diff --git a/src/soc/rockchip/rk3399/include/soc/grf.h b/src/soc/rockchip/rk3399/include/soc/grf.h
index 241c97f00b..aec9248fd6 100644
--- a/src/soc/rockchip/rk3399/include/soc/grf.h
+++ b/src/soc/rockchip/rk3399/include/soc/grf.h
@@ -123,7 +123,10 @@ struct rk3399_grf_regs {
 		u32 iomux_spi2;
 		u32 gpio2b_iomux;
 	};
-	u32 gpio2c_iomux;
+	union {
+		u32 gpio2c_iomux;
+		u32 iomux_spi5;
+	};
 	u32 gpio2d_iomux;
 	u32 gpio3a_iomux;
 	u32 gpio3b_iomux;
@@ -337,6 +340,8 @@ static struct rk3399_pmusgrf_regs * const rk3399_pmusgrf = (void *)PMUSGRF_BASE;
 #define IOMUX_SPI1_RX	RK_CLRSETBITS(3 << 14, 2 << 14)
 #define IOMUX_SPI1_CSCLKTX	RK_CLRSETBITS(0x3f << 0, 2 << 4 |\
 					      2 << 2 | 2 << 0)
+#define IOMUX_SPI5     RK_CLRSETBITS(0xff << 8, \
+				     2 << 14 | 2 << 12 | 2 << 10 | 2 << 8)
 #define IOMUX_SDMMC	RK_CLRSETBITS(0xfff, 1 << 10 | 1 << 8 | 1 << 6 |\
 					     1 << 4 | 1 << 2 | 1 << 0)
 #define IOMUX_I2C0_SCL	RK_CLRSETBITS(3 << 0, 2 << 0)