In order to access GPIO you can follow the kernel GPIO sysfs method that I posted here:
http://forums.freescale.com/t5/i-MX-Microprocessors/iMX28-SYSFS-and-GPIO/td-p/60938
For other peripherals I suggest to take a look at the Linux Reference manual that comes with the BSP documents.
Regards,
Fabio Estevam
Daiane,
Thanks for responding. The i.MX53 for example has GPIO (General Purpose I/O). Does the Ubuntu developement environment provided by FreeScale have drivers, or an API, for the GPIO? In general, you need functions to determine the direction of the I/O (input, output, tri-state), set the I/O, clear the I/O and get the current state of the I/O. Again, does FreeScale provide software to support the GPIO... as well as other peripherlas like CSPI, PWM ... etc.
bb
I don´t understand your question. Can you, please, make yourself clearer?
Do you know unit_test?