diff --git a/Documentation/devicetree/bindings/serial/of-serial.txt b/Documentation/devicetree/bindings/serial/of-serial.txt
index 8c4fd0332028b5952414182102f2f343a12e49ef..b52b98234b9b1d5380b1c8cd711637d0bee9f8b3 100644
--- a/Documentation/devicetree/bindings/serial/of-serial.txt
+++ b/Documentation/devicetree/bindings/serial/of-serial.txt
@@ -10,6 +10,7 @@ Required properties:
 	- "ns16850"
 	- "nvidia,tegra20-uart"
 	- "nxp,lpc3220-uart"
+	- "ralink,rt2880-uart"
 	- "ibm,qpace-nwp-serial"
 	- "altr,16550-FIFO32"
 	- "altr,16550-FIFO64"