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

[Richard Zhu]

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@xxxxxxx>
---
 .../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.
+
 additionalProperties: true
 
 ...
-- 
2.37.1