pwm: mtk-disp: Make use of devm_pwmchip_alloc() function

This prepares the pwm-mtk-disp 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: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/a70bf253dc41c61d9b901423710c97f235e372c3.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-mtk-disp.c

@@ -42,7 +42,6 @@ struct mtk_pwm_data {
 };
 
 struct mtk_disp_pwm {
-	struct pwm_chip chip;
 	const struct mtk_pwm_data *data;
 	struct clk *clk_main;
 	struct clk *clk_mm;
@@ -52,7 +51,7 @@ struct mtk_disp_pwm {
 
 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
 {
-	return container_of(chip, struct mtk_disp_pwm, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
@@ -231,12 +230,14 @@ static const struct pwm_ops mtk_disp_pwm_ops = {
 
 static int mtk_disp_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct mtk_disp_pwm *mdp;
 	int ret;
 
-	mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
-	if (!mdp)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*mdp));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	mdp = to_mtk_disp_pwm(chip);
 
 	mdp->data = of_device_get_match_data(&pdev->dev);
 
@@ -254,11 +255,9 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(mdp->clk_mm),
 				     "Failed to get mm clock\n");
 
-	mdp->chip.dev = &pdev->dev;
-	mdp->chip.ops = &mtk_disp_pwm_ops;
-	mdp->chip.npwm = 1;
+	chip->ops = &mtk_disp_pwm_ops;
 
-	ret = devm_pwmchip_add(&pdev->dev, &mdp->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");