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, 7 insertions, 1 deletions

diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index 87713572293f..5a4eacac0bbe 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -237,7 +237,9 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
                 brq.mrq.cmd = &brq.cmd;
                 brq.mrq.data = &brq.data;
 
-                brq.cmd.arg = req->sector << 9;
+                brq.cmd.arg = req->sector;
+                if (!mmc_card_blockaddr(card))
+                        brq.cmd.arg <<= 9;
                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
                 brq.data.blksz = 1 << md->block_bits;
                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
@@ -494,6 +496,10 @@ mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
         struct mmc_command cmd;
         int err;
 
+        /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
+        if (mmc_card_blockaddr(card))
+                return 0;
+
         mmc_card_claim_host(card);
         cmd.opcode = MMC_SET_BLOCKLEN;
         cmd.arg = 1 << md->block_bits;