dt-bindings: PCI: Add binding for Toshiba TC9563 PCIe switch

Add a device tree binding for the Toshiba TC9563 PCIe switch, which
provides an Ethernet MAC integrated to the 3rd downstream port and
two downstream PCIe ports.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251101-tc9563-v9-1-de3429f7787a@oss.qualcomm.com

Author: krishnachaitanya-linux

Documentation/devicetree/bindings/pci/toshiba,tc9563.yaml

@@ -0,0 +1,179 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/toshiba,tc9563.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Toshiba TC9563 PCIe switch
+
+maintainers:
+  - Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
+
+description: |
+  Toshiba TC9563 PCIe switch has one upstream and three downstream ports.
+  The 3rd downstream port has integrated endpoint device of Ethernet MAC.
+  Other two downstream ports are supposed to connect to external device.
+
+  The TC9563 PCIe switch can be configured through I2C interface before
+  PCIe link is established to change FTS, ASPM related entry delays,
+  tx amplitude etc for better power efficiency and functionality.
+
+properties:
+  compatible:
+    enum:
+      - pci1179,0623
+
+  reg:
+    maxItems: 1
+
+  resx-gpios:
+    maxItems: 1
+    description:
+      GPIO controlling the RESX# pin.
+
+  vdd18-supply: true
+
+  vdd09-supply: true
+
+  vddc-supply: true
+
+  vddio1-supply: true
+
+  vddio2-supply: true
+
+  vddio18-supply: true
+
+  i2c-parent:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description:
+      A phandle to the parent I2C node and the slave address of the device
+      used to configure tc9563 to change FTS, tx amplitude etc.
+    items:
+      - description: Phandle to the I2C controller node
+      - description: I2C slave address
+
+patternProperties:
+  "^pcie@[1-3],0$":
+    description:
+      child nodes describing the internal downstream ports of
+      the tc9563 switch.
+    type: object
+    allOf:
+      - $ref: "#/$defs/tc9563-node"
+      - $ref: /schemas/pci/pci-pci-bridge.yaml#
+    unevaluatedProperties: false
+
+$defs:
+  tc9563-node:
+    type: object
+
+    properties:
+      toshiba,tx-amplitude-microvolt:
+        description:
+          Change Tx Margin setting for low power consumption.
+
+      toshiba,no-dfe-support:
+        type: boolean
+        description:
+          Disable DFE (Decision Feedback Equalizer), which mitigates
+          intersymbol interference and some reflections caused by
+          impedance mismatches.
+
+required:
+  - resx-gpios
+  - vdd18-supply
+  - vdd09-supply
+  - vddc-supply
+  - vddio1-supply
+  - vddio2-supply
+  - vddio18-supply
+  - i2c-parent
+
+allOf:
+  - $ref: "#/$defs/tc9563-node"
+  - $ref: /schemas/pci/pci-bus-common.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    pcie {
+        #address-cells = <3>;
+        #size-cells = <2>;
+
+        pcie@0 {
+            device_type = "pci";
+            reg = <0x0 0x0 0x0 0x0 0x0>;
+
+            #address-cells = <3>;
+            #size-cells = <2>;
+            ranges;
+            bus-range = <0x01 0xff>;
+
+            pcie@0,0 {
+                compatible = "pci1179,0623";
+
+                reg = <0x10000 0x0 0x0 0x0 0x0>;
+                device_type = "pci";
+                #address-cells = <3>;
+                #size-cells = <2>;
+                ranges;
+                bus-range = <0x02 0xff>;
+
+                i2c-parent = <&qup_i2c 0x77>;
+
+                vdd18-supply = <&vdd>;
+                vdd09-supply = <&vdd>;
+                vddc-supply = <&vdd>;
+                vddio1-supply = <&vdd>;
+                vddio2-supply = <&vdd>;
+                vddio18-supply = <&vdd>;
+
+                resx-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+
+                pcie@1,0 {
+                    compatible = "pciclass,0604";
+                    reg = <0x20800 0x0 0x0 0x0 0x0>;
+                    #address-cells = <3>;
+                    #size-cells = <2>;
+                    device_type = "pci";
+                    ranges;
+                    bus-range = <0x03 0xff>;
+
+                    toshiba,no-dfe-support;
+                };
+
+                pcie@2,0 {
+                    compatible = "pciclass,0604";
+                    reg = <0x21000 0x0 0x0 0x0 0x0>;
+                    #address-cells = <3>;
+                    #size-cells = <2>;
+                    device_type = "pci";
+                    ranges;
+                    bus-range = <0x04 0xff>;
+                };
+
+                pcie@3,0 {
+                    compatible = "pciclass,0604";
+                    reg = <0x21800 0x0 0x0 0x0 0x0>;
+                    #address-cells = <3>;
+                    #size-cells = <2>;
+                    device_type = "pci";
+                    ranges;
+                    bus-range = <0x05 0xff>;
+
+                    toshiba,tx-amplitude-microvolt = <10>;
+
+                    ethernet@0,0 {
+                        reg = <0x50000 0x0 0x0 0x0 0x0>;
+                    };
+
+                    ethernet@0,1 {
+                        reg = <0x50100 0x0 0x0 0x0 0x0>;
+                    };
+                };
+            };
+        };
+    };