Function attimer_attach

freebsd/x86/isa/clock.c:556–620

}

static int
attimer_attach(device_t dev)
{
	struct attimer_softc *sc;
	rman_res_t s;
	int i;

	attimer_sc = sc = device_get_softc(dev);
	bzero(sc, sizeof(struct attimer_softc));
	if (!(sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
	    &sc->port_rid, IO_TIMER1, IO_TIMER1 + 3, 4, RF_ACTIVE)))
		device_printf(dev,"Warning: Couldn't map I/O.\n");
	i8254_intsrc = intr_lookup_source(0);
	if (i8254_intsrc != NULL)
		i8254_pending = i8254_intsrc->is_pic->pic_source_pending;
	resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "timecounter", &i8254_timecounter);
	set_i8254_freq(MODE_STOP, 0);
	if (i8254_timecounter) {
		sc->tc.tc_get_timecount = i8254_get_timecount;
		sc->tc.tc_counter_mask = 0xffff;
		sc->tc.tc_frequency = i8254_freq;
		sc->tc.tc_name = "i8254";
		sc->tc.tc_quality = 0;
		sc->tc.tc_priv = dev;
		tc_init(&sc->tc);
	}
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "clock", &i) != 0 || i != 0) {
	    	sc->intr_rid = 0;
		while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid,
		    &s, NULL) == 0 && s != 0)
			sc->intr_rid++;
		if (!(sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ,
		    &sc->intr_rid, 0, 0, 1, RF_ACTIVE))) {
			device_printf(dev,"Can't map interrupt.\n");
			return (0);
		}
		/* Dirty hack, to make bus_setup_intr to not enable source. */
		i8254_intsrc->is_handlers++;
		if ((bus_setup_intr(dev, sc->intr_res,
		    INTR_MPSAFE | INTR_TYPE_CLK,
		    (driver_filter_t *)clkintr, NULL,
		    sc, &sc->intr_handler))) {
			device_printf(dev, "Can't setup interrupt.\n");
			i8254_intsrc->is_handlers--;
			return (0);
		}
		i8254_intsrc->is_handlers--;
		i8254_intsrc->is_pic->pic_enable_intr(i8254_intsrc);
		sc->et.et_name = "i8254";
		sc->et.et_flags = ET_FLAGS_PERIODIC;
		if (!i8254_timecounter)
			sc->et.et_flags |= ET_FLAGS_ONESHOT;
		sc->et.et_quality = 100;
		sc->et.et_frequency = i8254_freq;
		sc->et.et_min_period = (0x0002LLU << 32) / i8254_freq;
		sc->et.et_max_period = (0xfffeLLU << 32) / i8254_freq;