dt-bindings: pci: Add Sophgo SG2044 PCIe host

The PCIe controller on the SG2044 is Designware based with custom app
registers.

Add binding document for SG2044 PCIe host controller.

Signed-off-by: Inochi Amaoto <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Reviewed-by: Rob Herring (Arm) <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: inochisa

Documentation/devicetree/bindings/pci/sophgo,sg2044-pcie.yaml

@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/sophgo,sg2044-pcie.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: DesignWare based PCIe Root Complex controller on Sophgo SoCs
+
+maintainers:
+  - Inochi Amaoto <[email protected]>
+
+description:
+  SG2044 SoC PCIe Root Complex controller is based on the Synopsys DesignWare
+  PCIe IP and thus inherits all the common properties defined in
+  snps,dw-pcie.yaml.
+
+allOf:
+  - $ref: /schemas/pci/pci-host-bridge.yaml#
+  - $ref: /schemas/pci/snps,dw-pcie.yaml#
+
+properties:
+  compatible:
+    const: sophgo,sg2044-pcie
+
+  reg:
+    items:
+      - description: Data Bus Interface (DBI) registers
+      - description: iATU registers
+      - description: Config registers
+      - description: Sophgo designed configuration registers
+
+  reg-names:
+    items:
+      - const: dbi
+      - const: atu
+      - const: config
+      - const: app
+
+  clocks:
+    items:
+      - description: core clk
+
+  clock-names:
+    items:
+      - const: core
+
+  interrupt-controller:
+    description: Interrupt controller node for handling legacy PCI interrupts.
+    type: object
+
+    properties:
+      "#address-cells":
+        const: 0
+
+      "#interrupt-cells":
+        const: 1
+
+      interrupt-controller: true
+
+      interrupts:
+        items:
+          - description: combined legacy interrupt
+
+    required:
+      - "#address-cells"
+      - "#interrupt-cells"
+      - interrupt-controller
+      - interrupts
+
+    additionalProperties: false
+
+  msi-parent: true
+
+  ranges:
+    maxItems: 5
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      pcie@6c00400000 {
+        compatible = "sophgo,sg2044-pcie";
+        reg = <0x6c 0x00400000 0x0 0x00001000>,
+              <0x6c 0x00700000 0x0 0x00004000>,
+              <0x40 0x00000000 0x0 0x00001000>,
+              <0x6c 0x00780c00 0x0 0x00000400>;
+        reg-names = "dbi", "atu", "config", "app";
+        #address-cells = <3>;
+        #size-cells = <2>;
+        bus-range = <0x00 0xff>;
+        clocks = <&clk 0>;
+        clock-names = "core";
+        device_type = "pci";
+        linux,pci-domain = <0>;
+        msi-parent = <&msi>;
+        ranges = <0x01000000 0x0  0x00000000  0x40 0x10000000  0x0 0x00200000>,
+                 <0x42000000 0x0  0x00000000  0x0  0x00000000  0x0 0x04000000>,
+                 <0x02000000 0x0  0x04000000  0x0  0x04000000  0x0 0x04000000>,
+                 <0x43000000 0x42 0x00000000  0x42 0x00000000  0x2 0x00000000>,
+                 <0x03000000 0x41 0x00000000  0x41 0x00000000  0x1 0x00000000>;
+
+        interrupt-controller {
+          #address-cells = <0>;
+          #interrupt-cells = <1>;
+          interrupt-controller;
+          interrupt-parent = <&intc>;
+          interrupts = <64 IRQ_TYPE_LEVEL_HIGH>;
+        };
+      };
+    };
+...