[PATCH v4 1/2] dt-bindings: adc: add AD7173

[mitrutzceclan <mitrutzceclan@gmail.com>]

From: Dumitru Ceclan <mitrutzceclan@gmail.com>

The AD7173 family offer a complete integrated Sigma-Delta ADC solution
which can be used in high precision, low noise single channel applications
or higher speed multiplexed applications. The Sigma-Delta ADC is intended
primarily for measurement of signals close to DC but also delivers
outstanding performance with input bandwidths out to ~10kHz.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com> # except reference_select
Signed-off-by: Dumitru Ceclan <mitrutzceclan@gmail.com>
---
V3 -> V4
 - include supply attributes
 - add channel attribute for selecting conversion reference

 .../bindings/iio/adc/adi,ad7173.yaml          | 166 ++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
new file mode 100644
index 000000000000..92aa352b6653
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
@@ -0,0 +1,166 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2023 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7173.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD7173 ADC device driver
+
+maintainers:
+  - Ceclan Dumitru <dumitru.ceclan@analog.com>
+
+description: |
+  Bindings for the Analog Devices AD717X ADC's. Datasheets for supported chips:
+    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
+    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
+    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
+    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7172-2
+      - adi,ad7173-8
+      - adi,ad7175-2
+      - adi,ad7176-2
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  spi-max-frequency:
+    maximum: 20000000
+
+  refin-supply:
+    description: external reference supply, can be used as reference for conversion.
+
+  refin2-supply:
+    description: external reference supply, can be used as reference for conversion.
+
+  avdd-supply:
+    description: avdd supply, can be used as reference for conversion.
+
+  dependencies:
+    refin2-supply:
+      properties:
+        compatible:
+          adi,ad7173-8
+
+  required:
+    - compatible
+    - reg
+    - interrupts
+
+patternProperties:
+  "^channel@[0-9a-f]$":
+    type: object
+    $ref: adc.yaml
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 15
+
+      diff-channels:
+        items:
+          minimum: 0
+          maximum: 31
+
+      adi,reference-select:
+        description: |
+          Select the reference source to use when converting on
+          the specific channel. Valid values are:
+          0: REFIN(+)/REFIN(−).
+          1: REFIN2(+)/REFIN2(−)
+          2: REFOUT/AVSS (Internal reference)
+          3: AVDD
+
+          External reference 2 only available on ad7173-8.
+          If not specified, internal reference used.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        enum: [0, 1, 2, 3]
+        default: 2
+
+      bipolar:
+        type: boolean
+
+    required:
+      - reg
+      - diff-channels
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: adi,ad7173-8
+    then:
+    else:
+      patternProperties:
+        "^channel@[0-9a-f]$":
+          properties:
+            enum: [0, 2, 3]
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      adc@0 {
+        compatible = "adi,ad7173-8";
+        reg = <0>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
+        interrupt-parent = <&gpio>;
+        spi-max-frequency = <5000000>;
+
+        channel@0 {
+          reg = <0>;
+          bipolar;
+          diff-channels = <0 1>;
+        };
+
+        channel@1 {
+          reg = <1>;
+          diff-channels = <2 3>;
+        };
+
+        channel@2 {
+          reg = <2>;
+          bipolar;
+          diff-channels = <4 5>;
+        };
+
+        channel@3 {
+          reg = <3>;
+          bipolar;
+          diff-channels = <6 7>;
+        };
+
+        channel@4 {
+          reg = <4>;
+          diff-channels = <8 9>;
+        };
+      };
+    };
-- 
2.42.0