[U-Boot] [PATCH 15/22] mmc: add a new mmc parameter to disable mmc clock

Simon Glass sjg at chromium.org
Mon May 15 03:28:17 UTC 2017


Hi,

On 12 May 2017 at 12:16, Jean-Jacques Hiblot <jjhiblot at ti.com> wrote:
> mmc clock has to be disabled in certain cases like during
> the voltage switch sequence. Modify mmc_set_clock function
> to take disable as an argument that signifies if the
> clock has to be enabled or disabled.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
> ---
>  drivers/mmc/fsl_esdhc.c |  2 +-
>  drivers/mmc/mmc.c       | 11 ++++++-----
>  include/mmc.h           |  3 ++-
>  3 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index f3c6358..b631392 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -658,7 +658,7 @@ static int esdhc_init(struct mmc *mmc)
>  #endif
>
>         /* Set the initial clock speed */
> -       mmc_set_clock(mmc, 400000);
> +       mmc_set_clock(mmc, 400000, false);
>
>         /* Disable the BRR and BWR bits in IRQSTAT */
>         esdhc_clrbits32(&regs->irqstaten, IRQSTATEN_BRR | IRQSTATEN_BWR);
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index 032260b..70b7d19 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -1216,7 +1216,7 @@ static int mmc_set_ios(struct mmc *mmc)
>  }
>  #endif
>
> -int mmc_set_clock(struct mmc *mmc, uint clock)
> +int mmc_set_clock(struct mmc *mmc, uint clock, u8 disable)
>  {
>         if (clock > mmc->cfg->f_max)
>                 clock = mmc->cfg->f_max;
> @@ -1225,6 +1225,7 @@ int mmc_set_clock(struct mmc *mmc, uint clock)
>                 clock = mmc->cfg->f_min;
>
>         mmc->clock = clock;
> +       mmc->clk_disable = disable;
>
>         return mmc_set_ios(mmc);
>  }
> @@ -1316,7 +1317,7 @@ static int sd_select_mode_and_width(struct mmc *mmc)
>
>                                 /* configure the bus mode (host) */
>                                 mmc_select_mode(mmc, mwt->mode);
> -                               mmc_set_clock(mmc, mmc->tran_speed);
> +                               mmc_set_clock(mmc, mmc->tran_speed, false);
>
>                                 err = sd_read_ssr(mmc);
>                                 if (!err)
> @@ -1327,7 +1328,7 @@ static int sd_select_mode_and_width(struct mmc *mmc)
>  error:
>                                 /* revert to a safer bus speed */
>                                 mmc_select_mode(mmc, SD_LEGACY);
> -                               mmc_set_clock(mmc, mmc->tran_speed);
> +                               mmc_set_clock(mmc, mmc->tran_speed, false);
>                         }
>                 }
>         }
> @@ -1465,7 +1466,7 @@ static int mmc_select_mode_and_width(struct mmc *mmc)
>
>                         /* configure the bus mode (host) */
>                         mmc_select_mode(mmc, mwt->mode);
> -                       mmc_set_clock(mmc, mmc->tran_speed);
> +                       mmc_set_clock(mmc, mmc->tran_speed, false);
>
>                         /* do a transfer to check the configuration */
>                         err = mmc_read_and_compare_ext_csd(mmc);
> @@ -1928,7 +1929,7 @@ static void mmc_set_initial_state(struct mmc *mmc)
>                 printf("failed to set signal voltage\n");
>
>         mmc_set_bus_width(mmc, 1);
> -       mmc_set_clock(mmc, 1);
> +       mmc_set_clock(mmc, 1, false);
>         mmc_select_mode(mmc, MMC_LEGACY);
>  }
>
> diff --git a/include/mmc.h b/include/mmc.h
> index 43d37a4..097a685 100644
> --- a/include/mmc.h
> +++ b/include/mmc.h
> @@ -466,6 +466,7 @@ struct mmc {
>         void *priv;
>         uint has_init;
>         int high_capacity;
> +       u8 clk_disable;

bool? Also add comment.

>         uint bus_width;
>         uint clock;
>         uint signal_voltage;
> @@ -557,7 +558,7 @@ int mmc_unbind(struct udevice *dev);
>  int mmc_initialize(bd_t *bis);
>  int mmc_init(struct mmc *mmc);
>  int mmc_read(struct mmc *mmc, u64 src, uchar *dst, int size);
> -int mmc_set_clock(struct mmc *mmc, uint clock);
> +int mmc_set_clock(struct mmc *mmc, uint clock, u8 disable);

Function comment

>  struct mmc *find_mmc_device(int dev_num);
>  int mmc_set_dev(int dev_num);
>  void print_mmc_devices(char separator);
> --
> 1.9.1
>


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