sdio: high-speed support

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 49 insertions, 3 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 4eab79e09ccc..fb99ccff9080 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -165,6 +165,36 @@ static int sdio_enable_wide(struct mmc_card *card)
 }
 
 /*
+ * Test if the card supports high-speed mode and, if so, switch to it.
+ */
+static int sdio_enable_hs(struct mmc_card *card)
+{
+        int ret;
+        u8 speed;
+
+        if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
+                return 0;
+
+        if (!card->cccr.high_speed)
+                return 0;
+
+        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
+        if (ret)
+                return ret;
+
+        speed |= SDIO_SPEED_EHS;
+
+        ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
+        if (ret)
+                return ret;
+
+        mmc_card_set_highspeed(card);
+        mmc_set_timing(card->host, MMC_TIMING_SD_HS);
+
+        return 0;
+}
+
+/*
  * Host is being removed. Free up the current card.
  */
 static void mmc_sdio_remove(struct mmc_host *host)
@@ -333,10 +363,26 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
                 goto remove;
 
         /*
-         * No support for high-speed yet, so just set
-         * the card's maximum speed.
+         * Switch to high-speed (if supported).
          */
-        mmc_set_clock(host, card->cis.max_dtr);
+        err = sdio_enable_hs(card);
+        if (err)
+                goto remove;
+
+        /*
+         * Change to the card's maximum speed.
+         */
+        if (mmc_card_highspeed(card)) {
+                /*
+                 * The SDIO specification doesn't mention how
+                 * the CIS transfer speed register relates to
+                 * high-speed, but it seems that 50 MHz is
+                 * mandatory.
+                 */
+                mmc_set_clock(host, 50000000);
+        } else {
+                mmc_set_clock(host, card->cis.max_dtr);
+        }
 
         /*
          * Switch to wider bus (if supported).