2 files changed, 62 insertions, 10 deletions

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index b0cd285d272a..8285842f19e9 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -189,6 +189,9 @@ static int mmc_decode_scr(struct mmc_card *card)
 
         scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);
         scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);
+        if (scr->sda_vsn == SCR_SPEC_VER_2)
+                /* Check if Physical Layer Spec v3.0 is supported */
+                scr->sda_spec3 = UNSTUFF_BITS(resp, 47, 1);
 
         if (UNSTUFF_BITS(resp, 55, 1))
                 card->erased_byte = 0xFF;
@@ -274,29 +277,74 @@ static int mmc_read_switch(struct mmc_card *card)
         status = kmalloc(64, GFP_KERNEL);
         if (!status) {
                 printk(KERN_ERR "%s: could not allocate a buffer for "
-                        "switch capabilities.\n", mmc_hostname(card->host));
+                        "switch capabilities.\n",
+                        mmc_hostname(card->host));
                 return -ENOMEM;
         }
 
+        /* Find out the supported Bus Speed Modes. */
         err = mmc_sd_switch(card, 0, 0, 1, status);
         if (err) {
-                /* If the host or the card can't do the switch,
-                 * fail more gracefully. */
-                if ((err != -EINVAL)
-                 && (err != -ENOSYS)
-                 && (err != -EFAULT))
+                /*
+                 * If the host or the card can't do the switch,
+                 * fail more gracefully.
+                 */
+                if (err != -EINVAL && err != -ENOSYS && err != -EFAULT)
                         goto out;
 
-                printk(KERN_WARNING "%s: problem reading switch "
-                        "capabilities, performance might suffer.\n",
+                printk(KERN_WARNING "%s: problem reading Bus Speed modes.\n",
                         mmc_hostname(card->host));
                 err = 0;
 
                 goto out;
         }
 
-        if (status[13] & 0x02)
-                card->sw_caps.hs_max_dtr = 50000000;
+        if (card->scr.sda_spec3) {
+                card->sw_caps.sd3_bus_mode = status[13];
+
+                /* Find out Driver Strengths supported by the card */
+                err = mmc_sd_switch(card, 0, 2, 1, status);
+                if (err) {
+                        /*
+                         * If the host or the card can't do the switch,
+                         * fail more gracefully.
+                         */
+                        if (err != -EINVAL && err != -ENOSYS && err != -EFAULT)
+                                goto out;
+
+                        printk(KERN_WARNING "%s: problem reading "
+                                "Driver Strength.\n",
+                                mmc_hostname(card->host));
+                        err = 0;
+
+                        goto out;
+                }
+
+                card->sw_caps.sd3_drv_type = status[9];
+
+                /* Find out Current Limits supported by the card */
+                err = mmc_sd_switch(card, 0, 3, 1, status);
+                if (err) {
+                        /*
+                         * If the host or the card can't do the switch,
+                         * fail more gracefully.
+                         */
+                        if (err != -EINVAL && err != -ENOSYS && err != -EFAULT)
+                                goto out;
+
+                        printk(KERN_WARNING "%s: problem reading "
+                                "Current Limit.\n",
+                                mmc_hostname(card->host));
+                        err = 0;
+
+                        goto out;
+                }
+
+                card->sw_caps.sd3_curr_limit = status[7];
+        } else {
+                if (status[13] & 0x02)
+                        card->sw_caps.hs_max_dtr = 50000000;
+        }
 
 out:
         kfree(status);
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 72a98681ef47..56f4d9234a66 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -67,6 +67,7 @@ struct mmc_ext_csd {
 
 struct sd_scr {
         unsigned char           sda_vsn;
+        unsigned char           sda_spec3;
         unsigned char           bus_widths;
 #define SD_SCR_BUS_WIDTH_1      (1<<0)
 #define SD_SCR_BUS_WIDTH_4      (1<<2)
@@ -80,6 +81,9 @@ struct sd_ssr {
 
 struct sd_switch_caps {
         unsigned int            hs_max_dtr;
+        unsigned int            sd3_bus_mode;
+        unsigned int            sd3_drv_type;
+        unsigned int            sd3_curr_limit;
 };
 
 struct sdio_cccr {