Commit Graph

23 Commits

Author SHA1 Message Date
Uwe Kleine-König
5d481e0742 pwm: stm32-lp: Make use of devm_pwmchip_alloc() function
This prepares the pwm-stm32-lp driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Link: https://lore.kernel.org/r/04af7b3d00bc932dd025200a3bf74527c29ca47a.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:25 +01:00
Uwe Kleine-König
0e89637a4f pwm: stm32-lp: Make use of pwmchip_parent() accessor
struct pwm_chip::dev is about to change. To not have to touch this
driver in the same commit as struct pwm_chip::dev, use the accessor
function provided for exactly this purpose.

Link: https://lore.kernel.org/r/d79148ed49389c657b72df05758032be2b516ceb.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:24 +01:00
Uwe Kleine-König
8f5e2dcbe2 pwm: stm32-lp: Prepare removing pwm_chip from driver data
This prepares the driver for further changes that will drop struct
pwm_chip chip from struct stm32_pwm_lp. Use the pwm_chip as driver
data instead of the stm32_pwm_lp to get access to the pwm_chip in
stm32_pwm_lp_suspend() without using priv->chip.

Link: https://lore.kernel.org/r/df47d1aff9b529c9a4762b6ba339a18cecba1497.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:24 +01:00
Uwe Kleine-König
3e4224a98b pwm: stm32-lp: Simplify code to determine the pwmchip's parent device
There is already a pointer to the pwmchip, make use of it directly
instead of using the struct stm32_pwm_lp *priv just obtained from
it. This also has the advantage of not using struct stm32_pwm_lp::chip
any more which will be dropped soon.

Link: https://lore.kernel.org/r/9ad2399e1a683a6344b12d7f70498393b8f8b9de.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:24 +01:00
Uwe Kleine-König
39dfb60c72 pwm: stm32-lp: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
This macro has the advantage over SIMPLE_DEV_PM_OPS that we don't have to
care about when the functions are actually used, so the corresponding
__maybe_unused can be dropped.

Also make use of pm_ptr() to discard all PM related stuff if CONFIG_PM
isn't enabled.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-12-20 16:04:13 +01:00
Uwe Kleine-König
384461abca pwm: Manage owner assignment implicitly for drivers
Instead of requiring each driver to care for assigning the owner member
of struct pwm_ops, handle that implicitly using a macro. Note that the
owner member has to be moved to struct pwm_chip, as the ops structure
usually lives in read-only memory and so cannot be modified.

The upside is that new low level drivers cannot forget the assignment and
save one line each. The pwm-crc driver didn't assign .owner, that's not
a problem in practice though as the driver cannot be compiled as a
module.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti
Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip
Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld
Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230804142707.412137-2-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>
2023-10-13 10:07:17 +02:00
Krzysztof Kozlowski
fa359c1938 pwm: stm32-lp: Drop of_match_ptr for ID table
The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might not be relevant here). This
also fixes the following compile error:

  drivers/pwm/pwm-stm32-lp.c:245:34: error: ‘stm32_pwm_lp_of_match’ defined but not used [-Werror=unused-const-variable=]

for builds with CONFIG_OF=n, CONFIG_PWM_STM32_LP=y and W=1.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-04-06 15:42:22 +02:00
Fabrice Gasnier
3066bc2d58 pwm: stm32-lp: fix the check on arr and cmp registers update
The ARR (auto reload register) and CMP (compare) registers are
successively written. The status bits to check the update of these
registers are polled together with regmap_read_poll_timeout().
The condition to end the loop may become true, even if one of the
register isn't correctly updated.
So ensure both status bits are set before clearing them.

Fixes: e70a540b4e ("pwm: Add STM32 LPTimer PWM driver")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-01-30 16:42:45 +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
85cad49f5e pwm: stm32-lp: Use regmap_clear_bits and regmap_set_bits where applicable
Found using coccinelle and the following semantic patch:

@@
expression map, reg, bits;
@@

- regmap_update_bits(map, reg, bits, bits)
+ regmap_set_bits(map, reg, bits)

@@
expression map, reg, bits;
@@

- regmap_update_bits(map, reg, bits, 0)
+ regmap_clear_bits(map, reg, bits)

Tested-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20221115111347.3705732-5-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 12:46:10 +01:00
Uwe Kleine-König
8614e21008 pwm: stm32-lp: Simplify using devm_pwmchip_add()
This allows to drop the platform_driver's remove function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:47 +02:00
Uwe Kleine-König
d44084c934 pwm: stm32-lp: Don't modify HW state in .remove() callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:37 +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
Guru Das Srinagesh
a9d887dc1c pwm: Convert period and duty cycle to u64
Because period and duty cycle are defined as ints with units of
nanoseconds, the maximum time duration that can be set is limited to
~2.147 seconds. Change their definitions to u64 in the structs of the
PWM framework so that higher durations may be set.

Also use the right format specifiers in debug prints in both core.c,
pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-17 20:42:11 +02:00
Fabrice Gasnier
c91e3234c6 pwm: stm32-lp: Add check in case requested period cannot be achieved
LPTimer can use a 32KHz clock for counting. It depends on clock tree
configuration. In such a case, PWM output frequency range is limited.
Although unlikely, nothing prevents user from requesting a PWM frequency
above counting clock (32KHz for instance):
- This causes (prd - 1) = 0xffff to be written in ARR register later in
the apply() routine.
This results in badly configured PWM period (and also duty_cycle).
Add a check to report an error is such a case.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-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
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
Fabrice Gasnier
cce4a833fc pwm: stm32-lp: Add power management support
Add suspend/resume PM sleep ops. When going to low power, enforce the PWM
channel isn't active. Let the PWM consumers disable it during their own
suspend sequence. Only perform a check here, and handle the pinctrl states.
See [1].
[1] https://lkml.org/lkml/2019/2/5/770

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25 14:49:50 +02:00
Fabrice Gasnier
2c2059c0b8 pwm: stm32-lp: Remove useless loop in stm32_pwm_lp_remove()
LPTimer has only one pwm channel (npwm = 1). Remove useless for loop
in remove routine.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-08-20 11:32:25 +02:00
Gerald Baeza
f6ea025f6e pwm: stm32: LPTimer: Use 3 cells ->of_xlate()
STM32 Low-Power Timer supports generic 3 cells PWM to encode PWM number,
period and polarity.

Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 00:54:56 +02:00
Benjamin Gaignard
d7a131d3a4 pwm: stm32: Adopt SPDX identifier
Add SPDX identifier to make it easier to determine the license of the
file.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-27 23:22:31 +02:00
Axel Lin
f83e2ae260 pwm: stm32-lp: Remove pwm_is_enabled() check before calling pwm_disable()
The same checking is done by the implementation of pwm_disable().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-11-15 11:02:06 +01:00
Fabrice Gasnier
e70a540b4e pwm: Add STM32 LPTimer PWM driver
Add support for single PWM channel on Low-Power Timer, that can be
found on some STM32 platforms.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2017-09-04 14:49:09 +01:00