dt-bindings: iio: dac: add mcp4728.yaml

Add documentation for MCP4728

Signed-off-by: Andrea Collamati <[e-mail]>
Reviewed-by: Conor Dooley <[e-mail]>
Link: https://lore.kernel.org/r/d93dd116[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/dac/microchip,mcp4728.yaml

···
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/iio/dac/microchip,mcp4728.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip MCP4728 DAC
+
+maintainers:
+  - Andrea Collamati <[e-mail]>
+
+description: |
+  MCP4728 is a quad channel, 12-bit voltage output
+  Digital-to-Analog Converter with non-volatile
+  memory and I2C compatible Serial Interface.
+  https://www.microchip.com/en-us/product/mcp4728
+
+properties:
+  compatible:
+    const: microchip,mcp4728
+
+  reg:
+    maxItems: 1
+
+  vdd-supply:
+    description: |
+      Provides both power and acts as the reference supply on the MCP4728
+      when Internal Vref is not selected.
+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dac@60 {
+            compatible = "microchip,mcp4728";
+            reg = <0x60>;
+            vdd-supply = <&vdac_vdd>;
+        };
+    };