Re: [PATCH v2 6/6] ASoC: dt-bindings: renesas,fsi: add support for multiple clocks

[Geert Uytterhoeven]

Hi Bui,

On Tue, 14 Apr 2026 at 12:41, Bui Duc Phuc <phucduc.bui@xxxxxxxxx> wrote:
> > Flexible is not allowed. Provide reasons for exception.
>
> I understand and will remove this approach and replace it with
> explicit valid clock combinations.
>
> > This goes to the "clocks:"
>
> Understood, I will move the description to "clocks".
>
> > > +    minItems: 1
> > > +    items:
> > > +      - const: own
> > > +      - &fsi_all_clks
> >
> > I don't understand this syntax.
>
> Understood, I will drop the YAML anchor and use explicit constraints instead.
>
> I will update it to the following structure:
>
>   clocks:
>     description: |
>       Clock driving the FSI Controller :
>       - "own": Main FSI module clock (must be first and always present)
>       - "spu": SPU bus/bridge clock. On R8A7740, this clock must be
>         enabled to allow register access as the FSI block is connected
>         behind the SPU bus.
>       - "icka" / "ickb": CPG DIV6 functional clocks for FSI port A/B
>       - "diva"/"divb": Internal FSI dividers for port A/B used for
>         audio clock generation
>       - "xcka"/"xckb": External clock inputs for FSI port A/B
>         provided by the board
>     minItems: 1
>     maxItems: 8

'move the description to "clocks"' means:

    clocks:
      minItems: 1
      items:
        - description: Main FSI module clock
        - description: SPU bus/bridge clock [...]
          [...[

>   clock-names:
>
>     minItems: 1
>     maxItems: 8

and:

    clock-names:
      minItems: 1
      items:
        - const: "fck"
        - const: "spu"
          [...]

But this imposes a fixed order, and would prevent optional
clocks in the middle of the list.

So you may be better off using a similar description like in
Documentation/devicetree/bindings/serial/renesas,scif.yaml

    clock-names:
      minItems: 1
      maxItems: 8
      items:
        - fck # Main FSI module clock
        - spu # optional SPU bus/bridge clock [...]
        - icka # optional CPG DIV6 functional clocks for FSI port A
        - ickb # optional CPG DIV6 functional clocks for FSI port B
          [...]

>
> allOf:
>   - $ref: dai-common.yaml#
>   - if:
>       properties:
>         compatible:
>           contains:
>             const: renesas,fsi2-r8a7740
>     then:
>       properties:
>         clock-names:
>           oneOf:
>             - items:
>                 - const: own
>                 - const: spu
>             - items:
>                 - const: own
>                 - const: spu
>                 - const: ickb
>                 - const: divb

+ the above making it stricter.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds