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Kernel driver macsmc-hwmon

Documentation/hwmon/macsmc-hwmon.rst

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.. SPDX-License-Identifier: GPL-2.0-only

Kernel driver macsmc-hwmon

Supported hardware

* Apple Silicon Macs (M1 and up)

Author: James Calligeros [email protected]

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