LEDS_UPDATE_INTERVAL
callout_reset(&sc->sc_c, mstohz(LEDS_UPDATE_INTERVAL), mpcsa_leds_timer, sc);
callout_schedule(&sc->sc_c, mstohz(LEDS_UPDATE_INTERVAL));
interval = (interval + LEDS_UPDATE_INTERVAL + 1) / LEDS_UPDATE_INTERVAL;