OMAP3 GPIO keyboard interface : simultaneous key input available ?

Champs,

My customer plans tous OMAP3 GPIO ports for keyboard input .

In this case,  is the multiple keyboard inputs simultaneously  available ?   

If yes, how many simultaneous inputs can be acceptable ?

In addition, is there any restriction of GPIO ports ?( any GPIO pins available for keyboard raw/column inputs ?)

Thanks and Regards,

Sumiko Yamaji