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55 commits

Author SHA1 Message Date
Rob Herring
0a41b0c5d9 pwm: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-07-24 13:28:05 +02:00
Heiner Kallweit
329db102a2 pwm: meson: make full use of common clock framework
Newer versions of the PWM block use a core clock with external mux,
divider, and gate. These components either don't exist any longer in
the PWM block, or they are bypassed.
To minimize needed changes for supporting the new version, the internal
divider and gate should be handled by CCF too.

I didn't see a good way to split the patch, therefore it's somewhat
bigger. What it does:

- The internal mux is handled by CCF already. Register also internal
  divider and gate with CCF, so that we have one representation of the
  input clock: [mux] parent of [divider] parent of [gate]

- Now that CCF selects an appropriate mux parent, we don't need the
  DT-provided default parent any longer. Accordingly we can also omit
  setting the mux parent directly in the driver.

- Instead of manually handling the pre-div divider value, let CCF
  set the input clock. Targeted input clock frequency is
  0xffff * 1/period for best precision.

- For the "inverted pwm disabled" scenario target an input clock
  frequency of ULONG_MAX. This ensures that the remaining low pulses
  have minimum length.

I don't have hw with the old PWM block, therefore I couldn't test this
patch. With the not yet included extension for the new PWM block
(channel->clk coming directly from get_clk(external_clk)) I didn't
notice any problem. My system uses PWM for the CPU voltage regulator
and for the SDIO 32kHz clock.

Note: The clock gate in the old PWM block is permanently disabled.
This seems to indicate that it's not used by the new PWM block.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:37 +02:00
Heiner Kallweit
3bddf73285 pwm: meson: don't use hdmi/video clock as mux parent
The meson_vclk code from the display driver may change the rate of the
video clock. Therefore better don't use it as pwm mux parent.
After removing this clock from the parent list pwm_gxbb_data and
pwm_g12a_ee_data are the same as pwm_meson8b_data. So we can remove
them.

Reported-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:37 +02:00
Heiner Kallweit
ed73300326 pwm: meson: switch to using struct clk_parent_data for mux parents
We'll use struct clk_parent_data for mux/div/gate initialization in the
follow-up patches. As a first step switch the mux from using
parent_names to clk_parent_data.

Suggested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:36 +02:00
Heiner Kallweit
bafa23b6c0 pwm: meson: remove not needed check in meson_pwm_calc
period >= duty implies that cnt >= duty_cnt. We verified before
that cnt <= 0xffff, therefore we can omit the check here.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:36 +02:00
Heiner Kallweit
87a2cbf02d pwm: meson: fix handling of period/duty if greater than UINT_MAX
state->period/duty are of type u64, and if their value is greater than
UINT_MAX, then the cast to uint will cause problems. Fix this by
changing the type of the respective local variables to u64.

Fixes: b79c3670e1 ("pwm: meson: Don't duplicate the polarity internally")
Cc: stable@vger.kernel.org
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:35 +02:00
Heiner Kallweit
6b9352f3f8 pwm: meson: modify and simplify calculation in meson_pwm_get_state
I don't see a reason why we should treat the case lo < hi differently
and return 0 as period and duty_cycle. The current logic was added with
c375bcbaab ("pwm: meson: Read the full hardware state in
meson_pwm_get_state()"), Martin as original author doesn't remember why
it was implemented this way back then.
So let's handle it as normal use case and also remove the optimization
for lo == 0. I think the improved readability is worth it.

Fixes: c375bcbaab ("pwm: meson: Read the full hardware state in meson_pwm_get_state()")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23 15:37:35 +02:00
Heiner Kallweit
9e4fa80ab7 pwm: meson: Fix g12a ao clk81 name
Fix the name of the aoclk81 clock. Apparently name aoclk81 as used by
the vendor driver was changed when mainlining the g12a clock driver.

Fixes: f41efceb46 ("pwm: meson: Add clock source configuration for Meson G12A")
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-04-13 11:25:36 +02:00
Heiner Kallweit
eb411c0cf5 pwm: meson: Fix axg ao mux parents
This fix is basically the same as 9bce02ef0d ("pwm: meson: Fix the
G12A AO clock parents order"). Vendor driver referenced there has
xtal as first parent also for axg ao. In addition fix the name
of the aoclk81 clock. Apparently name aoclk81 as used by the vendor
driver was changed when mainlining the axg clock driver.

