Re: [PATCH] mmc: sdhci-sprd: Fix the clock switch

[Ulf Hansson]

On Mon, 6 Nov 2023 at 11:40, Wenchao Chen <wenchao.chen@xxxxxxxxxx> wrote:
>
> Some SOCs have a "1x_enable" clock that needs to be turned on and off
> in probe, remove and runtime pm.

Well, first of all, what is a "1x_enable" clock and why do we need it?

Moreover, the clock needs to be described as a part of the DT bindings
for the sdhci-sprd mmc controller. That said, it looks like the
binding for the sdhci-sprd controller needs to be converted to the
yaml format first, can you please have a look at that too?

>
> Fixes: fb8bd90f83c4 ("mmc: sdhci-sprd: Add Spreadtrum's initial host controller")
> Signed-off-by: Wenchao Chen <wenchao.chen@xxxxxxxxxx>

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci-sprd.c | 29 +++++++++++++++++++++++++----
>  1 file changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> index 6b84ba27e6ab..3367f924dc5b 100644
> --- a/drivers/mmc/host/sdhci-sprd.c
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -83,6 +83,7 @@ struct sdhci_sprd_host {
>         u32 version;
>         struct clk *clk_sdio;
>         struct clk *clk_enable;
> +       struct clk *clk_1x_enable;
>         struct clk *clk_2x_enable;
>         struct pinctrl *pinctrl;
>         struct pinctrl_state *pins_uhs;
> @@ -784,6 +785,10 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
>         }
>         sprd_host->clk_enable = clk;
>
> +       clk = devm_clk_get(&pdev->dev, "1x_enable");
> +       if (!IS_ERR(clk))
> +               sprd_host->clk_1x_enable = clk;
> +
>         clk = devm_clk_get(&pdev->dev, "2x_enable");
>         if (!IS_ERR(clk))
>                 sprd_host->clk_2x_enable = clk;
> @@ -793,12 +798,16 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
>                 goto pltfm_free;
>
>         ret = clk_prepare_enable(sprd_host->clk_enable);
> +       if (ret)
> +               goto clk_sdio_disable;
> +
> +       ret = clk_prepare_enable(sprd_host->clk_1x_enable);
>         if (ret)
>                 goto clk_disable;
>
>         ret = clk_prepare_enable(sprd_host->clk_2x_enable);
>         if (ret)
> -               goto clk_disable2;
> +               goto clk_1x_disable;
>
>         sdhci_sprd_init_config(host);
>         host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
> @@ -858,10 +867,13 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
>
>         clk_disable_unprepare(sprd_host->clk_2x_enable);
>
> -clk_disable2:
> -       clk_disable_unprepare(sprd_host->clk_enable);
> +clk_1x_disable:
> +       clk_disable_unprepare(sprd_host->clk_1x_enable);
>
>  clk_disable:
> +       clk_disable_unprepare(sprd_host->clk_enable);
> +
> +clk_sdio_disable:
>         clk_disable_unprepare(sprd_host->clk_sdio);
>
>  pltfm_free:
> @@ -878,6 +890,7 @@ static void sdhci_sprd_remove(struct platform_device *pdev)
>
>         clk_disable_unprepare(sprd_host->clk_sdio);
>         clk_disable_unprepare(sprd_host->clk_enable);
> +       clk_disable_unprepare(sprd_host->clk_1x_enable);
>         clk_disable_unprepare(sprd_host->clk_2x_enable);
>
>         sdhci_pltfm_free(pdev);
> @@ -900,6 +913,7 @@ static int sdhci_sprd_runtime_suspend(struct device *dev)
>
>         clk_disable_unprepare(sprd_host->clk_sdio);
>         clk_disable_unprepare(sprd_host->clk_enable);
> +       clk_disable_unprepare(sprd_host->clk_1x_enable);
>         clk_disable_unprepare(sprd_host->clk_2x_enable);
>
>         return 0;
> @@ -915,10 +929,14 @@ static int sdhci_sprd_runtime_resume(struct device *dev)
>         if (ret)
>                 return ret;
>
> -       ret = clk_prepare_enable(sprd_host->clk_enable);
> +       ret = clk_prepare_enable(sprd_host->clk_1x_enable);
>         if (ret)
>                 goto clk_2x_disable;
>
> +       ret = clk_prepare_enable(sprd_host->clk_enable);
> +       if (ret)
> +               goto clk_1x_disable;
> +
>         ret = clk_prepare_enable(sprd_host->clk_sdio);
>         if (ret)
>                 goto clk_disable;
> @@ -931,6 +949,9 @@ static int sdhci_sprd_runtime_resume(struct device *dev)
>  clk_disable:
>         clk_disable_unprepare(sprd_host->clk_enable);
>
> +clk_1x_disable:
> +       clk_disable_unprepare(sprd_host->clk_1x_enable);
> +
>  clk_2x_disable:
>         clk_disable_unprepare(sprd_host->clk_2x_enable);
>
> --
> 2.17.1
>