pwm: tiecap: Change prototype of helpers to prepare further changes

This prepares the driver for further changes that will make it harder to
determine the pwm_chip from a given ecap_pwm_chip. To just not have to
do that, rework ecap_pwm_save_context() and ecap_pwm_restore_context
take a pwm_chip. Also use the pwm_chip as driver data instead of the
ecap_pwm_chip.

Link: https://lore.kernel.org/r/ed031f201ff52c6b298de2dc81b06aad3a0207f8.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-tiecap.c

@@ -218,6 +218,7 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct ecap_pwm_chip *pc;
+	struct pwm_chip *chip;
 	struct clk *clk;
 	int ret;
 
@@ -244,21 +245,22 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	pc->chip.dev = &pdev->dev;
-	pc->chip.ops = &ecap_pwm_ops;
-	pc->chip.npwm = 1;
+	chip = &pc->chip;
+	chip->dev = &pdev->dev;
+	chip->ops = &ecap_pwm_ops;
+	chip->npwm = 1;
 
 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pc->mmio_base))
 		return PTR_ERR(pc->mmio_base);
 
-	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, pc);
+	platform_set_drvdata(pdev, chip);
 	pm_runtime_enable(&pdev->dev);
 
 	return 0;
@@ -269,17 +271,21 @@ static void ecap_pwm_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 }
 
-static void ecap_pwm_save_context(struct ecap_pwm_chip *pc)
+static void ecap_pwm_save_context(struct pwm_chip *chip)
 {
-	pm_runtime_get_sync(pc->chip.dev);
+	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+
+	pm_runtime_get_sync(chip->dev);
 	pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);
 	pc->ctx.cap4 = readl(pc->mmio_base + CAP4);
 	pc->ctx.cap3 = readl(pc->mmio_base + CAP3);
-	pm_runtime_put_sync(pc->chip.dev);
+	pm_runtime_put_sync(chip->dev);
 }
 
-static void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
+static void ecap_pwm_restore_context(struct pwm_chip *chip)
 {
+	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+
 	writel(pc->ctx.cap3, pc->mmio_base + CAP3);
 	writel(pc->ctx.cap4, pc->mmio_base + CAP4);
 	writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);
@@ -287,10 +293,10 @@ static void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
 
 static int ecap_pwm_suspend(struct device *dev)
 {
-	struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
-	struct pwm_device *pwm = pc->chip.pwms;
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct pwm_device *pwm = chip->pwms;
 
-	ecap_pwm_save_context(pc);
+	ecap_pwm_save_context(chip);
 
 	/* Disable explicitly if PWM is running */
 	if (pwm_is_enabled(pwm))
@@ -301,14 +307,14 @@ static int ecap_pwm_suspend(struct device *dev)
 
 static int ecap_pwm_resume(struct device *dev)
 {
-	struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
-	struct pwm_device *pwm = pc->chip.pwms;
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct pwm_device *pwm = chip->pwms;
 
 	/* Enable explicitly if PWM was running */
 	if (pwm_is_enabled(pwm))
 		pm_runtime_get_sync(dev);
 
-	ecap_pwm_restore_context(pc);
+	ecap_pwm_restore_context(chip);
 	return 0;
 }