diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index b4a7e4fba90f..92061f8df31e 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -77,7 +77,7 @@ static struct variant_data variant_arm_extended_fifo = {
 static struct variant_data variant_u300 = {
 	.fifosize		= 16 * 4,
 	.fifohalfsize		= 8 * 4,
-	.clkreg_enable		= 1 << 13, /* HWFCEN */
+	.clkreg_enable		= MCI_ST_U300_HWFCEN,
 	.datalength_bits	= 16,
 	.sdio			= true,
 };
@@ -86,7 +86,7 @@ static struct variant_data variant_ux500 = {
 	.fifosize		= 30 * 4,
 	.fifohalfsize		= 8 * 4,
 	.clkreg			= MCI_CLK_ENABLE,
-	.clkreg_enable		= 1 << 14, /* HWFCEN */
+	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
 	.datalength_bits	= 24,
 	.sdio			= true,
 	.st_clkdiv		= true,
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index ec9a7bc6d0df..bb32e21c09db 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -11,23 +11,33 @@
 #define MCI_PWR_OFF		0x00
 #define MCI_PWR_UP		0x02
 #define MCI_PWR_ON		0x03
-#define MCI_DATA2DIREN		(1 << 2)
-#define MCI_CMDDIREN		(1 << 3)
-#define MCI_DATA0DIREN		(1 << 4)
-#define MCI_DATA31DIREN		(1 << 5)
 #define MCI_OD			(1 << 6)
 #define MCI_ROD			(1 << 7)
-/* The ST Micro version does not have ROD */
-#define MCI_FBCLKEN		(1 << 7)
-#define MCI_DATA74DIREN		(1 << 8)
+/*
+ * The ST Micro version does not have ROD and reuse the voltage registers
+ * for direction settings
+ */
+#define MCI_ST_DATA2DIREN	(1 << 2)
+#define MCI_ST_CMDDIREN		(1 << 3)
+#define MCI_ST_DATA0DIREN	(1 << 4)
+#define MCI_ST_DATA31DIREN	(1 << 5)
+#define MCI_ST_FBCLKEN		(1 << 7)
+#define MCI_ST_DATA74DIREN	(1 << 8)
 
 #define MMCICLOCK		0x004
 #define MCI_CLK_ENABLE		(1 << 8)
 #define MCI_CLK_PWRSAVE		(1 << 9)
 #define MCI_CLK_BYPASS		(1 << 10)
 #define MCI_4BIT_BUS		(1 << 11)
-/* 8bit wide buses supported in ST Micro versions */
+/*
+ * 8bit wide buses, hardware flow contronl, negative edges and clock inversion
+ * supported in ST Micro U300 and Ux500 versions
+ */
 #define MCI_ST_8BIT_BUS		(1 << 12)
+#define MCI_ST_U300_HWFCEN	(1 << 13)
+#define MCI_ST_UX500_NEG_EDGE	(1 << 13)
+#define MCI_ST_UX500_HWFCEN	(1 << 14)
+#define MCI_ST_UX500_CLK_INV	(1 << 15)
 
 #define MMCIARGUMENT		0x008
 #define MMCICOMMAND		0x00c
@@ -88,8 +98,9 @@
 #define MCI_RXFIFOEMPTY		(1 << 19)
 #define MCI_TXDATAAVLBL		(1 << 20)
 #define MCI_RXDATAAVLBL		(1 << 21)
-#define MCI_SDIOIT		(1 << 22)
-#define MCI_CEATAEND		(1 << 23)
+/* Extended status bits for the ST Micro variants */
+#define MCI_ST_SDIOIT		(1 << 22)
+#define MCI_ST_CEATAEND		(1 << 23)
 
 #define MMCICLEAR		0x038
 #define MCI_CMDCRCFAILCLR	(1 << 0)
@@ -102,8 +113,9 @@
 #define MCI_CMDSENTCLR		(1 << 7)
 #define MCI_DATAENDCLR		(1 << 8)
 #define MCI_DATABLOCKENDCLR	(1 << 10)
-#define MCI_SDIOITC		(1 << 22)
-#define MCI_CEATAENDC		(1 << 23)
+/* Extended status bits for the ST Micro variants */
+#define MCI_ST_SDIOITC		(1 << 22)
+#define MCI_ST_CEATAENDC	(1 << 23)
 
 #define MMCIMASK0		0x03c
 #define MCI_CMDCRCFAILMASK	(1 << 0)
@@ -127,8 +139,9 @@
 #define MCI_RXFIFOEMPTYMASK	(1 << 19)
 #define MCI_TXDATAAVLBLMASK	(1 << 20)
 #define MCI_RXDATAAVLBLMASK	(1 << 21)
-#define MCI_SDIOITMASK		(1 << 22)
-#define MCI_CEATAENDMASK	(1 << 23)
+/* Extended status bits for the ST Micro variants */
+#define MCI_ST_SDIOITMASK	(1 << 22)
+#define MCI_ST_CEATAENDMASK	(1 << 23)
 
 #define MMCIMASK1		0x040
 #define MMCIFIFOCNT		0x048