[PATCH] MMC: Proper MMC command classes support

Defines for the different command classes as defined in the MMC and SD
specifications.

Removes the check for high command classes and instead checks that the
command classes needed are present.
Previous solution killed forward compatibility at no apparent gain.

Signed-of-by: Pierre Ossman

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