Re: [PATCH 1/2] dt-bindings: clock: document the fsl-sai driver

[Michael Walle]

Am 2019-12-06 02:23, schrieb Michael Walle:
> Am 2019-12-05 16:16, schrieb Rob Herring:
> > On Sat, Nov 23, 2019 at 12:56:21AM +0100, Michael Walle wrote:
> > > Signed-off-by: Michael Walle <michael@xxxxxxxx>
> > > ---
> > >  .../bindings/clock/fsl,sai-clock.yaml         | 48 
> > > +++++++++++++++++++
> > >  1 file changed, 48 insertions(+)
> > >  create mode 100644 
> > > Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml
> > >
> > > diff --git 
> > > a/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml 
> > > b/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml
> > > new file mode 100644
> > > index 000000000000..7116c8bc24d3
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/clock/fsl,sai-clock.yaml
> > > @@ -0,0 +1,48 @@
> > > +# SPDX-License-Identifier: GPL-2.0
> >
> > Dual license new bindings please: (GPL-2.0-only OR BSD-2-Clause)
>
> sure.
>
> > > +%YAML 1.2
> > > +---
> > > +$id: 
> > > http://devicetree.org/schemas/bindings/clock/fsl,sai-clock.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Freescale SAI bitclock-as-a-clock binding
> > > +
> > > +maintainers:
> > > +  - Michael Walle <michael@xxxxxxxx>
> > > +
> > > +description: |
> > > +  It is possible to use the BCLK pin of a SAI module as a generic 
> > > clock
> > > +  output. Some SoC are very constrained in their pin multiplexer
> > > +  configuration. Eg. pins can only be changed groups. For example, 
> > > on the
> > > +  LS1028A SoC you can only enable SAIs in pairs. If you use only one 
> > > SAI,
> > > +  the second pins are wasted. Using this binding it is possible to 
> > > use the
> > > +  clock of the second SAI as a MCLK clock for an audio codec, for 
> > > example.
> > > +
> > > +  This is a composite of a gated clock and a divider clock.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: fsl,vf610-sai-clock
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    maxItems: 1
> > > +
> > > +  '#clock-cells':
> > > +    const: 0
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - clocks
> > > +  - '#clock-cells'
> > > +
> >
> > Add:
> >
> > additionalProperties: false
>
> ok.
>
> > > +examples:
> > > +  - |
> > > +    mclk: clock-mclk@f130080 {
> > > +        compatible = "fsl,vf610-sai-clock";
> > > +        reg = <0x0 0xf130080 0x0 0x80>;
> >
> > Examples are built now and this will fail because the default
> > #address-cells and #size-cells are 1.
>
> Mh, I've run the make dt_binding_check on this. It wasn't flagged,
> but I guess thats because its interpreted as two resources.
>
> I haven't found anything how you can change the default. Or do you
> mean I should change the example to just use one address cell and
> one size cell? But then how would that work for examples (on other
> bindings) where there should be size-cells = <0> for example.

I guess I've answered that question myself, see the v2 patch series.
https://lore.kernel.org/lkml/20191209233305.18619-1-michael@xxxxxxxx/

Thanks for the review.

> > > +        #clock-cells = <0>;
> > > +        clocks = <&parentclk>;
> > > +    };
> > > --
> > > 2.20.1