pwm: img: Prepare removing pwm_chip from driver data

This prepares the driver for further changes that will drop struct
pwm_chip chip from struct img_pwm_chip. Use the pwm_chip as driver data
instead of the img_pwm_chip to get access to the pwm_chip in
img_pwm_remove() and the PM callbacks without using imgchip->chip.

Link: https://lore.kernel.org/r/2ddf76d127f69eca7d9faa6475091e432e890ac9.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-img.c

@@ -224,7 +224,8 @@ MODULE_DEVICE_TABLE(of, img_pwm_of_match);
 
 static int img_pwm_runtime_suspend(struct device *dev)
 {
-	struct img_pwm_chip *imgchip = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct img_pwm_chip *imgchip = to_img_pwm_chip(chip);
 
 	clk_disable_unprepare(imgchip->pwm_clk);
 	clk_disable_unprepare(imgchip->sys_clk);
@@ -234,7 +235,8 @@ static int img_pwm_runtime_suspend(struct device *dev)
 
 static int img_pwm_runtime_resume(struct device *dev)
 {
-	struct img_pwm_chip *imgchip = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct img_pwm_chip *imgchip = to_img_pwm_chip(chip);
 	int ret;
 
 	ret = clk_prepare_enable(imgchip->sys_clk);
@@ -258,11 +260,13 @@ static int img_pwm_probe(struct platform_device *pdev)
 	int ret;
 	u64 val;
 	unsigned long clk_rate;
+	struct pwm_chip *chip;
 	struct img_pwm_chip *imgchip;
 
 	imgchip = devm_kzalloc(&pdev->dev, sizeof(*imgchip), GFP_KERNEL);
 	if (!imgchip)
 		return -ENOMEM;
+	chip = &imgchip->chip;
 
 	imgchip->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(imgchip->base))
@@ -287,7 +291,7 @@ static int img_pwm_probe(struct platform_device *pdev)
 		return PTR_ERR(imgchip->pwm_clk);
 	}
 
-	platform_set_drvdata(pdev, imgchip);
+	platform_set_drvdata(pdev, chip);
 
 	pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT);
 	pm_runtime_use_autosuspend(&pdev->dev);
@@ -314,11 +318,11 @@ static int img_pwm_probe(struct platform_device *pdev)
 	do_div(val, clk_rate);
 	imgchip->min_period_ns = val;
 
-	imgchip->chip.dev = &pdev->dev;
-	imgchip->chip.ops = &img_pwm_ops;
-	imgchip->chip.npwm = IMG_PWM_NPWM;
+	chip->dev = &pdev->dev;
+	chip->ops = &img_pwm_ops;
+	chip->npwm = IMG_PWM_NPWM;
 
-	ret = pwmchip_add(&imgchip->chip);
+	ret = pwmchip_add(chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
 		goto err_suspend;
@@ -337,19 +341,20 @@ static int img_pwm_probe(struct platform_device *pdev)
 
 static void img_pwm_remove(struct platform_device *pdev)
 {
-	struct img_pwm_chip *imgchip = platform_get_drvdata(pdev);
+	struct pwm_chip *chip = platform_get_drvdata(pdev);
 
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		img_pwm_runtime_suspend(&pdev->dev);
 
-	pwmchip_remove(&imgchip->chip);
+	pwmchip_remove(chip);
 }
 
 #ifdef CONFIG_PM_SLEEP
 static int img_pwm_suspend(struct device *dev)
 {
-	struct img_pwm_chip *imgchip = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct img_pwm_chip *imgchip = to_img_pwm_chip(chip);
 	int i, ret;
 
 	if (pm_runtime_status_suspended(dev)) {
@@ -358,7 +363,7 @@ static int img_pwm_suspend(struct device *dev)
 			return ret;
 	}
 
-	for (i = 0; i < imgchip->chip.npwm; i++)
+	for (i = 0; i < chip->npwm; i++)
 		imgchip->suspend_ch_cfg[i] = img_pwm_readl(imgchip,
 							   PWM_CH_CFG(i));
 
@@ -371,7 +376,8 @@ static int img_pwm_suspend(struct device *dev)
 
 static int img_pwm_resume(struct device *dev)
 {
-	struct img_pwm_chip *imgchip = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct img_pwm_chip *imgchip = to_img_pwm_chip(chip);
 	int ret;
 	int i;
 
@@ -379,13 +385,13 @@ static int img_pwm_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	for (i = 0; i < imgchip->chip.npwm; i++)
+	for (i = 0; i < chip->npwm; i++)
 		img_pwm_writel(imgchip, PWM_CH_CFG(i),
 			       imgchip->suspend_ch_cfg[i]);
 
 	img_pwm_writel(imgchip, PWM_CTRL_CFG, imgchip->suspend_ctrl_cfg);
 
-	for (i = 0; i < imgchip->chip.npwm; i++)
+	for (i = 0; i < chip->npwm; i++)
 		if (imgchip->suspend_ctrl_cfg & BIT(i))
 			regmap_clear_bits(imgchip->periph_regs,
 					  PERIP_PWM_PDM_CONTROL,