dt-bindings: iio: adc: add ad4851

Add devicetree bindings for ad485x family.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://patch.msgid.link/20250214131955.31973-9-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/adi,ad4851.yaml

@@ -0,0 +1,153 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2024 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4851.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD485X family
+
+maintainers:
+  - Sergiu Cuciurean <sergiu.cuciurean@analog.com>
+  - Dragos Bogdan <dragos.bogdan@analog.com>
+  - Antoniu Miclaus <antoniu.miclaus@analog.com>
+
+description: |
+  Analog Devices AD485X fully buffered, 8-channel simultaneous sampling,
+  16/20-bit, 1 MSPS data acquisition system (DAS) with differential, wide
+  common-mode range inputs.
+
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4855.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4856.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4857.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4858.pdf
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,ad4851
+      - adi,ad4852
+      - adi,ad4853
+      - adi,ad4854
+      - adi,ad4855
+      - adi,ad4856
+      - adi,ad4857
+      - adi,ad4858
+      - adi,ad4858i
+
+  reg:
+    maxItems: 1
+
+  vcc-supply: true
+
+  vee-supply: true
+
+  vdd-supply: true
+
+  vddh-supply: true
+
+  vddl-supply: true
+
+  vio-supply: true
+
+  vrefbuf-supply: true
+
+  vrefio-supply: true
+
+  pwms:
+    description: PWM connected to the CNV pin.
+    maxItems: 1
+
+  io-backends:
+    maxItems: 1
+
+  pd-gpios:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 25000000
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^channel(@[0-7])?$":
+    $ref: adc.yaml
+    type: object
+    description: Represents the channels which are connected to the ADC.
+
+    properties:
+      reg:
+        description:
+          The channel number, as specified in the datasheet (from 0 to 7).
+        minimum: 0
+        maximum: 7
+
+      diff-channels:
+        description:
+          Each channel can be configured as a bipolar differential channel.
+          The ADC uses the same positive and negative inputs for this.
+          This property must be specified as 'reg' (or the channel number) for
+          both positive and negative inputs (i.e. diff-channels = <reg reg>).
+          Since the configuration is bipolar differential, the 'bipolar'
+          property is required.
+        items:
+          minimum: 0
+          maximum: 7
+
+      bipolar: true
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - vcc-supply
+  - vee-supply
+  - vdd-supply
+  - vio-supply
+  - pwms
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0{
+            #address-cells = <1>;
+            #size-cells = <0>;
+            compatible = "adi,ad4858";
+            reg = <0>;
+            spi-max-frequency = <10000000>;
+            vcc-supply = <&vcc>;
+            vdd-supply = <&vdd>;
+            vee-supply = <&vee>;
+            vddh-supply = <&vddh>;
+            vddl-supply = <&vddl>;
+            vio-supply = <&vio>;
+            pwms = <&pwm_gen 0 0>;
+            io-backends = <&iio_backend>;
+
+            channel@0 {
+              reg = <0>;
+              diff-channels = <0 0>;
+              bipolar;
+            };
+
+            channel@1 {
+              reg = <1>;
+            };
+        };
+    };
+...