sound: snow: Add the binding file for snow

This file was missed when adding the sound driver to U-Boot. Bring it in
from Linux 5.0.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

diff --git a/doc/device-tree-bindings/sound/snow.txt b/doc/device-tree-bindings/sound/snow.txt
new file mode 100644 (file)
index 0000000..80fd9a8
--- /dev/null
+++ b/doc/device-tree-bindings/sound/snow.txt
@@ -0,0 +1,31 @@
+Audio Binding for Snow boards
+
+Required properties:
+- compatible : Can be one of the following,
+                       "google,snow-audio-max98090" or
+                       "google,snow-audio-max98091" or
+                       "google,snow-audio-max98095"
+- samsung,i2s-controller (deprecated): The phandle of the Samsung I2S controller
+- samsung,audio-codec (deprecated): The phandle of the audio codec
+
+Required sub-nodes:
+
+ - 'cpu' subnode with a 'sound-dai' property containing the phandle of the I2S
+    controller
+ - 'codec' subnode with a 'sound-dai' property containing list of phandles
+    to the CODEC nodes, first entry must be the phandle of the MAX98090,
+    MAX98091 or MAX98095 CODEC (exact device type is indicated by the compatible
+    string) and the second entry must be the phandle of the HDMI IP block node
+
+Optional:
+- samsung,model: The name of the sound-card
+
+Example:
+
+sound {
+               compatible = "google,snow-audio-max98095";
+
+               samsung,model = "Snow-I2S-MAX98095";
+               samsung,i2s-controller = <&i2s0>;
+               samsung,audio-codec = <&max98095>;
+};