rate = comspeed(rate, frequency);
rate = comspeed(comdefaultrate);
cominit(iot, iobase, rate, frequency, cflag, iohp)	bus_space_tag_t iot;	int iobase;	int rate, frequency;	tcflag_t cflag;	bus_space_handle_t *iohp;{	bus_space_handle_t ioh;	if (bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh))		return (ENOMEM); /* ??? */	bus_space_write_1(iot, ioh, com_lcr, LCR_EERS);	bus_space_write_1(iot, ioh, com_efr, 0);	bus_space_write_1(iot, ioh, com_lcr, LCR_DLAB);	rate = comspeed(rate, frequency);	bus_space_write_1(iot, ioh, com_dlbl, rate);	bus_space_write_1(iot, ioh, com_dlbh, rate >> 8);	bus_space_write_1(iot, ioh, com_lcr, com_cflag2lcr(cflag));	bus_space_write_1(iot, ioh, com_mcr, 0);	bus_space_write_1(iot, ioh, com_fifo,	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);	bus_space_write_1(iot, ioh, com_ier, 0);	*iohp = ioh;	return (0);}