linux-kernel - Re: [PATCH 2/2] watchdog: dw_wdt: Simplify clk management

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Date:   Wed, 26 Apr 2023 06:47:18 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     Wim Van Sebroeck <wim@...ux-watchdog.org>,
        linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org,
        linux-watchdog@...r.kernel.org
Subject: Re: [PATCH 2/2] watchdog: dw_wdt: Simplify clk management

On Wed, Apr 26, 2023 at 08:52:49AM +0200, Christophe JAILLET wrote:
> Use devm_clk_get_enabled() instead of hand-writing it.
> This saves some LoC.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>

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

> ---
> This change the order the resources will be released, so review with care.
> ---
>  drivers/watchdog/dw_wdt.c | 44 ++++++++++-----------------------------
>  1 file changed, 11 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
> index a1354a59eb37..84dca3695f86 100644
> --- a/drivers/watchdog/dw_wdt.c
> +++ b/drivers/watchdog/dw_wdt.c
> @@ -566,22 +566,16 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
>  	 * to the common timer/bus clocks configuration, in which the very
>  	 * first found clock supply both timer and APB signals.
>  	 */
> -	dw_wdt->clk = devm_clk_get(dev, "tclk");
> +	dw_wdt->clk = devm_clk_get_enabled(dev, "tclk");
>  	if (IS_ERR(dw_wdt->clk)) {
> -		dw_wdt->clk = devm_clk_get(dev, NULL);
> +		dw_wdt->clk = devm_clk_get_enabled(dev, NULL);
>  		if (IS_ERR(dw_wdt->clk))
>  			return PTR_ERR(dw_wdt->clk);
>  	}
>  
> -	ret = clk_prepare_enable(dw_wdt->clk);
> -	if (ret)
> -		return ret;
> -
>  	dw_wdt->rate = clk_get_rate(dw_wdt->clk);
> -	if (dw_wdt->rate == 0) {
> -		ret = -EINVAL;
> -		goto out_disable_clk;
> -	}
> +	if (dw_wdt->rate == 0)
> +		return -EINVAL;
>  
>  	/*
>  	 * Request APB clock if device is configured with async clocks mode.
> @@ -590,21 +584,13 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
>  	 * so the pclk phandle reference is left optional. If it couldn't be
>  	 * found we consider the device configured in synchronous clocks mode.
>  	 */
> -	dw_wdt->pclk = devm_clk_get_optional(dev, "pclk");
> -	if (IS_ERR(dw_wdt->pclk)) {
> -		ret = PTR_ERR(dw_wdt->pclk);
> -		goto out_disable_clk;
> -	}
> -
> -	ret = clk_prepare_enable(dw_wdt->pclk);
> -	if (ret)
> -		goto out_disable_clk;
> +	dw_wdt->pclk = devm_clk_get_optional_enabled(dev, "pclk");
> +	if (IS_ERR(dw_wdt->pclk))
> +		return PTR_ERR(dw_wdt->pclk);
>  
>  	dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
> -	if (IS_ERR(dw_wdt->rst)) {
> -		ret = PTR_ERR(dw_wdt->rst);
> -		goto out_disable_pclk;
> -	}
> +	if (IS_ERR(dw_wdt->rst))
> +		return PTR_ERR(dw_wdt->rst);
>  
>  	/* Enable normal reset without pre-timeout by default. */
>  	dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
> @@ -621,12 +607,12 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
>  				       IRQF_SHARED | IRQF_TRIGGER_RISING,
>  				       pdev->name, dw_wdt);
>  		if (ret)
> -			goto out_disable_pclk;
> +			return ret;
>  
>  		dw_wdt->wdd.info = &dw_wdt_pt_ident;
>  	} else {
>  		if (ret == -EPROBE_DEFER)
> -			goto out_disable_pclk;
> +			return ret;
>  
>  		dw_wdt->wdd.info = &dw_wdt_ident;
>  	}
> @@ -675,12 +661,6 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
>  
>  out_assert_rst:
>  	reset_control_assert(dw_wdt->rst);
> -
> -out_disable_pclk:
> -	clk_disable_unprepare(dw_wdt->pclk);
> -
> -out_disable_clk:
> -	clk_disable_unprepare(dw_wdt->clk);
>  	return ret;
>  }
>  
> @@ -692,8 +672,6 @@ static void dw_wdt_drv_remove(struct platform_device *pdev)
>  
>  	watchdog_unregister_device(&dw_wdt->wdd);
>  	reset_control_assert(dw_wdt->rst);
> -	clk_disable_unprepare(dw_wdt->pclk);
> -	clk_disable_unprepare(dw_wdt->clk);
>  }
>  
>  #ifdef CONFIG_OF
> -- 
> 2.34.1
>