tty/serial: at91: document clock properties

Document the clock properties required by the at91 usart driver.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 2191dcb9f1da..9c5d19ac935c 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -6,6 +6,9 @@ Required properties:
   additional mode or an USART new feature.
 - reg: Should contain registers location and length
 - interrupts: Should contain interrupt
+- clock-names: tuple listing input clock names.
+        Required elements: "usart"
+- clocks: phandles to input clocks.
 
 Optional properties:
 - atmel,use-dma-rx: use of PDC or DMA for receiving data
@@ -26,6 +29,8 @@ Example:
                 compatible = "atmel,at91sam9260-usart";
                 reg = <0xfff8c000 0x4000>;
                 interrupts = <7>;
+                clocks = <&usart0_clk>;
+                clock-names = "usart";
                 atmel,use-dma-rx;
                 atmel,use-dma-tx;
         };
@@ -35,6 +40,8 @@ Example:
                 compatible = "atmel,at91sam9260-usart";
                 reg = <0xf001c000 0x100>;
                 interrupts = <12 4 5>;
+                clocks = <&usart0_clk>;
+                clock-names = "usart";
                 atmel,use-dma-rx;
                 atmel,use-dma-tx;
                 dmas = <&dma0 2 0x3>,