Fixes: bccaa3f917 ("pwm: meson: Add clock source configuration for Meson-AXG")
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-04-13 11:23:50 +02:00
Uwe Kleine-König
8caa81eb95 pwm: meson: Explicitly set .polarity in .get_state()
The driver only supports normal polarity. Complete the implementation of
.get_state() by setting .polarity accordingly.

This fixes a regression that was possible since commit c73a310762
("pwm: Handle .get_state() failures") which stopped to zero-initialize
the state passed to the .get_state() callback. This was reported at
https://forum.odroid.com/viewtopic.php?f=177&t=46360 . While this was an
unintended side effect, the real issue is the driver's callback not
setting the polarity.

There is a complicating fact, that the .apply() callback fakes support
for inversed polarity. This is not (and cannot) be matched by
.get_state(). As fixing this isn't easy, only point it out in a comment
to prevent authors of other drivers from copying that approach.

Fixes: c375bcbaab ("pwm: meson: Read the full hardware state in meson_pwm_get_state()")
Reported-by: Munehisa Kamata <kamatam@amazon.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-03-23 14:44:42 +01:00
Uwe Kleine-König
6c452cff79 pwm: Make .get_state() callback return an error code
.get_state() might fail in some cases. To make it possible that a driver
signals such a failure change the prototype of .get_state() to return an
error code.

This patch was created using coccinelle and the following semantic patch:

@p1@
identifier getstatefunc;
identifier driver;
@@
 struct pwm_ops driver = {
        ...,
        .get_state = getstatefunc
        ,...
 };

@p2@
identifier p1.getstatefunc;
identifier chip, pwm, state;
@@
-void
+int
 getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state)
 {
   ...
-  return;
+  return 0;
   ...
 }

plus the actual change of the prototype in include/linux/pwm.h (plus some
manual fixing of indentions and empty lines).

So for now all drivers return success unconditionally. They are adapted
in the following patches to make the changes easier reviewable.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Acked-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-12-06 12:46:22 +01:00
Uwe Kleine-König
914195ec7e pwm: meson: Drop always false check from .apply()
The PWM core only calls the apply callback with a valid state pointer,
so don't repeat this check already done in the core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01 08:38:10 +01:00
Uwe Kleine-König
5f97f18fea pwm: meson: Simplify duplicated per-channel tracking
The driver tracks per-channel data via struct pwm_device::chip_data and
struct meson_pwm::channels[]. The latter holds the actual data, the former
is only a pointer to the latter. So simplify by using struct
meson_pwm::channels[] consistently.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01 08:34:19 +01:00
Uwe Kleine-König
cb971fdb45 pwm: meson: Drop useless check for channel data being NULL
In meson_pwm_free() the function pwm_get_chip_data() always returns a
non-NULL pointer because it's only called when the request callback
succeeded and this callback calls pwm_set_chip_data() in this case.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01 08:34:04 +01:00
Uwe Kleine-König
37349609f3 pwm: meson: Drop always false check from .request()
In .request() pwm_get_chip_data() returns NULL always since commit
e926b12c61 ("pwm: Clear chip_data in pwm_put()"). (And if it didn't
returning 0 would be wrong because then .request() wouldn't reenable
the clk which the other driver code depends on.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01 08:33:47 +01:00
Uwe Kleine-König
f41227eb8f pwm: meson: Simplify using devm_pwmchip_add()
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28 13:22:07 +02:00
Uwe Kleine-König
e9fdf122cf pwm: Simplify all drivers with explicit of_pwm_n_cells = 3
With the previous commit there is no need for the lowlevel driver any
more to specify it it uses two or three cells. So simplify accordingly.

The only non-trival change affects the pwm-rockchip driver: It used to only
support three cells if the hardware supports polarity. Now the default
number depends on the device tree which has to match hardware anyhow
(and if it doesn't the error is just a bit delayed as a PWM handle with
an inverted setting is catched when pwm_apply_state() is called).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:19:15 +02:00
Uwe Kleine-König
f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:53:00 +01:00
Yangtao Li
17076b10d4 pwm: meson: Convert to devm_platform_ioremap_resource()
Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:18:42 +01:00
Colin Ian King
437fb760d0 pwm: meson: Remove redundant assignment to variable fin_freq
The variable fin_freq is being initialized with a value that is never
read and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-03 21:40:56 +02:00
Krzysztof Kozlowski
b33d232e61 pwm: meson: Fix confusing indentation
Fix indentation of return block.  Smatch warning:
    drivers/pwm/pwm-meson.c:139 meson_pwm_request() warn: inconsistent indenting

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:05 +02:00
Uwe Kleine-König
71523d1812 pwm: Ensure pwm_apply_state() doesn't modify the state argument
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:

        #define PERIOD 5000000
        #define DUTY_LITTLE 10
        ...
        struct pwm_state state = {
                .period = PERIOD,
                .duty_cycle = DUTY_LITTLE,
                .polarity = PWM_POLARITY_NORMAL,
                .enabled = true,
        };

        pwm_apply_state(mypwm, &state);
        ...
        state.duty_cycle = PERIOD / 2;
        pwm_apply_state(mypwm, &state);

For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.

So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Martin Blumenstingl
4ae42ce793 pwm: meson: Add documentation to the driver
Add links to the datasheet and a short summary how the hardware works.
The goal is to make it easier for other developers to understand why the
pwm-meson driver is implemented the way it is.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Co-authored-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:10 +02:00
Martin Blumenstingl
7341c785d8 pwm: meson: Add support PWM_POLARITY_INVERSED when disabling
meson_pwm_apply() has to consider the PWM polarity when disabling the
output.
With enabled=false and polarity=PWM_POLARITY_NORMAL the output needs to
be LOW. The driver already supports this.
With enabled=false and polarity=PWM_POLARITY_INVERSED the output needs
to be HIGH. Implement this in the driver by internally enabling the
output with the same settings that we already use for "period == duty".

This fixes a PWM API violation which expects that the driver honors the
polarity also for enabled=false. Due to the IP block not supporting this
natively we only get "an as close as possible" to 100% HIGH signal (in
my test setup with input clock of 24MHz and measuring the output with a
logic analyzer at 24MHz sampling rate I got a duty cycle of 99.998475%
on a Khadas VIM).

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:10 +02:00
Martin Blumenstingl
d6885b3e0a pwm: meson: Don't cache struct pwm_state internally
The PWM core already caches the "current struct pwm_state" as the
"current state of the hardware registers" inside struct pwm_device.

Drop the struct pwm_state from struct meson_pwm_channel in favour of the
struct pwm_state in struct pwm_device. While here also drop any checks
based on the pwm_state because the PWM core already takes care of this.

No functional changes intended.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:10 +02:00
Martin Blumenstingl
c375bcbaab pwm: meson: Read the full hardware state in meson_pwm_get_state()
Update the meson_pwm_get_state() implementation to take care of all
information in the registers instead of only reading the "enabled"
state.

The PWM output is only enabled if two conditions are met:
1. the per-channel clock is enabled
2. the PWM output is enabled

Calculate the PWM period and duty cycle using the reverse formula which
we already have in meson_pwm_calc() and update struct pwm_state with the
results.

As result of this /sys/kernel/debug/pwm now shows the PWM state set by
the bootloader (or firmware) after booting Linux.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:10 +02:00
Martin Blumenstingl
fb2081e870 pwm: meson: Simplify the calculation of the pre-divider and count
Replace the loop to calculate the pre-divider and count with two
separate div64_u64() calculations. This makes the code easier to read
and improves the precision.

Three example cases:
1) 32.768kHz LPO clock for the SDIO wifi chip on Khadas VIM
   clock input: 500MHz (FCLK_DIV4)
   period: 30518ns
   duty cycle: 15259ns
old algorithm: pre_div=0, cnt=15259
new algorithm: pre_div=0, cnt=15259
(no difference in calculated values)

2) PWM LED on Khadas VIM
   clock input: 24MHz (XTAL)
   period: 7812500ns
   duty cycle: 7812500ns
old algorithm: pre_div=2, cnt=62004
new algorithm: pre_div=2, cnt=62500
Using a scope (24MHz sampling rate) shows the actual difference:
- old: 7753000ns, off by -59500ns (0.7616%)
- new: 7815000ns, off by +2500ns (0.032%)

3) Theoretical case where pre_div is different
   clock input: 24MHz (XTAL)
   period: 2730624ns
   duty cycle: 1365312ns
old algorithm: pre_div=1, cnt=32768
new algorithm: pre_div=0, cnt=65534
Using a scope (24MHz sampling rate) shows the actual difference:
- old: 2731000ns
- new: 2731000ns
(my scope is not precise enough to measure the difference if there's
any)

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:09 +02:00
Martin Blumenstingl
1064c6bace pwm: meson: Move pwm_set_chip_data() to meson_pwm_request()
All existing PWM drivers (except pwm-meson and two other ones) call
pwm_set_chip_data() from their pwm_ops.request() callback. Now that we
can access the struct meson_pwm_channel from struct meson_pwm we can do
the same.

