pwm: sun4i: Prepare removing pwm_chip from driver data

This prepares the driver for further changes that will drop struct
pwm_chip chip from struct sun4i_pwm_chip. Use the pwm_chip as driver
data instead of the sun4i_pwm_chip to get access to the pwm_chip in
sun4i_pwm_remove() without using sun4ichip->chip.
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/f8e3fb96fe341ba0a4bed982aa731c5c7c355b83.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-sun4i.c

@@ -384,12 +384,14 @@ MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
 
 static int sun4i_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct sun4i_pwm_chip *sun4ichip;
 	int ret;
 
 	sun4ichip = devm_kzalloc(&pdev->dev, sizeof(*sun4ichip), GFP_KERNEL);
 	if (!sun4ichip)
 		return -ENOMEM;
+	chip = &sun4ichip->chip;
 
 	sun4ichip->data = of_device_get_match_data(&pdev->dev);
 	if (!sun4ichip->data)
@@ -451,19 +453,19 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 		goto err_bus;
 	}
 
-	sun4ichip->chip.dev = &pdev->dev;
-	sun4ichip->chip.ops = &sun4i_pwm_ops;
-	sun4ichip->chip.npwm = sun4ichip->data->npwm;
+	chip->dev = &pdev->dev;
+	chip->ops = &sun4i_pwm_ops;
+	chip->npwm = sun4ichip->data->npwm;
 
 	spin_lock_init(&sun4ichip->ctrl_lock);
 
-	ret = pwmchip_add(&sun4ichip->chip);
+	ret = pwmchip_add(chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 		goto err_pwm_add;
 	}
 
-	platform_set_drvdata(pdev, sun4ichip);
+	platform_set_drvdata(pdev, chip);
 
 	return 0;
 
@@ -477,9 +479,10 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 
 static void sun4i_pwm_remove(struct platform_device *pdev)
 {
-	struct sun4i_pwm_chip *sun4ichip = platform_get_drvdata(pdev);
+	struct pwm_chip *chip = platform_get_drvdata(pdev);
+	struct sun4i_pwm_chip *sun4ichip = to_sun4i_pwm_chip(chip);
 
-	pwmchip_remove(&sun4ichip->chip);
+	pwmchip_remove(chip);
 
 	clk_disable_unprepare(sun4ichip->bus_clk);
 	reset_control_assert(sun4ichip->rst);