pwm: spear: Make use of devm_pwmchip_alloc() function

This prepares the pwm-spear 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/c67e3f26435a8fa047ad6887803dbcb9c1e032ee.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-spear.c

@@ -48,17 +48,15 @@
  *
  * @mmio_base: base address of pwm chip
  * @clk: pointer to clk structure of pwm chip
- * @chip: linux pwm chip representation
  */
 struct spear_pwm_chip {
 	void __iomem *mmio_base;
 	struct clk *clk;
-	struct pwm_chip chip;
 };
 
 static inline struct spear_pwm_chip *to_spear_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct spear_pwm_chip, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static inline u32 spear_pwm_readl(struct spear_pwm_chip *chip, unsigned int num,
@@ -194,13 +192,15 @@ static const struct pwm_ops spear_pwm_ops = {
 static int spear_pwm_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
+	struct pwm_chip *chip;
 	struct spear_pwm_chip *pc;
 	int ret;
 	u32 val;
 
-	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
-	if (!pc)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, NUM_PWM, sizeof(*pc));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	pc = to_spear_pwm_chip(chip);
 
 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pc->mmio_base))
@@ -211,9 +211,7 @@ static int spear_pwm_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
 				     "Failed to get clock\n");
 
-	pc->chip.dev = &pdev->dev;
-	pc->chip.ops = &spear_pwm_ops;
-	pc->chip.npwm = NUM_PWM;
+	chip->ops = &spear_pwm_ops;
 
 	if (of_device_is_compatible(np, "st,spear1340-pwm")) {
 		ret = clk_enable(pc->clk);
@@ -232,7 +230,7 @@ static int spear_pwm_probe(struct platform_device *pdev)
 		clk_disable(pc->clk);
 	}
 
-	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");