MAPLEPORT
if (MAPLEPORT(dev) >= MAPLE_PORTS)
if (!(sc->sc_port_units[MAPLEPORT(dev)] & (1 << MAPLESUBUNIT(dev))))
sc->sc_port_units_open[MAPLEPORT(dev)] |= 1 << MAPLESUBUNIT(dev);
sc->sc_port_units_open[MAPLEPORT(dev)] &= ~(1 << MAPLESUBUNIT(dev));
u = &sc->sc_unit[MAPLEPORT(dev)][MAPLESUBUNIT(dev)];