable a gate. Returns 0 if successful, -EIO otherwise */
|
|
|
|
|
static int clk_gate(struct ccu_data *ccu, const char *name,
|
|
|
|
|
struct bcm_clk_gate *gate, bool enable)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
bool success;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Avoid taking the lock if we can. We quietly ignore
|
|
|
|
|
* requests to change state that don't make sense.
|
|
|
|
|
*/
|
|
|
|
|
if (!gate_exists(gate) || !gate_is_sw_managed(gate))
|
|
|
|
|
return 0;
|
|
|
|
|
if (!enable && gate_is_no_disable(gate))
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
__ccu_write_enable(ccu);
|
|
|
|
|
|
|
|
|
|
success = __clk_gate(ccu, gate, enable);
|
|
|
|
|
|
|
|
|
|
__ccu_write_disable(ccu);
|
|
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
if (success)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
pr_err("%s: failed to %s gate for %s\n", __func__,
|
|
|
|
|
enable ? "enable" : "disable", name);
|
|
|
|
|
|
|
|
|
|
return -EIO;
|
|
|
|
|
}
|
|
|
|
|
|
2014-04-21 21:11:43 +00:00
|
|
|
/* Hysteresis operations */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If a clock gate requires a turn-off delay it will have
|
|
|
|
|
* "hysteresis" register bits defined. The first, if set, enables
|
|
|
|
|
* the delay; and if enabled, the second bit determines whether the
|
|
|
|
|
* delay is "low" or "high" (1 means high). For now, if it's
|
|
|
|
|
* defined for a clock, we set it.
|
|
|
|
|
*/
|
|
|
|
|
static bool hyst_init(struct ccu_data *ccu, struct bcm_clk_hyst *hyst)
|
|
|
|
|
{
|
|
|
|
|
u32 offset;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
u32 mask;
|
|
|
|
|
|
|
|
|
|
if (!hyst_exists(hyst))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
offset = hyst->offset;
|
|
|
|
|
mask = (u32)1 << hyst->en_bit;
|
|
|
|
|
mask |= (u32)1 << hyst->val_bit;
|
|
|
|
|
|
|
|
|
|
reg_val = __ccu_read(ccu, offset);
|
|
|
|
|
reg_val |= mask;
|
|
|
|
|
__ccu_write(ccu, offset, reg_val);
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
/* Trigger operations */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Caller must ensure CCU lock is held and access is enabled.
|
|
|
|
|
* Returns true if successful, false otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static bool __clk_trigger(struct ccu_data *ccu, struct bcm_clk_trig *trig)
|
|
|
|
|
{
|
|
|
|
|
/* Trigger the clock and wait for it to finish */
|
|
|
|
|
__ccu_write(ccu, trig->offset, 1 << trig->bit);
|
|
|
|
|
|
|
|
|
|
return __ccu_wait_bit(ccu, trig->offset, trig->bit, false);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Divider operations */
|
|
|
|
|
|
|
|
|
|
/* Read a divider value and return the scaled divisor it represents. */
|
|
|
|
|
static u64 divider_read_scaled(struct ccu_data *ccu, struct bcm_clk_div *div)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
u32 reg_div;
|
|
|
|
|
|
|
|
|
|
if (divider_is_fixed(div))
|
2014-04-07 13:22:12 +00:00
|
|
|
return (u64)div->u.fixed;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
2014-04-07 13:22:12 +00:00
|
|
|
reg_val = __ccu_read(ccu, div->u.s.offset);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
/* Extract the full divider field from the register value */
|
2014-04-07 13:22:12 +00:00
|
|
|
reg_div = bitfield_extract(reg_val, div->u.s.shift, div->u.s.width);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
/* Return the scaled divisor value it represents */
|
|
|
|
|
return scaled_div_value(div, reg_div);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Convert a divider's scaled divisor value into its recorded form
|
|
|
|
|
* and commit it into the hardware divider register.
|
|
|
|
|
*
|
|
|
|
|
* Returns 0 on success. Returns -EINVAL for invalid arguments.
|
|
|
|
|
* Returns -ENXIO if gating failed, and -EIO if a trigger failed.
|
|
|
|
|
*/
|
|
|
|
|
static int __div_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_div *div, struct bcm_clk_trig *trig)
|
|
|
|
|
{
|
|
|
|
|
bool enabled;
|
|
|
|
|
u32 reg_div;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
BUG_ON(divider_is_fixed(div));
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If we're just initializing the divider, and no initial
|
|
|
|
|
* state was defined in the device tree, we just find out
|
|
|
|
|
* what its current value is rather than updating it.
