[PATCH 3/3] Documentation: add Actions S900 clock bindings

[Manivannan Sadhasivam]

This patch adds clock bindings for Actions Semi S900 SoC.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
---
 .../bindings/clock/actions,s900-clock.txt          | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/actions,s900-clock.txt

diff --git a/Documentation/devicetree/bindings/clock/actions,s900-clock.txt b/Documentation/devicetree/bindings/clock/actions,s900-clock.txt
new file mode 100644
index 0000000..951d6ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/actions,s900-clock.txt
@@ -0,0 +1,47 @@
+* Actions s900 Clock Controller
+
+The Actions s900 clock controller generates and supplies clock to various
+controllers within the SoC. The clock binding described here is applicable to
+s900 SoC.
+
+Required Properties:
+
+- compatible: should be "actions,s900-clock"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- #clock-cells: should be 1.
+
+Each clock is assigned an identifier and client nodes can use this identifier
+to specify the clock which they consume.
+
+All available clocks are defined as preprocessor macros in
+dt-bindings/clock/actions,s900-clock.h header and can be used in device
+tree sources.
+
+External clocks:
+
+The hosc clock used as input for the plls is generated outside the SoC. It is
+expected that it is defined using standard clock bindings as "hosc".
+
+Actions s900 Clock Controller also require two more clocks:
+ - "losc" - internal low frequency oscillator
+ - "diff_24M" - internal differential 24MHz clock
+
+Example: Clock controller node:
+
+        clock: clock-controller at e0160000 {
+		compatible = "actions,s900-clock";
+		reg = <0 0xe0160000 0 0x1000>;
+		#clock-cells = <1>;
+	};
+
+Example: UART controller node that consumes clock generated by the clock
+controller:
+
+	serial5: uart at e012a000 {
+		compatible = "actions,s900-uart", "actions,owl-uart";
+		reg = <0x0 0xe012a000 0x0 0x2000>;
+		interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&clock CLK_UART5>;
+		clock-names = "uart";
+	};
-- 
2.7.4