ASoC: mxs: add device tree support for mxs-saif

Add device tree probe for mxs-saif driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/Documentation/devicetree/bindings/sound/mxs-saif.txt b/Documentation/devicetree/bindings/sound/mxs-saif.txt
new file mode 100644
index 0000000..c37ba61
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/mxs-saif.txt
@@ -0,0 +1,36 @@
+* Freescale MXS Serial Audio Interface (SAIF)
+
+Required properties:
+- compatible: Should be "fsl,<chip>-saif"
+- reg: Should contain registers location and length
+- interrupts: Should contain ERROR and DMA interrupts
+- fsl,saif-dma-channel: APBX DMA channel for the SAIF
+
+Optional properties:
+- fsl,saif-master: phandle to the master SAIF.  It's only required for
+  the slave SAIF.
+
+Note: Each SAIF controller should have an alias correctly numbered
+in "aliases" node.
+
+Example:
+
+aliases {
+	saif0 = &saif0;
+	saif1 = &saif1;
+};
+
+saif0: saif@80042000 {
+	compatible = "fsl,imx28-saif";
+	reg = <0x80042000 2000>;
+	interrupts = <59 80>;
+	fsl,saif-dma-channel = <4>;
+};
+
+saif1: saif@80046000 {
+	compatible = "fsl,imx28-saif";
+	reg = <0x80046000 2000>;
+	interrupts = <58 81>;
+	fsl,saif-dma-channel = <5>;
+	fsl,saif-master = <&saif0>;
+};