1 files changed, 3 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 9c5d19ac935c..17c1042b2df8 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -13,6 +13,8 @@ Required properties:
 Optional properties:
 - atmel,use-dma-rx: use of PDC or DMA for receiving data
 - atmel,use-dma-tx: use of PDC or DMA for transmitting data
+- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral
+  function pin for the USART RTS feature. If unsure, don't specify this property.
 - add dma bindings for dma transfer:
         - dmas: DMA specifier, consisting of a phandle to DMA controller node,
                 memory peripheral interface and USART DMA channel ID, FIFO configuration.
@@ -33,6 +35,7 @@ Example:
                 clock-names = "usart";
                 atmel,use-dma-rx;
                 atmel,use-dma-tx;
+                rts-gpios = <&pioD 15 0>;
         };
 
 - use DMA: