1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/hwmon/pwm-fan.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Fan connected to PWM lines
8
9 maintainers:
10 - Jean Delvare <jdelvare@suse.com>
11 - Guenter Roeck <linux@roeck-us.net>
12
13 properties:
14 compatible:
15 const: pwm-fan
16
17 cooling-levels:
18 description: PWM duty cycle values corresponding to thermal cooling states.
19 $ref: /schemas/types.yaml#/definitions/uint32-array
20 items:
21 maximum: 255
22
23 fan-supply:
24 description: Phandle to the regulator that provides power to the fan.
25
26 interrupts:
27 description:
28 This contains an interrupt specifier for each fan tachometer output
29 connected to an interrupt source. The output signal must generate a
30 defined number of interrupts per fan revolution, which require that
31 it must be self resetting edge interrupts.
32 maxItems: 1
33
34 pulses-per-revolution:
35 description:
36 Define the number of pulses per fan revolution for each tachometer
37 input as an integer.
38 $ref: /schemas/types.yaml#/definitions/uint32
39 minimum: 1
40 maximum: 4
41 default: 2
42
43 pwms:
44 description: The PWM that is used to control the fan.
45 maxItems: 1
46
47 "#cooling-cells": true
48
49 required:
50 - compatible
51 - pwms
52
53 additionalProperties: false
54
55 examples:
56 - |
57 pwm-fan {
58 compatible = "pwm-fan";
59 cooling-levels = <0 102 170 230>;
60 pwms = <&pwm 0 10000 0>;
61 #cooling-cells = <2>;
62 };
63
64 thermal-zones {
65 cpu_thermal: cpu-thermal {
66 thermal-sensors = <&tmu 0>;
67 polling-delay-passive = <0>;
68 polling-delay = <0>;
69
70 trips {
71 cpu_alert1: cpu-alert1 {
72 temperature = <100000>; /* millicelsius */
73 hysteresis = <2000>; /* millicelsius */
74 type = "passive";
75 };
76 };
77
78 cooling-maps {
79 map0 {
80 trip = <&cpu_alert1>;
81 cooling-device = <&fan0 0 1>;
82 };
83 };
84 };
85 };
86
87 - |
88 #include <dt-bindings/interrupt-controller/irq.h>
89
90 pwm-fan {
91 compatible = "pwm-fan";
92 pwms = <&pwm 0 40000 0>;
93 fan-supply = <®_fan>;
94 interrupt-parent = <&gpio5>;
95 interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
96 pulses-per-revolution = <2>;
97 };
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