pwm: sun4i: Make use of devm_pwmchip_alloc() function

This prepares the pwm-sun4i 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.
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/9d175b4e27878618cef2e75b6ecbf01ad5d18164.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-sun4i.c

@@ -81,7 +81,6 @@ struct sun4i_pwm_data {
 };
 
 struct sun4i_pwm_chip {
-	struct pwm_chip chip;
 	struct clk *bus_clk;
 	struct clk *clk;
 	struct reset_control *rst;
@@ -92,7 +91,7 @@ struct sun4i_pwm_chip {
 
 static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct sun4i_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *sun4ichip,
@@ -385,18 +384,20 @@ MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
 static int sun4i_pwm_probe(struct platform_device *pdev)
 {
 	struct pwm_chip *chip;
+	const struct sun4i_pwm_data *data;
 	struct sun4i_pwm_chip *sun4ichip;
 	int ret;
 
-	sun4ichip = devm_kzalloc(&pdev->dev, sizeof(*sun4ichip), GFP_KERNEL);
-	if (!sun4ichip)
-		return -ENOMEM;
-	chip = &sun4ichip->chip;
-
-	sun4ichip->data = of_device_get_match_data(&pdev->dev);
-	if (!sun4ichip->data)
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
 		return -ENODEV;
 
+	chip = devm_pwmchip_alloc(&pdev->dev, data->npwm, sizeof(*sun4ichip));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	sun4ichip = to_sun4i_pwm_chip(chip);
+
+	sun4ichip->data = data;
 	sun4ichip->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(sun4ichip->base))
 		return PTR_ERR(sun4ichip->base);
@@ -453,9 +454,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 		goto err_bus;
 	}
 
-	chip->dev = &pdev->dev;
 	chip->ops = &sun4i_pwm_ops;
-	chip->npwm = sun4ichip->data->npwm;
 
 	spin_lock_init(&sun4ichip->ctrl_lock);