|
|
|
|
|
*/
|
2014-04-07 13:22:12 +00:00
|
|
|
if (div->u.s.scaled_div == BAD_SCALED_DIV_VALUE) {
|
|
|
|
|
reg_val = __ccu_read(ccu, div->u.s.offset);
|
|
|
|
|
reg_div = bitfield_extract(reg_val, div->u.s.shift,
|
|
|
|
|
div->u.s.width);
|
|
|
|
|
div->u.s.scaled_div = scaled_div_value(div, reg_div);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Convert the scaled divisor to the value we need to record */
|
2014-04-07 13:22:12 +00:00
|
|
|
reg_div = divider(div, div->u.s.scaled_div);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
/* Clock needs to be enabled before changing the rate */
|
|
|
|
|
enabled = __is_clk_gate_enabled(ccu, gate);
|
|
|
|
|
if (!enabled && !__clk_gate(ccu, gate, true)) {
|
|
|
|
|
ret = -ENXIO;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Replace the divider value and record the result */
|
2014-04-07 13:22:12 +00:00
|
|
|
reg_val = __ccu_read(ccu, div->u.s.offset);
|
|
|
|
|
reg_val = bitfield_replace(reg_val, div->u.s.shift, div->u.s.width,
|
|
|
|
|
reg_div);
|
|
|
|
|
__ccu_write(ccu, div->u.s.offset, reg_val);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
/* If the trigger fails we still want to disable the gate */
|
|
|
|
|
if (!__clk_trigger(ccu, trig))
|
|
|
|
|
ret = -EIO;
|
|
|
|
|
|
|
|
|
|
/* Disable the clock again if it was disabled to begin with */
|
|
|
|
|
if (!enabled && !__clk_gate(ccu, gate, false))
|
|
|
|
|
ret = ret ? ret : -ENXIO; /* return first error */
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Initialize a divider by committing our desired state to hardware
|
|
|
|
|
* without the usual checks to see if it's already set up that way.
|
|
|
|
|
* Returns true if successful, false otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static bool div_init(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_div *div, struct bcm_clk_trig *trig)
|
|
|
|
|
{
|
|
|
|
|
if (!divider_exists(div) || divider_is_fixed(div))
|
|
|
|
|
return true;
|
|
|
|
|
return !__div_commit(ccu, gate, div, trig);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int divider_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_div *div, struct bcm_clk_trig *trig,
|
|
|
|
|
u64 scaled_div)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
u64 previous;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
BUG_ON(divider_is_fixed(div));
|
|
|
|
|
|
2014-04-07 13:22:12 +00:00
|
|
|
previous = div->u.s.scaled_div;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
if (previous == scaled_div)
|
|
|
|
|
return 0; /* No change */
|
|
|
|
|
|
2014-04-07 13:22:12 +00:00
|
|
|
div->u.s.scaled_div = scaled_div;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
__ccu_write_enable(ccu);
|
|
|
|
|
|
|
|
|
|
ret = __div_commit(ccu, gate, div, trig);
|
|
|
|
|
|
|
|
|
|
__ccu_write_disable(ccu);
|
|
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
if (ret)
|
2014-04-07 13:22:12 +00:00
|
|
|
div->u.s.scaled_div = previous; /* Revert the change */
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Common clock rate helpers */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Implement the common clock framework recalc_rate method, taking
|
|
|
|
|
* into account a divider and an optional pre-divider. The
|
|
|
|
|
* pre-divider register pointer may be NULL.
|
|
|
|
|
*/
|
|
|
|
|
static unsigned long clk_recalc_rate(struct ccu_data *ccu,
|
|
|
|
|
struct bcm_clk_div *div, struct bcm_clk_div *pre_div,
|
|
|
|
|
unsigned long parent_rate)
|
|
|
|
|
{
|
|
|
|
|
u64 scaled_parent_rate;
|
|
|
|
|
u64 scaled_div;
|
|
|
|
|
u64 result;
|
|
|
|
|
|
|
|
|
|
if (!divider_exists(div))
|
|
|
|
|
return parent_rate;
|
|
|
|
|
|
|
|
|
|
if (parent_rate > (unsigned long)LONG_MAX)
|
|
|
|
|
return 0; /* actually this would be a caller bug */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If there is a pre-divider, divide the scaled parent rate
|
|
|
|
|
* by the pre-divider value first. In this case--to improve
|
|
|
|
|
* accuracy--scale the parent rate by *both* the pre-divider
|
|
|
|
|
* value and the divider before actually computing the
|
|
|
|
|
* result of the pre-divider.
|
|
|
|
|
*
|
|
|
|
|
* If there's only one divider, just scale the parent rate.
|
|
|
|
|
*/
|
|
|
|
|
if (pre_div && divider_exists(pre_div)) {
|
|
|
|
|
u64 scaled_rate;
|
|
|
|
|
|
|
|
|
|
scaled_rate = scale_rate(pre_div, parent_rate);
|
|
|
|
|
scaled_rate = scale_rate(div, scaled_rate);
|
|
|
|
|
scaled_div = divider_read_scaled(ccu, pre_div);
|
2015-04-16 19:43:48 +00:00
|
|
|
scaled_parent_rate = DIV_ROUND_CLOSEST_ULL(scaled_rate,
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
scaled_div);
|
|
|
|
|
} else {
|
|
|
|
|
scaled_parent_rate = scale_rate(div, parent_rate);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Get the scaled divisor value, and divide the scaled
|
|
|
|
|
* parent rate by that to determine this clock's resulting
|
|
|
|
|
* rate.
|
|
|
|
|
*/
|
|
|
|
|
scaled_div = divider_read_scaled(ccu, div);
|
2015-04-16 19:43:48 +00:00
|
|
|
result = DIV_ROUND_CLOSEST_ULL(scaled_parent_rate, scaled_div);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return (unsigned long)result;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Compute the output rate produced when a given parent rate is fed
|
|
|
|
|
* into two dividers. The pre-divider can be NULL, and even if it's
|
|
|
|
|
* non-null it may be nonexistent. It's also OK for the divider to
|
|
|
|
|
* be nonexistent, and in that case the pre-divider is also ignored.
|
|
|
|
|
*
|
|
|
|
|
* If scaled_div is non-null, it is used to return the scaled divisor
|
|
|
|
|
* value used by the (downstream) divider to produce that rate.
|
|
|
|
|
*/
|
|
|
|
|
static long round_rate(struct ccu_data *ccu, struct bcm_clk_div *div,
|
|
|
|
|
struct bcm_clk_div *pre_div,
|
|
|
|
|
unsigned long rate, unsigned long parent_rate,
|
|
|
|
|
u64 *scaled_div)
|
|
|
|
|
{
|
|
|
|
|
u64 scaled_parent_rate;
|
|
|
|
|
u64 min_scaled_div;
|
|
|
|
|
u64 max_scaled_div;
|
|
|
|
|
u64 best_scaled_div;
|
|
|
|
|
u64 result;
|
|
|
|
|
|
|
|
|
|
BUG_ON(!divider_exists(div));
|
|
|
|
|
BUG_ON(!rate);
|
|
|
|
|
BUG_ON(parent_rate > (u64)LONG_MAX);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If there is a pre-divider, divide the scaled parent rate
|
|
|
|
|
* by the pre-divider value first. In this case--to improve
|
|
|
|
|
* accuracy--scale the parent rate by *both* the pre-divider
|
|
|
|
|
* value and the divider before actually computing the
|
|
|
|
|
* result of the pre-divider.
|
|
|
|
|
*
|
|
|
|
|
* If there's only one divider, just scale the parent rate.
|
|
|
|
|
*
|
|
|
|
|
* For simplicity we treat the pre-divider as fixed (for now).
|
|
|
|
|
*/
|
|
|
|
|
if (divider_exists(pre_div)) {
|
|
|
|
|
u64 scaled_rate;
|
|
|
|
|
u64 scaled_pre_div;
|
|
|
|
|
|
|
|
|
|
scaled_rate = scale_rate(pre_div, parent_rate);
|
|
|
|
|
scaled_rate = scale_rate(div, scaled_rate);
|
|
|
|
|
scaled_pre_div = divider_read_scaled(ccu, pre_div);
|
2015-04-16 19:43:48 +00:00
|
|
|
scaled_parent_rate = DIV_ROUND_CLOSEST_ULL(scaled_rate,
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
scaled_pre_div);
|
|
|
|
|
} else {
|
|
|
|
|
scaled_parent_rate = scale_rate(div, parent_rate);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Compute the best possible divider and ensure it is in
|
|
|
|
|
* range. A fixed divider can't be changed, so just report
|
|
|
|
|
* the best we can do.
|
|
|
|
|
*/
|
|
|
|
|
if (!divider_is_fixed(div)) {
|
2015-04-16 19:43:48 +00:00
|
|
|
best_scaled_div = DIV_ROUND_CLOSEST_ULL(scaled_parent_rate,
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
rate);
|
|
|
|
|
min_scaled_div = scaled_div_min(div);
|
|
|
|
|
max_scaled_div = scaled_div_max(div);
|
|
|
|
|
if (best_scaled_div > max_scaled_div)
|
|
|
|
|
best_scaled_div = max_scaled_div;
|
|
|
|
|
else if (best_scaled_div < min_scaled_div)
|
|
|
|
|
best_scaled_div = min_scaled_div;
|
|
|
|
|
} else {
|
|
|
|
|
best_scaled_div = divider_read_scaled(ccu, div);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* OK, figure out the resulting rate */
|
2015-04-16 19:43:48 +00:00
|
|
|
result = DIV_ROUND_CLOSEST_ULL(scaled_parent_rate, best_scaled_div);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
if (scaled_div)
|
|
|
|
|
*scaled_div = best_scaled_div;
|
|
|
|
|
|
|
|
|
|
return (long)result;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Common clock parent helpers */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* For a given parent selector (register field) value, find the
|
|
|
|
|
* index into a selector's parent_sel array that contains it.
|
|
|
|
|
* Returns the index, or BAD_CLK_INDEX if it's not found.
|
|
|
|
|
*/
|
|
|
|
|
static u8 parent_index(struct bcm_clk_sel *sel, u8 parent_sel)
|
|
|
|
|
{
|
|
|
|
|
u8 i;
|
|
|
|
|
|
|
|
|
|
BUG_ON(sel->parent_count > (u32)U8_MAX);
|
|
|
|
|
for (i = 0; i < sel->parent_count; i++)
|
|
|
|
|
if (sel->parent_sel[i] == parent_sel)
|
|
|
|
|
return i;
|
|
|
|
|
return BAD_CLK_INDEX;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Fetch the current value of the selector, and translate that into
|
|
|
|
|
* its corresponding index in the parent array we registered with
|
|
|
|
|
* the clock framework.
|
|
|
|
|
*
|
|
|
|
|
* Returns parent array index that corresponds with the value found,
|
|
|
|
|
* or BAD_CLK_INDEX if the found value is out of range.
|
|
|
|
|
*/
|
|
|
|
|
static u8 selector_read_index(struct ccu_data *ccu, struct bcm_clk_sel *sel)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
u32 parent_sel;
|
|
|
|
|
u8 index;
|
|
|
|
|
|
|
|
|
|
/* If there's no selector, there's only one parent */
|
|
|
|
|
if (!selector_exists(sel))
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
/* Get the value in the selector register */
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
reg_val = __ccu_read(ccu, sel->offset);
|
|
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
parent_sel = bitfield_extract(reg_val, sel->shift, sel->width);
|
|
|
|
|
|
|
|
|
|
/* Look up that selector's parent array index and return it */
|
|
|
|
|
index = parent_index(sel, parent_sel);
|
|
|
|
|
if (index == BAD_CLK_INDEX)
|
|
|
|
|
pr_err("%s: out-of-range parent selector %u (%s 0x%04x)\n",
|
|
|
|
|
__func__, parent_sel, ccu->name, sel->offset);
|
|
|
|
|
|
|
|
|
|
return index;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Commit our desired selector value to the hardware.
|
|
|
|
|
*
|
|
|
|
|
* Returns 0 on success. Returns -EINVAL for invalid arguments.
|
|
|
|
|
* Returns -ENXIO if gating failed, and -EIO if a trigger failed.
|
|
|
|
|
*/
|
|
|
|
|
static int
|
|
|
|
|
__sel_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_sel *sel, struct bcm_clk_trig *trig)
|
|
|
|
|
{
|
|
|
|
|
u32 parent_sel;
|
|
|
|
|
u32 reg_val;
|
|
|
|
|
bool enabled;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
BUG_ON(!selector_exists(sel));
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If we're just initializing the selector, and no initial
|
|
|
|
|
* state was defined in the device tree, we just find out
|
|
|
|
|
* what its current value is rather than updating it.
|
|
|
|
|
*/
|
|
|
|
|
if (sel->clk_index == BAD_CLK_INDEX) {
|
|
|
|
|
u8 index;
|
|
|
|
|
|
|
|
|
|
reg_val = __ccu_read(ccu, sel->offset);
|
|
|
|
|
parent_sel = bitfield_extract(reg_val, sel->shift, sel->width);
|
|
|
|
|
index = parent_index(sel, parent_sel);
|
|
|
|
|
if (index == BAD_CLK_INDEX)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
sel->clk_index = index;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
BUG_ON((u32)sel->clk_index >= sel->parent_count);
|
|
|
|
|
parent_sel = sel->parent_sel[sel->clk_index];
|
|
|
|
|
|
|
|
|
|
/* Clock needs to be enabled before changing the parent */
|
|
|
|
|
enabled = __is_clk_gate_enabled(ccu, gate);
|
|
|
|
|
if (!enabled && !__clk_gate(ccu, gate, true))
|
|
|
|
|
return -ENXIO;
|
|
|
|
|
|
|
|
|
|
/* Replace the selector value and record the result */
|
|
|
|
|
reg_val = __ccu_read(ccu, sel->offset);
|
|
|
|
|
reg_val = bitfield_replace(reg_val, sel->shift, sel->width, parent_sel);
|
|
|
|
|
__ccu_write(ccu, sel->offset, reg_val);
|
|
|
|
|
|
|
|
|
|
/* If the trigger fails we still want to disable the gate */
|
|
|
|
|
if (!__clk_trigger(ccu, trig))
|
|
|
|
|
ret = -EIO;
|
|
|
|
|
|
|
|
|
|
/* Disable the clock again if it was disabled to begin with */
|
|
|
|
|
if (!enabled && !__clk_gate(ccu, gate, false))
|
|
|
|
|
ret = ret ? ret : -ENXIO; /* return first error */
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Initialize a selector by committing our desired state to hardware
|
|
|
|
|
* without the usual checks to see if it's already set up that way.
|
|
|
|
|
* Returns true if successful, false otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static bool sel_init(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_sel *sel, struct bcm_clk_trig *trig)
|
|
|
|
|
{
|
|
|
|
|
if (!selector_exists(sel))
|
|
|
|
|
return true;
|
|
|
|
|
return !__sel_commit(ccu, gate, sel, trig);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Write a new value into a selector register to switch to a
|
|
|
|
|
* different parent clock. Returns 0 on success, or an error code
|
|
|
|
|
* (from __sel_commit()) otherwise.
|
|
|
|
|
*/
|
|
|
|
|
static int selector_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
|
|
|
|
|
struct bcm_clk_sel *sel, struct bcm_clk_trig *trig,
|
|
|
|
|
u8 index)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
u8 previous;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
previous = sel->clk_index;
|
|
|
|
|
if (previous == index)
|
|
|
|
|
return 0; /* No change */
|
|
|
|
|
|
|
|
|
|
sel->clk_index = index;
|
|
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
__ccu_write_enable(ccu);
|
|
|
|
|
|
|
|
|
|
ret = __sel_commit(ccu, gate, sel, trig);
|
|
|
|
|
|
|
|
|
|
__ccu_write_disable(ccu);
|
|
|
|
|
ccu_unlock(ccu, flags);
|
|
|
|
|
|
|
|
|
|
if (ret)
|
|
|
|
|
sel->clk_index = previous; /* Revert the change */
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Clock operations */
|
|
|
|
|
|
|
|
|
|
static int kona_peri_clk_enable(struct clk_hw *hw)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
2014-04-21 21:11:38 +00:00
|
|
|
return clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, true);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void kona_peri_clk_disable(struct clk_hw *hw)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
2014-04-21 21:11:38 +00:00
|
|
|
(void)clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, false);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int kona_peri_clk_is_enabled(struct clk_hw *hw)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return is_clk_gate_enabled(bcm_clk->ccu, gate) ? 1 : 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static unsigned long kona_peri_clk_recalc_rate(struct clk_hw *hw,
|
|
|
|
|
unsigned long parent_rate)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct peri_clk_data *data = bcm_clk->u.peri;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
return clk_recalc_rate(bcm_clk->ccu, &data->div, &data->pre_div,
|
|
|
|
|
parent_rate);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
|
|
|
|
|
unsigned long *parent_rate)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct bcm_clk_div *div = &bcm_clk->u.peri->div;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
if (!divider_exists(div))
|
2015-07-31 00:20:57 +00:00
|
|
|
return clk_hw_get_rate(hw);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
|
|
|
|
|
/* Quietly avoid a zero rate */
|
2014-04-07 13:22:12 +00:00
|
|
|
return round_rate(bcm_clk->ccu, div, &bcm_clk->u.peri->pre_div,
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
rate ? rate : 1, *parent_rate, NULL);
|
|
|
|
|
}
|
|
|
|
|
|
2015-07-07 18:48:08 +00:00
|
|
|
static int kona_peri_clk_determine_rate(struct clk_hw *hw,
|
|
|
|
|
struct clk_rate_request *req)
|
2014-05-27 16:56:56 +00:00
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2015-07-31 00:20:57 +00:00
|
|
|
struct clk_hw *current_parent;
|
2014-05-27 16:56:56 +00:00
|
|
|
unsigned long parent_rate;
|
|
|
|
|
unsigned long best_delta;
|
|
|
|
|
unsigned long best_rate;
|
|
|
|
|
u32 parent_count;
|
2015-07-07 18:48:08 +00:00
|
|
|
long rate;
|
2014-05-27 16:56:56 +00:00
|
|
|
u32 which;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If there is no other parent to choose, use the current one.
