TouchScreen, TouchPad, TouchIC
Atmel MaxTouch MXT224 IC
http://ww1.microchip.com/downloads/en/DeviceDoc/mXT224_1v6_Datasheet_IX.pdf
I found it on a broken Samsung S-Advance i9070 smartphone's display panel, also you can buy I2C touch panels like CTP043 built with this IC.
I couldn't access the communication lines easily, so I disassembled the module. As I only would like to access touch panel, not the display, I've disconnected it.
I've easily connected 2.8V and my CH341a USB/I2C adapter and it works well at 0x4a address.
If I'm right, - as there is a linux kernel driver for it, - somehow I can install it as an input device of my linux. I will try.