ASoC: img: Add binding document for Pistachio internal DAC

Add binding document for Pistachio Internal DAC

Signed-off-by: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/sound/img,pistachio-internal-dac.txt b/Documentation/devicetree/bindings/sound/img,pistachio-internal-dac.txt
new file mode 100644 (file)
index 0000000..4cc18fc
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/img,pistachio-internal-dac.txt
@@ -0,0 +1,18 @@
+Pistachio internal DAC DT bindings
+
+Required properties:
+
+  - compatible: "img,pistachio-internal-dac"
+
+  - img,cr-top : Must contain a phandle to the top level control syscon
+                node which contains the internal dac control registers
+
+  - VDD-supply : Digital power supply regulator (+1.8V or +3.3V)
+
+Examples:
+
+internal_dac: internal-dac {
+       compatible = "img,pistachio-internal-dac";
+       img,cr-top = <&cr_top>;
+       VDD-supply = <&supply3v3>;
+};