[PATCH] dt-bindings: timer: Add SiFive CLINT2

[Nick Hu]

Hi Rob and Conor

Thanks to all your feedback.

On Wed, Mar 12, 2025 at 4:46 AM Conor Dooley <conor at kernel.org> wrote:
>
> On Tue, Mar 11, 2025 at 02:59:53PM -0500, Rob Herring wrote:
> > On Tue, Mar 11, 2025 at 01:19:03PM +0800, Nick Hu wrote:
> > > Add compatible string and property for the SiFive CLINT v2.
> > >
> > > Signed-off-by: Nick Hu <nick.hu at sifive.com>
> > > Reviewed-by: Samuel Holland <samuel.holland at sifive.com>
> > > ---
> > >  .../bindings/timer/sifive,clint.yaml          | 19 +++++++++++++++++++
> > >  1 file changed, 19 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/timer/sifive,clint.yaml b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
> > > index 76d83aea4e2b..93d74c504b5f 100644
> > > --- a/Documentation/devicetree/bindings/timer/sifive,clint.yaml
> > > +++ b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
> > > @@ -36,6 +36,9 @@ properties:
> > >                - starfive,jh7110-clint   # StarFive JH7110
> > >                - starfive,jh8100-clint   # StarFive JH8100
> > >            - const: sifive,clint0        # SiFive CLINT v0 IP block
> >
> > Notice that we don't allow clint0 by itself. We shouldn't start now.
> >
> > > +      - items:
> >
> > If you don't have a specific one yet, then add '- {}' for the first
> > entry.
> >
Do you suggest something like the following?
     - items:
          - {}
          - const: sifive,clint2        # SiFive CLINT v2 IP block
        description: SiFive CLINT v2 is the HRT that supports the Zicntr

> > > +          - const: sifive,clint2        # SiFive CLINT v2 IP block
> > > +        description: SiFive CLINT v2 is the HRT that supports the Zicntr
> > >        - items:
> > >            - enum:
> > >                - allwinner,sun20i-d1-clint
> > > @@ -62,6 +65,22 @@ properties:
> > >      minItems: 1
> > >      maxItems: 4095
> > >
> > > +  sifive,fine-ctr-bits:
> > > +    description: The width in bits of the fine counter.
> >
> > maximum: 15
> >
> > Unless you know of a different maximum in which case why aren't you
> > documenting that too?
>
You are right. It's my bad. The maximum width should always be 15 in
sifive,clint2.
I should update to:
 sifive,fine-ctr-bits:
    maximum: 15
    description: The width in bits of the fine counter.

if:
  not:
    properties:
      compatible:
        contains:
          const: sifive,clint2
then:
  properties:
    sifive,fine-ctr-bits: false

> I'm curious why this is not something that can be discerned from the
> compatible. It's max 15, but are there actually versions of this with a
> less-than-15-bit width?
>
The width may be various on different platforms so it is possible to
have a less-than-15-bit width.

> >
> > > +
> > > +if:
> > > +  properties:
> > > +    compatible:
> > > +      contains:
> > > +        const: sifive,clint2
> > > +then:
> > > +  properties:
> > > +    sifive,fine-ctr-bits:
> > > +      maximum: 15
> > > +else:
> > > +  properties:
> > > +    sifive,fine-ctr-bits: false
> > > +
> > >  additionalProperties: false
> > >
> > >  required:
> > > --
> > > 2.17.1
> > >

Best Regards,
Nick