|
|
|
|
|
* Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
|
|
|
|
|
*/
|
|
|
|
|
WARN_ON_ONCE(bcm_clk->init_data.flags & CLK_SET_RATE_NO_REPARENT);
|
|
|
|
|
parent_count = (u32)bcm_clk->init_data.num_parents;
|
2015-07-07 18:48:08 +00:00
|
|
|
if (parent_count < 2) {
|
|
|
|
|
rate = kona_peri_clk_round_rate(hw, req->rate,
|
|
|
|
|
&req->best_parent_rate);
|
|
|
|
|
if (rate < 0)
|
|
|
|
|
return rate;
|
|
|
|
|
|
|
|
|
|
req->rate = rate;
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
2014-05-27 16:56:56 +00:00
|
|
|
|
|
|
|
|
/* Unless we can do better, stick with current parent */
|
2015-07-31 00:20:57 +00:00
|
|
|
current_parent = clk_hw_get_parent(hw);
|
|
|
|
|
parent_rate = clk_hw_get_rate(current_parent);
|
2015-07-07 18:48:08 +00:00
|
|
|
best_rate = kona_peri_clk_round_rate(hw, req->rate, &parent_rate);
|
|
|
|
|
best_delta = abs(best_rate - req->rate);
|
2014-05-27 16:56:56 +00:00
|
|
|
|
|
|
|
|
/* Check whether any other parent clock can produce a better result */
|
|
|
|
|
for (which = 0; which < parent_count; which++) {
|
2015-07-31 00:20:57 +00:00
|
|
|
struct clk_hw *parent = clk_hw_get_parent_by_index(hw, which);
|
2014-05-27 16:56:56 +00:00
|
|
|
unsigned long delta;
|
|
|
|
|
unsigned long other_rate;
|
|
|
|
|
|
|
|
|
|
BUG_ON(!parent);
|
|
|
|
|
if (parent == current_parent)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
/* We don't support CLK_SET_RATE_PARENT */
|
2015-07-31 00:20:57 +00:00
|
|
|
parent_rate = clk_hw_get_rate(parent);
|
2015-07-07 18:48:08 +00:00
|
|
|
other_rate = kona_peri_clk_round_rate(hw, req->rate,
|
|
|
|
|
&parent_rate);
|
|
|
|
|
delta = abs(other_rate - req->rate);
|
2014-05-27 16:56:56 +00:00
|
|
|
if (delta < best_delta) {
|
|
|
|
|
best_delta = delta;
|
|
|
|
|
best_rate = other_rate;
|
2015-07-31 00:20:57 +00:00
|
|
|
req->best_parent_hw = parent;
|
2015-07-07 18:48:08 +00:00
|
|
|
req->best_parent_rate = parent_rate;
|
2014-05-27 16:56:56 +00:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2015-07-07 18:48:08 +00:00
|
|
|
req->rate = best_rate;
|
|
|
|
|
return 0;
|
2014-05-27 16:56:56 +00:00
|
|
|
}
|
|
|
|
|
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct peri_clk_data *data = bcm_clk->u.peri;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
struct bcm_clk_sel *sel = &data->sel;
|
|
|
|
|
struct bcm_clk_trig *trig;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
BUG_ON(index >= sel->parent_count);
|
|
|
|
|
|
|
|
|
|
/* If there's only one parent we don't require a selector */
|
|
|
|
|
if (!selector_exists(sel))
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* The regular trigger is used by default, but if there's a
|
|
|
|
|
* pre-trigger we want to use that instead.
|
|
|
|
|
*/
|
|
|
|
|
trig = trigger_exists(&data->pre_trig) ? &data->pre_trig
|
|
|
|
|
: &data->trig;
|
|
|
|
|
|
|
|
|
|
ret = selector_write(bcm_clk->ccu, &data->gate, sel, trig, index);
|
|
|
|
|
if (ret == -ENXIO) {
|
2014-04-21 21:11:38 +00:00
|
|
|
pr_err("%s: gating failure for %s\n", __func__,
|
|
|
|
|
bcm_clk->init_data.name);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
ret = -EIO; /* Don't proliferate weird errors */
|
|
|
|
|
} else if (ret == -EIO) {
|
|
|
|
|
pr_err("%s: %strigger failed for %s\n", __func__,
|
|
|
|
|
trig == &data->pre_trig ? "pre-" : "",
|
2014-04-21 21:11:38 +00:00
|
|
|
bcm_clk->init_data.name);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static u8 kona_peri_clk_get_parent(struct clk_hw *hw)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct peri_clk_data *data = bcm_clk->u.peri;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
u8 index;
|
|
|
|
|
|
|
|
|
|
index = selector_read_index(bcm_clk->ccu, &data->sel);
|
|
|
|
|
|
|
|
|
|
/* Not all callers would handle an out-of-range value gracefully */
|
|
|
|
|
return index == BAD_CLK_INDEX ? 0 : index;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int kona_peri_clk_set_rate(struct clk_hw *hw, unsigned long rate,
|
|
|
|
|
unsigned long parent_rate)
|
|
|
|
|
{
|
|
|
|
|
struct kona_clk *bcm_clk = to_kona_clk(hw);
|
2014-04-07 13:22:12 +00:00
|
|
|
struct peri_clk_data *data = bcm_clk->u.peri;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
struct bcm_clk_div *div = &data->div;
|
|
|
|
|
u64 scaled_div = 0;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
if (parent_rate > (unsigned long)LONG_MAX)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
2015-07-31 00:20:57 +00:00
|
|
|
if (rate == clk_hw_get_rate(hw))
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
if (!divider_exists(div))
|
|
|
|
|
return rate == parent_rate ? 0 : -EINVAL;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* A fixed divider can't be changed. (Nor can a fixed
|
|
|
|
|
* pre-divider be, but for now we never actually try to
|
|
|
|
|
* change that.) Tolerate a request for a no-op change.
