Intel's GPU-Accelerated Precise Touch & Stylus Tech Still Not Mainlined For Linux

Intel's Precise Touch and Stylus (IPTS) technology offers GPU-accelerated multi-touch/stylus handling using OpenCL. While there have been kernel patches for a few months floating around, this support has yet to be merged into the mainline Linux kernel.

A Phoronix reader wrote in this morning to say that the IPTS code remains available for Linux but isn't mainline. He also pointed out that the IPTS support is needed for supporting the touchscreen/stylus on devices like the Microsoft Surface Pro 4.

The code for IPTS is housed via this GitHub repository. There are just a handful of changes made for supporting IPTS on Linux while the most recent changes were the end of June. Adding the driver required more than 7,000 lines of code plus changes to HID and the i915 graphics driver -- due to its use of GPU acceleration. The IPTS work was done by Intel developers but with the code not being touched in months it's not immediately clear if it's still being worked on or was just a one-off code dump with no apparent pursuit to mainline.

The Wiki page for the IPTS-Linux project does also indicate the GuC binary-only firmware is explicitly required for INTEL_MEI_ITOUCH support. There are also user-space components needed for supporting Intel Precise Touch on Linux.

It's not clear that these user-space components are open-source, which includes a configuration binary, a touch-vendor-provided OpenCL kernel binary with touch algorithms, and more. The Wiki page suggests users extract these needed binary files from Windows installations on supported touch platforms. If the user-space is indeed closed up, it could be a difficult road for getting the kernel-side work merged into the mainline kernel.

I don't have any access to any IPTS hardware myself, but if any users have more information on this Precise Touch & Stylus Technology feel free to share via the forums.