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>

1 files changed, 1 insertions, 0 deletions

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))