[PATCH v3 1/4] dt-bindings: soundwire: add slave bindings

[Srinivas Kandagatla]

This patch adds bindings for Soundwire Slave devices that includes how
SoundWire enumeration address and Link ID are used to represented in
SoundWire slave device tree nodes.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 .../devicetree/bindings/soundwire/slave.txt   | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soundwire/slave.txt

diff --git a/Documentation/devicetree/bindings/soundwire/slave.txt b/Documentation/devicetree/bindings/soundwire/slave.txt
new file mode 100644
index 000000000000..201f65d2fafa
--- /dev/null
+++ b/Documentation/devicetree/bindings/soundwire/slave.txt
@@ -0,0 +1,51 @@
+SoundWire slave device bindings.
+
+SoundWire is a 2-pin multi-drop interface with data and clock line.
+It facilitates development of low cost, efficient, high performance systems.
+
+SoundWire slave devices:
+Every SoundWire controller node can contain zero or more child nodes
+representing slave devices on the bus. Every SoundWire slave device is
+uniquely determined by the enumeration address containing 5 fields:
+SoundWire Version, Instance ID, Manufacturer ID, Part ID
+and Class ID for a device. Addition to below required properties,
+child nodes can have device specific bindings.
+
+Required properties:
+- compatible:	 "sdw<LinkID><VersionID><InstanceID><MFD><PID><CID>".
+		  Is the textual representation of SoundWire Enumeration
+		  address along with Link ID. compatible string should contain
+		  SoundWire Link ID, SoundWire Version ID, Instance ID,
+		  Manufacturer ID, Part ID and Class ID in order
+		  represented as above and shall be in lower-case hexadecimal
+		  with leading zeroes. Vaild sizes of these fields are
+		  LinkID is 1 nibble,
+		  Version ID is 1 nibble
+		  Instance ID in 1 nibble
+		  MFD in 4 nibbles
+		  PID in 4 nibbles
+		  CID is 2 nibbles
+
+		  Version number '0x1' represents SoundWire 1.0
+		  Version number '0x2' represents SoundWire 1.1
+		  ex: "sdw0110217201000" represents 0 LinkID,
+		  SoundWire 1.0 version slave with Instance ID 1.
+		  More Information on detail of encoding of these fields can be
+		  found in MIPI Alliance DisCo & SoundWire 1.0 Specifications.
+
+SoundWire example for Qualcomm's SoundWire controller:
+
+soundwire@c2d0000 {
+	compatible = "qcom,soundwire-v1.5.0"
+	reg = <0x0c2d0000 0x2000>;
+
+	spkr_left:wsa8810-left{
+		compatible = "sdw0110217201000";
+		...
+	};
+
+	spkr_right:wsa8810-right{
+		compatible = "sdw0120217201000";
+		...
+	};
+};
-- 
2.21.0