AMD recently published patches for the Linux kernel to implement AOD, an AMD Overclocking driver for Ryzen processors. Linux enthusiasts have long sought an official AMD Ryzen CPU overclocking driver for Linux akin to Ryzen Master on Windows and it's finally coming, at least from the kernel driver perspective.
AMD engineer Shyam Sundar S K posted the patches for the AMD Overclocking "AOD" WMI driver as an interface to the platform firmware for managing overclocking and power/current limits of modern Ryzen CPUs.
The driver in its initial form allows setting via sysfs a number of CPU tunables including the Package Power Tracking (PPT), Thermal Design Current (TDC), and Electrical Design Current (EDC) limits along with reading their supported range. SMT toggling can also be done via the interface as an alternative to the likes of Linux's "nosmt" option in disabling SMT at the platform level rather than kernel disabling. The current memory clocks can also be read via this AOD driver.
The power tunables aren't applied in real-time but go into effect at next reboot. The firmware does support many more commands compared to the few initially wired up and hopefully in time more of these controls will be enabled with this driver.
With this AMD overclocking driver all the controls are exposed via the sysfs interface. No AMD patches have surfaced for any sort of user-space GUI application for managing the controls. Presumably it will be like their AMD Radeon graphics driver settings where ultimately it's left up to independent developers and desktop environments for crafting their own custom GUIs for interacting with these sysfs knobs rather than any official AMD GUI application akin to Ryzen Master for Linux.
Those interested can find this initial AMD Ryzen overclocking Linux driver out for review on the mailing list. Nice seeing this long sought after AMD Linux CPU overclocking support finally coming officially out of the company and part of their expanded Linux support on the client side.