[PATCH v2 1/6] dt-bindings: hwmon: add binding for adi,adt7470

The Analog Devices ADT7470 is a temperature monitor and PWM fan
controller. It supports up to 10 external temperature sensors and
up to 4 PWM fan outputs.

Add the YAML device tree binding documentation for it. This includes
support for the thermal framework by defining the "#thermal-sensor-cells"
property, and support for the PWM subsystem by defining the "#pwm-cells"
property.

Signed-off-by: Luiz Angelo Daros de Luca <[email protected]>
---
 .../devicetree/bindings/hwmon/adi,adt7470.yaml     | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,adt7470.yaml b/Documentation/devicetree/bindings/hwmon/adi,adt7470.yaml
new file mode 100644
index 000000000000..14bb6359c91f
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/adi,adt7470.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/adi,adt7470.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices ADT7470 hwmon sensor
+
+maintainers:
+  - Luiz Angelo Daros de Luca <[email protected]>
+
+description: |
+  The ADT7470 is a temperature monitor and multiple PWM outputs.
+  It supports monitoring up to 10 external temperature sensors and controlling
+  up to four fans.
+
+properties:
+  compatible:
+    const: adi,adt7470
+
+  reg:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+    description: |
+      Number of cells in a PWM specifier.
+      - The first cell is the PWM channel (0 to 3).
+      - The second cell is the PWM period in nanoseconds.
+
+  "#thermal-sensor-cells":
+    const: 1
+    description: |
+      Number of cells required to uniquely identify the temperature sensors.
+      Valid index values are 0 to 9, corresponding to temp1 through temp10.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adt7470: hwmon@2f {
+            compatible = "adi,adt7470";
+            reg = <0x2f>;
+            #pwm-cells = <2>;
+            #thermal-sensor-cells = <1>;
+        };
+    };
+
+    fan0 {
+        compatible = "pwm-fan";
+        /* Connects to PWM channel 0 with a 50000 ns (20 kHz) period */
+        pwms = <&adt7470 0 50000>;
+        cooling-levels = <0 100 150 255>;
+    };

-- 
2.55.0