The Linux kernel’s Multi-Function Device (MFD) subsystem just got a significant boost for version 7.1. Changes merged this week wire up the Apple SMC power driver to the MFD core. Apple Silicon MacBooks can now report AC status, battery charging, and power metrics directly under the mainline kernel. This lands ahead of the merge window’s close on Sunday. Phoronix broke the news on April 23, detailing how Hector Martin, known for Asahi Linux work, originally crafted the macsmc-power driver . Refactoring made it upstream-ready, including tweaks for newer SMC firmware. The driver hit the power supply tree last week; now MFD enables it fully. Check the full MFD pull request for details. MFD handles hardware blocks offering multiple functions—like PMICs mixing regulators, GPIOs, and clocks. A single chip gets parsed into sub-devices. Clean integration matters. Developers avoid reinventing access logic. This isn’t isolated.…