|
|
|
|
|
*/
|
|
|
|
|
if (divider_is_fixed(&data->div))
|
|
|
|
|
return rate == parent_rate ? 0 : -EINVAL;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Get the scaled divisor value needed to achieve a clock
|
|
|
|
|
* rate as close as possible to what was requested, given
|
|
|
|
|
* the parent clock rate supplied.
|
|
|
|
|
*/
|
|
|
|
|
(void)round_rate(bcm_clk->ccu, div, &data->pre_div,
|
|
|
|
|
rate ? rate : 1, parent_rate, &scaled_div);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We aren't updating any pre-divider at this point, so
|
|
|
|
|
* we'll use the regular trigger.
|
|
|
|
|
*/
|
|
|
|
|
ret = divider_write(bcm_clk->ccu, &data->gate, &data->div,
|
|
|
|
|
&data->trig, scaled_div);
|
|
|
|
|
if (ret == -ENXIO) {
|
2014-04-21 21:11:38 +00:00
|
|
|
pr_err("%s: gating failure for %s\n", __func__,
|
|
|
|
|
bcm_clk->init_data.name);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
ret = -EIO; /* Don't proliferate weird errors */
|
|
|
|
|
} else if (ret == -EIO) {
|
2014-04-21 21:11:38 +00:00
|
|
|
pr_err("%s: trigger failed for %s\n", __func__,
|
|
|
|
|
bcm_clk->init_data.name);
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
struct clk_ops kona_peri_clk_ops = {
|
|
|
|
|
.enable = kona_peri_clk_enable,
|
|
|
|
|
.disable = kona_peri_clk_disable,
|
|
|
|
|
.is_enabled = kona_peri_clk_is_enabled,
|
|
|
|
|
.recalc_rate = kona_peri_clk_recalc_rate,
|
2014-05-27 16:56:56 +00:00
|
|
|
.determine_rate = kona_peri_clk_determine_rate,
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
.set_parent = kona_peri_clk_set_parent,
|
|
|
|
|
.get_parent = kona_peri_clk_get_parent,
|
|
|
|
|
.set_rate = kona_peri_clk_set_rate,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
/* Put a peripheral clock into its initial state */
|
|
|
|
|
static bool __peri_clk_init(struct kona_clk *bcm_clk)
|
|
|
|
|
{
|
|
|
|
|
struct ccu_data *ccu = bcm_clk->ccu;
|
2014-04-07 13:22:12 +00:00
|
|
|
struct peri_clk_data *peri = bcm_clk->u.peri;
|
2014-04-21 21:11:38 +00:00
|
|
|
const char *name = bcm_clk->init_data.name;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
struct bcm_clk_trig *trig;
|
|
|
|
|
|
|
|
|
|
BUG_ON(bcm_clk->type != bcm_clk_peri);
|
|
|
|
|
|
2014-04-21 21:11:42 +00:00
|
|
|
if (!policy_init(ccu, &peri->policy)) {
|
|
|
|
|
pr_err("%s: error initializing policy for %s\n",
|
|
|
|
|
__func__, name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
if (!gate_init(ccu, &peri->gate)) {
|
|
|
|
|
pr_err("%s: error initializing gate for %s\n", __func__, name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
2014-04-21 21:11:43 +00:00
|
|
|
if (!hyst_init(ccu, &peri->hyst)) {
|
|
|
|
|
pr_err("%s: error initializing hyst for %s\n", __func__, name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
if (!div_init(ccu, &peri->gate, &peri->div, &peri->trig)) {
|
|
|
|
|
pr_err("%s: error initializing divider for %s\n", __func__,
|
|
|
|
|
name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* For the pre-divider and selector, the pre-trigger is used
|
|
|
|
|
* if it's present, otherwise we just use the regular trigger.
