To my experience, Elantech touchpads are quite common at modern laptops and do have some issues arising from time to time. And I do have one in my Xiaomi RedmiBook laptop - it is ELAN2305:00 04F3:3122 (to my knowledge, it is connected via PS/2 interface).
After upgrading Linux kernel (to be exact, I am referring to sys-kernel/gentoo-kernel Gentoo package with savedconfig USE-flag enabled) from 5.15.88 to 6.1.22, I have lost my touchpad (only i2c device is seen but not detected by libinput).
Firstly, I assumed something was messed up in my config after upgrade from 5.x to 6.x branch. I have booted into Gentoo Minimal Installation CD, but the issue persisted.
At this step I was already confused, but after searching for similar problem I
have found AMD-specific Linux kernel config entry: CONFIG_PINCTRL_AMD.
After comparing 5.15.88’s and 6.1.22’s configs, I have found the reason why
touchpad stoped from proprely functioning at newer kernels:
CONFIG_PINCTRL_AMD=m. For some reason it cannot be built as a module anymore,
thus the change from
=y solved the issue. Thanks to @loqs for
mentioning this kernel knob!