spi: Add devicetree bindings documentation for Cadence SPI

Add spi-cadence bindings documentation.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/Documentation/devicetree/bindings/spi/spi-cadence.txt b/Documentation/devicetree/bindings/spi/spi-cadence.txt
new file mode 100644 (file)
index 0000000..94f0914
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-cadence.txt
@@ -0,0 +1,31 @@
+Cadence SPI controller Device Tree Bindings
+-------------------------------------------
+
+Required properties:
+- compatible           : Should be "cdns,spi-r1p6" or "xlnx,zynq-spi-r1p6".
+- reg                  : Physical base address and size of SPI registers map.
+- interrupts           : Property with a value describing the interrupt
+                         number.
+- interrupt-parent     : Must be core interrupt controller
+- clock-names          : List of input clock names - "ref_clk", "pclk"
+                         (See clock bindings for details).
+- clocks               : Clock phandles (see clock bindings for details).
+
+Optional properties:
+- num-cs               : Number of chip selects used.
+                         If a decoder is used, this will be the number of
+                         chip selects after the decoder.
+- is-decoded-cs                : Flag to indicate whether decoder is used or not.
+
+Example:
+
+       spi@e0007000 {
+               compatible = "xlnx,zynq-spi-r1p6";
+               clock-names = "ref_clk", "pclk";
+               clocks = <&clkc 26>, <&clkc 35>;
+               interrupt-parent = <&intc>;
+               interrupts = <0 49 4>;
+               num-cs = <4>;
+               is-decoded-cs = <0>;
+               reg = <0xe0007000 0x1000>;
+       } ;