pwm: stm32: Change prototype of a helper to prepare further changes

This prepares the driver for further changes that will make it harder to
determine the pwm_chip from a given stm32_pwm. To just not have to do
that, rework stm32_pwm_raw_capture() to take a pwm_chip.

Link: https://lore.kernel.org/r/33790c64563cb0434d7156d96f189c6037b3eb0b.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-stm32.c

@@ -90,11 +90,12 @@ static u32 active_channels(struct stm32_pwm *dev)
  * - Period     = t2 - t0
  * - Duty cycle = t1 - t0
  */
-static int stm32_pwm_raw_capture(struct stm32_pwm *priv, struct pwm_device *pwm,
+static int stm32_pwm_raw_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 				 unsigned long tmo_ms, u32 *raw_prd,
 				 u32 *raw_dty)
 {
-	struct device *parent = priv->chip.dev->parent;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	struct device *parent = pwmchip_parent(chip)->parent;
 	enum stm32_timers_dmas dma_id;
 	u32 ccen, ccr;
 	int ret;
@@ -170,7 +171,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	ret = clk_enable(priv->clk);
 	if (ret) {
-		dev_err(chip->dev, "failed to enable counter clock\n");
+		dev_err(pwmchip_parent(chip), "failed to enable counter clock\n");
 		goto unlock;
 	}
 
@@ -208,7 +209,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 			   TIM_CCER_CC12P : TIM_CCER_CC34P, pwm->hwpwm < 2 ?
 			   TIM_CCER_CC2P : TIM_CCER_CC4P);
 
-	ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+	ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd, &raw_dty);
 	if (ret)
 		goto stop;
 
@@ -229,7 +230,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 		/* 2nd measure with new scale */
 		psc /= scale;
 		regmap_write(priv->regmap, TIM_PSC, psc);
-		ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd,
+		ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd,
 					    &raw_dty);
 		if (ret)
 			goto stop;
@@ -257,7 +258,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 			   FIELD_PREP(TIM_CCMR_IC1PSC, icpsc) |
 			   FIELD_PREP(TIM_CCMR_IC2PSC, icpsc));
 
-	ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+	ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd, &raw_dty);
 	if (ret)
 		goto stop;