Re: [PATCH 19/23] watchdog: st_lpc_wdt: Convert to use device managed functions

[Patrice CHOTARD <patrice.chotard@st.com>]

Hi Guenter

On 4/9/19 7:23 PM, Guenter Roeck wrote:
> Use device managed functions to simplify error handling, reduce
> source code size, improve readability, and reduce the likelyhood of bugs.
> 
> 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
> - Introduce local variable 'struct device *dev' and use it instead of
>   dereferencing it repeatedly
> - Use devm_watchdog_register_driver() to register watchdog device
> 
> Cc: Patrice Chotard <patrice.chotard@st.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/watchdog/st_lpc_wdt.c | 47 ++++++++++++++++++++++++-------------------
>  1 file changed, 26 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/watchdog/st_lpc_wdt.c b/drivers/watchdog/st_lpc_wdt.c
> index 196fb4b72c5d..9a5ed95c3403 100644
> --- a/drivers/watchdog/st_lpc_wdt.c
> +++ b/drivers/watchdog/st_lpc_wdt.c
> @@ -142,10 +142,16 @@ static struct watchdog_device st_wdog_dev = {
>  	.ops		= &st_wdog_ops,
>  };
>  
> +static void st_clk_disable_unprepare(void *data)
> +{
> +	clk_disable_unprepare(data);
> +}
> +
>  static int st_wdog_probe(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
>  	const struct of_device_id *match;
> -	struct device_node *np = pdev->dev.of_node;
> +	struct device_node *np = dev->of_node;
>  	struct st_wdog *st_wdog;
>  	struct regmap *regmap;
>  	struct clk *clk;
> @@ -155,7 +161,7 @@ static int st_wdog_probe(struct platform_device *pdev)
>  
>  	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
>  	if (ret) {
> -		dev_err(&pdev->dev, "An LPC mode must be provided\n");
> +		dev_err(dev, "An LPC mode must be provided\n");
>  		return -EINVAL;
>  	}
>  
> @@ -163,13 +169,13 @@ static int st_wdog_probe(struct platform_device *pdev)
>  	if (mode != ST_LPC_MODE_WDT)
>  		return -ENODEV;
>  
> -	st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
> +	st_wdog = devm_kzalloc(dev, sizeof(*st_wdog), GFP_KERNEL);
>  	if (!st_wdog)
>  		return -ENOMEM;
>  
> -	match = of_match_device(st_wdog_match, &pdev->dev);
> +	match = of_match_device(st_wdog_match, dev);
>  	if (!match) {
> -		dev_err(&pdev->dev, "Couldn't match device\n");
> +		dev_err(dev, "Couldn't match device\n");
>  		return -ENODEV;
>  	}
>  	st_wdog->syscfg	= (struct st_wdog_syscfg *)match->data;
> @@ -180,17 +186,17 @@ static int st_wdog_probe(struct platform_device *pdev)
>  
>  	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
>  	if (IS_ERR(regmap)) {
> -		dev_err(&pdev->dev, "No syscfg phandle specified\n");
> +		dev_err(dev, "No syscfg phandle specified\n");
>  		return PTR_ERR(regmap);
>  	}
>  
> -	clk = devm_clk_get(&pdev->dev, NULL);
> +	clk = devm_clk_get(dev, NULL);
>  	if (IS_ERR(clk)) {
> -		dev_err(&pdev->dev, "Unable to request clock\n");
> +		dev_err(dev, "Unable to request clock\n");
>  		return PTR_ERR(clk);
>  	}
>  
> -	st_wdog->dev		= &pdev->dev;
> +	st_wdog->dev		= dev;
>  	st_wdog->base		= base;
>  	st_wdog->clk		= clk;
>  	st_wdog->regmap		= regmap;
> @@ -198,39 +204,40 @@ static int st_wdog_probe(struct platform_device *pdev)
>  	st_wdog->clkrate	= clk_get_rate(st_wdog->clk);
>  
>  	if (!st_wdog->clkrate) {
> -		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
> +		dev_err(dev, "Unable to fetch clock rate\n");
>  		return -EINVAL;
>  	}
>  	st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate;
> -	st_wdog_dev.parent = &pdev->dev;
> +	st_wdog_dev.parent = dev;
>  
>  	ret = clk_prepare_enable(clk);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Unable to enable clock\n");
> +		dev_err(dev, "Unable to enable clock\n");
>  		return ret;
>  	}
> +	ret = devm_add_action_or_reset(dev, st_clk_disable_unprepare, clk);
> +	if (ret)
> +		return ret;
>  
>  	watchdog_set_drvdata(&st_wdog_dev, st_wdog);
>  	watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT);
>  
>  	/* Init Watchdog timeout with value in DT */
> -	ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev);
> +	ret = watchdog_init_timeout(&st_wdog_dev, 0, dev);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n");
> -		clk_disable_unprepare(clk);
> +		dev_err(dev, "Unable to initialise watchdog timeout\n");
>  		return ret;
>  	}
>  
> -	ret = watchdog_register_device(&st_wdog_dev);
> +	ret = devm_watchdog_register_device(dev, &st_wdog_dev);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Unable to register watchdog\n");
> -		clk_disable_unprepare(clk);
> +		dev_err(dev, "Unable to register watchdog\n");
>  		return ret;
>  	}
>  
>  	st_wdog_setup(st_wdog, true);
>  
> -	dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s",
> +	dev_info(dev, "LPC Watchdog driver registered, reset type is %s",
>  		 st_wdog->warm_reset ? "warm" : "cold");
>  
>  	return ret;
> @@ -241,8 +248,6 @@ static int st_wdog_remove(struct platform_device *pdev)
>  	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
>  
>  	st_wdog_setup(st_wdog, false);
> -	watchdog_unregister_device(&st_wdog_dev);
> -	clk_disable_unprepare(st_wdog->clk);
>  
>  	return 0;
>  }
> 

Acked-by: Patrice Chotard <patrice.chotard@st.com>

Thanks