diff --git a/drivers/pinctrl/pinctrl-sunxi.c b/drivers/pinctrl/pinctrl-sunxi.c
index fb000b00c6d3..cb3d2300082c 100644
--- a/drivers/pinctrl/pinctrl-sunxi.c
+++ b/drivers/pinctrl/pinctrl-sunxi.c
@@ -217,11 +217,11 @@ static const struct sunxi_desc_pin sun5i_a13_pins[] = {
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PE10,
 		SUNXI_FUNCTION(0x0, "gpio_in"),
 		SUNXI_FUNCTION(0x1, "gpio_out"),
-		SUNXI_FUNCTION(0x4, "uart1")),
+		SUNXI_FUNCTION(0x4, "uart1")),		/* TX */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PE11,
 		SUNXI_FUNCTION(0x0, "gpio_in"),
 		SUNXI_FUNCTION(0x1, "gpio_out"),
-		SUNXI_FUNCTION(0x4, "uart1")),
+		SUNXI_FUNCTION(0x4, "uart1")),		/* RX */
 	/* Hole */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PF0,
 		SUNXI_FUNCTION(0x0, "gpio_in"),
@@ -254,11 +254,11 @@ static const struct sunxi_desc_pin sun5i_a13_pins[] = {
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PG3,
 		SUNXI_FUNCTION(0x0, "gpio_in"),
 		SUNXI_FUNCTION(0x1, "gpio_out"),
-		SUNXI_FUNCTION(0x4, "uart1")),
+		SUNXI_FUNCTION(0x4, "uart1")),		/* TX */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PG4,
 		SUNXI_FUNCTION(0x0, "gpio_in"),
 		SUNXI_FUNCTION(0x1, "gpio_out"),
-		SUNXI_FUNCTION(0x4, "uart1")),
+		SUNXI_FUNCTION(0x4, "uart1")),		/* RX */
 	/* Hole */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PG9,
 		SUNXI_FUNCTION(0x0, "gpio_in"),