[PATCH] watchdog: cadence: Use devm_clk_get_enabled() helper

[PATCH] watchdog: cadence: Use devm_clk_get_enabled() helper

[Christophe JAILLET]

The devm_clk_get_enabled() helper:
   - calls devm_clk_get()
   - calls clk_prepare_enable() and registers what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the need of a dedicated function used
with devm_add_action_or_reset().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/watchdog/cadence_wdt.c | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
index bc99e9164930..23d41043863f 100644
--- a/drivers/watchdog/cadence_wdt.c
+++ b/drivers/watchdog/cadence_wdt.c
@@ -274,11 +274,6 @@ static const struct watchdog_ops cdns_wdt_ops = {
 	.set_timeout = cdns_wdt_settimeout,
 };
 
-static void cdns_clk_disable_unprepare(void *data)
-{
-	clk_disable_unprepare(data);
-}
-
 /************************Platform Operations*****************************/
 /**
  * cdns_wdt_probe - Probe call for the device.
@@ -333,21 +328,11 @@ static int cdns_wdt_probe(struct platform_device *pdev)
 	watchdog_stop_on_reboot(cdns_wdt_device);
 	watchdog_set_drvdata(cdns_wdt_device, wdt);
 
-	wdt->clk = devm_clk_get(dev, NULL);
+	wdt->clk = devm_clk_get_enabled(dev, NULL);
 	if (IS_ERR(wdt->clk))
 		return dev_err_probe(dev, PTR_ERR(wdt->clk),
 				     "input clock not found\n");
 
-	ret = clk_prepare_enable(wdt->clk);
-	if (ret) {
-		dev_err(dev, "unable to enable clock\n");
-		return ret;
-	}
-	ret = devm_add_action_or_reset(dev, cdns_clk_disable_unprepare,
-				       wdt->clk);
-	if (ret)
-		return ret;
-
 	clock_f = clk_get_rate(wdt->clk);
 	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
 		wdt->prescaler = CDNS_WDT_PRESCALE_512;
-- 
2.34.1

Re: [PATCH] watchdog: cadence: Use devm_clk_get_enabled() helper

[Guenter Roeck]

On Sat, Dec 31, 2022 at 09:12:28AM +0100, Christophe JAILLET wrote:
> The devm_clk_get_enabled() helper:
>    - calls devm_clk_get()
>    - calls clk_prepare_enable() and registers what is needed in order to
>      call clk_disable_unprepare() when needed, as a managed resource.
> 
> This simplifies the code and avoids the need of a dedicated function used
> with devm_add_action_or_reset().
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/cadence_wdt.c | 17 +----------------
>  1 file changed, 1 insertion(+), 16 deletions(-)
> 
> diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
> index bc99e9164930..23d41043863f 100644
> --- a/drivers/watchdog/cadence_wdt.c
> +++ b/drivers/watchdog/cadence_wdt.c
> @@ -274,11 +274,6 @@ static const struct watchdog_ops cdns_wdt_ops = {
>  	.set_timeout = cdns_wdt_settimeout,
>  };
>  
> -static void cdns_clk_disable_unprepare(void *data)
> -{
> -	clk_disable_unprepare(data);
> -}
> -
>  /************************Platform Operations*****************************/
>  /**
>   * cdns_wdt_probe - Probe call for the device.
> @@ -333,21 +328,11 @@ static int cdns_wdt_probe(struct platform_device *pdev)
>  	watchdog_stop_on_reboot(cdns_wdt_device);
>  	watchdog_set_drvdata(cdns_wdt_device, wdt);
>  
> -	wdt->clk = devm_clk_get(dev, NULL);
> +	wdt->clk = devm_clk_get_enabled(dev, NULL);
>  	if (IS_ERR(wdt->clk))
>  		return dev_err_probe(dev, PTR_ERR(wdt->clk),
>  				     "input clock not found\n");
>  
> -	ret = clk_prepare_enable(wdt->clk);
> -	if (ret) {
> -		dev_err(dev, "unable to enable clock\n");
> -		return ret;
> -	}
> -	ret = devm_add_action_or_reset(dev, cdns_clk_disable_unprepare,
> -				       wdt->clk);
> -	if (ret)
> -		return ret;
> -
>  	clock_f = clk_get_rate(wdt->clk);
>  	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
>  		wdt->prescaler = CDNS_WDT_PRESCALE_512;
> -- 
> 2.34.1
>