On Wed, Aug 20, 2025 at 10:23:28AM +0800, 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. > > When the 3.3V auxiliary power is present, fetch this auxiliary regulator > at probe time and keep it enabled for the entire PCIe controller > lifecycle. This ensures support for outbound wake-up mechanism such as > WAKE# signaling. > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> Reviewed-by: Frank Li <Frank.Li@xxxxxxx> > --- > v5 changes: > - Use the vpcie3v3aux property instead of adding a duplicated one. > - Move the comments from the code changes into the description of > commit. > > v4 changes: > Move the dt-binding to snps,dw-pcie-common.yaml. > > v3 changes: > Add a new vaux power supply used to specify the regulator powered up the > WAKE# circuit on the connector when WAKE# is supported. > > v2 changes: > Update the commit message, and add reviewed-by from Frank. > https://patchwork.kernel.org/project/linux-pci/patch/20250619072438.125921-1-hongxing.zhu@xxxxxxx/ > --- > drivers/pci/controller/dwc/pci-imx6.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 5a38cfaf989b1..5067da14bc053 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -1739,6 +1739,10 @@ static int imx_pcie_probe(struct platform_device *pdev) > pci->max_link_speed = 1; > of_property_read_u32(node, "fsl,max-link-speed", &pci->max_link_speed); > > + ret = devm_regulator_get_enable_optional(&pdev->dev, "vpcie3v3aux"); > + if (ret < 0 && ret != -ENODEV) > + return dev_err_probe(dev, ret, "failed to enable pcie3v3vaux"); > + > imx_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie"); > if (IS_ERR(imx_pcie->vpcie)) { > if (PTR_ERR(imx_pcie->vpcie) != -ENODEV) > -- > 2.37.1 >
