Hello edcloudcycle,
The driver is on yocto drivers/clocksource/timer-imx-gpt.c
The timer module utilizes four hardware timers, to implement clock source and clock event objects.
This is done with the clocksource_mxc structure of struct clocksource type and clockevent_mxc structure of struct clockevent_device type. Both structures provide routines required for reading current timer values and scheduling the next timer event.
The driver works well if you want to change it you can do it.
Regards