AMD has submitted patches that would add an official Ryzen tuning driver, called AOD (AMD Overclocking Driver), to the Linux kernel, according to Phoronix's original report.
The patches are still working through review on the kernel mailing lists, so nothing has shipped in a mainstream release yet. Once merged, the driver would expose its controls through sysfs, the kernel's standard file-style interface that scripts and utilities can read and write. It starts with three things: toggling Simultaneous Multithreading (SMT, which lets each core run two threads) on the fly, reading memory clocks in real time, and early power tunables, which are still being wired up.
The SMT switch works through CPU hotplugging, the kernel's way of taking processor threads on and offline. That makes it an alternative to the old 'nosmt' boot parameter, which required a reboot to change.
There is no Linux version of Ryzen Master, the Windows tool for adjusting frequency curves and voltages, and AMD is not building one. It is repeating its approach with the open-source amdgpu graphics driver: write the kernel layer, then leave the front end to the community. Utilities such as CoreCtrl would be the likely candidates to add interfaces. The announced feature list does not include frequency or voltage controls, which are the settings most overclockers care about.
The value here is in the foundation. Until now, Linux tuning has meant reverse-engineering closed firmware hooks or leaning on machine-specific ACPI workarounds, which tend to break between boards and BIOS versions. An upstream driver gives tool authors one supported interface to target. Whether AMD later extends that interface to the controls Windows users already have is the question that decides if this is a tuning platform or mostly a monitoring and SMT switch.