diff --git a/include/omap3_spi.h b/include/omap3_spi.h
index cae3770..5381431 100644
--- a/include/omap3_spi.h
+++ b/include/omap3_spi.h
@@ -46,6 +46,8 @@
 
 #define OMAP4_MCSPI_REG_OFFSET	0x100
 
+#define OMAP4_MCSPI_CHAN_NB	4
+
 /* OMAP3 McSPI registers */
 struct mcspi_channel {
 	unsigned int chconf;		/* 0x2C, 0x40, 0x54, 0x68 */
@@ -64,7 +66,7 @@
 	unsigned int wakeupenable;	/* 0x20 */
 	unsigned int syst;		/* 0x24 */
 	unsigned int modulctrl;		/* 0x28 */
-	struct mcspi_channel channel[4];
+	struct mcspi_channel channel[OMAP4_MCSPI_CHAN_NB];
 	/* channel0: 0x2C - 0x3C, bus 0 & 1 & 2 & 3 */
 	/* channel1: 0x40 - 0x50, bus 0 & 1 */
 	/* channel2: 0x54 - 0x64, bus 0 & 1 */