[PATCH] mmc: Add support for mmc v4 high speed mode

This adds support for the high-speed modes defined by mmc v4
(assuming the host controller is up to it). On a TI sdhci controller,
it improves read speed from 1.3MBps to 2.3MBps. The TI controller can
only go up to 24MHz, but everything helps. Another person has taken
this basic patch and used it on a Nokia 770 to get a bigger boost
because that controller can run at 48MHZ.

Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 44 insertions, 3 deletions

diff --git a/include/linux/mmc/protocol.h b/include/linux/mmc/protocol.h
index 08dec8d9e703..311b6547f561 100644
--- a/include/linux/mmc/protocol.h
+++ b/include/linux/mmc/protocol.h
@@ -25,14 +25,16 @@
 #ifndef MMC_MMC_PROTOCOL_H
 #define MMC_MMC_PROTOCOL_H
 
-/* Standard MMC commands (3.1)           type  argument     response */
+/* Standard MMC commands (4.1)           type  argument     response */
    /* class 1 */
 #define MMC_GO_IDLE_STATE         0   /* bc                          */
 #define MMC_SEND_OP_COND          1   /* bcr  [31:0] OCR         R3  */
 #define MMC_ALL_SEND_CID          2   /* bcr                     R2  */
 #define MMC_SET_RELATIVE_ADDR     3   /* ac   [31:16] RCA        R1  */
 #define MMC_SET_DSR               4   /* bc   [31:16] RCA            */
+#define MMC_SWITCH                6   /* ac   [31:0] See below   R1b */
 #define MMC_SELECT_CARD           7   /* ac   [31:16] RCA        R1  */
+#define MMC_SEND_EXT_CSD          8   /* adtc                    R1  */
 #define MMC_SEND_CSD              9   /* ac   [31:16] RCA        R2  */
 #define MMC_SEND_CID             10   /* ac   [31:16] RCA        R2  */
 #define MMC_READ_DAT_UNTIL_STOP  11   /* adtc [31:0] dadr        R1  */
@@ -88,6 +90,17 @@
 #define SD_APP_SEND_SCR          51   /* adtc                    R1  */
 
 /*
+ * MMC_SWITCH argument format:
+ *
+ *      [31:26] Always 0
+ *      [25:24] Access Mode
+ *      [23:16] Location of target Byte in EXT_CSD
+ *      [15:08] Value Byte
+ *      [07:03] Always 0
+ *      [02:00] Command Set
+ */
+
+/*
   MMC status in R1
   Type
         e : error bit
@@ -230,13 +243,41 @@ struct _mmc_csd {
 
 #define CSD_STRUCT_VER_1_0  0           /* Valid for system specification 1.0 - 1.2 */
 #define CSD_STRUCT_VER_1_1  1           /* Valid for system specification 1.4 - 2.2 */
-#define CSD_STRUCT_VER_1_2  2           /* Valid for system specification 3.1       */
+#define CSD_STRUCT_VER_1_2  2           /* Valid for system specification 3.1 - 3.2 - 3.31 - 4.0 - 4.1 */
+#define CSD_STRUCT_EXT_CSD  3           /* Version is coded in CSD_STRUCTURE in EXT_CSD */
 
 #define CSD_SPEC_VER_0      0           /* Implements system specification 1.0 - 1.2 */
 #define CSD_SPEC_VER_1      1           /* Implements system specification 1.4 */
 #define CSD_SPEC_VER_2      2           /* Implements system specification 2.0 - 2.2 */
-#define CSD_SPEC_VER_3      3           /* Implements system specification 3.1 */
+#define CSD_SPEC_VER_3      3           /* Implements system specification 3.1 - 3.2 - 3.31 */
+#define CSD_SPEC_VER_4      4           /* Implements system specification 4.0 - 4.1 */
+
+/*
+ * EXT_CSD fields
+ */
+
+#define EXT_CSD_HS_TIMING       185     /* R/W */
+#define EXT_CSD_CARD_TYPE       196     /* RO */
+
+/*
+ * EXT_CSD field definitions
+ */
+
+#define EXT_CSD_CMD_SET_NORMAL          (1<<0)
+#define EXT_CSD_CMD_SET_SECURE          (1<<1)
+#define EXT_CSD_CMD_SET_CPSECURE        (1<<2)
+
+#define EXT_CSD_CARD_TYPE_26    (1<<0)  /* Card can run at 26MHz */
+#define EXT_CSD_CARD_TYPE_52    (1<<1)  /* Card can run at 52MHz */
+
+/*
+ * MMC_SWITCH access modes
+ */
 
+#define MMC_SWITCH_MODE_CMD_SET         0x00    /* Change the command set */
+#define MMC_SWITCH_MODE_SET_BITS        0x01    /* Set bits which are 1 in value */
+#define MMC_SWITCH_MODE_CLEAR_BITS      0x02    /* Clear bits which are 1 in value */
+#define MMC_SWITCH_MODE_WRITE_BYTE      0x03    /* Set target to value */
 
 /*
  * SD bus widths