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pwm: stm32: Implement .get_state()

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

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
[ukl: split off from a patch that also fixes clk enable count in .probe()]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Philipp Zabel 2023-10-19 22:07:03 +02:00 committed by Thierry Reding
parent 41fa8f57c0
commit e56ec7b752
1 changed files with 42 additions and 0 deletions
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42
drivers/pwm/pwm-stm32.c
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@ -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,
};