mmc: mmc: Add driver strength selection

Add the ability to set eMMC driver strength
for HS200 and HS400.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 4819cfb..15f2c4a 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -391,6 +391,7 @@
 #define EXT_CSD_TIMING_HS	1	/* High speed */
 #define EXT_CSD_TIMING_HS200	2	/* HS200 */
 #define EXT_CSD_TIMING_HS400	3	/* HS400 */
+#define EXT_CSD_DRV_STR_SHIFT	4	/* Driver Strength shift */
 
 #define EXT_CSD_SEC_ER_EN	BIT(0)
 #define EXT_CSD_SEC_BD_BLK_EN	BIT(2)
@@ -442,4 +443,6 @@
 #define MMC_SWITCH_MODE_CLEAR_BITS	0x02	/* Clear bits which are 1 in value */
 #define MMC_SWITCH_MODE_WRITE_BYTE	0x03	/* Set target to value */
 
+#define mmc_driver_type_mask(n)		(1 << (n))
+
 #endif /* LINUX_MMC_MMC_H */