dt-bindings: net: lan966x: Add lan966x-switch bindings

Document the lan966x switch device driver bindings
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/microchip,lan966x-switch.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/microchip,lan966x-switch.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip Lan966x Ethernet switch controller
+
+maintainers:
+  - Horatiu Vultur <horatiu.vultur@microchip.com>
+
+description: |
+  The lan966x switch is a multi-port Gigabit AVB/TSN Ethernet Switch with
+  two integrated 10/100/1000Base-T PHYs. In addition to the integrated PHYs,
+  it supports up to 2RGMII/RMII, up to 3BASE-X/SERDES/2.5GBASE-X and up to
+  2 Quad-SGMII/Quad-USGMII interfaces.
+
+properties:
+  $nodename:
+    pattern: "^switch@[0-9a-f]+$"
+
+  compatible:
+    const: microchip,lan966x-switch
+
+  reg:
+    items:
+      - description: cpu target
+      - description: general control block target
+
+  reg-names:
+    items:
+      - const: cpu
+      - const: gcb
+
+  interrupts:
+    minItems: 1
+    items:
+      - description: register based extraction
+      - description: frame dma based extraction
+
+  interrupt-names:
+    minItems: 1
+    items:
+      - const: xtr
+      - const: fdma
+
+  resets:
+    items:
+      - description: Reset controller used for switch core reset (soft reset)
+      - description: Reset controller used for releasing the phy from reset
+
+  reset-names:
+    items:
+      - const: switch
+      - const: phy
+
+  ethernet-ports:
+    type: object
+    patternProperties:
+      "^port@[0-9a-f]+$":
+        type: object
+
+        allOf:
+          - $ref: "http://devicetree.org/schemas/net/ethernet-controller.yaml#"
+
+        properties:
+          '#address-cells':
+            const: 1
+          '#size-cells':
+            const: 0
+
+          reg:
+            description:
+              Switch port number
+
+          phys:
+            description:
+              Phandle of a Ethernet SerDes PHY
+
+          phy-mode:
+            description:
+              This specifies the interface used by the Ethernet SerDes towards
+              the PHY or SFP.
+            enum:
+              - gmii
+              - sgmii
+              - qsgmii
+              - 1000base-x
+              - 2500base-x
+
+          phy-handle:
+            description:
+              Phandle of a Ethernet PHY.
+
+          sfp:
+            description:
+              Phandle of an SFP.
+
+          managed: true
+
+        required:
+          - reg
+          - phys
+          - phy-mode
+
+        oneOf:
+          - required:
+              - phy-handle
+          - required:
+              - sfp
+              - managed
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - interrupt-names
+  - resets
+  - reset-names
+  - ethernet-ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    switch: switch@e0000000 {
+      compatible = "microchip,lan966x-switch";
+      reg =  <0xe0000000 0x0100000>,
+             <0xe2000000 0x0800000>;
+      reg-names = "cpu", "gcb";
+      interrupts = <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
+      interrupt-names = "xtr";
+      resets = <&switch_reset 0>, <&phy_reset 0>;
+      reset-names = "switch", "phy";
+      ethernet-ports {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        port0: port@0 {
+          reg = <0>;
+          phy-handle = <&phy0>;
+          phys = <&serdes 0 0>;
+          phy-mode = "gmii";
+        };
+
+        port1: port@1 {
+          reg = <1>;
+          sfp = <&sfp_eth1>;
+          managed = "in-band-status";
+          phys = <&serdes 2 4>;
+          phy-mode = "sgmii";
+        };
+      };
+    };
+
+...