On Fri, Aug 09, 2019 at 02:34:04PM +0100, Srinivas Kandagatla wrote:
> 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
Can you convert this to DT schema given it is a common binding.
What does the host controller look like? You need to define the node
hierarchy. Bus controller schemas should then include the bus schema.
See spi-controller.yaml.
>
> 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
This can all be a regex.
> + 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";
The normal way to distinguish instances is with 'reg'. So I think you
need 'reg' with Instance ID moved there at least. Just guessing, but
perhaps Link ID, too? And for 2 different classes of device is that
enough?
Rob
