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path: root/drivers/pwm/pwm-stm32-lp.c
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2023-01-30pwm: stm32-lp: fix the check on arr and cmp registers updateFabrice Gasnier
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: e70a540b4e02 ("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>
2022-12-06pwm: Make .get_state() callback return an error codeUwe Kleine-König
.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>
2022-12-06pwm: stm32-lp: Use regmap_clear_bits and regmap_set_bits where applicableUwe Kleine-König
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>
2021-09-02pwm: stm32-lp: Simplify using devm_pwmchip_add()Uwe Kleine-König
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>
2021-09-02pwm: stm32-lp: Don't modify HW state in .remove() callbackUwe Kleine-König
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>
2021-05-25pwm: Simplify all drivers with explicit of_pwm_n_cells = 3Uwe Kleine-König
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>
2021-03-22pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König
Since commit 5e5da1e9fbee ("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>
2020-06-17pwm: Convert period and duty cycle to u64Guru Das Srinagesh
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>
2019-09-21pwm: stm32-lp: Add check in case requested period cannot be achievedFabrice Gasnier
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>
2019-09-21pwm: Ensure pwm_apply_state() doesn't modify the state argumentUwe Kleine-König
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>
2019-06-25pwm: stm32-lp: Add power management supportFabrice Gasnier
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>
2018-08-20pwm: stm32-lp: Remove useless loop in stm32_pwm_lp_remove()Fabrice Gasnier
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>
2018-03-28pwm: stm32: LPTimer: Use 3 cells ->of_xlate()Gerald Baeza
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>
2018-03-27pwm: stm32: Adopt SPDX identifierBenjamin Gaignard
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>
2017-11-15pwm: stm32-lp: Remove pwm_is_enabled() check before calling pwm_disable()Axel Lin
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>
2017-09-04pwm: Add STM32 LPTimer PWM driverFabrice Gasnier
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>