sdio: high-speed support

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

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 4eab79e09cccacbab8b7ecf7d2ae780f9e5b9e05..fb99ccff908077f1a5bdf1cdc78099fd0ecd19c2 100644 (file)
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -164,6 +164,36 @@ static int sdio_enable_wide(struct mmc_card *card)
        return 0;
 }
 
+/*
+ * 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.
  */
@@ -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).