Re: [PATCH V3] mmc: sdhci-of-dwcmshc: Use helper function devm_clk_get_enabled()

[Adrian Hunter <adrian.hunter@intel.com>]

On 24/08/23 11:46, Yi Yang wrote:
> Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for
> prepared and enabled clocks"), devm_clk_get() and clk_prepare_enable()
> can now be replaced by devm_clk_get_enabled() when the driver enables
> (and possibly prepares) the clocks for the whole lifetime of the device.
> Moreover, it is no longer necessary to unprepare and disable the clocks
> explicitly.
> 
> Signed-off-by: Yi Yang <yiyang13@huawei.com>
> ---
> v3: Fix err check logic
> v2: Remove clk_disable_unprepare in dwcmshc_remove()
> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 20 ++++++++------------
>  1 file changed, 8 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index 31c1892f4ecd..7e1cf78d9695 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -495,19 +495,19 @@ static int dwcmshc_probe(struct platform_device *pdev)
>  	priv = sdhci_pltfm_priv(pltfm_host);
>  
>  	if (dev->of_node) {
> -		pltfm_host->clk = devm_clk_get(dev, "core");
> +		pltfm_host->clk = devm_clk_get_enabled(dev, "core");
>  		if (IS_ERR(pltfm_host->clk)) {
>  			err = PTR_ERR(pltfm_host->clk);
> -			dev_err(dev, "failed to get core clk: %d\n", err);
> +			dev_err(dev, "failed to get or enable core clk: %d\n", err);
>  			goto free_pltfm;
>  		}
> -		err = clk_prepare_enable(pltfm_host->clk);
> -		if (err)
> -			goto free_pltfm;
>  
> -		priv->bus_clk = devm_clk_get(dev, "bus");
> -		if (!IS_ERR(priv->bus_clk))
> -			clk_prepare_enable(priv->bus_clk);
> +		priv->bus_clk = devm_clk_get_enabled(dev, "bus");

This should probably be devm_clk_get_enabled_optional()
Maybe someone who knows the hardware can confirm?

> +		if (IS_ERR(priv->bus_clk)) {
> +			err = PTR_ERR(priv->bus_clk);
> +			dev_err(dev, "failed to get or enable bus clk: %d\n", err);
> +			goto free_pltfm;
> +		}
>  	}
>  
>  	err = mmc_of_parse(host->mmc);
> @@ -564,8 +564,6 @@ static int dwcmshc_probe(struct platform_device *pdev)
>  err_setup_host:
>  	sdhci_cleanup_host(host);
>  err_clk:
> -	clk_disable_unprepare(pltfm_host->clk);
> -	clk_disable_unprepare(priv->bus_clk);
>  	if (rk_priv)
>  		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>  					   rk_priv->rockchip_clks);
> @@ -583,8 +581,6 @@ static void dwcmshc_remove(struct platform_device *pdev)
>  
>  	sdhci_remove_host(host, 0);
>  
> -	clk_disable_unprepare(pltfm_host->clk);
> -	clk_disable_unprepare(priv->bus_clk);
>  	if (rk_priv)
>  		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>  					   rk_priv->rockchip_clks);