7 Commits

Author SHA1 Message Date
Uwe Kleine-König
f7ca7b67a0 pwm: stm32-lp: Don't modify HW state in .remove() callback
[ Upstream commit d44084c93427bb0a9261432db1a8ca76a42d805e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 13:39:49 +02:00
Fabrice Gasnier
6534865953 pwm: stm32-lp: Add check in case requested period cannot be achieved
[ Upstream commit c91e3234c6035baf5a79763cb4fcd5d23ce75c2b ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11 18:21:17 +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