pwm: apple: Make use of devm_pwmchip_alloc() function

This prepares the pwm-apple 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/34cf20a82ca07bb4ec0578b193daa5caed37825e.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-apple.c

@@ -32,14 +32,13 @@
 #define APPLE_PWM_CTRL_OUTPUT_ENABLE BIT(14)
 
 struct apple_pwm {
-	struct pwm_chip chip;
 	void __iomem *base;
 	u64 clkrate;
 };
 
 static inline struct apple_pwm *to_apple_pwm(struct pwm_chip *chip)
 {
-	return container_of(chip, struct apple_pwm, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int apple_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -103,13 +102,16 @@ static const struct pwm_ops apple_pwm_ops = {
 
 static int apple_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct apple_pwm *fpwm;
 	struct clk *clk;
 	int ret;
 
-	fpwm = devm_kzalloc(&pdev->dev, sizeof(*fpwm), GFP_KERNEL);
-	if (!fpwm)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*fpwm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+
+	fpwm = to_apple_pwm(chip);
 
 	fpwm->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(fpwm->base))
@@ -129,11 +131,9 @@ static int apple_pwm_probe(struct platform_device *pdev)
 	if (fpwm->clkrate > NSEC_PER_SEC)
 		return dev_err_probe(&pdev->dev, -EINVAL, "pwm clock out of range");
 
-	fpwm->chip.dev = &pdev->dev;
-	fpwm->chip.npwm = 1;
-	fpwm->chip.ops = &apple_pwm_ops;
+	chip->ops = &apple_pwm_ops;
 
-	ret = devm_pwmchip_add(&pdev->dev, &fpwm->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "unable to add pwm chip");