Re: [PATCH 1/2] dt-bindings: nvme: Add apple,t8132-nvme-ans2 compatible

[Yureka Lilian]

On 8/12/26 10:46, Krzysztof Kozlowski wrote:
> On 12/08/2026 10:08, Yureka Lilian wrote:
> > Thank you for the quick feedback!
> >
> > On 8/12/26 01:11, Rob Herring wrote:
> > > On Tue, Aug 11, 2026 at 10:49:47PM +0200, Yureka Lilian wrote:
> > > > Add a new base compatible for the ANS2 NVMe on the Apple t8132 (M4) SoC,
> > > > which uses a separate MMIO base for its NVMMU.
> > > >
> > > > Signed-off-by: Yureka Lilian <yureka@xxxxxxxxxxxxxx>
> > > > ---
> > > >    .../devicetree/bindings/nvme/apple,nvme-ans.yaml   | 77 ++++++++++++++--------
> > > >    1 file changed, 48 insertions(+), 29 deletions(-)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml b/Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
> > > > index 4c0b1f90aff8..c8a41b268b9c 100644
> > > > --- a/Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
> > > > +++ b/Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
> > > > @@ -16,6 +16,7 @@ properties:
> > > >          - items:
> > > >              - const: apple,t6020-nvme-ans2
> > > >              - const: apple,t8103-nvme-ans2
> > > > +      - const: apple,t8132-nvme-ans2
> > > >          - items:
> > > >              - enum:
> > > >                  # Do not add additional SoC to this list.
> > > > @@ -24,16 +25,6 @@ properties:
> > > >                  - apple,t6000-nvme-ans2
> > > >              - const: apple,nvme-ans2
> > > >    
> > > > -  reg:
> > > > -    items:
> > > > -      - description: NVMe and NVMMU registers
> > > > -      - description: ANS2 co-processor control registers
> > > > -
> > > > -  reg-names:
> > > > -    items:
> > > > -      - const: nvme
> > > > -      - const: ans
> > > > -
> > > Keep properties defined at the top level. More below.
> > >
> > > >      resets:
> > > >        maxItems: 1
> > > >    
> > > > @@ -68,25 +59,53 @@ properties:
> > > >    
> > > >          The SART address filter is documented in iommu/apple,sart.yaml.
> > > >    
> > > > -if:
> > > > -  properties:
> > > > -    compatible:
> > > > -      contains:
> > > > -        enum:
> > > > -          - apple,t6000-nvme-ans2
> > > > -          - apple,t6020-nvme-ans2
> > > > -then:
> > > > -  properties:
> > > > -    power-domains:
> > > > -      minItems: 3
> > > > -    power-domain-names:
> > > > -      minItems: 3
> > > > -else:
> > > > -  properties:
> > > > -    power-domains:
> > > > -      maxItems: 2
> > > > -    power-domain-names:
> > > > -      maxItems: 2
> > > > +allOf:
> > > > +  - if:
> > > > +      properties:
> > > > +        compatible:
> > > > +          contains:
> > > > +            const: apple,t8132-nvme-ans2
> > > > +    then:
> > > > +      properties:
> > > > +        reg:
> > > > +          items:
> > > > +            - description: NVMMU registers
> > > > +            - description: NVMe registers
> > > > +            - description: ANS2 co-processor control registers
> > > > +        reg-names:
> > > > +          items:
> > > > +            - const: nvmmu
> > > > +            - const: nvme
> > > > +            - const: ans
> > > New entries go on the end.
> > Ack
> > > So nvmmu last and defined at the top level.
> > I did read the docs which said the properties should always be
> > introduced at the top-level, however I couldn't figure out how to
> > describe the intended constraints in this way.
> > > Then this is just 'minItems: 3'
> > >
> > > > +    else:
> > > > +      properties:
> > > > +        reg:
> > > > +          items:
> > > > +            - description: NVMe and NVMMU registers
> > > > +            - description: ANS2 co-processor control registers
> > > > +        reg-names:
> > > > +          items:
> > > > +            - const: nvme
> > > > +            - const: ans
> > > And 'maxItems: 2' on these 2.
> > When the three items are defined at the top-level, I can't seem to make
> > the dtbs_check work:
> >
> > [...]
> > arch/arm64/boot/dts/apple/t8112-j413.dtb: nvme@27bcc0000
> > (apple,t8112-nvme-ans2): reg: [[2, 2076966912, 0, 262144], [2,
> > 2000683008, 0, 16384]] is too short
> >       from schema $id: http://devicetree.org/schemas/nvme/apple,nvme-ans.yaml
> > arch/arm64/boot/dts/apple/t8112-j413.dtb: nvme@27bcc0000
> > (apple,t8112-nvme-ans2): reg-names: ['nvme', 'ans'] is too short
> >       from schema $id: http://devicetree.org/schemas/nvme/apple,nvme-ans.yaml
> > [...]
> >
> > despite this compatible falling into the "... else ... maxItems: 2" branch
> >
> > Would it be acceptable to define the reg and reg-names with just
> > minItems: 2, maxItems: 3, but without specific items or descriptions,
> > and then add the compatible-specific items and descriptions in the
> > conditional part below?
> No, because you do workaround for your own introduced problem. If you
> list the entries in top level in correct order, then everything will
> work fine with Rob's answer/comment.
>
> This is your case:
> https://elixir.bootlin.com/linux/v6.11-rc6/source/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml#L39

I had them in the correct order (nvmmu last), but was missing the 
minItems: 2 in the top-level. Problem solved.

> This is not your case:
> https://elixir.bootlin.com/linux/v6.11-rc6/source/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml#L127
> Unless you provide arguments why it is.
>
> Best regards,
> Krzysztof


Thanks for the patience,

- Yureka