pwm: rcar: Make use of devm_pwmchip_alloc() function

This prepares the pwm-rcar 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/a37a167364366b6cbe2dd299dce02731706213b2.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-rcar.c

@@ -38,14 +38,13 @@
 #define  RCAR_PWMCNT_PH0_SHIFT	0
 
 struct rcar_pwm_chip {
-	struct pwm_chip chip;
 	void __iomem *base;
 	struct clk *clk;
 };
 
 static inline struct rcar_pwm_chip *to_rcar_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct rcar_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static void rcar_pwm_write(struct rcar_pwm_chip *rp, u32 data,
@@ -206,9 +205,10 @@ static int rcar_pwm_probe(struct platform_device *pdev)
 	struct rcar_pwm_chip *rcar_pwm;
 	int ret;
 
-	rcar_pwm = devm_kzalloc(&pdev->dev, sizeof(*rcar_pwm), GFP_KERNEL);
-	if (rcar_pwm == NULL)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*rcar_pwm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	rcar_pwm = to_rcar_pwm_chip(chip);
 
 	rcar_pwm->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(rcar_pwm->base))
@@ -220,10 +220,7 @@ static int rcar_pwm_probe(struct platform_device *pdev)
 		return PTR_ERR(rcar_pwm->clk);
 	}
 
-	chip = &rcar_pwm->chip;
-	chip->dev = &pdev->dev;
 	chip->ops = &rcar_pwm_ops;
-	chip->npwm = 1;
 
 	platform_set_drvdata(pdev, chip);