dt-binding: hwmon: Add documentation for ADM1177

Documentation for ADM1177 was added.
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200114112159.25998-2-beniamin.bia@analog.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/hwmon/adi,adm1177.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/adi,adm1177.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices ADM1177 Hot Swap Controller and Digital Power Monitor
+
+maintainers:
+  - Michael Hennerich <michael.hennerich@analog.com>
+  - Beniamin Bia <beniamin.bia@analog.com>
+
+description: |
+  Analog Devices ADM1177 Hot Swap Controller and Digital Power Monitor
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,adm1177
+
+  reg:
+    maxItems: 1
+
+  avcc-supply:
+    description:
+      Phandle to the Avcc power supply
+
+  shunt-resistor-micro-ohms:
+    description:
+      The value of curent sense resistor in microohms. If not provided,
+      the current reading and overcurrent alert is disabled.
+
+  adi,shutdown-threshold-microamp:
+    description:
+      Specifies the current level at which an over current alert occurs.
+      If not provided, the overcurrent alert is configured to max ADC range
+      based on shunt-resistor-micro-ohms.
+
+  adi,vrange-high-enable:
+    description:
+      Specifies which internal voltage divider to be used. A 1 selects
+      a 7:2 voltage divider while a 0 selects a 14:1 voltage divider.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pwmon@5a {
+                compatible = "adi,adm1177";
+                reg = <0x5a>;
+                shunt-resistor-micro-ohms = <50000>; /* 50 mOhm */
+                adi,shutdown-threshold-microamp = <1059000>; /* 1.059 A */
+                adi,vrange-high-enable;
+        };
+    };
+...