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

[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.

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