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authorDoug Brown <doug@schmorgal.com>2022-12-02 21:35:21 +0300
committerThierry Reding <thierry.reding@gmail.com>2022-12-06 14:46:13 +0300
commit152f2d1def5e4b974947877126ff292a68a8c521 (patch)
treed4c2be676ea7464f4d2578d88a6347ee2b8e4ba5 /drivers/pwm
parentf956b838934ab06deeee2ce9d5c8dfe64e4beb24 (diff)
downloadlinux-152f2d1def5e4b974947877126ff292a68a8c521.tar.xz
pwm: pxa: Set duty cycle to 0 when disabling PWM
When disabling PWM, the duty cycle needs to be set to 0. This prevents the previous duty cycle from showing up momentarily when the clock is re-enabled next time. Because the clock has to be running in order to configure the duty cycle, unconditionally enable it early in pxa_pwm_apply and account for the correct enable count at the end. Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Doug Brown <doug@schmorgal.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20221113233639.24244-3-doug@schmorgal.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-pxa.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index 0ac052652c62..9ee9b41d62b8 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -105,24 +105,31 @@ static int pxa_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+ u64 duty_cycle;
int err;
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
- if (!state->enabled) {
- if (pwm->state.enabled)
- clk_disable_unprepare(pc->clk);
+ err = clk_prepare_enable(pc->clk);
+ if (err)
+ return err;
- return 0;
- }
+ duty_cycle = state->enabled ? state->duty_cycle : 0;
- err = pxa_pwm_config(chip, pwm, state->duty_cycle, state->period);
- if (err)
+ err = pxa_pwm_config(chip, pwm, duty_cycle, state->period);
+ if (err) {
+ clk_disable_unprepare(pc->clk);
return err;
+ }
+
+ if (state->enabled && !pwm->state.enabled)
+ return 0;
+
+ clk_disable_unprepare(pc->clk);
- if (!pwm->state.enabled)
- return clk_prepare_enable(pc->clk);
+ if (!state->enabled && pwm->state.enabled)
+ clk_disable_unprepare(pc->clk);
return 0;
}