dt-bindings: iio: amplifiers: Add AD8366 support

Add device tree binding documentation for amplifiers and digital
attenuators. This covers different device variants with similar
SPI control. Each device has its own gain range and step, hence
no fallback compatibles are used.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/amplifiers/adi,ad8366.yaml

@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/amplifiers/adi,ad8366.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD8366 and similar Gain Amplifiers and Digital Attenuators
+
+maintainers:
+  - Michael Hennerich <michael.hennerich@analog.com>
+  - Rodrigo Alencar <rodrigo.alencar@analog.com>
+
+description:
+  Digital Variable Gain Amplifiers (VGAs) and Digital Attenuators with
+  SPI interface.
+
+properties:
+  compatible:
+    enum:
+      - adi,ad8366
+      - adi,ada4961
+      - adi,adl5240
+      - adi,adrf5720
+      - adi,adrf5730
+      - adi,adrf5731
+      - adi,hmc271a
+      - adi,hmc792a
+      - adi,hmc1018a
+      - adi,hmc1019a
+      - adi,hmc1119
+
+  reg:
+    maxItems: 1
+
+  vcc-supply:
+    description: Regulator that provides power to the device.
+
+  reset-gpios:
+    maxItems: 1
+
+  enable-gpios:
+    maxItems: 1
+    description: Power-up or Serial Mode Enable GPIO.
+
+required:
+  - compatible
+  - reg
+  - vcc-supply
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              const: adi,hmc271a
+    then:
+      properties:
+        reset-gpios: false
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              anyOf:
+                - const: adi,ad8366
+                - const: adi,ada4961
+                - const: adi,adrf5720
+                - const: adi,adrf5730
+                - const: adi,adrf5731
+                - const: adi,hmc792a
+                - const: adi,hmc1018a
+                - const: adi,hmc1019a
+                - const: adi,hmc1119
+    then:
+      properties:
+        enable-gpios: false
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      amplifier@0 {
+        compatible = "adi,ad8366";
+        reg = <0>;
+        spi-max-frequency = <1000000>;
+        vcc-supply = <&vcc_3v3>;
+        enable-gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
+      };
+    };
+...

MAINTAINERS

@@ -1600,6 +1600,7 @@ M:	Rodrigo Alencar <rodrigo.alencar@analog.com>
 L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/amplifiers/adi,ad8366.yaml
 F:	drivers/iio/amplifiers/ad8366.c
 
 ANALOG DEVICES INC AD9467 DRIVER