Re: [PATCH V12 16/23] mmc: sdhci-uhs2: add clock operations

[Ulf Hansson]

On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@xxxxxxxxx> wrote:
>
> From: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
>
> This is a sdhci version of mmc's uhs2_[enable|disable]_clk operations.
>
> Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

The similar comments as posted for patch 15 applies to $subject patch
too. Please have a look at those and fix these for the $subject patch
too.

> ---
>
> Updates in V8:
>  - Remove unnecessary include file.
>  - read_poll_timeout() to instead of read_poll_timeout_atomic()
>    in sdhci_uhs2_enable_clk().
>  - Put the comment on the end and put the lines in descending
>    line length in sdhci_uhs2_enable_clk().
>  - Modify return value in sdhci_uhs2_enable_clk().
>
> Updates in V6:
>  - Remove unnecessary functions.
>
> ---
>
>  drivers/mmc/host/sdhci-uhs2.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 4c2a56629ab3..af1b0c5e48fd 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -329,6 +329,36 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>         return 0;
>  }
>
> +static int sdhci_uhs2_disable_clk(struct mmc_host *mmc)
> +{
> +       struct sdhci_host *host = mmc_priv(mmc);
> +       u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +
> +       clk &= ~SDHCI_CLOCK_CARD_EN;
> +       sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> +       return 0;
> +}
> +
> +static int sdhci_uhs2_enable_clk(struct mmc_host *mmc)
> +{
> +       struct sdhci_host *host = mmc_priv(mmc);
> +       u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +       int timeout_us = 20000; /* 20ms */
> +       u32 val;
> +
> +       clk |= SDHCI_CLOCK_CARD_EN;
> +       sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> +       if (read_poll_timeout(sdhci_readw, val, (val & SDHCI_CLOCK_INT_STABLE),
> +                             10, timeout_us, true, host, SDHCI_CLOCK_CONTROL)) {
> +               pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc));
> +               sdhci_dumpregs(host);
> +               return -EIO;
> +       }
> +       return 0;
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Driver init/exit                                                          *

Kind regards
Uffe