pwm: sifive: Prepare removing pwm_chip from driver data

This prepares the driver for further changes that will drop struct
pwm_chip chip from struct pwm_sifive_ddata. Use the pwm_chip as driver
data instead of the pwm_sifive_ddata to get access to the pwm_chip in
pwm_sifive_remove() without using ddata->chip. In the clock rate
notifier it's not possible to get the pwm_chip without adding a pointer
to this to struct pwm_sifive_ddata. Instead of that add a parent device
pointer which is all that is needed there.

Link: https://lore.kernel.org/r/b7b7985[e-mail]
Signed-off-by: Uwe Kleine-König <[e-mail]>

drivers/pwm/pwm-sifive.c

···
 
 struct pwm_sifive_ddata {
 	struct pwm_chip	chip;
+	struct device *parent;
 	struct mutex lock; /* lock to protect user_count and approx_period */
 	struct notifier_block notifier;
 	struct clk *clk;
···
 	/* As scale <= 15 the shift operation cannot overflow. */
 	num = (unsigned long long)NSEC_PER_SEC << (PWM_SIFIVE_CMPWIDTH + scale);
 	ddata->real_period = div64_ul(num, rate);
-	dev_dbg(ddata->chip.dev,
+	dev_dbg(ddata->parent,
 		"New real_period = %u ns\n", ddata->real_period);
 }
 
···
 
 	mutex_init(&ddata->lock);
 	chip = &ddata->chip;
-	chip->dev = dev;
+	chip->dev = ddata->parent = dev;
 	chip->ops = &pwm_sifive_ops;
 	chip->npwm = 4;
 
···
 		goto unregister_clk;
 	}
 
-	platform_set_drvdata(pdev, ddata);
+	platform_set_drvdata(pdev, chip);
 	dev_dbg(dev, "SiFive PWM chip registered %d PWMs\n", chip->npwm);
 
 	return 0;
···
 
 static void pwm_sifive_remove(struct platform_device *dev)
 {
-	struct pwm_sifive_ddata *ddata = platform_get_drvdata(dev);
+	struct pwm_chip *chip = platform_get_drvdata(dev);
+	struct pwm_sifive_ddata *ddata = pwm_sifive_chip_to_ddata(chip);
 	struct pwm_device *pwm;
 	int ch;
 
-	pwmchip_remove(&ddata->chip);
+	pwmchip_remove(chip);
 	clk_notifier_unregister(ddata->clk, &ddata->notifier);
 
-	for (ch = 0; ch < ddata->chip.npwm; ch++) {
-		pwm = &ddata->chip.pwms[ch];
+	for (ch = 0; ch < chip->npwm; ch++) {
+		pwm = &chip->pwms[ch];
 		if (pwm->state.enabled)
 			clk_disable(ddata->clk);
 	}