[PATCH v4 1/2] dt-bindings: PCI: dwc: Add vaux regulator

[Hongxing Zhu]

> -----Original Message-----
> From: Manivannan Sadhasivam <mani at kernel.org>
> Sent: 2025年8月19日 16:46
> To: Hongxing Zhu <hongxing.zhu at nxp.com>
> Cc: Frank Li <frank.li at nxp.com>; l.stach at pengutronix.de;
> lpieralisi at kernel.org; kwilczynski at kernel.org; robh at kernel.org;
> krzk+dt at kernel.org; conor+dt at kernel.org; bhelgaas at google.com;
> shawnguo at kernel.org; s.hauer at pengutronix.de; kernel at pengutronix.de;
> festevam at gmail.com; linux-pci at vger.kernel.org;
> linux-arm-kernel at lists.infradead.org; devicetree at vger.kernel.org;
> imx at lists.linux.dev; linux-kernel at vger.kernel.org
> Subject: Re: [PATCH v4 1/2] dt-bindings: PCI: dwc: Add vaux regulator
> 
> On Tue, Aug 19, 2025 at 03:16:29PM GMT, Richard Zhu wrote:
> > Refer to PCIe CEM r6.0, sec 2.3 WAKE# Signal, WAKE# signal is only
> > asserted by the Add-in Card when all its functions are in D3Cold state
> > and at least one of its functions is enabled for wakeup generation.
> >
> > The 3.3V auxiliary power (+3.3Vaux) must be present and used for
> > wakeup process. Since the main power supply would be gated off to let
> > Add-in Card to be in D3Cold, add the vaux and keep it enabled to power
> > up WAKE# circuit for the entire PCIe controller lifecycle when WAKE# is
> supported.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> > ---
> >  .../devicetree/bindings/pci/snps,dw-pcie-common.yaml        | 6
> ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> > b/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> > index 34594972d8dbe..5283f51388584 100644
> > --- a/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> > +++ b/Documentation/devicetree/bindings/pci/snps,dw-pcie-common.yaml
> > @@ -262,6 +262,12 @@ properties:
> >
> >    dma-coherent: true
> >
> > +  vaux-supply:
> > +    description: Should specify the regulator in charge of power source
> > +      of the WAKE# generation on the PCIe connector. When the WAKE#
> is
> > +      enabled, this regualor would be always on and used to power up
> > +      WAKE# circuit.
> 
> 3.3Vaux supply is already documented in the dtschema:
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Fdevicetree-org%2Fdt-schema%2Fblob%2Fmain%2Fdtschema%2Fsche
> mas%2Fpci%2Fpci-bus-common.yaml%23L179&data=05%7C02%7Chongxing.z
> hu%40nxp.com%7C010fb118c1384dfa2b1a08dddefcd0ff%7C686ea1d3bc2b4c
> 6fa92cd99c5c301635%7C0%7C0%7C638911899600090830%7CUnknown%7CT
> WFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXa
> W4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=%2Bh
> CgrwfHFGY2D5%2B8dS4XRl4hoQWG0JpUmG5BZhRyW%2B8%3D&reserved=0
> 
> So you should use that instead.
Okay, got that, thanks.

Best Regards
Richard Zhu
> 
> - Mani
> 
> --
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