mmc: MMC boot partitions support.

Allows device MMC boot partitions to be accessed. MMC partitions are
treated effectively as separate block devices on the same MMC card.

Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 17 insertions, 5 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 396cb23625d..a2c795e8f9d 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -288,7 +288,10 @@ static int mmc_read_ext_csd(struct mmc_card *card)
 
         if (card->ext_csd.rev >= 3) {
                 u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
-                card->ext_csd.bootconfig = ext_csd[EXT_CSD_BOOT_CONFIG];
+                card->ext_csd.part_config = ext_csd[EXT_CSD_PART_CONFIG];
+
+                /* EXT_CSD value is in units of 10ms, but we store in ms */
+                card->ext_csd.part_time = 10 * ext_csd[EXT_CSD_PART_SWITCH_TIME];
 
                 /* Sleep / awake timeout in 100ns units */
                 if (sa_shift > 0 && sa_shift <= 0x17)
@@ -302,6 +305,12 @@ static int mmc_read_ext_csd(struct mmc_card *card)
                         ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] << 10;
 
                 card->ext_csd.rel_sectors = ext_csd[EXT_CSD_REL_WR_SEC_C];
+
+                /*
+                 * There are two boot regions of equal size, defined in
+                 * multiples of 128K.
+                 */
+                card->ext_csd.boot_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
         }
 
         if (card->ext_csd.rev >= 4) {
@@ -576,10 +585,13 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
         /*
          * Ensure eMMC user default partition is enabled
          */
-        if (card->ext_csd.bootconfig & 0x7) {
-                card->ext_csd.bootconfig &= ~0x7;
-                mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_CONFIG,
-                           card->ext_csd.bootconfig, 0);
+        if (card->ext_csd.part_config & EXT_CSD_PART_CONFIG_ACC_MASK) {
+                card->ext_csd.part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
+                err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONFIG,
+                                 card->ext_csd.part_config,
+                                 card->ext_csd.part_time);
+                if (err && err != -EBADMSG)
+                        goto free_card;
         }
 
         /*