The Real Time Clock (RTC) driver changes were merged today for Linux 6.19 ahead of the merge window wrapping up on Sunday.
While the RTC driver changes are typically not too notable, with Linux 6.19 there are new RTC drivers introduced for Apple and NVIDIA hardware.
On the Apple Silicon side is upstreaming the “rtc-macsmc” driver written by Hector Martin back when he was leading the Asahi Linux project. This driver is for the RTC that is part of Apple’s PMU IC that in turn is abstracted out by Apple’s System Management Controller (SMC). The RTC counter is accessed via the SMC and this now-upstream Linux driver provides that Apple Mac SMC RTC support.
The new NVIDIA RTC driver is “NVVRS” and is for their Voltage Regulator Specification (VRS) real-time clock on ARM64/Tegra platforms.
The NVIDIA VRS RTC is used for system time handling, system time across boot, waking system from suspend/shutdown and similar functionality on the Jetson AGX Orin, IGX Orin, Jetson Orin NX, and Jetson Orin Nano boards so far.
The RTC pull for Linux 6.19 also landed a Andes ATCRTC100 real-time clock driver too. More details on the Linux 6.19 RTC changes via this Git merge.
