As part of work going back to 2019, an engineer on Google’s Chromium OS team submitted an updated proposal on Monday for seeking to standardize the haptic touchpad support within the Linux kernel.
An updated design proposal was posted around Linux user-space and HID driver support for haptic touchpads. With there being multiple concurrent efforts working on haptic touchpads with force sensors and haptic actuators to replace traditional buttons, Google engineers are working to ensure Linux has a solid design for supporting haptic touchpads and in turn Chrome/Chromium OS.
Develop a standard protocol to allow userspace applications to communicate with haptic touchpads, and minimize duplicated code and effort.
Requirements:
1. Support UI-initiated haptic feedback.
2. Allow userspace to control when button press and button release haptic effects are triggered. (Useful when detecting a false click, changing force thresholds, or sending context-dependent effects).
3. Reveal force sensor readings to userspace applications.
4. Only allow OS-controlled haptic feedback for those systems which support it.
If this interests you, their technical design document and HID subsystem patch proposals can be found via this Linux kernel mailing list thread. With more laptops coming to market soon equipped with haptic touchpads, this will become a more important topic for vendors in ensuring good Linux hardware support.
