BCM2835_STIMER_CLO
stcl = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO);
last = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO);
BCM2835_STIMER_CLO);
curr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO);
return bus_space_read_4(sc->sc_iot, sc->sc_ioh, BCM2835_STIMER_CLO);