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>

6 files changed, 60 insertions, 6 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;
                 }
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 7bd49234cd88..8ce082781ccb 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -48,6 +48,7 @@ struct mmc_ext_csd {
         unsigned int            sa_timeout;             /* Units: 100ns */
         unsigned int            hs_max_dtr;
         unsigned int            sectors;
+        unsigned int            card_type;
         unsigned int            hc_erase_size;          /* In sectors */
         unsigned int            hc_erase_timeout;       /* In milliseconds */
         unsigned int            sec_trim_mult;  /* Secure trim multiplier  */
@@ -113,6 +114,7 @@ struct mmc_card {
 #define MMC_STATE_READONLY      (1<<1)          /* card is read-only */
 #define MMC_STATE_HIGHSPEED     (1<<2)          /* card is in high speed mode */
 #define MMC_STATE_BLOCKADDR     (1<<3)          /* card uses block-addressing */
+#define MMC_STATE_HIGHSPEED_DDR (1<<4)          /* card is in high speed mode */
         unsigned int            quirks;         /* card quirks */
 #define MMC_QUIRK_LENIENT_FN0   (1<<0)          /* allow SDIO FN0 writes outside of the VS CCCR range */
 #define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1)    /* use func->cur_blksize */
@@ -154,11 +156,13 @@ struct mmc_card {
 #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_ddr_mode(c)    ((c)->state & MMC_STATE_HIGHSPEED_DDR)
 
 #define mmc_card_set_present(c) ((c)->state |= MMC_STATE_PRESENT)
 #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_set_ddr_mode(c) ((c)->state |= MMC_STATE_HIGHSPEED_DDR)
 
 static inline int mmc_card_lenient_fn0(const struct mmc_card *c)
 {
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 7429033acb66..d0fbcacab52c 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -109,6 +109,7 @@ struct mmc_data {
 #define MMC_DATA_WRITE  (1 << 8)
 #define MMC_DATA_READ   (1 << 9)
 #define MMC_DATA_STREAM (1 << 10)
+#define MMC_DDR_MODE    (1 << 11)
 
         unsigned int            bytes_xfered;
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ccac56ae1286..6711eb8715ba 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -158,6 +158,10 @@ struct mmc_host {
 #define MMC_CAP_NONREMOVABLE    (1 << 8)        /* Nonremovable e.g. eMMC */
 #define MMC_CAP_WAIT_WHILE_BUSY (1 << 9)        /* Waits while card is busy */
 #define MMC_CAP_ERASE           (1 << 10)       /* Allow erase/trim commands */
+#define MMC_CAP_1_8V_DDR        (1 << 11)       /* can support */
+                                                /* DDR mode at 1.8V */
+#define MMC_CAP_1_2V_DDR        (1 << 12)       /* can support */
+                                                /* DDR mode at 1.2V */
 
         mmc_pm_flag_t           pm_caps;        /* supported pm features */
 
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index dd11ae51fb68..956fbd877692 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -277,11 +277,19 @@ struct _mmc_csd {
 
 #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 */
-#define EXT_CSD_CARD_TYPE_MASK  0x3     /* Mask out reserved and DDR bits */
+#define EXT_CSD_CARD_TYPE_MASK  0xF     /* Mask out reserved bits */
+#define EXT_CSD_CARD_TYPE_DDR_1_8V  (1<<2)   /* Card can run at 52MHz */
+                                             /* DDR mode @1.8V or 3V I/O */
+#define EXT_CSD_CARD_TYPE_DDR_1_2V  (1<<3)   /* Card can run at 52MHz */
+                                             /* DDR mode @1.2V I/O */
+#define EXT_CSD_CARD_TYPE_DDR_52       (EXT_CSD_CARD_TYPE_DDR_1_8V  \
+                                        | EXT_CSD_CARD_TYPE_DDR_1_2V)
 
 #define EXT_CSD_BUS_WIDTH_1     0       /* Card is in 1 bit mode */
 #define EXT_CSD_BUS_WIDTH_4     1       /* Card is in 4 bit mode */
 #define EXT_CSD_BUS_WIDTH_8     2       /* Card is in 8 bit mode */
+#define EXT_CSD_DDR_BUS_WIDTH_4 5       /* Card is in 4 bit DDR mode */
+#define EXT_CSD_DDR_BUS_WIDTH_8 6       /* Card is in 8 bit DDR mode */
 
 #define EXT_CSD_SEC_ER_EN       BIT(0)
 #define EXT_CSD_SEC_BD_BLK_EN   BIT(2)