Re: [PATCH v4 4/9] ASoC: dt-bindings: wcd938x-sdw: add bindings for wcd938x-sdw

[Srinivas Kandagatla]

On 15/04/2021 17:39, Rob Herring wrote:
> On Wed, Apr 14, 2021 at 04:48:40PM +0100, Srinivas Kandagatla wrote:
> > Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC
> > connected over SoundWire. This device has two SoundWire devices RX and
> > TX respectively. This bindings is for those slave devices on WCD9380/WCD9385.
> >
> > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > ---
> >   .../bindings/sound/qcom,wcd938x-sdw.yaml      | 61 +++++++++++++++++++
> >   1 file changed, 61 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/sound/qcom,wcd938x-sdw.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd938x-sdw.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd938x-sdw.yaml
> > new file mode 100644
> > index 000000000000..fff33c65491b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/sound/qcom,wcd938x-sdw.yaml
> > @@ -0,0 +1,61 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/sound/qcom,wcd938x-sdw.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Bindings for Qualcomm SoundWire Slave devices on WCD9380/WCD9385
> > +
> > +maintainers:
> > +  - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > +
> > +description: |
> > +  Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC.
> > +  It has RX and TX Soundwire slave devices. This bindings is for the
> > +  slave devices.
> > +
> > +properties:
> > +  compatible:
> > +    const: sdw20217010d00
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  qcom,direction:
> > +    description: direction of the SoundWire device instance
> > +    enum:
> > +      - rx
> > +      - tx
>
> Was thinking these were some established bus properties...
>
> This would just be implied by the 'reg' property index. You could define
> 'reg-names' too I guess.
>
> > +
> > +  qcom,port-mapping:
> > +    description: |
> > +      Specifies static port mapping between slave and master ports.
> > +      In the order of slave port index.
> > +    $ref: /schemas/types.yaml#/definitions/uint32-array
> > +    minItems: 4
> > +    maxItems: 5
>
> qcom,rx-port-mapping and qcom,tx-port-mapping?

If we have this property then "qcom,direction" becomes redundant.

> Or keep a single property and the driver knows how many slave ports for
> each direction. IOW, an array of 9 with first 4 entries for tx and last
> 5 for rx.

We can't have a single property with 9 entries as these are two separate 
devices, rx SoundWire Slave has 5 ports implemented where as tx SounWire 
slave has only 4 ports implemented in hw.

And the are on different SoundWire buses.

--srini
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - qcom,direction
> > +  - qcom,port-mapping
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    soundwire@3230000 {
> > +        #address-cells = <2>;
> > +        #size-cells = <0>;
> > +        reg = <0x03230000 0x2000>;
> > +
> > +        codec@0,3 {
> > +            compatible = "sdw20217010d00";
> > +            reg  = <0 3>;
> > +            qcom,direction = "tx";
> > +            qcom,port-mapping = <2 3 4 5>;
> > +        };
> > +    };
> > +
> > +...
> > --
> > 2.21.0