macsmc driver extended to replace aging applesmc on Intel Macs

Linux kernel developer Atharva Tiwari has submitted an RFC patch series to extend the macsmc driver—originally written for Apple Silicon Macs under the Asahi Linux project—to also handle older Intel-based Macs. The existing applesmc driver for Intel Macs has become difficult to maintain, with fan control, sensors, light sensor, motion sensor, and keyboard backlight functionality all crammed into a single monolithic file with its own SMC communication protocol.

The SMC hardware itself operates identically across both Intel and Apple Silicon platforms, differing only in the communication interface used to reach it. This architectural similarity allows the newer, cleaner macsmc driver to subsume Intel Mac support while reusing substantial portions of the Asahi-developed code. The patch series is currently under review and has not yet been merged into mainline.

Driver architecture and Intel Mac changes

• Code consolidation: The patch series enables macsmc to replace applesmc entirely, eliminating a large monolithic driver where all SMC-related functionality was intermingled in a single file.
• Shared Asahi implementation: Core SMC logic from the Apple Silicon macsmc driver is reused for Intel Macs, since the system management controller behaves identically on both architectures.
• Interface abstraction: The only platform difference is the SMC communication interface; the patch adds the Intel-specific transport layer while keeping the higher-level sensor and control code common.
• Scope of affected subsystems: The unified driver handles fan control, thermal sensors, ambient light sensor, motion sensor, and keyboard backlight across both Intel and Apple Silicon Macs.
• Review status: The code was posted as an RFC (Request for Comments) series and remains under community review before any mainline kernel inclusion.

Why it matters

For Linux users running distributions on older Intel Macs, this driver unification promises more maintainable hardware support and easier addition of new machine variants. It also demonstrates how the Asahi Linux project's driver investments for Apple Silicon are flowing back to benefit the broader Mac-on-Linux ecosystem, including hardware that Apple itself has long discontinued.