watchdog: xilinx: Add missing binding

Document current driver binding.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
new file mode 100644 (file)
index 0000000..6d63782
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
@@ -0,0 +1,23 @@
+Xilinx AXI/PLB soft-core watchdog Device Tree Bindings
+---------------------------------------------------------
+
+Required properties:
+- compatible           : Should be "xlnx,xps-timebase-wdt-1.00.a" or
+                         "xlnx,xps-timebase-wdt-1.01.a".
+- reg                  : Physical base address and size
+
+Optional properties:
+- clock-frequency      : Frequency of clock in Hz
+- xlnx,wdt-enable-once : 0 - Watchdog can be restarted
+                         1 - Watchdog can be enabled just once
+- xlnx,wdt-interval    : Watchdog timeout interval in 2^<val> clock cycles,
+                         <val> is integer from 8 to 31.
+
+Example:
+axi-timebase-wdt@40100000 {
+       clock-frequency = <50000000>;
+       compatible = "xlnx,xps-timebase-wdt-1.00.a";
+       reg = <0x40100000 0x10000>;
+       xlnx,wdt-enable-once = <0x0>;
+       xlnx,wdt-interval = <0x1b>;
+} ;