If you switch from Windows to Linux the touch panel reports the positions in absolute coordinates. So I figured out the protocol. Then I disassembled the windows driver to get the init sequence.
write_ack(fd, 0xe6); write_ack(fd, 0xf3); write_ack(fd, 0x28); write_ack(fd, 0xe8); write_ack(fd, 0x3); write_ack(fd, 0xe8); write_ack(fd, 0x7); write_ack(fd, 0xf4); write_ack(fd, 0xf4); write_ack(fd, 0xf4);
Byte 0 ------ Bit 0: - Bit 1: - Bit 2: if set, pen is pressed on the screen Bit 3: if not set, report comes from the pen Bit 4: Bit 8 of x Bit 5: Bit 9 of x Bit 6: Bit 8 of y Bit 7: Bit 9 of y Byte 1 ------ Bit 0 - 7 of the x coordinate Byte 2 ------ Bit 0 - 7 of the y coordinate
(0, 0) is on the left bottom.