2 files changed, 32 insertions, 1 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 6f221dc029ad..2d24a123f0b0 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -165,6 +165,29 @@ static int sdio_enable_wide(struct mmc_card *card)
 }
 
 /*
+ * If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)
+ * of the card. This may be required on certain setups of boards,
+ * controllers and embedded sdio device which do not need the card's
+ * pull-up. As a result, card detection is disabled and power is saved.
+ */
+static int sdio_disable_cd(struct mmc_card *card)
+{
+        int ret;
+        u8 ctrl;
+
+        if (!card->cccr.disable_cd)
+                return 0;
+
+        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
+        if (ret)
+                return ret;
+
+        ctrl |= SDIO_BUS_CD_DISABLE;
+
+        return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
+}
+
+/*
  * Test if the card supports high-speed mode and, if so, switch to it.
  */
 static int sdio_enable_hs(struct mmc_card *card)
@@ -385,6 +408,13 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
                 goto remove;
 
         /*
+         * If needed, disconnect card detection pull-up resistor.
+         */
+        err = sdio_disable_cd(card);
+        if (err)
+                goto remove;
+
+        /*
          * Initialize (but don't add) all present functions.
          */
         for (i = 0;i < funcs;i++) {
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 58f59174c64b..00db39cceadc 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -64,7 +64,8 @@ struct sdio_cccr {
                                 low_speed:1,
                                 wide_bus:1,
                                 high_power:1,
-                                high_speed:1;
+                                high_speed:1,
+                                disable_cd:1;
 };
 
 struct sdio_cis {