Commit 152f2d1d authored by Doug Brown's avatar Doug Brown Committed by Thierry Reding
Browse files

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: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarDoug Brown <doug@schmorgal.com>
Reviewed-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221113233639.24244-3-doug@schmorgal.com


Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent f956b838

drivers/pwm/pwm-pxa.c

+16 −9
Original line number Diff line number Diff line
@@ -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)

	err = clk_prepare_enable(pc->clk);

	if (err)

		return err;



	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;

	}



	err = pxa_pwm_config(chip, pwm, state->duty_cycle, state->period);

	if (err)

		return err;

	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;

}