diff options
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/sd.c | 94 |
1 files changed, 22 insertions, 72 deletions
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 33c6f26c68d..8460568e521 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -290,8 +290,12 @@ static int mmc_read_switch(struct mmc_card *card) return -ENOMEM; } - /* Find out the supported Bus Speed Modes. */ - err = mmc_sd_switch(card, 0, 0, 1, status); + /* + * Find out the card's support bits with a mode 0 operation. + * The argument does not matter, as the support bits do not + * change with the arguments. + */ + err = mmc_sd_switch(card, 0, 0, 0, status); if (err) { /* * If the host or the card can't do the switch, @@ -312,46 +316,8 @@ static int mmc_read_switch(struct mmc_card *card) if (card->scr.sda_spec3) { card->sw_caps.sd3_bus_mode = status[13]; - - /* Find out Driver Strengths supported by the card */ - err = mmc_sd_switch(card, 0, 2, 1, status); - if (err) { - /* - * If the host or the card can't do the switch, - * fail more gracefully. - */ - if (err != -EINVAL && err != -ENOSYS && err != -EFAULT) - goto out; - - pr_warning("%s: problem reading " - "Driver Strength.\n", - mmc_hostname(card->host)); - err = 0; - - goto out; - } - + /* Driver Strengths supported by the card */ card->sw_caps.sd3_drv_type = status[9]; - - /* Find out Current Limits supported by the card */ - err = mmc_sd_switch(card, 0, 3, 1, status); - if (err) { - /* - * If the host or the card can't do the switch, - * fail more gracefully. - */ - if (err != -EINVAL && err != -ENOSYS && err != -EFAULT) - goto out; - - pr_warning("%s: problem reading " - "Current Limit.\n", - mmc_hostname(card->host)); - err = 0; - - goto out; - } - - card->sw_caps.sd3_curr_limit = status[7]; } out: @@ -560,41 +526,24 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status) * Current limit switch is only defined for SDR50, SDR104, and DDR50 * bus speed modes. For other bus speed modes, we do not change the * current limit. + * We only check host's capability here, if we set a limit that is + * higher than the card's maximum current, the card will be using its + * maximum current, e.g. if the card's maximum current is 300ma, and + * when we set current limit to 200ma, the card will draw 200ma, and + * when we set current limit to 400/600/800ma, the card will draw its + * maximum 300ma from the host. */ if ((card->sd_bus_speed == UHS_SDR50_BUS_SPEED) || (card->sd_bus_speed == UHS_SDR104_BUS_SPEED) || (card->sd_bus_speed == UHS_DDR50_BUS_SPEED)) { - if (card->host->caps & MMC_CAP_MAX_CURRENT_800) { - if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_800) - current_limit = SD_SET_CURRENT_LIMIT_800; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_600) - current_limit = SD_SET_CURRENT_LIMIT_600; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_400) - current_limit = SD_SET_CURRENT_LIMIT_400; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_200) - current_limit = SD_SET_CURRENT_LIMIT_200; - } else if (card->host->caps & MMC_CAP_MAX_CURRENT_600) { - if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_600) - current_limit = SD_SET_CURRENT_LIMIT_600; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_400) - current_limit = SD_SET_CURRENT_LIMIT_400; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_200) - current_limit = SD_SET_CURRENT_LIMIT_200; - } else if (card->host->caps & MMC_CAP_MAX_CURRENT_400) { - if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_400) - current_limit = SD_SET_CURRENT_LIMIT_400; - else if (card->sw_caps.sd3_curr_limit & - SD_MAX_CURRENT_200) - current_limit = SD_SET_CURRENT_LIMIT_200; - } else if (card->host->caps & MMC_CAP_MAX_CURRENT_200) { - if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_200) - current_limit = SD_SET_CURRENT_LIMIT_200; - } + if (card->host->caps & MMC_CAP_MAX_CURRENT_800) + current_limit = SD_SET_CURRENT_LIMIT_800; + else if (card->host->caps & MMC_CAP_MAX_CURRENT_600) + current_limit = SD_SET_CURRENT_LIMIT_600; + else if (card->host->caps & MMC_CAP_MAX_CURRENT_400) + current_limit = SD_SET_CURRENT_LIMIT_400; + else if (card->host->caps & MMC_CAP_MAX_CURRENT_200) + current_limit = SD_SET_CURRENT_LIMIT_200; } if (current_limit != SD_SET_CURRENT_NO_CHANGE) { @@ -607,6 +556,7 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status) mmc_hostname(card->host)); } + return 0; } |