dt-bindings: PCI: qcom,pcie-sa8255p: Document ECAM compliant PCIe root complex

Document the required configuration to enable the PCIe Root Complex on
SA8255p, which is managed by firmware using power-domain based handling
and configured as ECAM compliant.

Signed-off-by: Mayank Rana <mayank.rana@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: add "ECAM" in reg description]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250616224259.3549811-4-mayank.rana@oss.qualcomm.com

1 files changed, 122 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8255p.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8255p.yaml
new file mode 100644
index 000000000000..ef705a02fcd9
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8255p.yaml
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/qcom,pcie-sa8255p.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm SA8255p based firmware managed and ECAM compliant PCIe Root Complex
+
+maintainers:
+  - Bjorn Andersson <andersson@kernel.org>
+  - Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+description:
+  Qualcomm SA8255p SoC PCIe root complex controller is based on the Synopsys
+  DesignWare PCIe IP which is managed by firmware, and configured in ECAM mode.
+
+properties:
+  compatible:
+    const: qcom,pcie-sa8255p
+
+  reg:
+    description:
+      The base address and size of the ECAM area for accessing PCI
+      Configuration Space, as accessed from the parent bus. The base
+      address corresponds to the first bus in the "bus-range" property. If
+      no "bus-range" is specified, this will be bus 0 (the default).
+    maxItems: 1
+
+  ranges:
+    description:
+      As described in IEEE Std 1275-1994, but must provide at least a
+      definition of non-prefetchable memory. One or both of prefetchable Memory
+      may also be provided.
+    minItems: 1
+    maxItems: 2
+
+  interrupts:
+    minItems: 8
+    maxItems: 8
+
+  interrupt-names:
+    items:
+      - const: msi0
+      - const: msi1
+      - const: msi2
+      - const: msi3
+      - const: msi4
+      - const: msi5
+      - const: msi6
+      - const: msi7
+
+  power-domains:
+    maxItems: 1
+
+  dma-coherent: true
+  iommu-map: true
+
+required:
+  - compatible
+  - reg
+  - ranges
+  - power-domains
+  - interrupts
+  - interrupt-names
+
+allOf:
+  - $ref: /schemas/pci/pci-host-bridge.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        pci@1c00000 {
+           compatible = "qcom,pcie-sa8255p";
+           reg = <0x4 0x00000000 0 0x10000000>;
+           device_type = "pci";
+           #address-cells = <3>;
+           #size-cells = <2>;
+           ranges = <0x02000000 0x0 0x40100000 0x0 0x40100000 0x0 0x1ff00000>,
+                    <0x43000000 0x4 0x10100000 0x4 0x10100000 0x0 0x40000000>;
+           bus-range = <0x00 0xff>;
+           dma-coherent;
+           linux,pci-domain = <0>;
+           power-domains = <&scmi5_pd 0>;
+           iommu-map = <0x0 &pcie_smmu 0x0000 0x1>,
+                       <0x100 &pcie_smmu 0x0001 0x1>;
+           interrupt-parent = <&intc>;
+           interrupts = <GIC_SPI 307 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 308 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 309 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 312 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 313 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 314 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 374 IRQ_TYPE_LEVEL_HIGH>,
+                        <GIC_SPI 375 IRQ_TYPE_LEVEL_HIGH>;
+           interrupt-names = "msi0", "msi1", "msi2", "msi3",
+                                  "msi4", "msi5", "msi6", "msi7";
+
+           #interrupt-cells = <1>;
+           interrupt-map-mask = <0 0 0 0x7>;
+           interrupt-map = <0 0 0 1 &intc GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
+                           <0 0 0 2 &intc GIC_SPI 149 IRQ_TYPE_LEVEL_HIGH>,
+                           <0 0 0 3 &intc GIC_SPI 150 IRQ_TYPE_LEVEL_HIGH>,
+                           <0 0 0 4 &intc GIC_SPI 151 IRQ_TYPE_LEVEL_HIGH>;
+
+           pcie@0 {
+                   device_type = "pci";
+                   reg = <0x0 0x0 0x0 0x0 0x0>;
+                   bus-range = <0x01 0xff>;
+
+                   #address-cells = <3>;
+                   #size-cells = <2>;
+                   ranges;
+            };
+        };
+    };