[PATCH] dt-bindings: mfd: aspeed,ast2x00-scu: allow #size-cells range

[Ryan Chen]

> Subject: Re: [PATCH] dt-bindings: mfd: aspeed,ast2x00-scu: allow #size-cells
> range
> 
> On 20/10/2025 04:07, Ryan Chen wrote:
> > The #size-cells property in the Aspeed SCU binding is currently fixed
> > to a constant value of 1. However, newer SoCs (ex. AST2700) may
> > require two size cells to describe certain subregions or
> 
> "may"? So there is no issue yet?

while I submit ast2700 platform,
These warnings appear when validating the AST2700 EVB device tree.
The SCU nodes on AST2700 have subdevices (such as clock and reset controllers)
that require two address cells, which is not allowed by the current `const: 1`
constraint in the schema. 

Here is the related report:
  https://lkml.org/lkml/2025/9/2/1165

The errors are:
  arch/arm64/boot/dts/aspeed/ast2700-evb.dtb: syscon at 12c02000 (aspeed,ast2700-scu0): #size-cells: 1 was expected
    from schema $id: http://devicetree.org/schemas/mfd/aspeed,ast2x00-scu.yaml#
  arch/arm64/boot/dts/aspeed/ast2700-evb.dtb: syscon at 14c02000 (aspeed,ast2700-scu1): '#size-cells' is a required property
    from schema $id: http://devicetree.org/schemas/mfd/aspeed,ast2x00-scu.yaml#


> 
> > subdevices.
> >
> > This patch updates the schema to allow #size-cells values in the range
> > of 1 to 2. This makes the binding more flexible while maintaining
> > compatibility with existing platforms.
> > It also resolves dt-binding validation warnings reported by `make
> > dt_binding_check`.
> 
> Bu there is a warning? Which warning? On which file?
> 
> >
> > Signed-off-by: Ryan Chen <ryan_chen at aspeedtech.com>
> > ---
> >  Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> > b/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> > index 5eccd10d95ce..1d3f686577db 100644
> > --- a/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> > +++ b/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> > @@ -38,7 +38,8 @@ properties:
> >      maximum: 2
> >
> >    '#size-cells':
> > -    const: 1
> > +    minimum: 1
> > +    maximum: 2
> 
> That's just enum.

Thank advise.
Will use enum: [1, 2] 
> 
> >
> >    '#clock-cells':
> >      const: 1
> 
> 
> Best regards,
> Krzysztof