IOHIDDeviceRegisterInputValueCallback(device, input_callback, (__bridge void*)controller);
Joystick *js = [[Joystick alloc] initWithDevice:device];
js.index = findAvailableIndex(controller.joysticks, js);
IOHIDDeviceRegisterInputValueCallback(device, input_callback, (__bridge void*)controller);
Joystick *js = [[Joystick alloc] initWithDevice:device];
js.index = findAvailableIndex(controller.joysticks, js);