Convert spaces to tabs
Add a simple .gitignore
Remove unneeded file gpio.h
proper use of input_mt library

Still some work to do, but better with this:
- drivers should not care about tracking id
Use a reasonable value for the number of touches

255 is pretty big, and it takes a lot of space to allocate the memory
to handle such big number of touches in the kernel, and later in
X/libinput.

Clamp to ten.
Strip trailing spaces
Remove unused #defines

GTP_CREATE_WR_NODE and GUP_USE_HEADER_FILE are unused.
GTP_DEBUG_ARRAY_ON is unused and has no point:
printk("%*ph", size, array); does the job better
Format braces according to kernel coding style

Plus some tabs changes
Strip trailing whitespaces in gt9xx.h
Removed custom GTP_GPIO_AS_INT

It is defined as gpio_direction_input, so use the kernel API
Remove unused custom GTP_GPIO_GET_VALUE
Remove custom GTP_GPIO_OUTPUT

and use the kernel API gpio_direction_output()
Remove unused GTP_GPIO_REQUEST
Remove custom GTP_GPIO_FREE

and use the kernel API gpio_free()