IMXUART_UCR2
bus_space_write_2(iot, ioh, IMXUART_UCR2, sc->sc_ucr2);
sc->sc_ucr2 = bus_space_read_2(iot, ioh, IMXUART_UCR2);
bus_space_write_2(iot, ioh, IMXUART_UCR2, sc->sc_ucr2);
sc->sc_ucr2 = bus_space_read_4(iot, ioh, IMXUART_UCR2);
bus_space_write_4(iot, ioh, IMXUART_UCR2, sc->sc_ucr2);