ASoC: ak4104: add DT bindings

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Documentation/devicetree/bindings/sound/ak4104.txt

+AK4104 S/PDIF transmitter
+
+This device supports SPI mode only.
+
+Required properties:
+
+  - compatible : "asahi-kasei,ak4104"
+
+  - reg : The chip select number on the SPI bus
+
+Example:
+
+spdif: ak4104@0 {
+	compatible = "asahi-kasei,ak4104";
+	reg = <0>;
+	spi-max-frequency = <5000000>;
+};

sound/soc/codecs/ak4104.c

@@ -258,10 +258,17 @@ static int __devexit ak4104_spi_remove(struct spi_device *spi)
 	return 0;
 }
 
+static const struct of_device_id ak4104_of_match[] = {
+	{ .compatible = "asahi-kasei,ak4104", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ak4104_of_match);
+
 static struct spi_driver ak4104_spi_driver = {
 	.driver  = {
 		.name   = DRV_NAME,
 		.owner  = THIS_MODULE,
+		.of_match_table = ak4104_of_match,
 	},
 	.probe  = ak4104_spi_probe,
 	.remove = __devexit_p(ak4104_spi_remove),