linux-kernel - [PATCH 32/62] watchdog: meson_gxbb_wdt: Convert to use device managed functions and other improvements

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Date:   Tue, 10 Jan 2017 16:44:41 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Wim Van Sebroeck <wim@...ana.be>
Cc:     linux-watchdog@...r.kernel.org, linux-kernel@...r.kernel.org,
        Guenter Roeck <linux@...ck-us.net>,
        Carlo Caione <carlo@...one.org>,
        Kevin Hilman <khilman@...libre.com>,
        linux-amlogic@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 32/62] watchdog: meson_gxbb_wdt: Convert to use device managed functions and other improvements

Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.
Other improvements as listed below.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts used
to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Use devm_add_action_or_reset() for calls to clk_disable_unprepare
- Check return value from clk_prepare_enable()
- Replace 'val = e; return val;' with 'return e;'
- Replace 'if (e) return e; return 0;' with 'return e;'
- Drop assignments to otherwise unused variables
- Replace 'if (e) { return expr; }' with 'if (e) return expr;'
- Drop remove function
- Use devm_watchdog_register_driver() to register watchdog device
- Replace shutdown function with call to watchdog_stop_on_reboot()

Cc: Carlo Caione <carlo@...one.org>
Cc: Kevin Hilman <khilman@...libre.com>
Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/watchdog/meson_gxbb_wdt.c | 38 ++++++++++----------------------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 45d47664a00a..913d8a644460 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -203,7 +203,14 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(data->clk))
 		return PTR_ERR(data->clk);
 
-	clk_prepare_enable(data->clk);
+	ret = clk_prepare_enable(data->clk);
+	if (ret)
+		return ret;
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       (void(*)(void *))clk_disable_unprepare,
+				       data->clk);
+	if (ret)
+		return ret;
 
 	platform_set_drvdata(pdev, data);
 
@@ -224,37 +231,12 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
 
-	ret = watchdog_register_device(&data->wdt_dev);
-	if (ret) {
-		clk_disable_unprepare(data->clk);
-		return ret;
-	}
-
-	return 0;
-}
-
-static int meson_gxbb_wdt_remove(struct platform_device *pdev)
-{
-	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
-
-	watchdog_unregister_device(&data->wdt_dev);
-
-	clk_disable_unprepare(data->clk);
-
-	return 0;
-}
-
-static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
-{
-	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
-
-	meson_gxbb_wdt_stop(&data->wdt_dev);
+	watchdog_stop_on_reboot(&data->wdt_dev);
+	return devm_watchdog_register_device(&pdev->dev, &data->wdt_dev);
 }
 
 static struct platform_driver meson_gxbb_wdt_driver = {
 	.probe	= meson_gxbb_wdt_probe,
-	.remove	= meson_gxbb_wdt_remove,
-	.shutdown = meson_gxbb_wdt_shutdown,
 	.driver = {
 		.name = "meson-gxbb-wdt",
 		.pm = &meson_gxbb_wdt_pm_ops,
-- 
2.7.4