GPIO access problem with R-Car Starter Kit Pro
Fragment of a discussion from Talk:R-Car/Boards/Yocto-Gen3
I think gpio module is initialized in ATF until v2.12.0 at least.
But, for any reasons, it maybe removed.
So, it may work to add to initialize any register (it is clock of modules? , or switch of module?) to your program.
Is it possible to investigate how to initialize gpio module?