[PATCH] sd: SD 4-bit bus

Infrastructure for 4-bit bus transfers with SD cards.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 8c5f71376e41..6014160d9c06 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -57,6 +57,11 @@ struct mmc_ios {
 #define MMC_POWER_OFF           0
 #define MMC_POWER_UP            1
 #define MMC_POWER_ON            2
+
+        unsigned char   bus_width;              /* data bus width */
+
+#define MMC_BUS_WIDTH_1         0
+#define MMC_BUS_WIDTH_4         2
 };
 
 struct mmc_host_ops {
@@ -77,6 +82,10 @@ struct mmc_host {
         unsigned int            f_max;
         u32                     ocr_avail;
 
+        unsigned long           caps;           /* Host capabilities */
+
+#define MMC_CAP_4_BIT_DATA      (1 << 0)        /* Can the host do 4 bit transfers */
+
         /* host specific block data */
         unsigned int            max_seg_size;   /* see blk_queue_max_segment_size */
         unsigned short          max_hw_segs;    /* see blk_queue_max_hw_segments */
diff --git a/include/linux/mmc/protocol.h b/include/linux/mmc/protocol.h
index 896342817b97..f819cae92266 100644
--- a/include/linux/mmc/protocol.h
+++ b/include/linux/mmc/protocol.h
@@ -236,5 +236,12 @@ struct _mmc_csd {
 #define CSD_SPEC_VER_2      2           /* Implements system specification 2.0 - 2.2 */
 #define CSD_SPEC_VER_3      3           /* Implements system specification 3.1 */
 
+
+/*
+ * SD bus widths
+ */
+#define SD_BUS_WIDTH_1      0
+#define SD_BUS_WIDTH_4      2
+
 #endif  /* MMC_MMC_PROTOCOL_H */