Intel Timed I/O Driver Being Worked On For The Linux Kernel

As a new hardware feature for Intel IoT and server platforms not previously announced at large, Intel Timed I/O is being worked on in a new open-source Linux kernel driver.

Aside from a few Linux kernel mailing list posts, I haven't seen Intel Timed I/O mentioned or brought up at all elsewhere. Intel Timed I/O is intended for IoT and server platforms to help with time synchronization between multiple devices and to be much more precise than existing time synchronization solutions. Given the lack of announcements around Intel Timed I/O, this appears to be primarily for future Intel Xeon processors... I've found some documentation that points it on the client side at least being found since Elkhart Lake and Tigerlake SoCs.

In an LKML post on Monday the Intel Timed I/O feature was summed up as, "Intel Timed I/O is a precise device (10s of nanoseconds), that can send out pulses. This is needed in IoT and server applications to measure offset between system clocks on multiple devices."

Merged last year to the Linux kernel was the NVIDIA-developed Hardware Timestamping Engine "HTE" in the Linux 5.19 kernel. Prior kernel mailing list discussions sought to add the Intel Timed I/O driver there but apparently is not a good match. Others have suggested as well making it a common clk driver or within the GPIO area of the kernel. Yesterday's kernel mailing list thread is now trying to evaluate the possibility of Linux Timed I/O as being a Linux PPS (Pulse Per Second) driver.

We'll see what comes about with this Intel Timed I/O driver effort for PPS with the Linux kernel.