2 files changed, 31 insertions, 1 deletions

diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index b5b4a7b11903..d4eee99c2bf6 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -383,7 +383,10 @@ static int mmc_blk_probe(struct mmc_card *card)
         struct mmc_blk_data *md;
         int err;
 
-        if (card->csd.cmdclass & ~0x1ff)
+        /*
+         * Check that the card supports the command class(es) we need.
+         */
+        if (!(card->csd.cmdclass & CCC_BLOCK_READ))
                 return -ENODEV;
 
         if (card->csd.read_blkbits < 9) {
diff --git a/include/linux/mmc/protocol.h b/include/linux/mmc/protocol.h
index 7b904c5102f6..896342817b97 100644
--- a/include/linux/mmc/protocol.h
+++ b/include/linux/mmc/protocol.h
@@ -195,6 +195,33 @@ struct _mmc_csd {
 #define MMC_VDD_35_36   0x00800000      /* VDD voltage 3.5 ~ 3.6 */
 #define MMC_CARD_BUSY   0x80000000      /* Card Power up status bit */
 
+/*
+ * Card Command Classes (CCC)
+ */
+#define CCC_BASIC               (1<<0)  /* (0) Basic protocol functions */
+                                        /* (CMD0,1,2,3,4,7,9,10,12,13,15) */
+#define CCC_STREAM_READ         (1<<1)  /* (1) Stream read commands */
+                                        /* (CMD11) */
+#define CCC_BLOCK_READ          (1<<2)  /* (2) Block read commands */
+                                        /* (CMD16,17,18) */
+#define CCC_STREAM_WRITE        (1<<3)  /* (3) Stream write commands */
+                                        /* (CMD20) */
+#define CCC_BLOCK_WRITE         (1<<4)  /* (4) Block write commands */
+                                        /* (CMD16,24,25,26,27) */
+#define CCC_ERASE               (1<<5)  /* (5) Ability to erase blocks */
+                                        /* (CMD32,33,34,35,36,37,38,39) */
+#define CCC_WRITE_PROT          (1<<6)  /* (6) Able to write protect blocks */
+                                        /* (CMD28,29,30) */
+#define CCC_LOCK_CARD           (1<<7)  /* (7) Able to lock down card */
+                                        /* (CMD16,CMD42) */
+#define CCC_APP_SPEC            (1<<8)  /* (8) Application specific */
+                                        /* (CMD55,56,57,ACMD*) */
+#define CCC_IO_MODE             (1<<9)  /* (9) I/O mode */
+                                        /* (CMD5,39,40,52,53) */
+#define CCC_SWITCH              (1<<10) /* (10) High speed switch */
+                                        /* (CMD6,34,35,36,37,50) */
+                                        /* (11) Reserved */
+                                        /* (CMD?) */
 
 /*
  * CSD field definitions