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Subject[PATCH] mmc: MMC 4.4 DDR support
Date
Add support for Dual Data Rate MMC cards as defined in the 4.4
specification.

Cc: linux-mmc@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
---
drivers/mmc/card/block.c | 10 +++++++---
drivers/mmc/core/mmc.c | 37 +++++++++++++++++++++++++++++++++++--
include/linux/mmc/card.h | 5 +++++
include/linux/mmc/core.h | 1 +
include/linux/mmc/host.h | 4 ++++
include/linux/mmc/mmc.h | 11 +++++++++--
6 files changed, 61 insertions(+), 7 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index cb9fbc8..4eb84eb 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -299,7 +299,8 @@ static int mmc_blk_issue_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;
@@ -569,8 +570,11 @@ 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 89f7a25..1d33503 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -227,6 +227,21 @@ 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;
@@ -444,6 +459,18 @@ 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) &&
@@ -451,10 +478,16 @@ 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 d02d2c6..7d0aca8 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -44,6 +44,7 @@ struct mmc_ext_csd {
unsigned int sa_timeout; /* Units: 100ns */
unsigned int hs_max_dtr;
unsigned int sectors;
+ unsigned int card_type;
};

struct sd_scr {
@@ -97,6 +98,8 @@ 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 */
+ /* dual data rate 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 */
@@ -129,11 +132,13 @@ struct mmc_card {
#define mmc_card_present(c) ((c)->state & MMC_STATE_PRESENT)
#define mmc_card_readonly(c) ((c)->state & MMC_STATE_READONLY)
#define mmc_card_highspeed(c) ((c)->state & MMC_STATE_HIGHSPEED)
+#define mmc_card_ddr_mode(c) ((c)->state & MMC_STATE_HIGHSPEED_DDR)
#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_readonly(c) ((c)->state |= MMC_STATE_READONLY)
#define mmc_card_set_highspeed(c) ((c)->state |= MMC_STATE_HIGHSPEED)
+#define mmc_card_set_ddr_mode(c) ((c)->state |= MMC_STATE_HIGHSPEED_DDR)
#define mmc_card_set_blockaddr(c) ((c)->state |= MMC_STATE_BLOCKADDR)

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 e4898e9..b31e47a 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -107,6 +107,7 @@ 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 f65913c..c775290 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -155,6 +155,10 @@ struct mmc_host {
#define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */
#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_1_8V_DDR (1 << 10) /* can support */
+ /* DDR mode at 1.8V */
+#define MMC_CAP_1_2V_DDR (1 << 11) /* 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 8a49cbf..fc446de 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -268,11 +268,18 @@ 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 */

/*
* MMC_SWITCH access modes
--
1.6.3.3


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