linux-kernel - [PATCH 16/22] watchdog: pic32-wdt: Convert to use device managed functions and other improvements

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Date:   Wed, 10 Apr 2019 09:27:57 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Wim Van Sebroeck <wim@...ux-watchdog.org>
Cc:     linux-watchdog@...r.kernel.org, linux-kernel@...r.kernel.org,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 16/22] watchdog: pic32-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

- Drop assignments to otherwise unused variables
- Drop empty remove function
- Use devm_add_action_or_reset() for calls to clk_disable_unprepare
- Introduce local variable 'struct device *dev' and use it instead of
  dereferencing it repeatedly
- Use devm_watchdog_register_driver() to register watchdog device

Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/watchdog/pic32-wdt.c | 58 ++++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 34 deletions(-)

diff --git a/drivers/watchdog/pic32-wdt.c b/drivers/watchdog/pic32-wdt.c
index 455ec38363a6..540500940cc0 100644
--- a/drivers/watchdog/pic32-wdt.c
+++ b/drivers/watchdog/pic32-wdt.c
@@ -166,13 +166,19 @@ static const struct of_device_id pic32_wdt_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, pic32_wdt_dt_ids);
 
+static void pic32_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
 static int pic32_wdt_drv_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	int ret;
 	struct watchdog_device *wdd = &pic32_wdd;
 	struct pic32_wdt *wdt;
 
-	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
 		return -ENOMEM;
 
@@ -180,73 +186,57 @@ static int pic32_wdt_drv_probe(struct platform_device *pdev)
 	if (IS_ERR(wdt->regs))
 		return PTR_ERR(wdt->regs);
 
-	wdt->rst_base = devm_ioremap(&pdev->dev, PIC32_BASE_RESET, 0x10);
+	wdt->rst_base = devm_ioremap(dev, PIC32_BASE_RESET, 0x10);
 	if (!wdt->rst_base)
 		return -ENOMEM;
 
-	wdt->clk = devm_clk_get(&pdev->dev, NULL);
+	wdt->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(wdt->clk)) {
-		dev_err(&pdev->dev, "clk not found\n");
+		dev_err(dev, "clk not found\n");
 		return PTR_ERR(wdt->clk);
 	}
 
 	ret = clk_prepare_enable(wdt->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "clk enable failed\n");
+		dev_err(dev, "clk enable failed\n");
 		return ret;
 	}
+	ret = devm_add_action_or_reset(dev, pic32_clk_disable_unprepare,
+				       wdt->clk);
+	if (ret)
+		return ret;
 
 	if (pic32_wdt_is_win_enabled(wdt)) {
-		dev_err(&pdev->dev, "windowed-clear mode is not supported.\n");
-		ret = -ENODEV;
-		goto out_disable_clk;
+		dev_err(dev, "windowed-clear mode is not supported.\n");
+		return -ENODEV;
 	}
 
-	wdd->timeout = pic32_wdt_get_timeout_secs(wdt, &pdev->dev);
+	wdd->timeout = pic32_wdt_get_timeout_secs(wdt, dev);
 	if (!wdd->timeout) {
-		dev_err(&pdev->dev,
-			"failed to read watchdog register timeout\n");
-		ret = -EINVAL;
-		goto out_disable_clk;
+		dev_err(dev, "failed to read watchdog register timeout\n");
+		return -EINVAL;
 	}
 
-	dev_info(&pdev->dev, "timeout %d\n", wdd->timeout);
+	dev_info(dev, "timeout %d\n", wdd->timeout);
 
 	wdd->bootstatus = pic32_wdt_bootstatus(wdt) ? WDIOF_CARDRESET : 0;
 
 	watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
 	watchdog_set_drvdata(wdd, wdt);
 
-	ret = watchdog_register_device(wdd);
+	ret = devm_watchdog_register_device(dev, wdd);
 	if (ret) {
-		dev_err(&pdev->dev, "watchdog register failed, err %d\n", ret);
-		goto out_disable_clk;
+		dev_err(dev, "watchdog register failed, err %d\n", ret);
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, wdd);
 
 	return 0;
-
-out_disable_clk:
-	clk_disable_unprepare(wdt->clk);
-
-	return ret;
-}
-
-static int pic32_wdt_drv_remove(struct platform_device *pdev)
-{
-	struct watchdog_device *wdd = platform_get_drvdata(pdev);
-	struct pic32_wdt *wdt = watchdog_get_drvdata(wdd);
-
-	watchdog_unregister_device(wdd);
-	clk_disable_unprepare(wdt->clk);
-
-	return 0;
 }
 
 static struct platform_driver pic32_wdt_driver = {
 	.probe		= pic32_wdt_drv_probe,
-	.remove		= pic32_wdt_drv_remove,
 	.driver		= {
 		.name		= "pic32-wdt",
 		.of_match_table = of_match_ptr(pic32_wdt_dt_ids),
-- 
2.7.4