BBC_GPIOBANK_INDEX
BBC_GPIOBANK_INDEX, 0x22);
bus_space_read_1(sc->sc_iot, sc->sc_gpiobankh, BBC_GPIOBANK_INDEX);
bus_space_write_1(sc->sc_iot, sc->sc_gpiobankh,BBC_GPIOBANK_INDEX, reg);
bus_space_read_1(sc->sc_iot, sc->sc_gpiobankh, BBC_GPIOBANK_INDEX);