diff --git a/arch/arm/boot/dts/imx51-pinfunc.h b/arch/arm/boot/dts/imx51-pinfunc.h
index 9eb92abaeb6d..82eae3c8a3ce 100644
--- a/arch/arm/boot/dts/imx51-pinfunc.h
+++ b/arch/arm/boot/dts/imx51-pinfunc.h
@@ -536,7 +536,6 @@
 #define MX51_PAD_DISPB2_SER_CLK__DISP1_PIN7		0x2c4 0x6c4 0x000 0x3 0x0
 #define MX51_PAD_DISPB2_SER_CLK__DISPB2_SER_CLK		0x2c4 0x6c4 0x000 0x0 0x0
 #define MX51_PAD_DISPB2_SER_CLK__GPIO3_7		0x2c4 0x6c4 0x990 0x4 0x1
-#define MX51_PAD_DISPB2_SER_RS__DISP1_EXT_CLK		0x2c8 0x6c8 0x000 0x2 0x0
 #define MX51_PAD_DISPB2_SER_RS__DISP1_PIN16		0x2c8 0x6c8 0x000 0x2 0x0
 #define MX51_PAD_DISPB2_SER_RS__DISP1_PIN8		0x2c8 0x6c8 0x000 0x3 0x0
 #define MX51_PAD_DISPB2_SER_RS__DISPB2_SER_RS		0x2c8 0x6c8 0x000 0x0 0x0