diff --git a/app/driver/spi.c b/app/driver/spi.c
index 4581e457..eff583cf 100644
--- a/app/driver/spi.c
+++ b/app/driver/spi.c
@@ -87,14 +87,12 @@ void spi_master_init(uint8 spi_no, unsigned cpol, unsigned cpha, uint32_t clock_
 
 	SET_PERI_REG_MASK(SPI_USER(spi_no), SPI_CS_SETUP|SPI_CS_HOLD|SPI_RD_BYTE_ORDER|SPI_WR_BYTE_ORDER|SPI_DOUTDIN);
 
-	//set clock polarity
-	// TODO: This doesn't work
-	//if (cpol == 1) {
-	//    SET_PERI_REG_MASK(SPI_CTRL2(spi_no), (SPI_CK_OUT_HIGH_MODE<<SPI_CK_OUT_HIGH_MODE_S));
-	//} else {
-	//    SET_PERI_REG_MASK(SPI_CTRL2(spi_no), (SPI_CK_OUT_LOW_MODE<<SPI_CK_OUT_LOW_MODE_S));
-	//}
-	//os_printf("SPI_CTRL2 is %08x\n",READ_PERI_REG(SPI_CTRL2(spi_no)));
+	//set clock polarity (Reference: http://bbs.espressif.com/viewtopic.php?f=49&t=1570)
+	if (cpol == 1) {
+		SET_PERI_REG_MASK(SPI_PIN(spi_no), SPI_IDLE_EDGE);
+	} else {
+		CLEAR_PERI_REG_MASK(SPI_PIN(spi_no), SPI_IDLE_EDGE);
+	}
 
 	//set clock phase
 	if (cpha == 1) {
diff --git a/app/include/driver/spi_register.h b/app/include/driver/spi_register.h
index e0756ef9..340559ae 100644
--- a/app/include/driver/spi_register.h
+++ b/app/include/driver/spi_register.h
@@ -102,6 +102,7 @@
 #define SPI_CS2_DIS (BIT(2))
 #define SPI_CS1_DIS (BIT(1))
 #define SPI_CS0_DIS (BIT(0))
+#define SPI_IDLE_EDGE (BIT(29))
 
 #define SPI_SLAVE(i)                          (REG_SPI_BASE(i)  + 0x30)
 #define SPI_SYNC_RESET (BIT(31))
diff --git a/app/modules/spi.c b/app/modules/spi.c
index f7e8a853..ec0a30c8 100644
--- a/app/modules/spi.c
+++ b/app/modules/spi.c
@@ -30,10 +30,6 @@ static int spi_setup( lua_State *L )
   if (cpol != PLATFORM_SPI_CPOL_LOW && cpol != PLATFORM_SPI_CPOL_HIGH) {
     return luaL_error( L, "wrong arg type" );
   }
-  // CPOL_HIGH is not implemented, see app/driver/spi.c spi_master_init()
-  if (cpol == PLATFORM_SPI_CPOL_HIGH) {
-    return luaL_error( L, "cpol=high is not implemented" );
-  }
 
   if (cpha != PLATFORM_SPI_CPHA_LOW && cpha != PLATFORM_SPI_CPHA_HIGH) {
     return luaL_error( L, "wrong arg type" );