mmc: Add 8-bit bus width support

Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

2 files changed, 16 insertions, 4 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index fdd7c760be8c..c232d11a7ed4 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -434,13 +434,24 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
          * Activate wide bus (if supported).
          */
         if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
-                (host->caps & MMC_CAP_4_BIT_DATA)) {
+            (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
+                unsigned ext_csd_bit, bus_width;
+
+                if (host->caps & MMC_CAP_8_BIT_DATA) {
+                        ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
+                        bus_width = MMC_BUS_WIDTH_8;
+                } else {
+                        ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
+                        bus_width = MMC_BUS_WIDTH_4;
+                }
+
                 err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-                        EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_4);
+                                 EXT_CSD_BUS_WIDTH, ext_csd_bit);
+
                 if (err)
                         goto free_card;
 
-                mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
+                mmc_set_bus_width(card->host, bus_width);
         }
 
         if (!oldcard)
@@ -624,4 +635,3 @@ err:
 
         return err;
 }
-
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f842f234e44f..4e457256bd33 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -41,6 +41,7 @@ struct mmc_ios {
 
 #define MMC_BUS_WIDTH_1         0
 #define MMC_BUS_WIDTH_4         2
+#define MMC_BUS_WIDTH_8         3
 
         unsigned char   timing;                 /* timing specification used */
 
@@ -116,6 +117,7 @@ struct mmc_host {
 #define MMC_CAP_SDIO_IRQ        (1 << 3)        /* Can signal pending SDIO IRQs */
 #define MMC_CAP_SPI             (1 << 4)        /* Talks only SPI protocols */
 #define MMC_CAP_NEEDS_POLL      (1 << 5)        /* Needs polling for card-detection */
+#define MMC_CAP_8_BIT_DATA      (1 << 6)        /* Can the host do 8 bit transfers */
 
         /* host specific block data */
         unsigned int            max_seg_size;   /* see blk_queue_max_segment_size */