diff --git a/include/mmc.h b/include/mmc.h
index 711cb5d1..032873c 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -226,6 +226,7 @@
 #define EXT_CSD_HS_TIMING		185	/* R/W */
 #define EXT_CSD_REV			192	/* RO */
 #define EXT_CSD_CARD_TYPE		196	/* RO */
+#define EXT_CSD_PART_SWITCH_TIME	199	/* RO */
 #define EXT_CSD_SEC_CNT			212	/* RO, 4 bytes */
 #define EXT_CSD_HC_WP_GRP_SIZE		221	/* RO */
 #define EXT_CSD_HC_ERASE_GRP_SIZE	224	/* RO */
@@ -587,6 +588,7 @@
 	u8 wr_rel_set;
 	u8 part_config;
 	u8 gen_cmd6_time;
+	u8 part_switch_time;
 	uint tran_speed;
 	uint legacy_speed; /* speed for the legacy mode provided by the card */
 	uint read_bl_len;
@@ -833,6 +835,9 @@
 # endif
 int mmc_get_env_dev(void);
 
+/* Minimum partition switch timeout in units of 10-milliseconds */
+#define MMC_MIN_PART_SWITCH_TIME	30 /* 300 ms */
+
 /* Set block count limit because of 16 bit register limit on some hardware*/
 #ifndef CONFIG_SYS_MMC_MAX_BLK_COUNT
 #define CONFIG_SYS_MMC_MAX_BLK_COUNT 65535