Kernel driver macsmc-hwmon

Supported hardware

• Apple Silicon Macs (M1 and up)

Author: James Calligeros <jcalligeros99@gmail.com>

Description

macsmc-hwmon exposes the Apple System Management controller’s temperature, voltage, current and power sensors, as well as fan speed and control capabilities, via hwmon.

Because each Apple Silicon Mac exposes a different set of sensors (e.g. the MacBooks expose battery telemetry that is not present on the desktop Macs), sensors present on any given machine are described via Devicetree. The driver picks these up and registers them with hwmon when probed.

Manual fan speed is supported via the fan_control module parameter. This is disabled by default and marked as unsafe, as it cannot be proven that the system will fail safe if overheating due to manual fan control being used.

sysfs interface

currX_input

Ammeter value

currX_label

Ammeter label

fanX_input

Current fan speed

fanX_label

Fan label

fanX_min

Minimum possible fan speed

fanX_max

Maximum possible fan speed

fanX_target

Current fan setpoint

inX_input

Voltmeter value

inX_label

Voltmeter label

powerX_input

Power meter value

powerX_label

Power meter label

tempX_input

Temperature sensor value

tempX_label

Temperature sensor label