Linux driver for Intel Touch Host Controller

NOTE: This driver is included in the Linux Surface kernel.

The ithc kernel module provides support for the Intel Touch Host Controller, which is used for the touchscreens in some newer Intel-based devices, such as the Surface Pro 7+, Surface Pro 8, X1 Fold, etc.

The module works as an HID transport driver. For Surface devices, you will also need to install IPTSD to enable multi-touch and pen support. Without IPTSD, only single touch will work. Non-Microsoft devices use standard HID data, and don't need IPTSD.

Installation with DKMS

• Install prerequisites (e.g. Debian packages: dkms and linux-headers-amd64)
• sudo make dkms-install
• sudo modprobe ithc (or reboot)
• Check dmesg for ithc messages/errors.

Installation without DKMS

• Install prerequisites (e.g. Debian packages: build-essential and linux-headers-amd64)
• make && sudo make install
• sudo modprobe ithc (or reboot)
• Check dmesg for ithc messages/errors.

Known issues

On Lakefield and Tiger Lake devices (SP7+/SP8/SLS/SL4/X1Fold) the driver may fail to start correctly, and you will see the following error in dmesg: "Blocked an interrupt request due to source-id verification failure".

To fix this, apply one of the following workarounds:

1. Add the kernel parameter intremap=nosid and reboot. If you're using GRUB on Debian/Ubuntu, you can do this with sudo make set-nosid.
2. Apply intel-iommu.patch to your kernel.
3. Use the driver in polling mode by setting the poll module parameter. Run echo options ithc poll | sudo tee /etc/modprobe.d/ithc-poll.conf and reload the module or reboot.

License

Public domain/CC0. (Files are marked GPL/BSD since that is preferred for the kernel.)