pwm: sti: Prepare removing pwm_chip from driver data

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

Link: https://lore.kernel.org/r/56d53372aacff6871df4d6c6779c9dac94592696.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-sti.c

@@ -570,6 +570,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct sti_pwm_compat_data *cdata;
+	struct pwm_chip *chip;
 	struct sti_pwm_chip *pc;
 	unsigned int i;
 	int irq, ret;
@@ -577,6 +578,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)
 		return -ENOMEM;
+	chip = &pc->chip;
 
 	cdata = devm_kzalloc(dev, sizeof(*cdata), GFP_KERNEL);
 	if (!cdata)
@@ -653,9 +655,9 @@ static int sti_pwm_probe(struct platform_device *pdev)
 			return -ENOMEM;
 	}
 
-	pc->chip.dev = dev;
-	pc->chip.ops = &sti_pwm_ops;
-	pc->chip.npwm = max(cdata->pwm_num_devs, cdata->cpt_num_devs);
+	chip->dev = dev;
+	chip->ops = &sti_pwm_ops;
+	chip->npwm = max(cdata->pwm_num_devs, cdata->cpt_num_devs);
 
 	for (i = 0; i < cdata->cpt_num_devs; i++) {
 		struct sti_cpt_ddata *ddata = &cdata->ddata[i];
@@ -664,23 +666,24 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		mutex_init(&ddata->lock);
 	}
 
-	ret = pwmchip_add(&pc->chip);
+	ret = pwmchip_add(chip);
 	if (ret < 0) {
 		clk_unprepare(pc->pwm_clk);
 		clk_unprepare(pc->cpt_clk);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, pc);
+	platform_set_drvdata(pdev, chip);
 
 	return 0;
 }
 
 static void sti_pwm_remove(struct platform_device *pdev)
 {
-	struct sti_pwm_chip *pc = platform_get_drvdata(pdev);
+	struct pwm_chip *chip = platform_get_drvdata(pdev);
+	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
 
-	pwmchip_remove(&pc->chip);
+	pwmchip_remove(chip);
 
 	clk_unprepare(pc->pwm_clk);
 	clk_unprepare(pc->cpt_clk);