serial: 8250_uniphier: add bindings document for UniPhier UART

This is binding information for the UniPhier on-chip UART driver
(drivers/tty/serial/8250/8250_uniphier.c).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/serial/uniphier-uart.txt b/Documentation/devicetree/bindings/serial/uniphier-uart.txt
new file mode 100644
index 000000000000..0b3892a7a528
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/uniphier-uart.txt
@@ -0,0 +1,23 @@
+UniPhier UART controller
+
+Required properties:
+- compatible: should be "socionext,uniphier-uart".
+- reg: offset and length of the register set for the device.
+- interrupts: a single interrupt specifier.
+- clocks: phandle to the input clock.
+
+Optional properties:
+- fifo-size: the RX/TX FIFO size.  Defaults to 64 if not specified.
+
+Example:
+        aliases {
+                serial0 = &serial0;
+        };
+
+        serial0: serial@54006800 {
+                compatible = "socionext,uniphier-uart";
+                reg = <0x54006800 0x40>;
+                interrupts = <0 33 4>;
+                clocks = <&uart_clk>;
+                fifo-size = <64>;
+        };