Commit graph

14 commits

Author SHA1 Message Date
Anson Huang
6e6cdf6656 ARM: imx: avoid calling clk APIs in idle thread which may cause schedule
As clk_pllv3_wait_lock will call usleep_range, and the clk APIs
mutex lock may be held when CPU entering idle, so calling clk
APIs must be avoided in cpu idle thread, this is to avoid reschedule
warning in cpu idle, just access register directly to achieve that.

bad: scheduling from the idle thread!
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc1+ #657
Backtrace:
[<80012188>] (dump_backtrace) from [<8001246c>] (show_stack+0x18/0x1c)
 r6:808c0038 r5:00000000 r4:808e5a1c r3:00000000
[<80012454>] (show_stack) from [<8064b2ec>] (dump_stack+0x84/0x9c)
[<8064b268>] (dump_stack) from [<80055ee0>] (dequeue_task_idle+0x20/0x30)
 r5:808bef40 r4:bf7dff40
[<80055ec0>] (dequeue_task_idle) from [<8004f028>] (dequeue_task+0x30/0x50)
 r4:bf7dff40 r3:80055ec0
[<8004eff8>] (dequeue_task) from [<800503c0>] (deactivate_task+0x30/0x34)
 r4:bf7dff40
[<80050390>] (deactivate_task) from [<8064d8e4>] (__schedule+0x2c8/0x5c0)
[<8064d61c>] (__schedule) from [<8064dc14>] (schedule+0x38/0x88)
 r10:80912964 r9:808c1e50 r8:808c0038 r7:808cbf30 r6:80e128ec r5:60000093
 r4:80912968
[<8064dbdc>] (schedule) from [<8064dfec>] (schedule_preempt_disabled+0x10/0x14)
[<8064dfdc>] (schedule_preempt_disabled) from [<8064ebc0>] (mutex_lock_nested+0x1c0/0x3c0)
[<8064ea00>] (mutex_lock_nested) from [<804ae71c>] (clk_prepare_lock+0x44/0xe4)
 r10:806554cc r9:bf7df1bc r8:808cf4f8 r7:808cf544 r6:bf7df1b8 r5:808c0010
 r4:80e69750
[<804ae6d8>] (clk_prepare_lock) from [<804af214>] (clk_get_rate+0x14/0x64)
 r6:bf7df1b8 r5:00000002 r4:bf017000 r3:80922ad0
[<804af200>] (clk_get_rate) from [<80025d30>] (imx6sl_set_wait_clk+0x18/0x20)
 r5:00000002 r4:00000001
[<80025d18>] (imx6sl_set_wait_clk) from [<80023454>] (imx6sl_enter_wait+0x20/0x48)
[<80023434>] (imx6sl_enter_wait) from [<80477c24>] (cpuidle_enter_state+0x44/0xfc)
 r4:3c386e48 r3:80023434
[<80477be0>] (cpuidle_enter_state) from [<80477dd8>] (cpuidle_idle_call+0xfc/0x160)
 r8:808cf4f8 r7:00000001 r6:80e69534 r5:00000000 r4:bf7df1b8
[<80477cdc>] (cpuidle_idle_call) from [<8000f61c>] (arch_cpu_idle+0x10/0x50)
 r9:808c0000 r8:00000000 r7:80921a89 r6:808c8938 r5:808c899c r4:808c0000
[<8000f60c>] (arch_cpu_idle) from [<8006fa94>] (cpu_startup_entry+0x108/0x160)
[<8006f98c>] (cpu_startup_entry) from [<806452ac>] (rest_init+0xb4/0xdc)
 r7:808afae0
[<806451f8>] (rest_init) from [<8086fb58>] (start_kernel+0x328/0x38c)
 r6:ffffffff r5:808c8880 r4:808c8a30
[<8086f830>] (start_kernel) from [<80008074>] (0x80008074)

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2014-03-05 10:35:21 +08:00
Anson Huang
17626b7cfc ARM: imx: add always-on clock array for i.mx6sl to maintain correct usecount
IPG, ARM and MMDC's clock should be enabled during kernel boot up,
so we need to maintain their usecount, otherwise, they may be
disabled unexpectedly if their children's clock are turned off, and
caused their parent PLLs also get disabled, which is incorrect.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2014-03-05 10:35:14 +08:00
Liu Ying
b21c22e3a9 ARM: imx: clk-imx6sl: Suppress duplicate const sparse warning
There should be no duplicate const specifiers for those static
constant character string arrays defined for clock mux options.
Also, the arrays are only taken as the 5th argument for the
imx_clk_mux() function, which is in the type of 'const char
**parents'.  So, let's remove the 2nd const specifier right
after 'char'.

