pwm: rockchip: Make use of devm_pwmchip_alloc() function

This prepares the pwm-rockchip 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/61a3f48710e3e795beb2e496c8c673bbc0f6c932.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-rockchip.c

@@ -30,7 +30,6 @@
 #define PWM_LP_DISABLE		(0 << 8)
 
 struct rockchip_pwm_chip {
-	struct pwm_chip chip;
 	struct clk *clk;
 	struct clk *pclk;
 	const struct rockchip_pwm_data *data;
@@ -54,7 +53,7 @@ struct rockchip_pwm_data {
 
 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct rockchip_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int rockchip_pwm_get_state(struct pwm_chip *chip,
@@ -302,10 +301,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 	bool enabled;
 	int ret, count;
 
-	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
-	if (!pc)
-		return -ENOMEM;
-	chip = &pc->chip;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*pc));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	pc = to_rockchip_pwm_chip(chip);
 
 	pc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pc->base))
@@ -342,9 +341,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, chip);
 
 	pc->data = device_get_match_data(&pdev->dev);
-	chip->dev = &pdev->dev;
 	chip->ops = &rockchip_pwm_ops;
-	chip->npwm = 1;
 
 	enable_conf = pc->data->enable_conf;
 	ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);