Paridhi,
Be sure to read the comments in the cpp file. I have a lot of technical detail that I cover there. Since you are looking at the touchscreen driver, does that mean you got past some of the other display errors you had? Care to post some details to help others?
The driver isn't a normal Linux driver. It is just a user-mode application that talks to a Linux driver. You need the uinput kernel module installed but that is the only thing you need to do with the kernel. You compile the cpp file with gcc. I compiled it directly on the Galileo board but Bobzin posted some info on how to cross compile. The compiler flags to specify are in the touch.cpp comments. Once compiled, you just run it. As long as it is running, it will be polling the device and sending the touchscreen cooridinates to the uinput driver. Any application, such as XOrg that supports the kernel input driver interface will see it just the same as if you plugged in a USB touchscreen.