This patch fixes these sparse warnings:
arch/arm/mach-imx/clk-imx6sl.c:21:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:22:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:23:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:24:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:25:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:26:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:27:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:28:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:29:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:30:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:31:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:32:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:33:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:34:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:35:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:36:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:37:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:38:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:39:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:40:25: warning: duplicate const
arch/arm/mach-imx/clk-imx6sl.c:41:25: warning: duplicate const

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2014-03-05 10:35:07 +08:00
Anson Huang
751f7e999a ARM: imx: add cpuidle support for i.mx6sl
Add cpuidle support for i.MX6SL, currently only support
two cpuidle levels(ARM wfi and WAIT mode), and add software
workaround for WAIT mode errata as below:

ERR005311 CCM: After exit from WAIT mode, unwanted interrupt(s) taken
          during WAIT mode entry process could cause cache memory
          corruption.

Software workaround:
    To prevent this issue from occurring, software should ensure that
the ARM to IPG clock ratio is less than 12:5 (that is < 2.4x), before
entering WAIT mode.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2014-03-05 10:35:01 +08:00
Anson Huang
848db4a0a1 ARM: imx: AHB rate must be set to 132MHz on i.mx6sl
The reset value of AHB divider is 3, so current AHB rate
is 99MHz which is not correct for kernel, need to ensure
AHB rate is 132MHz in clk driver, as ipg is sourcing from
AHB, and it should be 66MHz by default.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2014-03-05 10:35:00 +08:00
Philipp Zabel
e7c57ecd60 ARM: imx6: Initialize low-power mode early again
Since commit 9e8147bb5e
"ARM: imx6q: move low-power code out of clock driver"
the kernel fails to boot on i.MX6Q/D if preemption is
enabled (CONFIG_PREEMPT=y). The kernel just hangs
before the console comes up.

The above commit moved the initalization of the low-power
mode setting (enabling clocked WAIT states), which was
introduced in commit 83ae20981a
"ARM: imx: correct low-power mode setting", from
imx6q_clks_init to imx6q_pm_init. Now it is called
much later, after all cores are enabled.

This patch moves the low-power mode initialization back
to imx6q_clks_init again (and to imx6sl_clks_init).

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
2014-02-10 10:37:32 -08:00
Nicolin Chen
8962a5dbe0 ARM: imx6sl: Add missing spba clock to clock tree
We are missing spba clock in imx6sl's clock tree, thus add it.

Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-12-31 09:36:37 +08:00
Nicolin Chen
238fb18214 ARM: imx6sl: Add missing pll4_audio_div to the clock tree
There's a dividor for pll4_audio clock missing in clock tree, thus add it.

Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-12-31 09:36:36 +08:00
Nicolin Chen
4390e62260 ARM: imx6: Derive spdif clock from pll3_pfd3_454m
SPDIF can derive a TX clock for playback from one of its clock sources --
spdif root clock to match its supporting sample rates. So this patch set
the spdif root clock's parent to pll3_pfd3_454m since the pll3_pfd3_454m
can approximately meet its sample rate requirement.

Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-12-31 09:36:34 +08:00
Shawn Guo
4e5d0d6184 ARM: imx: rename IMX6SL_CLK_CLK_END to IMX6SL_CLK_END
The macro name IMX6SL_CLK_CLK_END is a little insane.  Rename it to
IMX6SL_CLK_END.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-12-31 09:36:23 +08:00
Shawn Guo
9ba64fe3eb ARM: imx: enable suspend for imx6sl
The imx6sl low power mode implementation inherits imx6q/dl one,
and pm-imx6q.c can just work for imx6sl with some minor updates.
Let's enable imx6sl suspend support by reusing pm-imx6q.c and use
cpu_is_imxXX() to handle the those minor differences between imx6sl
and imx6q/dl.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-10-21 09:39:27 +08:00
Liu Ying
dfd871442e ARM: imx6: change some clocks to fixup clocks
All the clocks controlled by the register 'CCM Serial Clock
Multiplexer Register 1' should be fixup clocks. This patch
changes those clocks from basic multiplexer or divider clocks
to fixup clocks.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-08-16 13:11:25 +08:00
Shawn Guo
53bb71da1c ARM: imx6: use common of_clk_init() call to initialize clocks
Instead of explicitly calling clock initialization functions, we can
declare the functions with CLK_OF_DECLARE() and then call common
of_clk_init() to have them invoked properly.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-06-17 15:45:14 +08:00
Shawn Guo
45fe681034 ARM: imx: add clock support for imx6sl
Add clock support for i.MX6 SoloLite.  It uses the dtc marco support to
define all clock IDs in imx6sl-clock.h, which will be included by both
clock driver and device tree sources, so that the data will stay sync
all the time between kernel and DT.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-06-17 15:45:11 +08:00