Re: [PATCH 1/2] dt-bindings: PCI: qcom: Add SC8280XP/SA8540P interconnects

[Johan Hovold <johan@kernel.org>]

On Thu, Oct 20, 2022 at 08:29:02AM -0400, Krzysztof Kozlowski wrote:
> On 20/10/2022 03:57, Johan Hovold wrote:
> > On Wed, Oct 19, 2022 at 10:37:31AM -0400, Krzysztof Kozlowski wrote:
> >> On 17/10/2022 07:24, Johan Hovold wrote:
> >>> Add the missing SC8280XP/SA8540P "pcie-mem" and "cpu-pcie" interconnect
> >>> paths to the bindings.
> >>>
> >>> Fixes: 76d777ae045e ("dt-bindings: PCI: qcom: Add SC8280XP to binding")
> >>> Fixes: 76c4207f4085 ("dt-bindings: PCI: qcom: Add SA8540P to binding")
> >>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> >>> ---
> >>>  .../devicetree/bindings/pci/qcom,pcie.yaml    | 25 +++++++++++++++++++
> >>>  1 file changed, 25 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> >>> index 22a2aac4c23f..a55434f95edd 100644
> >>> --- a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> >>> +++ b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml

> > Are you suggesting something like moving the names to the common
> > constraints for now:
> > 
> >   interconnects:
> >     maxItems: 2
> > 
> >   interconnect-names:
> >     items:
> >       - const: pcie-mem
> >       - const: cpu-pcie
> > 
> > and then in the allOf:
> > 
> >   - if:
> >       properties:
> >         compatible:
> >           contains:
> >             enum:
> >               - qcom,pcie-sa8540p
> >               - qcom,pcie-sc8280xp
> >     then:
> >       required:
> >         - interconnects
> >         - interconnect-names
> >     else:
> >       properties:
> >         interconnects: false
> >         interconnect-names: false
> > 
> > This way we'd catch anyone adding interconnects to a DTS without first
> > updating the bindings, but it also seems to go against the idea of
> > bindings fully describing the hardware by saying that no other platforms
> > have interconnects (when they actually do even if we don't describe it
> > just yet).
> 
> You can add a comment to the else like "TODO: Not described yet". I
> would prefer to have specific but incomplete bindings, instead of loose
> one which later might cause people adding whatever names they like.
> 
> > Or should we do the above but without the else clause to have some
> > constraints in place on the names at least?
> 
> This would work as well if you think the names are applicable for other
> devices.

I think that's a reasonable assumption so I'll go with this alternative.

Thanks!

Johan