We received word on Twitter today that J0lama updated his DualShock 4 USB Linux Library bringing it to DS4Lib 1.0 and adding TouchPAD Tracking support with help from s0cKrate5! 
Download: DS4Lib-master.zip / DS4Lib GIT / DS4Lib Website / J0lama Twitter / J0lama YouTube Channel / J0lama Github
To quote from the updated README.md: DS4Lib 1.0
Introduction
This is a simple Linux library written to control the Dualshock 4 through USB. This library reads the data from a temporal file created in /dev/input/ when you plug in the DS4.
Functions
All functions are in ds4.h. Include this file to your proyect to be able to use DS4Lib.
DS4Lib 1.0 adds touchpad tracking. You can get the status of the new pressable buttons (TPAD_CLICK, TPAD_TOUCH) declared in buttons with the usual button_pressed() function. You can also retrieve the coordinates of your finger on the touchpad with the new 'ds4_get_tpad_coord(DS4_CONTROLLER * ds4)' function.
x-axis
In future versions DS4Lib will include tracking of touchPAD and gyroscope/accelerometer values in real time.
Changelog
DS4Lib 1.0: Add Touchpad tracking
DS4Lib 0.9: Add Joystick tracking.
j0lama: Buttons and Joysticks tracking.
s0cKrate5: TouchPAD tracking.
Thanks @j0lama for the message on Twitter of your DS4Lib 1.0 update!
Download: DS4Lib-master.zip / DS4Lib GIT / DS4Lib Website / J0lama Twitter / J0lama YouTube Channel / J0lama Github
To quote from the updated README.md: DS4Lib 1.0
Introduction

Functions
All functions are in ds4.h. Include this file to your proyect to be able to use DS4Lib.
- DS4_CONTROLLER * ini_DS4();
- int free_DS4(DS4_CONTROLLER * ds4);
- int button_pressed(DS4_CONTROLLER * ds4, int Button);
- int ds4_update_status(DS4_CONTROLLER * ds4, char * data);
- int ds4_print_status(DS4_CONTROLLER * ds4);
- int ds4_get_joyL_hor(DS4_CONTROLLER * ds4);
- int ds4_get_joyL_ver(DS4_CONTROLLER * ds4);
- int ds4_get_joyR_hor(DS4_CONTROLLER * ds4);
- int ds4_get_joyR_ver(DS4_CONTROLLER * ds4);
- int ds4_get_tpad_coord(DS4_CONTROLLER * ds4);*

x-axis
Code:
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Changelog
DS4Lib 1.0: Add Touchpad tracking
DS4Lib 0.9: Add Joystick tracking.
- Tracking of all buttons and Joysticks.
- Tracking of all buttons.
j0lama: Buttons and Joysticks tracking.
s0cKrate5: TouchPAD tracking.
Thanks @j0lama for the message on Twitter of your DS4Lib 1.0 update!