dt-bindings: hwmon: Add AXI FAN Control documentation

Document the AXI FAN Control IP core devicetree bindings.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191009102806.262241-2-nuno.sa@analog.com
[groeck: adi,pulses-per-revolution -> pulses-per-revolution]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/hwmon/adi,axi-fan-control.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2019 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bindings/hwmon/adi,axi-fan-control.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AXI FAN Control Device Tree Bindings
+
+maintainers:
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |+
+  Bindings for the Analog Devices AXI FAN Control driver. Spefications of the
+  core can be found in:
+
+  https://wiki.analog.com/resources/fpga/docs/axi_fan_control
+
+properties:
+  compatible:
+    enum:
+        - adi,axi-fan-control-1.00.a
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  pulses-per-revolution:
+    description:
+      Value specifying the number of pulses per revolution of the controlled
+      FAN.
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [1, 2, 4]
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+  - pulses-per-revolution
+
+examples:
+  - |
+    fpga_axi: fpga-axi@0 {
+            #address-cells = <0x2>;
+            #size-cells = <0x1>;
+
+            axi_fan_control: axi-fan-control@80000000 {
+                    compatible = "adi,axi-fan-control-1.00.a";
+                    reg = <0x0 0x80000000 0x10000>;
+                    clocks = <&clk 71>;
+                    interrupts = <0 110 0>;
+                    pulses-per-revolution = <2>;
+            };
+    };
+...

MAINTAINERS

@@ -2963,6 +2963,7 @@ W:	http://ez.analog.com/community/linux-device-drivers
 L:	linux-hwmon@vger.kernel.org
 S:	Supported
 F:	drivers/hwmon/axi-fan-control.c
+F:	Documentation/devicetree/bindings/hwmon/adi,axi-fan-control.yaml
 
 AXXIA I2C CONTROLLER
 M:	Krzysztof Adamski <krzysztof.adamski@nokia.com>