dt-bindings: proximity: provide vcnl3020 device tree binding document

Mostly standard i2c driver with some additional led-current option
for vcnl3020.
Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/proximity/vishay,vcnl3020.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/proximity/vishay,vcnl3020.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Integrated Proximity Sensor With Infrared Emitter
+
+maintainers:
+  - Ivan Mikhaylov <i.mikhaylov@yadro.com>
+
+description: |
+  The VCNL3020 is a fully integrated proximity sensor. Fully integrated means
+  that the infrared emitter is included in the package. It has 16-bit
+  resolution. It includes a signal processing IC and features standard I2C
+  communication interface. It features an interrupt function.
+
+  Specifications about the devices can be found at:
+  https://www.vishay.com/docs/84150/vcnl3020.pdf
+
+properties:
+  compatible:
+    enum:
+      - vishay,vcnl3020
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vdd-supply:
+    description: Regulator that provides power to the sensor
+
+  vddio-supply:
+    description: Regulator that provides power to the bus
+
+  vishay,led-current-microamp:
+    description:
+      The driver current for the LED used in proximity sensing.
+    enum: [0, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000,
+          100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000,
+          180000, 190000, 200000]
+    default: 20000
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        proximity@13 {
+              compatible = "vishay,vcnl3020";
+              reg = <0x13>;
+              vishay,led-current-microamp = <200000>;
+        };
+    };