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From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 7 Nov 2022 21:12:51 +0100
Message-ID: <CAPDyKFq8Z+emgNToxE4hOzv1gZRcDzykwLJL=otv+7HGWP1fEw@mail.gmail.com>
Subject: Re: [PATCH] mmc: sdhci-of-arasan: Add support for dynamic configuration
To:     Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>
Cc:     Michal Simek <michal.simek@xilinx.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, saikrishna12468@gmail.com,
        git@amd.com
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On Wed, 19 Oct 2022 at 07:49, Sai Krishna Potthuri
<sai.krishna.potthuri@amd.com> wrote:
>
> Add dynamic configuration support for Xilinx ZynqMP which takes care of
> configuring the SD secure space configuration registers using EEMI APIs,
> performing SD reset assert and deassert.
> High level sequence:
> - Check for the PM dynamic configuration support, if no error proceed with
> SD dynamic configurations(next steps) otherwise skip the dynamic
> configuration.
> - Put the SD Controller in reset.
> - Configure SD Fixed configurations.
> - Configure the SD Slot Type.
> - Configure the BASE_CLOCK.
> - Configure the 8-bit support.
> - Bring the SD Controller out of reset.
> - Wait for 1msec delay.
>
> Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@amd.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sdhci-of-arasan.c | 69 ++++++++++++++++++++++++++++++
>  1 file changed, 69 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 3997cad1f793..f051f3802aff 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -21,6 +21,7 @@
>  #include <linux/of_device.h>
>  #include <linux/phy/phy.h>
>  #include <linux/regmap.h>
> +#include <linux/reset.h>
>  #include <linux/of.h>
>  #include <linux/firmware/xlnx-zynqmp.h>
>
> @@ -1521,6 +1522,65 @@ static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan,
>         return 0;
>  }
>
> +static int sdhci_zynqmp_set_dynamic_config(struct device *dev,
> +                                          struct sdhci_arasan_data *sdhci_arasan)
> +{
> +       struct sdhci_host *host = sdhci_arasan->host;
> +       struct clk_hw *hw = &sdhci_arasan->clk_data.sdcardclk_hw;
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +       const char *clk_name = clk_hw_get_name(hw);
> +       u32 mhz, node_id = !strcmp(clk_name, "clk_out_sd0") ? NODE_SD_0 : NODE_SD_1;
> +       struct reset_control *rstc;
> +       int ret;
> +
> +       /* Obtain SDHC reset control */
> +       rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
> +       if (IS_ERR(rstc)) {
> +               dev_err(dev, "Cannot get SDHC reset.\n");
> +               return PTR_ERR(rstc);
> +       }
> +
> +       ret = reset_control_assert(rstc);
> +       if (ret)
> +               return ret;
> +
> +       ret = zynqmp_pm_set_sd_config(node_id, SD_CONFIG_FIXED, 0);
> +       if (ret)
> +               return ret;
> +
> +       ret = zynqmp_pm_set_sd_config(node_id, SD_CONFIG_EMMC_SEL,
> +                                     !!(host->mmc->caps & MMC_CAP_NONREMOVABLE));
> +       if (ret)
> +               return ret;
> +
> +       mhz = DIV_ROUND_CLOSEST_ULL(clk_get_rate(pltfm_host->clk), 1000000);
> +       if (mhz > 100 && mhz <= 200)
> +               mhz = 200;
> +       else if (mhz > 50 && mhz <= 100)
> +               mhz = 100;
> +       else if (mhz > 25 && mhz <= 50)
> +               mhz = 50;
> +       else
> +               mhz = 25;
> +
> +       ret = zynqmp_pm_set_sd_config(node_id, SD_CONFIG_BASECLK, mhz);
> +       if (ret)
> +               return ret;
> +
> +       ret = zynqmp_pm_set_sd_config(node_id, SD_CONFIG_8BIT,
> +                                     !!(host->mmc->caps & MMC_CAP_8_BIT_DATA));
> +       if (ret)
> +               return ret;
> +
> +       ret = reset_control_deassert(rstc);
> +       if (ret)
> +               return ret;
> +
> +       usleep_range(1000, 1500);
> +
> +       return 0;
> +}
> +
>  static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
>  {
>         struct sdhci_host *host = sdhci_arasan->host;
> @@ -1685,6 +1745,15 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>                 goto unreg_clk;
>         }
>
> +       if (of_device_is_compatible(np, "xlnx,zynqmp-8.9a")) {
> +               ret = zynqmp_pm_is_function_supported(PM_IOCTL, IOCTL_SET_SD_CONFIG);
> +               if (!ret) {
> +                       ret = sdhci_zynqmp_set_dynamic_config(dev, sdhci_arasan);
> +                       if (ret)
> +                               goto unreg_clk;
> +               }
> +       }
> +
>         sdhci_arasan->phy = ERR_PTR(-ENODEV);
>         if (of_device_is_compatible(np, "arasan,sdhci-5.1")) {
>                 sdhci_arasan->phy = devm_phy_get(dev, "phy_arasan");
> --
> 2.17.1
>