mmc: Add support for SDHC cards

Thanks to the generous donation of an SDHC card by John Gilmore, and
the surprisingly enlightened decision by the SD Card Association to
publish useful specs, I've been able to bash out support for SDHC. The
changes are not too profound:

i) Add a card flag indicating the card uses block level addressing and
check it in the block driver. As we never took advantage of byte-level
addressing, this simply involves skipping the block -> byte
translation when sending commands.

ii) The layout of the CSD is changed - a set of fields are discarded
to make space for a larger C_SIZE. We did not reference any of the
discarded fields except those related to the C_SIZE.

iii) Read and write timeouts are fixed values and not calculated from
CSD values.

iv) Before invoking SEND_APP_OP_COND, we must invoke the new
SEND_IF_COND to inform the card we support SDHC.

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

3 files changed, 16 insertions, 1 deletions

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index d0e6a5497614..e45712acfac5 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -71,6 +71,7 @@ struct mmc_card {
 #define MMC_STATE_SDCARD        (1<<3)          /* is an SD card */
 #define MMC_STATE_READONLY      (1<<4)          /* card is read-only */
 #define MMC_STATE_HIGHSPEED     (1<<5)          /* card is in high speed mode */
+#define MMC_STATE_BLOCKADDR     (1<<6)          /* card uses block-addressing */
         u32                     raw_cid[4];     /* raw card CID */
         u32                     raw_csd[4];     /* raw card CSD */
         u32                     raw_scr[2];     /* raw card SCR */
@@ -87,6 +88,7 @@ struct mmc_card {
 #define mmc_card_sd(c)          ((c)->state & MMC_STATE_SDCARD)
 #define mmc_card_readonly(c)    ((c)->state & MMC_STATE_READONLY)
 #define mmc_card_highspeed(c)   ((c)->state & MMC_STATE_HIGHSPEED)
+#define mmc_card_blockaddr(c)   ((c)->state & MMC_STATE_BLOCKADDR)
 
 #define mmc_card_set_present(c) ((c)->state |= MMC_STATE_PRESENT)
 #define mmc_card_set_dead(c)    ((c)->state |= MMC_STATE_DEAD)
@@ -94,6 +96,7 @@ struct mmc_card {
 #define mmc_card_set_sd(c)      ((c)->state |= MMC_STATE_SDCARD)
 #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
 #define mmc_card_set_highspeed(c) ((c)->state |= MMC_STATE_HIGHSPEED)
+#define mmc_card_set_blockaddr(c) ((c)->state |= MMC_STATE_BLOCKADDR)
 
 #define mmc_card_name(c)        ((c)->cid.prod_name)
 #define mmc_card_id(c)          ((c)->dev.bus_id)
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index bcf24909d677..cdc54be804f1 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -43,6 +43,7 @@ struct mmc_command {
 #define MMC_RSP_R2      (MMC_RSP_PRESENT|MMC_RSP_136|MMC_RSP_CRC)
 #define MMC_RSP_R3      (MMC_RSP_PRESENT)
 #define MMC_RSP_R6      (MMC_RSP_PRESENT|MMC_RSP_CRC|MMC_RSP_OPCODE)
+#define MMC_RSP_R7      (MMC_RSP_PRESENT|MMC_RSP_CRC|MMC_RSP_OPCODE)
 
 #define mmc_resp_type(cmd)      ((cmd)->flags & (MMC_RSP_PRESENT|MMC_RSP_136|MMC_RSP_CRC|MMC_RSP_BUSY|MMC_RSP_OPCODE))
 
diff --git a/include/linux/mmc/protocol.h b/include/linux/mmc/protocol.h
index 2dce60c43f4b..c90b6768329d 100644
--- a/include/linux/mmc/protocol.h
+++ b/include/linux/mmc/protocol.h
@@ -79,9 +79,12 @@
 #define MMC_GEN_CMD              56   /* adtc [0] RD/WR          R1  */
 
 /* SD commands                           type  argument     response */
-  /* class 8 */
+  /* class 0 */
 /* This is basically the same command as for MMC with some quirks. */
 #define SD_SEND_RELATIVE_ADDR     3   /* bcr                     R6  */
+#define SD_SEND_IF_COND           8   /* bcr  [11:0] See below   R7  */
+
+  /* class 10 */
 #define SD_SWITCH                 6   /* adtc [31:0] See below   R1  */
 
   /* Application commands */
@@ -115,6 +118,14 @@
  */
 
 /*
+ * SD_SEND_IF_COND argument format:
+ *
+ *      [31:12] Reserved (0)
+ *      [11:8] Host Voltage Supply Flags
+ *      [7:0] Check Pattern (0xAA)
+ */
+
+/*
   MMC status in R1
   Type
         e : error bit