dt-bindings: PCI: pci-ep: Document 'linux,pci-domain' property

'linux,pci-domain' property provides the PCI domain number for the PCI
endpoint controllers in a SoC. If this property is not present, then an
unstable (across boots) unique number will be assigned.

Devicetrees can specify the domain number based on the actual hardware
instance of the PCI endpoint controllers in the SoC.

Link: https://lore.kernel.org/linux-pci/20240828-pci-qcom-hotplug-v4-4-263a385fbbcb@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/pci/pci-ep.yaml b/Documentation/devicetree/bindings/pci/pci-ep.yaml
index 0b5456ee21ebb41c5af976ccfc3ebe97723ca7b8..f75000e3093db83b2d1665b48bcfdc239d07d7ab 100644 (file)
--- a/Documentation/devicetree/bindings/pci/pci-ep.yaml
+++ b/Documentation/devicetree/bindings/pci/pci-ep.yaml
@@ -42,6 +42,17 @@ properties:
     default: 1
     maximum: 16
 
+  linux,pci-domain:
+    description:
+      If present this property assigns a fixed PCI domain number to a PCI
+      Endpoint Controller, otherwise an unstable (across boots) unique number
+      will be assigned. It is required to either not set this property at all
+      or set it for all PCI endpoint controllers in the system, otherwise
+      potentially conflicting domain numbers may be assigned to endpoint
+      controllers. The domain number for each endpoint controller in the system
+      must be unique.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
 required:
   - compatible
 

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-ep.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-ep.yaml
index 46802f7d94826d76ce9d765300c076df5e2129c8..1226ee5d08d1ae909b07b0d78014618c4c74e9a8 100644 (file)
--- a/Documentation/devicetree/bindings/pci/qcom,pcie-ep.yaml
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-ep.yaml
@@ -280,4 +280,5 @@ examples:
         phy-names = "pciephy";
         max-link-speed = <3>;
         num-lanes = <2>;
+        linux,pci-domain = <0>;
     };