I2C is OK but :
[ 2.341891] mk_arcade_joystick_rpi: at least one device must be specified
3 possibility in mk_arcade_joystick.conf: all lines are commented, 2 lines are uncommented or a error in the uncommented line.
"options mk_arcade_joystick_rpi ..." need to be in one line, commented or not.
Edit: "gpio" part need 21 numbers, you have 20, add ",-1" at the end and retry please
[ 2.341891] mk_arcade_joystick_rpi: at least one device must be specified
3 possibility in mk_arcade_joystick.conf: all lines are commented, 2 lines are uncommented or a error in the uncommented line.
"options mk_arcade_joystick_rpi ..." need to be in one line, commented or not.
Edit: "gpio" part need 21 numbers, you have 20, add ",-1" at the end and retry please