Re: [PATCH v2 1/3] dt-bindings: PCI: qcom: Move phy, wake & reset gpio's to root port

[Manivannan Sadhasivam]

On Mon, Apr 14, 2025 at 02:50:19PM +0200, Caleb Connolly wrote:
> 
> 
> On 4/14/25 10:04, Dmitry Baryshkov wrote:
> > On Mon, Apr 14, 2025 at 11:09:12AM +0530, Krishna Chaitanya Chundru wrote:
> > > Move the phy, phy-names, wake-gpio's to the pcie root port node instead of
> > > the bridge node, as agreed upon in multiple places one instance is[1].
> > > 
> > > Update the qcom,pcie-common.yaml to include the phy, phy-names, and
> > > wake-gpios properties in the root port node. There is already reset-gpio
> > > defined for PERST# in pci-bus-common.yaml, start using that property
> > > instead of perst-gpio.
> > > 
> > > For backward compatibility, do not remove any existing properties in the
> > > bridge node.
> > > 
> > > [1] https://lore.kernel.org/linux-pci/20241211192014.GA3302752@bhelgaas/
> > > 
> > > Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
> > > ---
> > >   .../devicetree/bindings/pci/qcom,pcie-common.yaml      | 18 ++++++++++++++++++
> > >   .../devicetree/bindings/pci/qcom,pcie-sc7280.yaml      | 17 +++++++++++++----
> > >   2 files changed, 31 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-common.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-common.yaml
> > > index 0480c58f7d998adbac4c6de20cdaec945b3bab21..16e9acba1559b457da8a8a9dda4a22b226808f86 100644
> > > --- a/Documentation/devicetree/bindings/pci/qcom,pcie-common.yaml
> > > +++ b/Documentation/devicetree/bindings/pci/qcom,pcie-common.yaml
> > > @@ -85,6 +85,24 @@ properties:
> > >     opp-table:
> > >       type: object
> > > +patternProperties:
> > > +  "^pcie@":
> > > +    type: object
> > > +    $ref: /schemas/pci/pci-pci-bridge.yaml#
> > > +
> > > +    properties:
> > > +      reg:
> > > +        maxItems: 1
> > > +
> > > +      phys:
> > > +        maxItems: 1
> > > +
> > > +      wake-gpios:
> > > +        description: GPIO controlled connection to WAKE# signal
> > > +        maxItems: 1
> > > +
> > > +    unevaluatedProperties: false
> > 
> > Please mark old properties as deprecated.
> 
> Since this is a trivial change, just moving two properties, I don't see why
> it makes sense to deprecate -- just remove the old properties, and move over
> all the platforms at once.
> 

This will be an ABI break. You should not remove properties all of a sudden
without first deprecating them (even if you convert all upstream DTS at once).
ABI is for older DTS also.

- Mani

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