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From:   Guenter Roeck <linux@roeck-us.net>
To:     Wim Van Sebroeck <wim@linux-watchdog.org>
Cc:     linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
        Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 13/22] watchdog: davinci_wdt: Convert to use device managed functions and other improvements
Date:   Mon,  8 Apr 2019 12:38:37 -0700
Message-Id: <1554752326-13319-14-git-send-email-linux@roeck-us.net>
In-Reply-To: <1554752326-13319-1-git-send-email-linux@roeck-us.net>
References: <1554752326-13319-1-git-send-email-linux@roeck-us.net>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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

- Drop assignments to otherwise unused variables
- Drop unnecessary braces around conditional return statements
- Drop empty remove function
- Use devm_add_action_or_reset() for calls to clk_disable_unprepare
- Use local variable 'struct device *dev' consistently
- Use devm_watchdog_register_driver() to register watchdog device

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/watchdog/davinci_wdt.c | 41 ++++++++++++++++-------------------------
 1 file changed, 16 insertions(+), 25 deletions(-)

diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
index 7daa15df74a5..7b2ee35b5ffd 100644
--- a/drivers/watchdog/davinci_wdt.c
+++ b/drivers/watchdog/davinci_wdt.c
@@ -191,6 +191,11 @@ static const struct watchdog_ops davinci_wdt_ops = {
 	.restart	= davinci_wdt_restart,
 };
 
+static void davinci_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
 static int davinci_wdt_probe(struct platform_device *pdev)
 {
 	int ret = 0;
@@ -206,15 +211,19 @@ static int davinci_wdt_probe(struct platform_device *pdev)
 
 	if (IS_ERR(davinci_wdt->clk)) {
 		if (PTR_ERR(davinci_wdt->clk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "failed to get clock node\n");
+			dev_err(dev, "failed to get clock node\n");
 		return PTR_ERR(davinci_wdt->clk);
 	}
 
 	ret = clk_prepare_enable(davinci_wdt->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "failed to prepare clock\n");
+		dev_err(dev, "failed to prepare clock\n");
 		return ret;
 	}
+	ret = devm_add_action_or_reset(dev, davinci_clk_disable_unprepare,
+				       davinci_wdt->clk);
+	if (ret)
+		return ret;
 
 	platform_set_drvdata(pdev, davinci_wdt);
 
@@ -224,7 +233,7 @@ static int davinci_wdt_probe(struct platform_device *pdev)
 	wdd->min_timeout	= 1;
 	wdd->max_timeout	= MAX_HEARTBEAT;
 	wdd->timeout		= DEFAULT_HEARTBEAT;
-	wdd->parent		= &pdev->dev;
+	wdd->parent		= dev;
 
 	watchdog_init_timeout(wdd, heartbeat, dev);
 
@@ -235,33 +244,16 @@ static int davinci_wdt_probe(struct platform_device *pdev)
 	watchdog_set_restart_priority(wdd, 128);
 
 	davinci_wdt->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(davinci_wdt->base)) {
-		ret = PTR_ERR(davinci_wdt->base);
-		goto err_clk_disable;
-	}
+	if (IS_ERR(davinci_wdt->base))
+		return PTR_ERR(davinci_wdt->base);
 
-	ret = watchdog_register_device(wdd);
+	ret = devm_watchdog_register_device(dev, wdd);
 	if (ret) {
 		dev_err(dev, "cannot register watchdog device\n");
-		goto err_clk_disable;
+		return ret;
 	}
 
 	return 0;
-
-err_clk_disable:
-	clk_disable_unprepare(davinci_wdt->clk);
-
-	return ret;
-}
-
-static int davinci_wdt_remove(struct platform_device *pdev)
-{
-	struct davinci_wdt_device *davinci_wdt = platform_get_drvdata(pdev);
-
-	watchdog_unregister_device(&davinci_wdt->wdd);
-	clk_disable_unprepare(davinci_wdt->clk);
-
-	return 0;
 }
 
 static const struct of_device_id davinci_wdt_of_match[] = {
@@ -276,7 +268,6 @@ static struct platform_driver platform_wdt_driver = {
 		.of_match_table = davinci_wdt_of_match,
 	},
 	.probe = davinci_wdt_probe,
-	.remove = davinci_wdt_remove,
 };
 
 module_platform_driver(platform_wdt_driver);
-- 
2.7.4