GPIO_PEUP
reg = bus_space_read_4(sc->sc_iot, sc->sc_gpio_ioh, GPIO_PEUP);
bus_space_write_4(sc->sc_iot, sc->sc_gpio_ioh, GPIO_PEUP, reg);
peup = bus_space_read_4(iot, gpioh, GPIO_PEUP);
bus_space_write_4(iot, gpioh, GPIO_PEUP, peup);
IOW(S3C2410_GPIO_BASE+GPIO_PEUP, 0xffff);