diff options
| -rw-r--r-- | drivers/mmc/mmc.c | 39 |
1 files changed, 33 insertions, 6 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index d858127132..84d157ff40 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -754,7 +754,8 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value) } #if !CONFIG_IS_ENABLED(MMC_TINY) -static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode) +static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode, + bool hsdowngrade) { int err; int speed_bits; @@ -788,6 +789,20 @@ static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode) if (err) return err; +#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \ + CONFIG_IS_ENABLED(MMC_HS400_SUPPORT) + /* + * In case the eMMC is in HS200/HS400 mode and we are downgrading + * to HS mode, the card clock are still running much faster than + * the supported HS mode clock, so we can not reliably read out + * Extended CSD. Reconfigure the controller to run at HS mode. + */ + if (hsdowngrade) { + mmc_select_mode(mmc, MMC_HS); + mmc_set_clock(mmc, mmc_mode2freq(mmc, MMC_HS), false); + } +#endif + if ((mode == MMC_HS) || (mode == MMC_HS_52)) { /* Now check to see that it worked */ err = mmc_send_ext_csd(mmc, test_csd); @@ -1849,7 +1864,7 @@ static int mmc_select_hs400(struct mmc *mmc) int err; /* Set timing to HS200 for tuning */ - err = mmc_set_card_speed(mmc, MMC_HS_200); + err = mmc_set_card_speed(mmc, MMC_HS_200, false); if (err) return err; @@ -1865,7 +1880,7 @@ static int mmc_select_hs400(struct mmc *mmc) } /* Set back to HS */ - mmc_set_card_speed(mmc, MMC_HS); + mmc_set_card_speed(mmc, MMC_HS, false); mmc_set_clock(mmc, mmc_mode2freq(mmc, MMC_HS), false); err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, @@ -1873,7 +1888,7 @@ static int mmc_select_hs400(struct mmc *mmc) if (err) return err; - err = mmc_set_card_speed(mmc, MMC_HS_400); + err = mmc_set_card_speed(mmc, MMC_HS_400, false); if (err) return err; @@ -1920,7 +1935,19 @@ static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps) return -ENOTSUPP; } - mmc_set_clock(mmc, mmc->legacy_speed, MMC_CLK_ENABLE); +#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \ + CONFIG_IS_ENABLED(MMC_HS400_SUPPORT) + /* + * In case the eMMC is in HS200/HS400 mode, downgrade to HS mode + * before doing anything else, since a transition from either of + * the HS200/HS400 mode directly to legacy mode is not supported. + */ + if (mmc->selected_mode == MMC_HS_200 || + mmc->selected_mode == MMC_HS_400) + mmc_set_card_speed(mmc, MMC_HS, true); + else +#endif + mmc_set_clock(mmc, mmc->legacy_speed, MMC_CLK_ENABLE); for_each_mmc_mode_by_pref(card_caps, mwt) { for_each_supported_width(card_caps & mwt->widths, @@ -1952,7 +1979,7 @@ static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps) } } else { /* configure the bus speed (card) */ - err = mmc_set_card_speed(mmc, mwt->mode); + err = mmc_set_card_speed(mmc, mwt->mode, false); if (err) goto error; |