Move the call to pwm_set_chip_data() to meson_pwm_request() and drop the
custom meson_pwm_add_channels(). This makes the implementation
consistent with other drivers and makes it slightly more obvious
thatpwm_get_chip_data() cannot be used from pwm_ops.get_state() (because
that's called by the PWM core before pwm_ops.request()).

No functional changes intended.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:09 +02:00
Martin Blumenstingl
8bbf316453 pwm: meson: Add the per-channel register offsets and bits in a struct
Introduce struct meson_pwm_channel_data which contains the per-channel
offsets for the PWM register and REG_MISC_AB bits. Replace the existing
switch (pwm->hwpwm) statements with an access to the new struct.

This simplifies the code and will make it easier to implement
pwm_ops.get_state() because the switch-case which all per-channel
registers and offsets (as previously implemented in meson_pwm_enable())
doesn't have to be duplicated.

No functional changes intended.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:09 +02:00
Martin Blumenstingl
a50a49a451 pwm: meson: Add the meson_pwm_channel data to struct meson_pwm
Make struct meson_pwm_channel accessible from struct meson_pwm.

PWM core has a limitation: per-channel data can only be set after
pwmchip_add() is called. However, pwmchip_add() internally calls
pwm_ops.get_state(). If pwm_ops.get_state() needs access to the
per-channel data it has to obtain it from struct pwm_chip and struct
pwm_device's hwpwm information.

Add a struct meson_pwm_channel for each PWM channel to struct meson_pwm
so the pwm_ops.get_state() callback can be implemented as it needs
access to the clock from struct meson_pwm_channel.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:08 +02:00
Martin Blumenstingl
7e0321629c pwm: meson: Pass struct pwm_device to meson_pwm_calc()
meson_pwm_calc() is the last function that accepts a struct
meson_pwm_channel. meson_pwm_enable(), meson_pwm_disable() and
meson_pwm_apply() for example are all taking a struct pwm_device as
parameter. When they need the struct meson_pwm_channel these functions
simply call pwm_get_chip_data() internally.

Make meson_pwm_calc() consistent with the other functions in the
meson-pwm driver by passing struct pwm_device to it as well. The value
of the "id" parameter is actually pwm->hwpwm, but the driver never read
the "id" parameter, which is why there's no replacement for it in the
new code.

No functional changes.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:08 +02:00
Martin Blumenstingl
b79c3670e1 pwm: meson: Don't duplicate the polarity internally
Let meson_pwm_calc() use the polarity from struct pwm_state directly.
This removes a level of indirection where meson_pwm_apply() first had to
set a driver-internal inverter mask which was then only used by
meson_pwm_calc().

Instead of adding the polarity as parameter to meson_pwm_calc() switch
to struct pwm_state directly to make it easier to see where the
parameters are actually coming from.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:08 +02:00
Martin Blumenstingl
33cefd84d2 pwm: meson: Change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK
MISC_CLK_SEL_WIDTH is only used in one place where it's converted into
a bit-mask. Rename and change the macro to be a bit-mask so that
conversion is not needed anymore. No functional changes intended.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:08 +02:00
Martin Blumenstingl
181164b669 pwm: meson: Use GENMASK and FIELD_PREP for the lo and hi values
meson_pwm_calc() ensures that "lo" is always less than 16 bits wide
(otherwise it would overflow into the "hi" part of the REG_PWM_{A,B}
register).
Use GENMASK and FIELD_PREP for the lo and hi values to make it easier to
spot how wide these are internally. Additionally this is a preparation
step for the .get_state() implementation where the GENMASK() for lo and
hi becomes handy because it can be used with FIELD_GET() to extract the
values from the register REG_PWM_{A,B} register.

No functional changes intended.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:07 +02:00
Martin Blumenstingl
ba4004c715 pwm: meson: Use devm_clk_get_optional() to get the input clock
Simplify the code which fetches the input clock for a PWM channel by
using devm_clk_get_optional().
This comes with a small functional change: previously all errors except
EPROBE_DEFER were ignored. Now all other errors are also treated as
errors. If no input clock is present devm_clk_get_optional() will return
NULL instead of an error which matches the behavior of the old code.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:07 +02:00
Martin Blumenstingl
084f137600 pwm: meson: Unify the parameter list of meson_pwm_{enable, disable}
This is a preparation for a future cleanup. Pass struct pwm_device
instead of passing the individual values required by each function as
these can be obtained for each struct pwm_device instance.

