Commit e56ec7b7 authored by Philipp Zabel's avatar Philipp Zabel Committed by Thierry Reding
Browse files

pwm: stm32: Implement .get_state() 



Implement the &pwm_ops->get_state callback so drivers can inherit PWM
state set by the bootloader.

Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
[ukl: split off from a patch that also fixes clk enable count in .probe()]
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: default avatarFabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 41fa8f57

drivers/pwm/pwm-stm32.c

+42 −0
Original line number Diff line number Diff line
@@ -471,8 +471,50 @@ static int stm32_pwm_apply_locked(struct pwm_chip *chip, struct pwm_device *pwm, 
	return ret;

}



static int stm32_pwm_get_state(struct pwm_chip *chip,

			       struct pwm_device *pwm, struct pwm_state *state)

{

	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);

	int ch = pwm->hwpwm;

	unsigned long rate;

	u32 ccer, psc, arr, ccr;

	u64 dty, prd;

	int ret;



	mutex_lock(&priv->lock);



	ret = regmap_read(priv->regmap, TIM_CCER, &ccer);

	if (ret)

		goto out;



	state->enabled = ccer & (TIM_CCER_CC1E << (ch * 4));

	state->polarity = (ccer & (TIM_CCER_CC1P << (ch * 4))) ?

			  PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;

	ret = regmap_read(priv->regmap, TIM_PSC, &psc);

	if (ret)

		goto out;

	ret = regmap_read(priv->regmap, TIM_ARR, &arr);

	if (ret)

		goto out;

	ret = regmap_read(priv->regmap, TIM_CCR1 + 4 * ch, &ccr);

	if (ret)

		goto out;



	rate = clk_get_rate(priv->clk);



	prd = (u64)NSEC_PER_SEC * (psc + 1) * (arr + 1);

	state->period = DIV_ROUND_UP_ULL(prd, rate);

	dty = (u64)NSEC_PER_SEC * (psc + 1) * ccr;

	state->duty_cycle = DIV_ROUND_UP_ULL(dty, rate);



out:

	mutex_unlock(&priv->lock);

	return ret;

}



static const struct pwm_ops stm32pwm_ops = {

	.apply = stm32_pwm_apply_locked,

	.get_state = stm32_pwm_get_state,

	.capture = IS_ENABLED(CONFIG_DMA_ENGINE) ? stm32_pwm_capture : NULL,

};