Intel Touch Host Controller "THC" Driver Support Being Worked On For Linux

The newest Linux driver being developed by Intel is for the Touch Host Controller (THC) as a new high performance input tech for enhancing touch screen, touch pad, and stylus input handling.

Intel Touch Host Controller IP originates from the Tigerlake days but has been extended since -- most recently for Lunar Lake with industrial standard HID over I2C support. Intel engineer Even Xu explains in the patch series introducing Intel THC support for Linux:

"THC IP now evoluates to V4, it can support 3 different modes: IPTS, HIDSPI and HIDI2C. Here are upgrade history:
- THC v1, for TGL/LKF, supports intel private IPTS (Intel Precise Touch and Stylus) protocol ( IPTS mode)
- THC v2, for ADL, add industrial standard HID over SPI protocol support (HIDSPI mode)
- THC v3, for MTL, enhance HID over SPI mode
- THC v4, for LNL, add inudstrial standard HID over I2C protocol support (HIDI2C mode)

Linux Surface community already implemented IPTS mode. These patch series provides THC HIDSPI mode and THC HIDI2C mode support on Linux.

These patch series includes:
1. Document for THC hardware and software introduction.
2. Intel THC Hardware layer driver which provides control interfaces for protocol layer.
3. Intel QuickSPI (R) driver working as a HIDSPI device driver which implements HID over SPI protocol and flow.
4. Intel QuickI2C (R) driver working as a HIDI2C device driver which implements HID over I2C protocol and flow."

This is some nearly 8k lines of code working out this new Intel THC driver support for Linux systems.

This documentation patch covers more details on the Intel THC architecture. If Intel THC support interests you, learn more via this patch series.