dt-bindings: ASoC: Add Spreadtrum DMA platform documentation

Add documentation for Spreadtrum DMA platform driver.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/sound/sprd-pcm.txt b/Documentation/devicetree/bindings/sound/sprd-pcm.txt
new file mode 100644 (file)
index 0000000..4b23e84
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/sprd-pcm.txt
@@ -0,0 +1,23 @@
+* Spreadtrum DMA platfrom bindings
+
+Required properties:
+- compatible: Should be "sprd,pcm-platform".
+- dmas: Specify the list of DMA controller phandle and DMA request line ordered pairs.
+- dma-names: Identifier string for each DMA request line in the dmas property.
+  These strings correspond 1:1 with the ordered pairs in dmas.
+
+Example:
+
+       audio_platform:platform@0 {
+               compatible = "sprd,pcm-platform";
+               dmas = <&agcp_dma 1 1>, <&agcp_dma 2 2>,
+                    <&agcp_dma 3 3>, <&agcp_dma 4 4>,
+                    <&agcp_dma 5 5>, <&agcp_dma 6 6>,
+                    <&agcp_dma 7 7>, <&agcp_dma 8 8>,
+                    <&agcp_dma 9 9>, <&agcp_dma 10 10>;
+               dma-names = "normal_p_l", "normal_p_r",
+                       "normal_c_l", "normal_c_r",
+                       "voice_c", "fast_p",
+                       "loop_c", "loop_p",
+                       "voip_c", "voip_p";
+       };