dt-bindings: PCI: Add STM32MP25 PCIe Endpoint bindings

STM32MP25 PCIe Controller is based on the DesignWare core configured as
endpoint mode from the SYSCFG register.

Signed-off-by: Christian Bruel <christian.bruel@foss.st.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250820075411.1178729-6-christian.bruel@foss.st.com

Documentation/devicetree/bindings/pci/st,stm32-pcie-ep.yaml

@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/st,stm32-pcie-ep.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics STM32MP25 PCIe Endpoint
+
+maintainers:
+  - Christian Bruel <christian.bruel@foss.st.com>
+
+description:
+  PCIe endpoint controller based on the Synopsys DesignWare PCIe core.
+
+allOf:
+  - $ref: /schemas/pci/snps,dw-pcie-ep.yaml#
+  - $ref: /schemas/pci/st,stm32-pcie-common.yaml#
+
+properties:
+  compatible:
+    const: st,stm32mp25-pcie-ep
+
+  reg:
+    items:
+      - description: Data Bus Interface (DBI) registers.
+      - description: Data Bus Interface (DBI) shadow registers.
+      - description: Internal Address Translation Unit (iATU) registers.
+      - description: PCIe configuration registers.
+
+  reg-names:
+    items:
+      - const: dbi
+      - const: dbi2
+      - const: atu
+      - const: addr_space
+
+  reset-gpios:
+    description: GPIO controlled connection to PERST# signal
+    maxItems: 1
+
+  phys:
+    maxItems: 1
+
+required:
+  - phys
+  - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/st,stm32mp25-rcc.h>
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/phy/phy.h>
+    #include <dt-bindings/reset/st,stm32mp25-rcc.h>
+
+    pcie-ep@48400000 {
+        compatible = "st,stm32mp25-pcie-ep";
+        reg = <0x48400000 0x400000>,
+              <0x48500000 0x100000>,
+              <0x48700000 0x80000>,
+              <0x10000000 0x10000000>;
+        reg-names = "dbi", "dbi2", "atu", "addr_space";
+        clocks = <&rcc CK_BUS_PCIE>;
+        phys = <&combophy PHY_TYPE_PCIE>;
+        resets = <&rcc PCIE_R>;
+        pinctrl-names = "default", "init";
+        pinctrl-0 = <&pcie_pins_a>;
+        pinctrl-1 = <&pcie_init_pins_a>;
+        reset-gpios = <&gpioj 8 GPIO_ACTIVE_LOW>;
+        access-controllers = <&rifsc 68>;
+        power-domains = <&CLUSTER_PD>;
+    };