pwm: berlin: Make use of devm_pwmchip_alloc() function

This prepares the pwm-berlin 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/52866502c96a80d1c30be003dc1f5a89a4d230cc.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-berlin.c

@@ -49,7 +49,6 @@ struct berlin_pwm_channel {
 };
 
 struct berlin_pwm_chip {
-	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
 	struct berlin_pwm_channel channel[BERLIN_PWM_NUMPWMS];
@@ -57,7 +56,7 @@ struct berlin_pwm_chip {
 
 static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct berlin_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *bpc,
@@ -202,9 +201,10 @@ static int berlin_pwm_probe(struct platform_device *pdev)
 	struct berlin_pwm_chip *bpc;
 	int ret;
 
-	bpc = devm_kzalloc(&pdev->dev, sizeof(*bpc), GFP_KERNEL);
-	if (!bpc)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, BERLIN_PWM_NUMPWMS, sizeof(*bpc));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	bpc = to_berlin_pwm_chip(chip);
 
 	bpc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(bpc->base))
@@ -214,10 +214,7 @@ static int berlin_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(bpc->clk))
 		return PTR_ERR(bpc->clk);
 
-	chip = &bpc->chip;
-	chip->dev = &pdev->dev;
 	chip->ops = &berlin_pwm_ops;
-	chip->npwm = BERLIN_PWM_NUMPWMS;
 
 	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)