Following the recent Apple SMC driver upstreaming to handle rebooting Apple Silicon Macs under Linux, the latest code volleyed on the kernel mailing list for review is support for handling laptop lid events and power buttons. Plus Apple sensor monitoring driver support too.
Posted to the Linux kernel mailing list this week by James Calligeros were patches he along with Hector Martin and Sven Peter had worked on for Asahi Linux. These patches enable the RTC, HWMON, and HID sub-devices of the Apple System Management Controller (SMC).
The RTC driver is needed for getting and setting the system clock. The HWMON driver exposes various hardware monitoring metrics such as for thermal and power. Among the hardware monitoring data exposed from the Apple SMC are the current, fan control mode/minimum/maximum, power endpoints, temperatures, and voltage.
Lastly SMC driver support is also needed for handling the hardware power buttons and lid switch open/close events under Linux. Power button presses and lid opening/closing are emitted as HID events on the Apple Silicon devices.
This patch series is now out for review for working to upstream these important Apple Silicon support additions to the mainline Linux kernel. For now the Apple Silicon Linux support continues to be focused on the M1 and M2 hardware with the M3/M4 bring-up still slowly being worked on downstream in Asahi Linux.
