mmc: MMC 4.4 DDR support

Add support for Dual Data Rate MMC cards as defined in the 4.4
specification.

Signed-off-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
Cc: linux-mmc@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Tested-by Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 42 insertions, 5 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 759a105cb216..aab593480975 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -373,7 +373,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
                         readcmd = MMC_READ_SINGLE_BLOCK;
                         writecmd = MMC_WRITE_BLOCK;
                 }
-
+                if (mmc_card_ddr_mode(card))
+                        brq.data.flags |= MMC_DDR_MODE;
                 if (rq_data_dir(req) == READ) {
                         brq.cmd.opcode = readcmd;
                         brq.data.flags |= MMC_DATA_READ;
@@ -655,8 +656,11 @@ 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))
+        /*
+         * Block-addressed and ddr mode supported cards
+         * ignore MMC_SET_BLOCKLEN.
+         */
+        if (mmc_card_blockaddr(card) || mmc_card_ddr_mode(card))
                 return 0;
 
         mmc_claim_host(card->host);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 6570c03f9c76..66c4a59fee5f 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -258,6 +258,21 @@ static int mmc_read_ext_csd(struct mmc_card *card)
         }
 
         switch (ext_csd[EXT_CSD_CARD_TYPE] & EXT_CSD_CARD_TYPE_MASK) {
+        case EXT_CSD_CARD_TYPE_DDR_52 | EXT_CSD_CARD_TYPE_52 |
+             EXT_CSD_CARD_TYPE_26:
+                card->ext_csd.hs_max_dtr = 52000000;
+                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_52;
+                break;
+        case EXT_CSD_CARD_TYPE_DDR_1_2V | EXT_CSD_CARD_TYPE_52 |
+             EXT_CSD_CARD_TYPE_26:
+                card->ext_csd.hs_max_dtr = 52000000;
+                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_1_2V;
+                break;
+        case EXT_CSD_CARD_TYPE_DDR_1_8V | EXT_CSD_CARD_TYPE_52 |
+             EXT_CSD_CARD_TYPE_26:
+                card->ext_csd.hs_max_dtr = 52000000;
+                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_1_8V;
+                break;
         case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
                 card->ext_csd.hs_max_dtr = 52000000;
                 break;
@@ -503,6 +518,18 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
         mmc_set_clock(host, max_dtr);
 
         /*
+         * Activate DDR50 mode (if supported).
+         */
+        if (mmc_card_highspeed(card)) {
+                if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_8V)
+                        && (host->caps & (MMC_CAP_1_8V_DDR)))
+                                mmc_card_set_ddr_mode(card);
+                else if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_2V)
+                        && (host->caps & (MMC_CAP_1_2V_DDR)))
+                                mmc_card_set_ddr_mode(card);
+        }
+
+        /*
          * Activate wide bus (if supported).
          */
         if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
@@ -510,10 +537,16 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
                 unsigned ext_csd_bit, bus_width;
 
                 if (host->caps & MMC_CAP_8_BIT_DATA) {
-                        ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
+                        if (mmc_card_ddr_mode(card))
+                                ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_8;
+                        else
+                                ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
                         bus_width = MMC_BUS_WIDTH_8;
                 } else {
-                        ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
+                        if (mmc_card_ddr_mode(card))
+                                ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_4;
+                        else
+                                ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
                         bus_width = MMC_BUS_WIDTH_4;
                 }