|
|
|
|
|
*/
|
|
|
|
|
trig = trigger_exists(&peri->pre_trig) ? &peri->pre_trig
|
|
|
|
|
: &peri->trig;
|
|
|
|
|
|
|
|
|
|
if (!div_init(ccu, &peri->gate, &peri->pre_div, trig)) {
|
|
|
|
|
pr_err("%s: error initializing pre-divider for %s\n", __func__,
|
|
|
|
|
name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!sel_init(ccu, &peri->gate, &peri->sel, trig)) {
|
|
|
|
|
pr_err("%s: error initializing selector for %s\n", __func__,
|
|
|
|
|
name);
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool __kona_clk_init(struct kona_clk *bcm_clk)
|
|
|
|
|
{
|
|
|
|
|
switch (bcm_clk->type) {
|
|
|
|
|
case bcm_clk_peri:
|
|
|
|
|
return __peri_clk_init(bcm_clk);
|
|
|
|
|
default:
|
|
|
|
|
BUG();
|
|
|
|
|
}
|
2015-05-01 19:21:53 +00:00
|
|
|
return false;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Set a CCU and all its clocks into their desired initial state */
|
|
|
|
|
bool __init kona_ccu_init(struct ccu_data *ccu)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
unsigned int which;
|
2015-07-31 00:20:57 +00:00
|
|
|
struct kona_clk *kona_clks = ccu->kona_clks;
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
bool success = true;
|
|
|
|
|
|
|
|
|
|
flags = ccu_lock(ccu);
|
|
|
|
|
__ccu_write_enable(ccu);
|
|
|
|
|
|
2016-06-01 23:15:05 +00:00
|
|
|
for (which = 0; which < ccu->clk_num; which++) {
|
|
|
|
|
struct kona_clk *bcm_clk = &kona_clks[which];
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
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2016-06-01 23:15:05 +00:00
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if (!bcm_clk->ccu)
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clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
continue;
|
2016-06-01 23:15:05 +00:00
|
|
|
|
clk: bcm281xx: add initial clock framework support
Add code for device tree support of clocks in the BCM281xx family of
SoCs. Machines in this family use peripheral clocks implemented by
"Kona" clock control units (CCUs). (Other Broadcom SoC families use
Kona style CCUs as well, but support for them is not yet upstream.)
A BCM281xx SoC has multiple CCUs, each of which manages a set of
clocks on the SoC. A Kona peripheral clock is composite clock that
may include a gate, a parent clock multiplexor, and zero, one
or two dividers. There is a variety of gate types, and many gates
implement hardware-managed gating (often called "auto-gating").
Most dividers divide their input clock signal by an integer value
(one or more). There are also "fractional" dividers which allow
division by non-integer values. To accomodate such dividers,
clock rates and dividers are generally maintained by the code in
"scaled" form, which allows integer and fractional dividers to
be handled in a uniform way.
If present, the gate for a Kona peripheral clock must be enabled
when a change is made to its multiplexor or one of its dividers.
Additionally, dividers and multiplexors have trigger registers which
must be used whenever the divider value or selected parent clock is
changed. The same trigger is often used for a divider and
multiplexor, and a BCM281xx peripheral clock occasionally has two
triggers.
The gate, dividers, and parent clock selector are treated in this
code as "components" of a peripheral clock. Their functionality is
implemented directly--e.g. the common clock framework gate
implementation is not used for a Kona peripheral clock gate. (This
has being considered though, and the intention is to evolve this
code to leverage common code as much as possible.)
The source code is divided into three general portions:
drivers/clk/bcm/clk-kona.h
drivers/clk/bcm/clk-kona.c
These implement the basic Kona clock functionality,
including the clk_ops methods and various routines to
manipulate registers and interpret their values. This
includes some functions used to set clocks to a desired
initial state (though this feature is only partially
implemented here).
drivers/clk/bcm/clk-kona-setup.c
This contains generic run-time initialization code for
data structures representing Kona CCUs and clocks. This
encapsulates the clock structure initialization that can't
be done statically. Note that there is a great deal of
validity-checking code here, making explicit certain
assumptions in the code. This is mostly useful for adding
new clock definitions and could possibly be disabled for
production use.
drivers/clk/bcm/clk-bcm281xx.c
This file defines the specific CCUs used by BCM281XX family
SoCs, as well as the specific clocks implemented by each.
It declares a device tree clock match entry for each CCU
defined.
include/dt-bindings/clock/bcm281xx.h
This file defines the selector (index) values used to
identify a particular clock provided by a CCU. It consists
entirely of C preprocessor constants, to be used by both the
C source and device tree source files.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>
2014-02-14 18:29:18 +00:00
|
|
|
success &= __kona_clk_init(bcm_clk);
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}
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__ccu_write_disable(ccu);
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ccu_unlock(ccu, flags);
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return success;
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}
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