adds file for description on device node bindings for RTC 
found on Xilinx Zynq Ultrascale+ MPSoC. 

Signed-off-by: Suneel Garapati <suneel....@xilinx.com <javascript:>> 
--- 
Changes v2 
- add examples for interrupt-names 
- change alm to alarm 
--- 
 Documentation/devicetree/bindings/rtc/xlnx-rtc.txt | 25 
++++++++++++++++++++++ 
 1 file changed, 25 insertions(+) 
 create mode 100644 Documentation/devicetree/bindings/rtc/xlnx-rtc.txt 

diff --git a/Documentation/devicetree/bindings/rtc/xlnx-rtc.txt 

b/Documentation/devicetree/bindings/rtc/xlnx-rtc.txt 
new file mode 100644 
index 0000000..0df6f01 

--- /dev/null 
+++ b/Documentation/devicetree/bindings/rtc/xlnx-rtc.txt 

@@ -0,0 +1,25 @@ 
+* Xilinx Zynq Ultrascale+ MPSoC Real Time Clock 
+ 
+RTC controller for the Xilinx Zynq MPSoC Real Time Clock 
+Separate IRQ lines for seconds and alarm 
+ 
+Required properties: 
+- compatible: Should be "xlnx,zynqmp-rtc" 
+- reg: Physical base address of the controller and length 
+       of memory mapped region. 
+- interrupts: IRQ lines for the RTC. 
+- interrupt-names: interrupt line names eg. "sec" "alarm" 
+ 
+Optional: 
+- calibration: calibration value for 1 sec period which will 
+                be programmed directly to calibration register 
+ 
+Example: 
+rtc: rtc@ffa60000 { 
+        compatible = "xlnx,zynqmp-rtc"; 
+        reg = <0x0 0xffa60000 0x100>; 
+        interrupt-parent = <&gic>; 
+        interrupts = <0 26 4>, <0 27 4>; 
+        interrupt-names = "alarm", "sec"; 
+        calibration = <0x198233>; 
+}; 

-- 
2.1.2