dt-bindings: iio: dac: adi,ad5064: Document bindings for many different DACs

Note this is documenting bindings that have effectively existing ever
since this driver was merged. The naming conventions for the ADI
parts are inconsistent on the data sheets which has lead to a mixture
of -X and -reference voltage part naming.  We could attempt to clean this
up, but as we are stuck supporting the existing binding it is probably
not worthwhile.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210627163244.1090296-3-jic23@kernel.org

Documentation/devicetree/bindings/iio/dac/adi,ad5064.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,ad5064.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD5064 and similar DACs
+
+maintainers:
+  - Lars-Peter Clausen <lars@metafoo.de>
+  - Jonathan Cameron <jic23@kernel.org>
+
+description: |
+   A range of similar DAC devices with between 1 and 12 channels. Some parts
+   have internal references, others require a single shared external reference
+   and the remainder have a separate reference pin for each DAC.
+
+properties:
+  compatible:
+    oneOf:
+      - description: I2C devics
+        enum:
+          - adi,ad5024
+          - adi,ad5025
+          - adi,ad5044
+          - adi,ad5045
+          - adi,ad5064
+          - adi,ad5064-1
+          - adi,ad5065
+          - adi,ad5628-1
+          - adi,ad5628-2
+          - adi,ad5648-1
+          - adi,ad5648-2
+          - adi,ad5666-1
+          - adi,ad5666-2
+          - adi,ad5668-1
+          - adi,ad5668-2
+          - adi,ad5668-3
+      - description: SPI devices
+        enum:
+          - adi,ad5625
+          - adi,ad5625r-1v25
+          - adi,ad5625r-2v5
+          - adi,ad5627
+          - adi,ad5627r-1v25
+          - adi,ad5627r-2v5
+          - adi,ad5629-1
+          - adi,ad5629-2
+          - adi,ad5629-3
+          - adi,ad5645r-1v25
+          - adi,ad5645r-2v5
+          - adi,ad5665
+          - adi,ad5665r-1v25
+          - adi,ad5665r-2v5
+          - adi,ad5667
+          - adi,ad5667r-1v25
+          - adi,ad5667r-2v5
+          - adi,ad5669-1
+          - adi,ad5669-2
+          - adi,ad5669-3
+          - lltc,ltc2606
+          - lltc,ltc2607
+          - lltc,ltc2609
+          - lltc,ltc2616
+          - lltc,ltc2617
+          - lltc,ltc2619
+          - lltc,ltc2626
+          - lltc,ltc2627
+          - lltc,ltc2629
+          - lltc,ltc2631-l12
+          - lltc,ltc2631-h12
+          - lltc,ltc2631-l10
+          - lltc,ltc2631-h10
+          - lltc,ltc2631-l8
+          - lltc,ltc2631-h8
+          - lltc,ltc2633-l12
+          - lltc,ltc2633-h12
+          - lltc,ltc2633-l10
+          - lltc,ltc2633-h10
+          - lltc,ltc2633-l8
+          - lltc,ltc2633-h8
+          - lltc,ltc2635-l12
+          - lltc,ltc2635-h12
+          - lltc,ltc2635-l10
+          - lltc,ltc2635-h10
+          - lltc,ltc2635-l8
+          - lltc,ltc2635-h8
+
+  reg:
+    maxItems: 1
+
+  vrefA-supply: true
+  vrefB-supply: true
+  vrefC-supply: true
+  vrefD-supply: true
+  vref-supply: true
+
+  spi-max-frequency: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - # Shared external vref, no internal reference
+    if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad5064-1
+              - adi,ad5625
+              - adi,ad5627
+              - adi,ad5665
+              - adi,ad5667
+              - lltc,ltc2606
+              - lltc,ltc2607
+              - lltc,ltc2616
+              - lltc,ltc2617
+              - lltc,ltc2626
+              - lltc,ltc2627
+    then:
+      properties:
+        vref-supply: true
+        vrefA-supply: false
+        vrefB-supply: false
+        vrefC-supply: false
+        vrefD-supply: false
+      required:
+        - vref-supply
+  - # Shared external vref, internal reference available
+    if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad5625r-1v25
+              - adi,ad5625r-2v5
+              - adi,ad5627r-1v25
+              - adi,ad5627r-2v5
+              - adi,ad5628-1
+              - adi,ad5628-2
+              - adi,ad5629-1
+              - adi,ad5629-2
+              - adi,ad5629-3
+              - adi,ad5645r-1v25
+              - adi,ad5645r-2v5
+              - adi,ad5647r-1v25
+              - adi,ad5647r-2v5
+              - adi,ad5648-1
+              - adi,ad5648-2
+              - adi,ad5665r-1v25
+              - adi,ad5665r-2v5
+              - adi,ad5666-1
+              - adi,ad5666-2
+              - adi,ad5667r-1v25
+              - adi,ad5667r-2v5
+              - adi,ad5668-1
+              - adi,ad5668-2
+              - adi,ad5668-3
+              - adi,ad5669-1
+              - adi,ad5669-2
+              - adi,ad5669-3
+              - lltc,ltc2631-l12
+              - lltc,ltc2631-h12
+              - lltc,ltc2631-l10
+              - lltc,ltc2631-h10
+              - lltc,ltc2631-l8
+              - lltc,ltc2631-h8
+              - lltc,ltc2633-l12
+              - lltc,ltc2633-h12
+              - lltc,ltc2633-l10
+              - lltc,ltc2633-h10
+              - lltc,ltc2633-l8
+              - lltc,ltc2633-h8
+              - lltc,ltc2635-l12
+              - lltc,ltc2635-h12
+              - lltc,ltc2635-l10
+              - lltc,ltc2635-h10
+              - lltc,ltc2635-l8
+              - lltc,ltc2635-h8
+    then:
+      properties:
+        vref-supply: true
+        vrefA-supply: false
+        vrefB-supply: false
+        vrefC-supply: false
+        vrefD-supply: false
+  - # 4 input devices, separate vrefs, no internal reference
+    if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad5024
+              - adi,ad5044
+              - adi,ad5064
+              - lltc,ltc2609
+              - lltc,ltc2619
+              - lltc,ltc2629
+    then:
+      properties:
+        vrefA-supply: true
+        vrefB-supply: true
+        vrefC-supply: true
+        vrefD-supply: true
+        vref-supply: false
+      required:
+        - vrefA-supply
+        - vrefB-supply
+        - vrefC-supply
+        - vrefD-supply
+  - # 2 input devices, separate vrefs, no internal reference
+    if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad5025
+              - adi,ad5045
+              - adi,ad5065
+    then:
+      properties:
+        vrefA-supply: true
+        vrefB-supply: true
+        vrefC-supply: false
+        vrefD-supply: false
+        vref-supply: false
+      required:
+        - vrefA-supply
+        - vrefB-supply
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dac@0 {
+            reg = <0>;
+            compatible = "adi,ad5625";
+            vref-supply = <&dac_vref>;
+        };
+    };
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dac@0 {
+            reg = <0>;
+            compatible = "adi,ad5625r-1v25";
+        };
+    };
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dac@42 {
+            reg = <0x42>;
+            compatible = "adi,ad5024";
+            vrefA-supply = <&dac_vref>;
+            vrefB-supply = <&dac_vref>;
+            vrefC-supply = <&dac_vref2>;
+            vrefD-supply = <&dac_vref2>;
+        };
+    };
+...