xref: /linux/Documentation/hwmon/macsmc-hwmon.rst (revision 84318277d6334c6981ab326d4acc87c6a6ddc9b8)
1.. SPDX-License-Identifier: GPL-2.0-only
2
3Kernel driver macsmc-hwmon
4==========================
5
6Supported hardware
7
8    * Apple Silicon Macs (M1 and up)
9
10Author: James Calligeros <jcalligeros99@gmail.com>
11
12Description
13-----------
14
15macsmc-hwmon exposes the Apple System Management controller's
16temperature, voltage, current and power sensors, as well as
17fan speed and control capabilities, via hwmon.
18
19Because each Apple Silicon Mac exposes a different set of sensors
20(e.g. the MacBooks expose battery telemetry that is not present on
21the desktop Macs), sensors present on any given machine are described
22via Devicetree. The driver picks these up and registers them with
23hwmon when probed.
24
25Manual fan speed is supported via the fan_control module parameter. This
26is disabled by default and marked as unsafe, as it cannot be proven that
27the system will fail safe if overheating due to manual fan control being
28used.
29
30sysfs interface
31---------------
32
33currX_input
34    Ammeter value
35
36currX_label
37    Ammeter label
38
39fanX_input
40    Current fan speed
41
42fanX_label
43    Fan label
44
45fanX_min
46    Minimum possible fan speed
47
48fanX_max
49    Maximum possible fan speed
50
51fanX_target
52    Current fan setpoint
53
54inX_input
55    Voltmeter value
56
57inX_label
58    Voltmeter label
59
60powerX_input
61    Power meter value
62
63powerX_label
64    Power meter label
65
66tempX_input
67    Temperature sensor value
68
69tempX_label
70    Temperature sensor label
71
72