Re: [PATCH v4 2/6] dt-bindings: audio-graph-card: Add plls and sysclks properties

[Richard Fitzgerald]

On 13/01/2021 15:22, Rob Herring wrote:
> On Fri, Jan 08, 2021 at 04:04:57PM +0000, Richard Fitzgerald wrote:
> > The audio-graph-card driver has properties for configuring the clocking
> > for DAIs within a component, but is missing properties for setting
> > up the PLLs and sysclks of the component.
> >
> > This patch adds the two new properties 'plls' and 'sysclks' so that the
> > audio-graph-driver can fully configure the component clocking.
>
> I'm not sure this makes sense to be generic, but if so, we already have
> the clock binding and should use (and possibly extend) that.
>
> This appears to all be configuration of clocks within the codec, so
> these properties belong in the codec or cpu nodes.

audio-graph-card doesn't have codec or cpu nodes. Those were in
simple-card but are replaced in audio-graph-card by a simple phandle
array forming a graph.

I could assume that all clock settings apply to the codec and that there
is only ever one codec in an audio-graph-card configuration.

> > Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> >   .../bindings/sound/audio-graph.yaml           | 46 +++++++++++++++++++
> >   1 file changed, 46 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/sound/audio-graph.yaml b/Documentation/devicetree/bindings/sound/audio-graph.yaml
> > index 4b46794e5153..9e0819205a17 100644
> > --- a/Documentation/devicetree/bindings/sound/audio-graph.yaml
> > +++ b/Documentation/devicetree/bindings/sound/audio-graph.yaml
> > @@ -39,6 +39,52 @@ properties:
> >     mic-det-gpio:
> >       maxItems: 1
> >   
> > +  plls:
> > +    description: |
> > +      A list of component pll settings. There are 4 cells per PLL setting:
> > +        - phandle to the node of the codec or cpu component,
> > +        - component PLL id,
> > +        - component clock source id,
> > +        - frequency (in Hz) of the PLL output clock.
>
> assigned-clocks binding can set frequencies and parent clocks.
>
> 'pll' is too specific to the implementation. You may want to configure
> the freq and parent of something that's not a pll.
>
> > +      The PLL id and clock source id are specific to the particular component
> > +      so see the relevant component driver for the ids. Typically the
> > +      clock source id indicates the pin the source clock is connected to.
> > +      The same phandle can appear in multiple entries so that several plls
> > +      can be set in the same component.
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +
> > +  plls-clocks:
> > +    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
> > +    description: |
> > +      A list of clock names giving the source clock for each setting
> > +      in the plls property.
> > +
> > +  sysclks:
> > +    description: |
> > +      A list of component sysclk settings. There are 4 cells per sysclk
> > +      setting:
> > +        - phandle to the node of the codec or cpu component,
> > +        - component sysclk id,
> > +        - component clock source id,
> > +        - direction of the clock: 0 if the clock is an input to the component,
> > +          1 if it is an output.
>
> A clock provider and consumer would provide the direction.
>
> > +      The sysclk id and clock source id are specific to the particular
> > +      component so see the relevant component driver for the ids. Typically
> > +      the clock source id indicates the pin the source clock is connected to.
> > +      The same phandle can appear in multiple entries so that several sysclks
> > +      can be set in the same component.
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +
> > +  sysclks-clocks:
> > +    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
> > +    description: |
> > +      A list of clock names giving the source clock for each setting
> > +      in the sysclks property.
> > +
> > +dependencies:
> > +  plls: [ plls-clocks ]
> > +  sysclks: [ sysclks-clocks ]
> > +
> >   required:
> >     - dais
> >   
> > --
> > 2.20.1