SSD210 Write GPIO reg C script

Im reading the files reg_rw.c and gpio_mmap.c trying understand and use the regs, i have a many questions

  1. Why it’s necessary do a shift in bank and offset? Always it will be the same?

  2. Why in reg_rw.c the value write in the reg is

    (0x5B or 0x58)

and in gpio_mmap.c it’s

(0x7B or 0x78)

i understand that the gpio is different, even reading readme in SSD210 Checklist i don’t get the idea.

  1. Can i run a C script without use the devMemMMap and only use registers?