As a nice side-effect the driver now uses "switch (pwm->hwpwm)"
everywhere. Before some functions used "switch (id)" while others used
"switch (pwm->hwpwm)".

No functional changes.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:06 +02:00
Neil Armstrong
9bce02ef0d pwm: meson: Fix the G12A AO clock parents order
The Amlogic G12A and G12B Documentation is wrong, the AO xtal and clk81
clock source order is reversed, and validated when adding DVFS support
by using the PWM AO D output to control the CPU supply voltage.

The vendor tree also uses the reversed xtal and clk81 order at [1].

[1] https://github.com/hardkernel/linux/blob/odroidn2-4.9.y/drivers/amlogic/pwm/pwm_meson.c#L462

Fixes: f41efceb46 ("pwm: meson: Add clock source configuration for Meson G12A")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25 14:57:44 +02:00
Neil Armstrong
1cdb44135d pwm: meson: Update with SPDX Licence identifier
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25 14:57:14 +02:00
Linus Torvalds
cece6460c2 pwm: Changes for v5.2-rc1
Nothing out of the ordinary this cycle. The bulk of this is a collection
 of fixes for existing drivers and some cleanups. There's one new driver
 for i.MX SoCs and addition of support for some new variants to existing
 drivers.
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Merge tag 'pwm/for-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Nothing out of the ordinary this cycle.

  The bulk of this is a collection of fixes for existing drivers and
  some cleanups. There's one new driver for i.MX SoCs and addition of
  support for some new variants to existing drivers"

* tag 'pwm/for-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: meson: Add clock source configuration for Meson G12A
  dt-bindings: pwm: Update bindings for the Meson G12A Family
  pwm: samsung: Don't uses devm_*() functions in ->request()
  pwm: Clear chip_data in pwm_put()
  pwm: Add i.MX TPM PWM driver support
  dt-bindings: pwm: Add i.MX TPM PWM binding
  pwm: imx27: Use devm_platform_ioremap_resource() to simplify code
  pwm: meson: Use the spin-lock only to protect register modifications
  pwm: meson: Don't disable PWM when setting duty repeatedly
  pwm: meson: Consider 128 a valid pre-divider
  pwm: sysfs: fix typo "its" -> "it's"
  pwm: tiehrpwm: Enable compilation for ARCH_K3
  dt-bindings: pwm: tiehrpwm: Add TI AM654 SoC specific compatible
  pwm: tiehrpwm: Update shadow register for disabling PWMs
  pwm: img: Turn final 'else if' into 'else' in img_pwm_config
  pwm: Fix deadlock warning when removing PWM device
2019-05-10 12:57:15 -04:00
Neil Armstrong
f41efceb46 pwm: meson: Add clock source configuration for Meson G12A
For the PWM controller in the Meson G12A SoC, the EE domain and AO domain
have different clock sources. This patch tries to describe them in the
DT compatible data. The two AO PWM controller has different clock source,
but the first AO controller (A & B) can reuse the AXG parents name.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09 17:29:31 +02:00
Martin Blumenstingl
f173747fff pwm: meson: Use the spin-lock only to protect register modifications
Holding the spin-lock for all of the code in meson_pwm_apply() can
result in a "BUG: scheduling while atomic". This can happen because
clk_get_rate() (which is called from meson_pwm_calc()) may sleep.
Only hold the spin-lock when modifying registers to solve this.

The reason why we need a spin-lock in the driver is because the
REG_MISC_AB register is shared between the two channels provided by one
PWM controller. The only functions where REG_MISC_AB is modified are
meson_pwm_enable() and meson_pwm_disable() so the register reads/writes
in there need to be protected by the spin-lock.

The original code also used the spin-lock to protect the values in
struct meson_pwm_channel. This could be necessary if two consumers can
use the same PWM channel. However, PWM core doesn't allow this so we
don't need to protect the values in struct meson_pwm_channel with a
lock.

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09 16:51:13 +02:00
Bichao Zheng
a279345807 pwm: meson: Don't disable PWM when setting duty repeatedly
There is an abnormally low about 20ms,when setting duty repeatedly.
Because setting the duty will disable PWM and then enable. Delete
this operation now.

