pwm: lpc18xx-sct: Prepare removing pwm_chip from driver data

This prepares the driver for further changes that will drop struct
pwm_chip chip from struct lpc18xx_pwm_chip. Use the pwm_chip as driver
data instead of the lpc18xx_pwm_chip to get access to the pwm_chip in
lpc18xx_pwm_remove() without using lpc18xx_pwm->chip.

Link: https://lore.kernel.org/r/b7bf8c421ff754ec3e985ec6235f4ddd6e5e27a4.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-lpc18xx-sct.c

@@ -348,6 +348,7 @@ MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);
 
 static int lpc18xx_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct lpc18xx_pwm_chip *lpc18xx_pwm;
 	int ret;
 	u64 val;
@@ -356,6 +357,7 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 				   GFP_KERNEL);
 	if (!lpc18xx_pwm)
 		return -ENOMEM;
+	chip = &lpc18xx_pwm->chip;
 
 	lpc18xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(lpc18xx_pwm->base))
@@ -386,9 +388,9 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 	lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,
 						  lpc18xx_pwm->clk_rate);
 
-	lpc18xx_pwm->chip.dev = &pdev->dev;
-	lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
-	lpc18xx_pwm->chip.npwm = LPC18XX_NUM_PWMS;
+	chip->dev = &pdev->dev;
+	chip->ops = &lpc18xx_pwm_ops;
+	chip->npwm = LPC18XX_NUM_PWMS;
 
 	/* SCT counter must be in unify (32 bit) mode */
 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
@@ -420,21 +422,22 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 	val |= LPC18XX_PWM_PRE(0);
 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);
 
-	ret = pwmchip_add(&lpc18xx_pwm->chip);
+	ret = pwmchip_add(chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add failed\n");
 
-	platform_set_drvdata(pdev, lpc18xx_pwm);
+	platform_set_drvdata(pdev, chip);
 
 	return 0;
 }
 
 static void lpc18xx_pwm_remove(struct platform_device *pdev)
 {
-	struct lpc18xx_pwm_chip *lpc18xx_pwm = platform_get_drvdata(pdev);
+	struct pwm_chip *chip = platform_get_drvdata(pdev);
+	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
 	u32 val;
 
-	pwmchip_remove(&lpc18xx_pwm->chip);
+	pwmchip_remove(chip);
 
 	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL,