diff --git a/Documentation/devicetree/bindings/serial/mtk-uart.txt b/Documentation/devicetree/bindings/serial/mtk-uart.txt
index c6b5262eb352..6fdffb735fb9 100644
--- a/Documentation/devicetree/bindings/serial/mtk-uart.txt
+++ b/Documentation/devicetree/bindings/serial/mtk-uart.txt
@@ -23,7 +23,12 @@ Required properties:
 
 - reg: The base address of the UART register bank.
 
-- interrupts: A single interrupt specifier.
+- interrupts:
+  index 0: an interrupt specifier for the UART controller itself
+  index 1: optional, an interrupt specifier with edge sensitivity on Rx pin to
+           support Rx in-band wake up. If one would like to use this feature,
+           one must create an addtional pinctrl to reconfigure Rx pin to normal
+           GPIO before suspend.
 
 - clocks : Must contain an entry for each entry in clock-names.
   See ../clocks/clock-bindings.txt for details.
@@ -39,7 +44,11 @@ Example:
 	uart0: serial@11006000 {
 		compatible = "mediatek,mt6589-uart", "mediatek,mt6577-uart";
 		reg = <0x11006000 0x400>;
-		interrupts = <GIC_SPI 51 IRQ_TYPE_LEVEL_LOW>;
+		interrupts = <GIC_SPI 51 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_SPI 52 IRQ_TYPE_EDGE_FALLING>;
 		clocks = <&uart_clk>, <&bus_clk>;
 		clock-names = "baud", "bus";
+		pinctrl-names = "default", "sleep";
+		pinctrl-0 = <&uart_pin>;
+		pinctrl-1 = <&uart_pin_sleep>;
 	};