pwm: ep93xx: Make use of devm_pwmchip_alloc() function

This prepares the pwm-ep93xx 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/9420eeca1eb18fada4a15c897f60696b7b22b532.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-ep93xx.c

@@ -36,12 +36,11 @@
 struct ep93xx_pwm {
 	void __iomem *base;
 	struct clk *clk;
-	struct pwm_chip chip;
 };
 
 static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
 {
-	return container_of(chip, struct ep93xx_pwm, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -163,12 +162,14 @@ static const struct pwm_ops ep93xx_pwm_ops = {
 
 static int ep93xx_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct ep93xx_pwm *ep93xx_pwm;
 	int ret;
 
-	ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
-	if (!ep93xx_pwm)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*ep93xx_pwm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	ep93xx_pwm = to_ep93xx_pwm(chip);
 
 	ep93xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ep93xx_pwm->base))
@@ -178,11 +179,9 @@ static int ep93xx_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(ep93xx_pwm->clk))
 		return PTR_ERR(ep93xx_pwm->clk);
 
-	ep93xx_pwm->chip.dev = &pdev->dev;
-	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
-	ep93xx_pwm->chip.npwm = 1;
+	chip->ops = &ep93xx_pwm_ops;
 
-	ret = devm_pwmchip_add(&pdev->dev, &ep93xx_pwm->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)
 		return ret;