pwm: samsung: Make use of devm_pwmchip_alloc() function

This prepares the pwm-samsung driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Link: https://lore.kernel.org/r/f188e68bdea8d5a24277a10c8c9a6350a9c246ac.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-samsung.c

@@ -69,7 +69,6 @@ struct samsung_pwm_channel {
 
 /**
  * struct samsung_pwm_chip - private data of PWM chip
- * @chip:		generic PWM chip
  * @variant:		local copy of hardware variant data
  * @inverter_mask:	inverter status for all channels - one bit per channel
  * @disabled_mask:	disabled status for all channels - one bit per channel
@@ -80,7 +79,6 @@ struct samsung_pwm_channel {
  * @channel:		per channel driver data
  */
 struct samsung_pwm_chip {
-	struct pwm_chip chip;
 	struct samsung_pwm_variant variant;
 	u8 inverter_mask;
 	u8 disabled_mask;
@@ -110,7 +108,7 @@ static DEFINE_SPINLOCK(samsung_pwm_lock);
 static inline
 struct samsung_pwm_chip *to_samsung_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct samsung_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static inline unsigned int to_tcon_channel(unsigned int channel)
@@ -549,14 +547,12 @@ static int pwm_samsung_probe(struct platform_device *pdev)
 	unsigned int chan;
 	int ret;
 
-	our_chip = devm_kzalloc(&pdev->dev, sizeof(*our_chip), GFP_KERNEL);
-	if (our_chip == NULL)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, SAMSUNG_PWM_NUM, sizeof(*our_chip));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	our_chip = to_samsung_pwm_chip(chip);
 
-	chip = &our_chip->chip;
-	chip->dev = &pdev->dev;
 	chip->ops = &pwm_samsung_ops;
-	chip->npwm = SAMSUNG_PWM_NUM;
 	our_chip->inverter_mask = BIT(SAMSUNG_PWM_NUM) - 1;
 
 	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {