dt-bindings: net: pse-pd: Add bindings for Si3474 PSE controller

Add the Si3474 I2C Power Sourcing Equipment controller device tree
bindings documentation.

Signed-off-by: Piotr Kubik <piotr.kubik@adtran.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/71a67c6f-6fce-49c7-96ec-554602dbd4f1@adtran.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Documentation/devicetree/bindings/net/pse-pd/skyworks,si3474.yaml

@@ -0,0 +1,144 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/pse-pd/skyworks,si3474.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Skyworks Si3474 Power Sourcing Equipment controller
+
+maintainers:
+  - Piotr Kubik <piotr.kubik@adtran.com>
+
+allOf:
+  - $ref: pse-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - skyworks,si3474
+
+  reg:
+    maxItems: 2
+
+  reg-names:
+    items:
+      - const: main
+      - const: secondary
+
+  channels:
+    description: The Si3474 is a single-chip PoE PSE controller managing
+      8 physical power delivery channels. Internally, it's structured
+      into two logical "Quads".
+      Quad 0 Manages physical channels ('ports' in datasheet) 0, 1, 2, 3
+      Quad 1 Manages physical channels ('ports' in datasheet) 4, 5, 6, 7.
+
+    type: object
+    additionalProperties: false
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+    patternProperties:
+      '^channel@[0-7]$':
+        type: object
+        additionalProperties: false
+
+        properties:
+          reg:
+            maxItems: 1
+
+        required:
+          - reg
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+
+required:
+  - compatible
+  - reg
+  - pse-pis
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ethernet-pse@26 {
+        compatible = "skyworks,si3474";
+        reg-names = "main", "secondary";
+        reg = <0x26>, <0x27>;
+
+        channels {
+          #address-cells = <1>;
+          #size-cells = <0>;
+          phys0_0: channel@0 {
+            reg = <0>;
+          };
+          phys0_1: channel@1 {
+            reg = <1>;
+          };
+          phys0_2: channel@2 {
+            reg = <2>;
+          };
+          phys0_3: channel@3 {
+            reg = <3>;
+          };
+          phys0_4: channel@4 {
+            reg = <4>;
+          };
+          phys0_5: channel@5 {
+            reg = <5>;
+          };
+          phys0_6: channel@6 {
+            reg = <6>;
+          };
+          phys0_7: channel@7 {
+            reg = <7>;
+          };
+        };
+        pse-pis {
+          #address-cells = <1>;
+          #size-cells = <0>;
+          pse_pi0: pse-pi@0 {
+            reg = <0>;
+            #pse-cells = <0>;
+            pairset-names = "alternative-a", "alternative-b";
+            pairsets = <&phys0_0>, <&phys0_1>;
+            polarity-supported = "MDI-X", "S";
+            vpwr-supply = <&reg_pse>;
+          };
+          pse_pi1: pse-pi@1 {
+            reg = <1>;
+            #pse-cells = <0>;
+            pairset-names = "alternative-a", "alternative-b";
+            pairsets = <&phys0_2>, <&phys0_3>;
+            polarity-supported = "MDI-X", "S";
+            vpwr-supply = <&reg_pse>;
+          };
+          pse_pi2: pse-pi@2 {
+            reg = <2>;
+            #pse-cells = <0>;
+            pairset-names = "alternative-a", "alternative-b";
+            pairsets = <&phys0_4>, <&phys0_5>;
+            polarity-supported = "MDI-X", "S";
+            vpwr-supply = <&reg_pse>;
+          };
+          pse_pi3: pse-pi@3 {
+            reg = <3>;
+            #pse-cells = <0>;
+            pairset-names = "alternative-a", "alternative-b";
+            pairsets = <&phys0_6>, <&phys0_7>;
+            polarity-supported = "MDI-X", "S";
+            vpwr-supply = <&reg_pse>;
+          };
+        };
+      };
+    };