Re: [PATCH v4 3/5] mmc: step power class after final selection of bus mode

[Ulf Hansson <ulf.hansson@linaro.org>]

On 26 March 2014 12:00, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> Power class is changed once only after selection of bus modes
> including speed and bus-width finishes finally.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
> Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>

Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

> ---
>  drivers/mmc/core/mmc.c |   96 +++++++++++++++++++++++++++--------------------
>  1 files changed, 55 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 97f1912..480c100 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -732,17 +732,13 @@ static struct device_type mmc_type = {
>   * extended CSD register, select it by executing the
>   * mmc_switch command.
>   */
> -static int mmc_select_powerclass(struct mmc_card *card,
> -               unsigned int bus_width)
> +static int __mmc_select_powerclass(struct mmc_card *card,
> +                                  unsigned int bus_width)
>  {
> -       int err = 0;
> +       struct mmc_host *host = card->host;
> +       struct mmc_ext_csd *ext_csd = &card->ext_csd;
>         unsigned int pwrclass_val = 0;
> -       struct mmc_host *host;
> -
> -       BUG_ON(!card);
> -
> -       host = card->host;
> -       BUG_ON(!host);
> +       int err = 0;
>
>         /* Power class selection is supported for versions >= 4.0 */
>         if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
> @@ -754,14 +750,14 @@ static int mmc_select_powerclass(struct mmc_card *card,
>
>         switch (1 << host->ios.vdd) {
>         case MMC_VDD_165_195:
> -               if (host->ios.clock <= 26000000)
> -                       pwrclass_val = card->ext_csd.raw_pwr_cl_26_195;
> -               else if (host->ios.clock <= 52000000)
> +               if (host->ios.clock <= MMC_HIGH_26_MAX_DTR)
> +                       pwrclass_val = ext_csd->raw_pwr_cl_26_195;
> +               else if (host->ios.clock <= MMC_HIGH_52_MAX_DTR)
>                         pwrclass_val = (bus_width <= EXT_CSD_BUS_WIDTH_8) ?
> -                               card->ext_csd.raw_pwr_cl_52_195 :
> -                               card->ext_csd.raw_pwr_cl_ddr_52_195;
> -               else if (host->ios.clock <= 200000000)
> -                       pwrclass_val = card->ext_csd.raw_pwr_cl_200_195;
> +                               ext_csd->raw_pwr_cl_52_195 :
> +                               ext_csd->raw_pwr_cl_ddr_52_195;
> +               else if (host->ios.clock <= MMC_HS200_MAX_DTR)
> +                       pwrclass_val = ext_csd->raw_pwr_cl_200_195;
>                 break;
>         case MMC_VDD_27_28:
>         case MMC_VDD_28_29:
> @@ -772,14 +768,14 @@ static int mmc_select_powerclass(struct mmc_card *card,
>         case MMC_VDD_33_34:
>         case MMC_VDD_34_35:
>         case MMC_VDD_35_36:
> -               if (host->ios.clock <= 26000000)
> -                       pwrclass_val = card->ext_csd.raw_pwr_cl_26_360;
> -               else if (host->ios.clock <= 52000000)
> +               if (host->ios.clock <= MMC_HIGH_26_MAX_DTR)
> +                       pwrclass_val = ext_csd->raw_pwr_cl_26_360;
> +               else if (host->ios.clock <= MMC_HIGH_52_MAX_DTR)
>                         pwrclass_val = (bus_width <= EXT_CSD_BUS_WIDTH_8) ?
> -                               card->ext_csd.raw_pwr_cl_52_360 :
> -                               card->ext_csd.raw_pwr_cl_ddr_52_360;
> -               else if (host->ios.clock <= 200000000)
> -                       pwrclass_val = card->ext_csd.raw_pwr_cl_200_360;
> +                               ext_csd->raw_pwr_cl_52_360 :
> +                               ext_csd->raw_pwr_cl_ddr_52_360;
> +               else if (host->ios.clock <= MMC_HS200_MAX_DTR)
> +                       pwrclass_val = ext_csd->raw_pwr_cl_200_360;
>                 break;
>         default:
>                 pr_warning("%s: Voltage range not supported "
> @@ -805,6 +801,37 @@ static int mmc_select_powerclass(struct mmc_card *card,
>         return err;
>  }
>
> +static int mmc_select_powerclass(struct mmc_card *card)
> +{
> +       struct mmc_host *host = card->host;
> +       u32 bus_width, ext_csd_bits;
> +       int err, ddr;
> +
> +       /* Power class selection is supported for versions >= 4.0 */
> +       if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
> +               return 0;
> +
> +       bus_width = host->ios.bus_width;
> +       /* Power class values are defined only for 4/8 bit bus */
> +       if (bus_width == MMC_BUS_WIDTH_1)
> +               return 0;
> +
> +       ddr = card->mmc_avail_type & EXT_CSD_CARD_TYPE_DDR_52;
> +       if (ddr)
> +               ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
> +                       EXT_CSD_DDR_BUS_WIDTH_8 : EXT_CSD_DDR_BUS_WIDTH_4;
> +       else
> +               ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
> +                       EXT_CSD_BUS_WIDTH_8 :  EXT_CSD_BUS_WIDTH_4;
> +
> +       err = __mmc_select_powerclass(card, ext_csd_bits);
> +       if (err)
> +               pr_warn("%s: power class selection to bus width %d ddr %d failed\n",
> +                       mmc_hostname(host), 1 << bus_width, ddr);
> +
> +       return err;
> +}
> +
>  /*
>   * Selects the desired buswidth and switch to the HS200 mode
>   * if bus width set without error
> @@ -1166,11 +1193,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>
>                 ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
>                                 EXT_CSD_BUS_WIDTH_8 : EXT_CSD_BUS_WIDTH_4;
> -               err = mmc_select_powerclass(card, ext_csd_bits);
> -               if (err)
> -                       pr_warning("%s: power class selection to bus width %d"
> -                                  " failed\n", mmc_hostname(card->host),
> -                                  1 << bus_width);
>         }
>
>         /*
> @@ -1199,12 +1221,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>                         bus_width = bus_widths[idx];
>                         if (bus_width == MMC_BUS_WIDTH_1)
>                                 ddr = 0; /* no DDR for 1-bit width */
> -                       err = mmc_select_powerclass(card, ext_csd_bits[idx][0]);
> -                       if (err)
> -                               pr_warning("%s: power class selection to "
> -                                          "bus width %d failed\n",
> -                                          mmc_hostname(card->host),
> -                                          1 << bus_width);
>
>                         err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>                                          EXT_CSD_BUS_WIDTH,
> @@ -1229,13 +1245,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>                 }
>
>                 if (!err && ddr) {
> -                       err = mmc_select_powerclass(card, ext_csd_bits[idx][1]);
> -                       if (err)
> -                               pr_warning("%s: power class selection to "
> -                                          "bus width %d ddr %d failed\n",
> -                                          mmc_hostname(card->host),
> -                                          1 << bus_width, ddr);
> -
>                         err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>                                          EXT_CSD_BUS_WIDTH,
>                                          ext_csd_bits[idx][1],
> @@ -1273,6 +1282,11 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>         }
>
>         /*
> +        * Choose the power class with selected bus interface
> +        */
> +       mmc_select_powerclass(card);
> +
> +       /*
>          * Enable HPI feature (if supported)
>          */
>         if (card->ext_csd.hpi) {
> --
> 1.7.0.4
>
>