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Bichao Zheng <bichao.zheng@amlogic.com>
[ Dropped code instead of hiding it behind a comment ]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09 16:50:35 +02:00
Martin Blumenstingl
51496e4446 pwm: meson: Consider 128 a valid pre-divider
The pre-divider allows configuring longer PWM periods compared to using
the input clock directly. The pre-divider is 7 bit wide, meaning it's
maximum value is 128 (the register value is off-by-one: 0x7f or 127).

Change the loop to also allow for the maximum possible value to be
considered valid.

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09 16:50:04 +02:00
Stephen Boyd
90b6c5c73c clk: Remove CLK_IS_BASIC clk flag
This flag was historically used to indicate that a clk is a "basic" type
of clk like a mux, divider, gate, etc. This never turned out to be very
useful though because it was hard to cleanly split "basic" clks from
other clks in a system. This one flag was a way for type introspection
and it just didn't scale. If anything, it was used by the TI clk driver
to indicate that a clk_hw wasn't contained in the SoC specific clk
structure. We can get rid of this define now that TI is finding those
clks a different way.

Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: <linux-mips@vger.kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: <linux-pwm@vger.kernel.org>
Cc: <linux-amlogic@lists.infradead.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-26 10:40:49 -07:00
Jerome Brunet
b96e9eb628 pwm: meson: Fix mux clock names
Current clock name looks like this:
/soc/bus@ffd00000/pwm@1b000#mux0

This is bad because CCF uses the clock to create a directory in clk debugfs.
With such name, the directory creation (silently) fails and the debugfs
entry end up being created at the debugfs root.

With this change, the clock name will now be:
ffd1b000.pwm#mux0

This matches the clock naming scheme used in the ethernet and mmc driver.
It also fixes the problem with debugfs.

Fixes: 36af66a790 ("pwm: Convert to using %pOF instead of full_name")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-08-20 11:32:25 +02:00
Martin Blumenstingl
735596ca8a pwm: meson: Fix allocation of PWM channel array
Using the pwm-meson driver on the 32-bit SoCs causes memory corruption.
The result are some hard-to-explain errors, for example
devm_clk_register() crashes with a NULL dereference somewhere deep in
the common clock framework code. In some cases the kernel even refused
to boot when any of the PWM controllers were enabled on Meson8b.

The root cause is an incorrect memory size in the devm_kcalloc() call in
meson_pwm_probe(). The code allocates an array of meson_pwm_channel
structs, but the size given is the size of the meson_pwm struct (which
seems like a small copy-and-paste error, as meson_pwm is allocated a few
lines above).

Even with this typo the code seemed to work fine on the 64-bit GX SoCs
(maybe due to the structs having the same size in the compiled result,
but I haven't checked this further).

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-04-30 10:32:30 +02:00
Jian Hu
bccaa3f917 pwm: meson: Add clock source configuration for Meson-AXG
For PWM controller in the Meson-AXG SoC, the EE domain and AO domain
have different clock sources. This patch tries to describe them in the
DT compatible data.

Signed-off-by: Jian Hu <jian.hu@amlogic.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-12-05 09:51:36 +01:00
Rob Herring
36af66a790 pwm: Convert to using %pOF instead of full_name
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-25 13:38:22 +02:00
Jerome Brunet
fd7b2be8cb pwm: meson: Improve PWM calculation precision
When using input clocks with high rates, such as clk81 (166MHz), the
fin_ns = NSEC_PER_SEC / fin_freq can introduce a significant error.

Ex: fin_freq = 166666667, NSEC_PER_SEC = 1000000000
    fin_ns = 5,9999999

which is, of course, rounded down to 5. This introduces an error of ~20%
on the period requested from the PWM.

This patch uses ps instead of ns (and 64 bit integers) to perform the
calculation. This should give a good enough precision.

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

squash! pwm: meson: Improve pwm calculation precision
2017-07-06 17:15:43 +02:00
Jerome Brunet
d396b20a1e pwm: meson: Add compatible for the gxbb ao PWMs
On the gxbb (and gxl) family, the PWMs of the AO domain require a
specific compatible because the possible input clocks are different
from the EE PWMs input clocks.

Since the number of possible input clocks is also different, the
'num_parents' field is added to all the Meson PWM data.

Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06 09:05:22 +02:00