dt-bindings: PCI: renesas: Add R-Car Gen4 PCIe Endpoint

Document bindings for Renesas R-Car Gen4 and R-Car S4-8 (R8A779F0)
PCIe endpoint module.

Link: https://lore.kernel.org/linux-pci/20231018085631.1121289-12-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>

Documentation/devicetree/bindings/pci/rcar-gen4-pci-ep.yaml

@@ -0,0 +1,115 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2022-2023 Renesas Electronics Corp.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/rcar-gen4-pci-ep.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car Gen4 PCIe Endpoint
+
+maintainers:
+  - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
+
+allOf:
+  - $ref: snps,dw-pcie-ep.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: renesas,r8a779f0-pcie-ep   # R-Car S4-8
+      - const: renesas,rcar-gen4-pcie-ep  # R-Car Gen4
+
+  reg:
+    maxItems: 7
+
+  reg-names:
+    items:
+      - const: dbi
+      - const: dbi2
+      - const: atu
+      - const: dma
+      - const: app
+      - const: phy
+      - const: addr_space
+
+  interrupts:
+    maxItems: 3
+
+  interrupt-names:
+    items:
+      - const: dma
+      - const: sft_ce
+      - const: app
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: core
+      - const: ref
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: pwr
+
+  max-link-speed:
+    maximum: 4
+
+  num-lanes:
+    maximum: 4
+
+  max-functions:
+    maximum: 2
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+  - power-domains
+  - resets
+  - reset-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r8a779f0-cpg-mssr.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/power/r8a779f0-sysc.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        pcie0_ep: pcie-ep@e65d0000 {
+            compatible = "renesas,r8a779f0-pcie-ep", "renesas,rcar-gen4-pcie-ep";
+            reg = <0 0xe65d0000 0 0x2000>, <0 0xe65d2000 0 0x1000>,
+                  <0 0xe65d3000 0 0x2000>, <0 0xe65d5000 0 0x1200>,
+                  <0 0xe65d6200 0 0x0e00>, <0 0xe65d7000 0 0x0400>,
+                  <0 0xfe000000 0 0x400000>;
+            reg-names = "dbi", "dbi2", "atu", "dma", "app", "phy", "addr_space";
+            interrupts = <GIC_SPI 417 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 418 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 422 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "dma", "sft_ce", "app";
+            clocks = <&cpg CPG_MOD 624>, <&pcie0_clkref>;
+            clock-names = "core", "ref";
+            power-domains = <&sysc R8A779F0_PD_ALWAYS_ON>;
+            resets = <&cpg 624>;
+            reset-names = "pwr";
+            max-link-speed = <4>;
+            num-lanes = <2>;
+            max-functions = /bits/ 8 <2>;
+        };
+    };