[U-Boot] [PATCH 04/22] mmc: add a function to read and test the ext csd (mmc >= 4)

[Simon Glass]

On 12 May 2017 at 12:16, Jean-Jacques Hiblot <jjhiblot at ti.com> wrote:
> This will be reused later in the selection of high speed and ddr modes.
>
> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
> ---
>  drivers/mmc/mmc.c | 49 +++++++++++++++++++++++++++++--------------------
>  1 file changed, 29 insertions(+), 20 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>

Please add a function comment.

>
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index 4bd6a96..344d760 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -1146,10 +1146,35 @@ static int sd_select_bus_freq_width(struct mmc *mmc)
>         return 0;
>  }
>
> -static int mmc_select_bus_freq_width(struct mmc *mmc)
> +static int mmc_read_and_compare_ext_csd(struct mmc *mmc)
>  {
> -       ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
> +       int err;
>         const u8 *ext_csd = mmc->ext_csd;
> +       ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
> +
> +       err = mmc_send_ext_csd(mmc, test_csd);
> +       if (err)
> +               return err;
> +
> +       /* Only compare read only fields */
> +       if (ext_csd[EXT_CSD_PARTITIONING_SUPPORT]
> +               == test_csd[EXT_CSD_PARTITIONING_SUPPORT] &&
> +           ext_csd[EXT_CSD_HC_WP_GRP_SIZE]
> +               == test_csd[EXT_CSD_HC_WP_GRP_SIZE] &&
> +           ext_csd[EXT_CSD_REV]
> +               == test_csd[EXT_CSD_REV] &&
> +           ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
> +               == test_csd[EXT_CSD_HC_ERASE_GRP_SIZE] &&
> +           memcmp(&ext_csd[EXT_CSD_SEC_CNT],
> +                   &test_csd[EXT_CSD_SEC_CNT], 4) == 0)
> +               return 0;
> +
> +       return -EBADMSG;
> +}
> +
> +
> +static int mmc_select_bus_freq_width(struct mmc *mmc)
> +{
>         /* An array of possible bus widths in order of preference */
>         static const unsigned ext_csd_bits[] = {
>                 EXT_CSD_DDR_BUS_WIDTH_8,
> @@ -1222,25 +1247,9 @@ static int mmc_select_bus_freq_width(struct mmc *mmc)
>                 mmc->ddr_mode = (caps & MMC_MODE_DDR_52MHz) ? 1 : 0;
>                 mmc_set_bus_width(mmc, widths[idx]);
>
> -               err = mmc_send_ext_csd(mmc, test_csd);
> -
> -               if (err)
> -                       continue;
> -
> -               /* Only compare read only fields */
> -               if (ext_csd[EXT_CSD_PARTITIONING_SUPPORT]
> -                       == test_csd[EXT_CSD_PARTITIONING_SUPPORT] &&
> -                   ext_csd[EXT_CSD_HC_WP_GRP_SIZE]
> -                       == test_csd[EXT_CSD_HC_WP_GRP_SIZE] &&
> -                   ext_csd[EXT_CSD_REV]
> -                       == test_csd[EXT_CSD_REV] &&
> -                   ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
> -                       == test_csd[EXT_CSD_HC_ERASE_GRP_SIZE] &&
> -                   memcmp(&ext_csd[EXT_CSD_SEC_CNT],
> -                           &test_csd[EXT_CSD_SEC_CNT], 4) == 0)
> +               err = mmc_read_and_compare_ext_csd(mmc);
> +               if (!err)
>                         break;
> -               else
> -                       err = -EBADMSG;
>         }
>
>         if (err)
> --
> 1.9.1
>