[PATCH v3 5/5] ASoC: dwc: Add documentation for I2S DT

[Andrew Jackson <andrew.jackson@arm.com>]

From: Andrew Jackson <Andrew.Jackson@arm.com>

Add documentation for Designware I2S hardware block.  The block requires
two clocks (one for audio sampling, the other for APB) and DMA channels
for receive and transmit.

Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
---
 .../devicetree/bindings/sound/designware-i2s.txt   |   32 ++++++++++++++++++++
 1 files changed, 32 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/sound/designware-i2s.txt

diff --git a/Documentation/devicetree/bindings/sound/designware-i2s.txt b/Documentation/devicetree/bindings/sound/designware-i2s.txt
new file mode 100644
index 0000000..cdee591
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/designware-i2s.txt
@@ -0,0 +1,32 @@
+DesignWare I2S controller
+
+Required properties:
+ - compatible : Must be "snps,designware-i2s"
+ - reg : Must contain I2S core's registers location and length
+ - clocks : Pairs of phandle and specifier referencing the controller's clocks.
+   The controller expects two clocks, the clock used for the APB interface and
+   the clock used as the sampling rate reference clock sample.
+ - clock-names : "apb_plck" for the clock to the APB interface, "i2sclk" for the sample
+   rate reference clock.
+ - dmas: Pairs of phandle and specifier for the DMA channels that are used by
+   the core. The core expects one or two dma channels, one for transmit and one for
+   receive.
+ - dma-names : "tx" for the transmit channel, "rx" for the receive channel.
+
+For more details on the 'dma', 'dma-names', 'clock' and 'clock-names' properties
+please check:
+	* resource-names.txt
+	* clock/clock-bindings.txt
+	* dma/dma.txt
+
+Example:
+
+	soc_i2s: i2s@7ff90000 {
+		compatible = "snps,designware-i2s";
+		reg = <0x0 0x7ff90000 0x0 0x1000>;
+		clocks = <&scpi_i2sclk 0>, <&soc_refclk100mhz>;
+		clock-names = "i2sclk", "apb_pclk";
+		#sound-dai-cells = <0>;
+		dmas = <&dma0 5>;
+		dma-names = "tx";
+	};
-- 
1.7.1