mmc: recognize CSD structure

The eMMC spec 4.4 and 4.3 + additional feature chips has CSD structure
version 3 and version 3 have to check the CSD_STRUCTURE byte in the
EXT_CSD register.

Also fix EXT_CSD revision message.

[akpm@linux-foundation.org: fix comment, per Chris Ball]
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 21 insertions, 7 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 89f7a25b7ac1..cd8d3d2ea901 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -114,17 +114,18 @@ static int mmc_decode_cid(struct mmc_card *card)
 static int mmc_decode_csd(struct mmc_card *card)
 {
         struct mmc_csd *csd = &card->csd;
-        unsigned int e, m, csd_struct;
+        unsigned int e, m;
         u32 *resp = card->raw_csd;
 
         /*
          * We only understand CSD structure v1.1 and v1.2.
          * v1.2 has extra information in bits 15, 11 and 10.
+         * We also support eMMC v4.4 & v4.41.
          */
-        csd_struct = UNSTUFF_BITS(resp, 126, 2);
-        if (csd_struct != 1 && csd_struct != 2) {
+        csd->structure = UNSTUFF_BITS(resp, 126, 2);
+        if (csd->structure == 0) {
                 printk(KERN_ERR "%s: unrecognised CSD structure version %d\n",
-                        mmc_hostname(card->host), csd_struct);
+                        mmc_hostname(card->host), csd->structure);
                 return -EINVAL;
         }
 
@@ -207,11 +208,22 @@ static int mmc_read_ext_csd(struct mmc_card *card)
                 goto out;
         }
 
+        /* Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register */
+        if (card->csd.structure == 3) {
+                int ext_csd_struct = ext_csd[EXT_CSD_STRUCTURE];
+                if (ext_csd_struct > 2) {
+                        printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
+                                "version %d\n", mmc_hostname(card->host),
+                                        ext_csd_struct);
+                        err = -EINVAL;
+                        goto out;
+                }
+        }
+
         card->ext_csd.rev = ext_csd[EXT_CSD_REV];
         if (card->ext_csd.rev > 5) {
-                printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
-                        "version %d\n", mmc_hostname(card->host),
-                        card->ext_csd.rev);
+                printk(KERN_ERR "%s: unrecognised EXT_CSD revision %d\n",
+                        mmc_hostname(card->host), card->ext_csd.rev);
                 err = -EINVAL;
                 goto out;
         }
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index d02d2c6e0cfe..c83c7a7303fd 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -24,6 +24,7 @@ struct mmc_cid {
 };
 
 struct mmc_csd {
+        unsigned char           structure;
         unsigned char           mmca_vsn;
         unsigned short          cmdclass;
         unsigned short          tacc_clks;
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 8a49cbf0376d..52ce98866287 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -254,6 +254,7 @@ struct _mmc_csd {
 #define EXT_CSD_BUS_WIDTH       183     /* R/W */
 #define EXT_CSD_HS_TIMING       185     /* R/W */
 #define EXT_CSD_CARD_TYPE       196     /* RO */
+#define EXT_CSD_STRUCTURE       194     /* RO */
 #define EXT_CSD_REV             192     /* RO */
 #define EXT_CSD_SEC_CNT         212     /* RO, 4 bytes */
 #define EXT_CSD_S_A_TIMEOUT     217