pwm: twl-led: Make use of devm_pwmchip_alloc() function

This prepares the pwm-twl-led 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/5bac90addb3a178ef958a2a524c6ec7e3eea3e6a.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-twl-led.c

@@ -62,13 +62,12 @@
 #define TWL6040_LED_MODE_MASK	0x03
 
 struct twl_pwmled_chip {
-	struct pwm_chip chip;
 	struct mutex mutex;
 };
 
 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
 {
-	return container_of(chip, struct twl_pwmled_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -345,25 +344,29 @@ static const struct pwm_ops twl6030_pwmled_ops = {
 
 static int twl_pwmled_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct twl_pwmled_chip *twl;
-
-	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
-	if (!twl)
-		return -ENOMEM;
+	unsigned int npwm;
+	const struct pwm_ops *ops;
 
 	if (twl_class_is_4030()) {
-		twl->chip.ops = &twl4030_pwmled_ops;
-		twl->chip.npwm = 2;
+		ops = &twl4030_pwmled_ops;
+		npwm = 2;
 	} else {
-		twl->chip.ops = &twl6030_pwmled_ops;
-		twl->chip.npwm = 1;
+		ops = &twl6030_pwmled_ops;
+		npwm = 1;
 	}
 
-	twl->chip.dev = &pdev->dev;
+	chip = devm_pwmchip_alloc(&pdev->dev, npwm, sizeof(*twl));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	twl = to_twl(chip);
+
+	chip->ops = ops;
 
 	mutex_init(&twl->mutex);
 
-	return devm_pwmchip_add(&pdev->dev, &twl->chip);
+	return devm_pwmchip_add(&pdev->dev, chip);
 }
 
 #ifdef CONFIG_OF