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pwm: pxa: Set duty cycle to 0 when disabling PWM

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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>
This commit is contained in:
Doug Brown 2022-12-02 19:35:21 +01:00 committed by Thierry Reding
parent f956b83893
commit 152f2d1def
1 changed files with 17 additions and 10 deletions
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27
drivers/pwm/pwm-pxa.c
View file

@ -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);
return 0;
}
err = pxa_pwm_config(chip, pwm, state->duty_cycle, state->period);
err = clk_prepare_enable(pc->clk);
if (err)
return err;
if (!pwm->state.enabled)
return clk_prepare_enable(pc->clk);
duty_cycle = state->enabled ? state->duty_cycle : 0;
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 (!state->enabled && pwm->state.enabled)
clk_disable_unprepare(pc->clk);
return 0;
}