pwm: spear: Simplify using devm functions

With devm_clk_get_prepared() the call to clk_unprepare() can be dropped
from the error path and the remove callback. With devm_pwmchip_add()
pwmchip_remove() can be dropped. Then the remove callback is empty and
can go away, too. With spear_pwm_remove() the last user of
platform_get_drvdata() is gone and so platform_set_drvdata() can be
dropped, too.

Also use dev_err_probe() for simplified (and improved) error reporting.

Link: https://lore.kernel.org/r/20230929161918.2410424-7-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Author: Uwe Kleine-König

drivers/pwm/pwm-spear.c

@@ -206,26 +206,21 @@ static int spear_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pc->mmio_base))
 		return PTR_ERR(pc->mmio_base);
 
-	pc->clk = devm_clk_get(&pdev->dev, NULL);
+	pc->clk = devm_clk_get_prepared(&pdev->dev, NULL);
 	if (IS_ERR(pc->clk))
-		return PTR_ERR(pc->clk);
-
-	platform_set_drvdata(pdev, pc);
+		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+				     "Failed to get clock\n");
 
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &spear_pwm_ops;
 	pc->chip.npwm = NUM_PWM;
 
-	ret = clk_prepare(pc->clk);
-	if (ret)
-		return ret;
-
 	if (of_device_is_compatible(np, "st,spear1340-pwm")) {
 		ret = clk_enable(pc->clk);
-		if (ret) {
-			clk_unprepare(pc->clk);
-			return ret;
-		}
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					     "Failed to enable clk\n");
+
 		/*
 		 * Following enables PWM chip, channels would still be
 		 * enabled individually through their control register
@@ -237,23 +232,11 @@ static int spear_pwm_probe(struct platform_device *pdev)
 		clk_disable(pc->clk);
 	}
 
-	ret = pwmchip_add(&pc->chip);
-	if (ret < 0) {
-		clk_unprepare(pc->clk);
-		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
-	}
+	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");
 
-	return ret;
-}
-
-static void spear_pwm_remove(struct platform_device *pdev)
-{
-	struct spear_pwm_chip *pc = platform_get_drvdata(pdev);
-
-	pwmchip_remove(&pc->chip);
-
-	/* clk was prepared in probe, hence unprepare it here */
-	clk_unprepare(pc->clk);
+	return 0;
 }
 
 static const struct of_device_id spear_pwm_of_match[] = {
@@ -270,7 +253,6 @@ static struct platform_driver spear_pwm_driver = {
 		.of_match_table = spear_pwm_of_match,
 	},
 	.probe = spear_pwm_probe,
-	.remove_new = spear_pwm_remove,
 };
 
 module_platform_driver(spear_pwm_driver);