Re: [PATCH v2 3/8] dt-bindings: PCI: renesas-pci-usb: Allow multiple clocks

[Rob Herring <robh@kernel.org>]

On Wed, Apr 20, 2022 at 03:07:59PM +0200, Herve Codina wrote:
> Hi Geert, Rob,
> 
> On Thu, 14 Apr 2022 10:35:07 +0200
> Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> 
> > Hi Hervé,
> > 
> > On Thu, Apr 14, 2022 at 9:40 AM Herve Codina <herve.codina@bootlin.com> wrote:
> > > Define that multiple clocks can be present at clocks property.
> > >
> > > Signed-off-by: Herve Codina <herve.codina@bootlin.com>  
> > 
> > Thanks for your patch!
> > 
> > > --- a/Documentation/devicetree/bindings/pci/renesas,pci-usb.yaml
> > > +++ b/Documentation/devicetree/bindings/pci/renesas,pci-usb.yaml
> > > @@ -54,7 +54,8 @@ properties:
> > >        Standard property that helps to define the interrupt mapping.
> > >
> > >    clocks:
> > > -    description: The reference to the device clock.
> > > +    description:
> > > +      The references to the device clocks (several clocks can be referenced).  
> > 
> > Please describe the clocks, and add the missing "clock-names" property.
> > 
> > >
> > >    bus-range:
> > >      description: |  
> > 
> > I think it would be better to combine this with [PATCH v2 4/8], as the
> > additional clocks are only present on RZ/N1.
> > 
> > Then you can easily add json-schema logic to enforce the correct
> > number of clocks, depending on the compatible value.
> 
> Sure.
> 
> Is there a way to have the clocks description depending on the compatible value.
> I mean something like:
> --- 8< ---
> properties:
>   clocks:
>     maxItems: 1

This would need to cover both cases:

minItems: 1
maxItems: 3

> 
> if:
>   properties:
>     compatible:
>       contains:
>         enum:
>           - renesas,pci-r9a06g032
>           - renesas,pci-rzn1
> 
> then:
>   properties:
>     clocks:
>       items:
>         - description: Internal bus clock (AHB) for HOST
>         - description: Internal bus clock (AHB) Power Management
>         - description: PCI clock for USB subsystem
>       minItems: 3
>       maxItems: 3

Don't need minItems or maxItems here. 3 is the default size based on 
'items' length.

> 
> else:
>   properties:
>     items:

I think you meant for this to be under 'clocks'.

>        - description: Device clock
>     clocks:
>       minItems: 1
>       maxItems: 1

Just 'maxItems' is enough.

> --- 8< ---
> 
> In fact, I would like to describe the 3 clocks only for the r9a06g032 SOC
> and the rzn1 family and have an other description for the other 'compatible'.
> 
> I cannot succeed to do it.
> 
> The only thing I can do is to leave the description of the 3 clocks out of the
> conditional part. This leads to :
> 
> --- 8< ---
> properties:
>   clocks:
>     items:
>       - description: Internal bus clock (AHB) for HOST
>       - description: Internal bus clock (AHB) Power Management
>       - description: PCI clock for USB subsystem
>     minItems: 1
> 
> if:
>   properties:
>     compatible:
>       contains:
>         enum:
>           - renesas,pci-r9a06g032
>           - renesas,pci-rzn1
> 
> then:
>   properties:
>     clocks:
>       minItems: 3
>       maxItems: 3

minItems is enough.

> 
> else:
>   properties:
>     clocks:
>       minItems: 1
>       maxItems: 1

This doesn't seem right as the description of the first clock is wrong 
for this case.

I would go with the first way.

Rob