Re: [PATCH 18/23] watchdog: 1: Convert to use device managed functions and other improvements

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Apr 09, 2019 at 10:23:56AM -0700, Guenter Roeck wrote:
> 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
> 
> - Replace devm_add_action() followed by failure action with
>   devm_add_action_or_reset()
> - Replace 'val = e; return val;' with 'return e;'
> - Introduce local variable 'struct device *dev' and use it instead of
>   dereferencing it repeatedly
> - Use devm_watchdog_register_driver() to register watchdog device
> 
Hmm, something went wrong with the subject line. Should have been
"watchdog: sprd_wdt:". Sorry for that.

Guenter

> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/watchdog/sprd_wdt.c | 38 ++++++++++++++++++--------------------
>  1 file changed, 18 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/watchdog/sprd_wdt.c b/drivers/watchdog/sprd_wdt.c
> index a63163a93777..14874e9b207b 100644
> --- a/drivers/watchdog/sprd_wdt.c
> +++ b/drivers/watchdog/sprd_wdt.c
> @@ -245,9 +245,7 @@ static u32 sprd_wdt_get_timeleft(struct watchdog_device *wdd)
>  	u32 val;
>  
>  	val = sprd_wdt_get_cnt_value(wdt);
> -	val = val / SPRD_WDT_CNT_STEP;
> -
> -	return val;
> +	return val / SPRD_WDT_CNT_STEP;
>  }
>  
>  static const struct watchdog_ops sprd_wdt_ops = {
> @@ -269,10 +267,11 @@ static const struct watchdog_info sprd_wdt_info = {
>  
>  static int sprd_wdt_probe(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
>  	struct sprd_wdt *wdt;
>  	int ret;
>  
> -	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> +	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
>  	if (!wdt)
>  		return -ENOMEM;
>  
> @@ -280,57 +279,56 @@ static int sprd_wdt_probe(struct platform_device *pdev)
>  	if (IS_ERR(wdt->base))
>  		return PTR_ERR(wdt->base);
>  
> -	wdt->enable = devm_clk_get(&pdev->dev, "enable");
> +	wdt->enable = devm_clk_get(dev, "enable");
>  	if (IS_ERR(wdt->enable)) {
> -		dev_err(&pdev->dev, "can't get the enable clock\n");
> +		dev_err(dev, "can't get the enable clock\n");
>  		return PTR_ERR(wdt->enable);
>  	}
>  
> -	wdt->rtc_enable = devm_clk_get(&pdev->dev, "rtc_enable");
> +	wdt->rtc_enable = devm_clk_get(dev, "rtc_enable");
>  	if (IS_ERR(wdt->rtc_enable)) {
> -		dev_err(&pdev->dev, "can't get the rtc enable clock\n");
> +		dev_err(dev, "can't get the rtc enable clock\n");
>  		return PTR_ERR(wdt->rtc_enable);
>  	}
>  
>  	wdt->irq = platform_get_irq(pdev, 0);
>  	if (wdt->irq < 0) {
> -		dev_err(&pdev->dev, "failed to get IRQ resource\n");
> +		dev_err(dev, "failed to get IRQ resource\n");
>  		return wdt->irq;
>  	}
>  
> -	ret = devm_request_irq(&pdev->dev, wdt->irq, sprd_wdt_isr,
> -			       IRQF_NO_SUSPEND, "sprd-wdt", (void *)wdt);
> +	ret = devm_request_irq(dev, wdt->irq, sprd_wdt_isr, IRQF_NO_SUSPEND,
> +			       "sprd-wdt", (void *)wdt);
>  	if (ret) {
> -		dev_err(&pdev->dev, "failed to register irq\n");
> +		dev_err(dev, "failed to register irq\n");
>  		return ret;
>  	}
>  
>  	wdt->wdd.info = &sprd_wdt_info;
>  	wdt->wdd.ops = &sprd_wdt_ops;
> -	wdt->wdd.parent = &pdev->dev;
> +	wdt->wdd.parent = dev;
>  	wdt->wdd.min_timeout = SPRD_WDT_MIN_TIMEOUT;
>  	wdt->wdd.max_timeout = SPRD_WDT_MAX_TIMEOUT;
>  	wdt->wdd.timeout = SPRD_WDT_MAX_TIMEOUT;
>  
>  	ret = sprd_wdt_enable(wdt);
>  	if (ret) {
> -		dev_err(&pdev->dev, "failed to enable wdt\n");
> +		dev_err(dev, "failed to enable wdt\n");
>  		return ret;
>  	}
> -	ret = devm_add_action(&pdev->dev, sprd_wdt_disable, wdt);
> +	ret = devm_add_action_or_reset(dev, sprd_wdt_disable, wdt);
>  	if (ret) {
> -		sprd_wdt_disable(wdt);
> -		dev_err(&pdev->dev, "Failed to add wdt disable action\n");
> +		dev_err(dev, "Failed to add wdt disable action\n");
>  		return ret;
>  	}
>  
>  	watchdog_set_nowayout(&wdt->wdd, WATCHDOG_NOWAYOUT);
> -	watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
> +	watchdog_init_timeout(&wdt->wdd, 0, dev);
>  
> -	ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdd);
> +	ret = devm_watchdog_register_device(dev, &wdt->wdd);
>  	if (ret) {
>  		sprd_wdt_disable(wdt);
> -		dev_err(&pdev->dev, "failed to register watchdog\n");
> +		dev_err(dev, "failed to register watchdog\n");
>  		return ret;
>  	}
>  	platform_set_drvdata(pdev, wdt);