maple_enable_periodic
maple_enable_periodic(sc->sc_dev, u, fn->f_funcno, 0);
void maple_enable_periodic(device_t, struct maple_unit *,
maple_enable_periodic(parent, sc->sc_unit, MAPLE_FN_KEYBOARD, 1);
maple_enable_periodic(sc->sc_parent, sc->sc_unit, MAPLE_FN_MOUSE, 1);
maple_enable_periodic(sc->sc_parent, sc->sc_unit, MAPLE_FN_MOUSE, 0);