Re: [RESEND PATCH v4 1/4] dt-bindings: soundwire: add slave bindings

[Srinivas Kandagatla]

thanks for reviewing the patch!

On 27/08/2019 21:20, Rob Herring wrote:
> On Fri, Aug 23, 2019 at 12:23:40PM +0530, Vinod Koul wrote:
> > On 23-08-19, 00:37, 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>
> > > ---
> > >   .../soundwire/soundwire-controller.yaml       | 75 +++++++++++++++++++
> > >   1 file changed, 75 insertions(+)
> > >   create mode 100644 Documentation/devicetree/bindings/soundwire/soundwire-controller.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/soundwire/soundwire-controller.yaml b/Documentation/devicetree/bindings/soundwire/soundwire-controller.yaml
> > > new file mode 100644
> > > index 000000000000..91aa6c6d6266
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/soundwire/soundwire-controller.yaml
> > > @@ -0,0 +1,75 @@
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/soundwire/soundwire-controller.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: SoundWire Controller Generic Binding
> >
> > Controller does not make sense here, why not use spec terminology and
> > say "SoundWire Slave Generic Binding"
>
> It's both IMO. It's describing the structure of child devices of a
> controller (aka a bus).
>
> > > +
> > > +maintainers:
> > > +  - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > > +
> > > +description: |
> > > +  SoundWire busses can be described with a node for the SoundWire controller
> > > +  device and a set of child nodes for each SoundWire slave on the bus.
> > > +
> > > +properties:
> > > +  $nodename:
> > > +    pattern: "^soundwire(@.*|-[0-9a-f])*$"
>
> '-[0-9a-f]' was to handle cases like spi-gpio or i2c-gpio. Would a
> bit banged interface be possible here?

Highly unlikely!


> > > +
> > > +  "#address-cells":
> > > +    const: 2
> > > +
> > > +  "#size-cells":
> > > +    const: 0
> > > +
> > > +patternProperties:
> > > +  "^.*@[0-9a-f]+$":
>
> If there are distinct fields in the address, they are typically comma
> separated in the unit-address.

okay, will fix that in next version!


> > > +    type: object
> > > +
> > > +    properties:
> > > +      compatible:
> > > +      pattern: "^sdw[0-9][0-9a-f]{4}[0-9a-f]{4}[0-9a-f]{2}$"
> > > +      description:
> > > +	  Is the textual representation of SoundWire Enumeration
> > > +	  address. compatible string should contain SoundWire Version ID,
> > > +	  Manufacturer ID, Part ID and Class ID in order and shall be in
> > > +	  lower-case hexadecimal with leading zeroes.
> > > +	  Valid sizes of these fields are
> > > +	  Version ID is 1 nibble, number '0x1' represents SoundWire 1.0
> > > +	  and '0x2' represents SoundWire 1.1 and so on.
> > > +	  MFD is 4 nibbles
> > > +	  PID is 4 nibbles
> > > +	  CID is 2 nibbles
> > > +	  More Information on detail of encoding of these fields can be
> > > +	  found in MIPI Alliance DisCo & SoundWire 1.0 Specifications.
> > > +
> > > +      reg:
> > > +        maxItems: 1
> > > +        description:
> > > +          Instance ID and Link ID of SoundWire Device Address.
> >
> > This looks better :) Thanks.
> >
> > Apart from the minor nit above this looks good to me, I can merge the
> > sdw parts if Rob is fine with them.
> >
> > Thanks
> >
> > > +
> > > +    required:
> > > +      - compatible
> > > +      - reg
> > > +
> > > +examples:
> > > +  - |
> > > +    soundwire@c2d0000 {
> > > +        #address-cells = <2>;
> > > +        #size-cells = <0>;
> > > +        compatible = "qcom,soundwire-v1.5.0";
>
> This will probably change once I review it. :)

:-)

thanks,
srini
> > > +        reg = <0x0c2d0000 0x2000>;
> > > +
> > > +        speaker@1 {
> > > +            compatible = "sdw10217201000";
> > > +            reg = <1 0>;
> > > +        };
> > > +
> > > +        speaker@2 {
> > > +            compatible = "sdw10217201000";
> > > +            reg = <2 0>;
> > > +        };
> > > +    };
> > > +
> > > +...
> > > --
> > > 2.21.0
> >
> > --
> > ~Vinod