[PATCH] mmc: sdhci-of-dwcmshc: properly determine max clock on Rockchip

[Ulf Hansson]

On Fri, 10 Mar 2023 at 02:04, Vasily Khoruzhick <anarsoul at gmail.com> wrote:
>
> Currently .get_max_clock returns the current clock rate for cclk_emmc
> on rk35xx, thus max clock gets set to whatever bootloader set it to.
>
> In case of u-boot, it is intentionally reset to 50 MHz if it boots
> from eMMC, see mmc_deinit() in u-boot sources. As a result, HS200 and
> HS400 modes are never selected by Linux, because dwcmshc_rk35xx_postinit
> clears appropriate caps if host->mmc->f_max is < 52MHz
>
> cclk_emmc is not a fixed clock on rk35xx, so using
> sdhci_pltfm_clk_get_max_clock is not appropriate here.
>
> Implement rk35xx_get_max_clock that returns actual max clock for cclk_emmc.
>
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index d1490469184b..e68cd87998c8 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -126,6 +126,13 @@ static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
>                 return pltfm_host->clock;
>  }
>
> +static unsigned int rk35xx_get_max_clock(struct sdhci_host *host)
> +{
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +
> +       return clk_round_rate(pltfm_host->clk, ULONG_MAX);
> +}
> +
>  static void dwcmshc_check_auto_cmd23(struct mmc_host *mmc,
>                                      struct mmc_request *mrq)
>  {
> @@ -343,7 +350,7 @@ static const struct sdhci_ops sdhci_dwcmshc_rk35xx_ops = {
>         .set_clock              = dwcmshc_rk3568_set_clock,
>         .set_bus_width          = sdhci_set_bus_width,
>         .set_uhs_signaling      = dwcmshc_set_uhs_signaling,
> -       .get_max_clock          = sdhci_pltfm_clk_get_max_clock,
> +       .get_max_clock          = rk35xx_get_max_clock,
>         .reset                  = rk35xx_sdhci_reset,
>         .adma_write_desc        = dwcmshc_adma_write_desc,
>  };
> --
> 2.39.2
>