dt-bindings: i2c: add bindings for microchip mpfs i2c

Add device tree bindings for the i2c controller on
the Microchip PolarFire SoC.
Signed-off-by: Daire McNamara <daire.mcnamara@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Documentation/devicetree/bindings/i2c/microchip,corei2c.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/microchip,corei2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip MPFS I2C Controller Device Tree Bindings
+
+maintainers:
+  - Daire McNamara <daire.mcnamara@microchip.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+        - const: microchip,mpfs-i2c # Microchip PolarFire SoC compatible SoCs
+        - const: microchip,corei2c-rtl-v7 # Microchip Fabric based i2c IP core
+      - const: microchip,corei2c-rtl-v7 # Microchip Fabric based i2c IP core
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-frequency:
+    description: |
+      Desired I2C bus clock frequency in Hz. As only Standard and Fast
+      modes are supported, possible values are 100000 and 400000.
+    enum: [100000, 400000]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c@2010a000 {
+      compatible = "microchip,mpfs-i2c", "microchip,corei2c-rtl-v7";
+      reg = <0x2010a000 0x1000>;
+      clocks = <&clkcfg 15>;
+      interrupt-parent = <&plic>;
+      interrupts = <58>;
+      clock-frequency = <100000>;
+    };
+...