eMMC specification in section "Access partitions" says that all reset events will restore the access bits in PARTITION_CONFIG CSD register to default User Data Area value (0b000).
So read partition access bits from PARTITION_CONFIG CSD register before issuing card reset. This allows SPL/U-Boot to get information which eMMC partition was in use before SPL/U-Boot was booted. For some platforms this is the way how to determinate boot partition from which BootROM loaded SPL.
Signed-off-by: Pali Rohár pali@kernel.org --- drivers/mmc/mmc.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index dde251c87bc7..771432de354d 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -2329,8 +2329,17 @@ static int mmc_startup_v4(struct mmc *mmc) /* store the partition info of emmc */ mmc->part_support = ext_csd[EXT_CSD_PARTITIONING_SUPPORT]; if ((ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & PART_SUPPORT) || - ext_csd[EXT_CSD_BOOT_MULT]) - mmc->part_config = ext_csd[EXT_CSD_PART_CONF]; + ext_csd[EXT_CSD_BOOT_MULT]) { + /* + * At this stage PART_ACCESS_MASK bits in ext_csd[] are already cleared. + * But it is possible that they were already filled into mmc->part_config. + */ + if (mmc->part_config == MMCPART_NOAVAILABLE) + mmc->part_config = ext_csd[EXT_CSD_PART_CONF]; + else + mmc->part_config = (ext_csd[EXT_CSD_PART_CONF] & ~PART_ACCESS_MASK) | + (mmc->part_config & PART_ACCESS_MASK); + } if (part_completed && (ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & ENHNCD_SUPPORT)) mmc->part_attr = ext_csd[EXT_CSD_PARTITIONS_ATTRIBUTE]; @@ -2600,7 +2609,6 @@ static int mmc_startup(struct mmc *mmc) #if CONFIG_IS_ENABLED(MMC_WRITE) mmc->erase_grp_size = 1; #endif - mmc->part_config = MMCPART_NOAVAILABLE;
err = mmc_startup_v4(mmc); if (err) @@ -2848,9 +2856,26 @@ int mmc_get_op_cond(struct mmc *mmc, bool quiet) return err; mmc->ddr_mode = 0;
+ mmc->part_config = MMCPART_NOAVAILABLE; + retry: mmc_set_initial_state(mmc);
+ /* + * Read partition access bits from partition config register before card reset command + * because these bits are reset to default value (User Data Area) during card reset. + * This allows us to preserve original value of partition access bits used by the code + * which loaded us (for example BootROM) and use it for board specific boot purposes. + */ + if (mmc->part_config == MMCPART_NOAVAILABLE) { + ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN); + err = mmc_send_ext_csd(mmc, ext_csd); + if (err == 0 && + ((ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & PART_SUPPORT) || + ext_csd[EXT_CSD_BOOT_MULT])) + mmc->part_config = ext_csd[EXT_CSD_PART_CONF] & PART_ACCESS_MASK; + } + /* Reset the Card */ err = mmc_go_idle(mmc);