ASoC: sunxi: add sun4i SPDIF transceiver

Add devicetree bindings for the SPDIF transceiver found on
found on Allwinners A10 and A20 SoCs.

Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/sound/sunxi,sun4i-spdif.txt b/Documentation/devicetree/bindings/sound/sunxi,sun4i-spdif.txt
new file mode 100644 (file)
index 0000000..13503aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/sunxi,sun4i-spdif.txt
@@ -0,0 +1,39 @@
+Allwinner Sony/Philips Digital Interface Format (S/PDIF) Controller
+
+The Allwinner S/PDIF audio block is a transceiver that allows the
+processor to receive and transmit digital audio via an coaxial cable or
+a fibre cable.
+For now only playback is supported.
+
+Required properties:
+
+  - compatible         : should be one of the following:
+    - "allwinner,sun4i-a10-spdif": for the Allwinner A10 SoC
+
+  - reg                        : Offset and length of the register set for the device.
+
+  - interrupts         : Contains the spdif interrupt.
+
+  - dmas               : Generic dma devicetree binding as described in
+                         Documentation/devicetree/bindings/dma/dma.txt.
+
+  - dma-names          : Two dmas have to be defined, "tx" and "rx".
+
+  - clocks             : Contains an entry for each entry in clock-names.
+
+  - clock-names                : Includes the following entries:
+       "apb"             clock for the spdif bus.
+       "spdif"           clock for spdif controller.
+
+Example:
+
+spdif: spdif@01c21000 {
+       compatible = "allwinner,sun4i-a10-spdif";
+       reg = <0x01c21000 0x40>;
+       interrupts = <13>;
+       clocks = <&apb0_gates 1>, <&spdif_clk>;
+       clock-names = "apb", "spdif";
+       dmas = <&dma 0 2>, <&dma 0 2>;
+       dma-names = "rx", "tx";
+       status = "okay";
+};