dt-bindings: rtc: Add Spreadtrum SC27xx RTC documentation

This patch adds the binding documentation for Spreadtrum SC27xx series
RTC device.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/Documentation/devicetree/bindings/rtc/sprd,sc27xx-rtc.txt b/Documentation/devicetree/bindings/rtc/sprd,sc27xx-rtc.txt
new file mode 100644 (file)
index 0000000..7c170da
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/sprd,sc27xx-rtc.txt
@@ -0,0 +1,27 @@
+Spreadtrum SC27xx Real Time Clock
+
+Required properties:
+- compatible: should be "sprd,sc2731-rtc".
+- reg: address offset of rtc register.
+- interrupt-parent: phandle for the interrupt controller.
+- interrupts: rtc alarm interrupt.
+
+Example:
+
+       sc2731_pmic: pmic@0 {
+               compatible = "sprd,sc2731";
+               reg = <0>;
+               spi-max-frequency = <26000000>;
+               interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
+               interrupt-controller;
+               #interrupt-cells = <2>;
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               rtc@280 {
+                       compatible = "sprd,sc2731-rtc";
+                       reg = <0x280>;
+                       interrupt-parent = <&sc2731_pmic>;
+                       interrupts = <2 IRQ_TYPE_LEVEL_HIGH>;
+               };
+       };