Re: [PATCH] dt-bindings: PCI: qcom: Fix register maps items and add 3.3V supply

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Tue, Jun 04, 2024 at 05:58:06PM -0600, Rob Herring wrote:
> On Tue, Jun 04, 2024 at 07:05:12PM +0300, Abel Vesa wrote:
> > All PCIe controllers found on X1E80100 have MHI register region and
> > VDDPE supplies. Add them to the schema as well.
> > 
> > Fixes: 692eadd51698 ("dt-bindings: PCI: qcom: Document the X1E80100 PCIe Controller")
> > Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> > ---
> > This patchset fixes the following warning:
> > https://lore.kernel.org/all/171751454535.785265.18156799252281879515.robh@kernel.org/
> > 
> > Also fixes a MHI reg region warning that will be triggered by the following patch:
> > https://lore.kernel.org/all/20240604-x1e80100-dts-fixes-pcie6a-v2-1-0b4d8c6256e5@linaro.org/
> > ---
> >  Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml
> > index 1074310a8e7a..7ceba32c4cf9 100644
> > --- a/Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml
> > +++ b/Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml
> > @@ -19,11 +19,10 @@ properties:
> >      const: qcom,pcie-x1e80100
> >  
> >    reg:
> > -    minItems: 5
> > +    minItems: 6
> >      maxItems: 6
> >  
> >    reg-names:
> > -    minItems: 5
> >      items:
> >        - const: parf # Qualcomm specific registers
> >        - const: dbi # DesignWare PCIe registers
> > @@ -71,6 +70,9 @@ properties:
> >        - const: pci # PCIe core reset
> >        - const: link_down # PCIe link down reset
> >  
> > +  vddpe-3v3-supply:
> > +    description: A phandle to the PCIe endpoint power supply
> 
> TBC, this is a rail on the host side provided to a card? If so, we have 
> standard properties for standard PCI voltage rails.

There is a 'vpcie3v3-supply' property and it should satisfy the requirement. But
'vddpe-3v3-supply' is already used on multiple Qcom SoCs. So changing the name
in dts warrants the driver to support both supplies for backwards compatibility,
but that should be fine.

> It is also preferred that you put them in a root port node rather than the
> host bridge.

Even though the resource split between root port and host bridge is not clear in
Qcom SoCs, I think from logical stand point it makes sense.

- Mani

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