Enable the vaux 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>
---
drivers/pci/controller/dwc/pci-imx6.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 5a38cfaf989b1..1c1dce2d87e44 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -159,6 +159,7 @@ struct imx_pcie {
u32 tx_deemph_gen2_6db;
u32 tx_swing_full;
u32 tx_swing_low;
+ struct regulator *vaux;
struct regulator *vpcie;
struct regulator *vph;
void __iomem *phy_base;
@@ -1739,6 +1740,20 @@ 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);
+ /*
+ * 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, get the vaux and keep it
+ * enabled to power up WAKE# circuit for the entire PCIe controller
+ * lifecycle when WAKE# is supported.
+ */
+ ret = devm_regulator_get_enable_optional(&pdev->dev, "vaux");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "failed to enable vaux");
+
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
