OEMs can configure the Platform Temperature Control (PTC) thresholds via the BIOS/firmware and the temperatures are supplied via the Platform Environment Control Interface (PECI). PTC can work without the involvement of the operating system but the newly-posted Linux patches are being done to allow tuning it.
On the basis that some OEMs may set too aggressive of a temperature target limit, the Intel PTC Linux patches allow manipulating the target limits so you aren't cutting back the power/performance too much. These Linux patches also allow confirming that the firmware support is in place and enabled.
The patches acknowledge that Intel PTC is found with Lunar Lake SoCs and upcoming Panther Lake SoCs due to the presence of a new "PROC_THERMAL_FEATURE_PTC" bit.
On patched kernels, the Intel PTC temperature controls can be manipulated via writing to the /sys/bus/pci/devices/0000\:00\:04.0/platform_temperature_*_control sysfs directories with a temperature target "temperature_target" specified in milli-degrees Celsius. There is also an "enable" sysfs file for disabling a given PTC temperature control.
Those interested in this new Intel Platform Temperature Control Linux work for their int340x driver can find them under review on the Linux kernel mailing list .