> -----Original Message----- > From: Francesco Dolcini <francesco@xxxxxxxxxx> > Sent: Monday, April 7, 2025 3:23 PM > To: Sherry Sun <sherry.sun@xxxxxxx> > Cc: Francesco Dolcini <francesco@xxxxxxxxxx>; Hongxing Zhu > <hongxing.zhu@xxxxxxx>; l.stach@xxxxxxxxxxxxxx; lpieralisi@xxxxxxxxxx; > kw@xxxxxxxxx; robh@xxxxxxxxxx; bhelgaas@xxxxxxxxxx; > krzysztof.kozlowski+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; > shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; > festevam@xxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; linux- > pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH V2 2/4] dt-bindings: imx6q-pcie: Add wake-gpios property > > On Mon, Apr 07, 2025 at 07:18:32AM +0000, Sherry Sun wrote: > > > > > > > -----Original Message----- > > > From: Francesco Dolcini <francesco@xxxxxxxxxx> > > > Sent: Friday, April 4, 2025 5:42 PM > > > To: Sherry Sun <sherry.sun@xxxxxxx> > > > Cc: Hongxing Zhu <hongxing.zhu@xxxxxxx>; l.stach@xxxxxxxxxxxxxx; > > > lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; robh@xxxxxxxxxx; > > > bhelgaas@xxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; > > > conor+dt@xxxxxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; > > > kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; dl-linux-imx <linux- > > > imx@xxxxxxx>; linux-pci@xxxxxxxxxxxxxxx; linux-arm- > > > kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > > > kernel@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH V2 2/4] dt-bindings: imx6q-pcie: Add wake-gpios > > > property > > > > > > Hello > > > > > > On Wed, Dec 13, 2023 at 05:28:48PM +0800, Sherry Sun wrote: > > > > Add wake-gpios property that can be used to wakeup the host processor. > > > > > > > > Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> > > > > Reviewed-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > > > --- > > > > Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml | 6 > > > > ++++++ > > > > 1 file changed, 6 insertions(+) > > > > > > > > diff --git > > > > a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml > > > > b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml > > > > index 81bbb8728f0f..fba757d937e1 100644 > > > > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml > > > > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.yaml > > > > @@ -72,6 +72,12 @@ properties: > > > > L=operation state) (optional required). > > > > type: boolean > > > > > > > > + wake-gpios: > > > > + description: If present this property specifies WAKE# sideband > signaling > > > > + to implement wakeup functionality. This is an input GPIO > > > > + pin for the > > > Root > > > > + Port mode here. Host drivers will wakeup the host using the IRQ > > > > + corresponding to the passed GPIO. > > > > + > > > > > > From what I know it is possible to share the same WAKE# signal for > > > multiple root ports. Is this going to work fine with this binding? > > > Same question on the driver. > > > > > > We do have design exactly like that, so it's not a theoretical question. > > > > > The current design doesn't support such case, maybe some changes in > > the driver could achieve that (mark the wake-gpio as > > GPIOD_FLAGS_BIT_NONEXCLUSIVE and the interrupt as IRQF_SHARED, > etc.). > > Can you consider implementing this? > > > But usually each RC has its own WAKE# pin assigned. We have not come > > across a case where multiple RC share the same WAKE# pin. > > We do have such design, with an NXP iMX95 SoC, available now. > Hi Francesco, Now the patch set is pending, please check the comment under https://patchwork.kernel.org/project/linux-pci/cover/20231213092850.1706042-1-sherry.sun@xxxxxxx/ . Seems this property should be put into the common PCI root port schema, now it relies on the pci-bus.yaml splitting job Rob is doing. Best Regards Sherry
