dcm.c

早期freebsd实现

{
	int unit = UNIT(dev);
	register struct tty *tp;
 
	tp = &dcm_tty[unit];
	/*
	 * XXX we disallow virtual consoles if the physical console is
	 * a serial port.  This is in case there is a display attached that
	 * is not the console.  In that situation we don't need/want the X
	 * server taking over the console.
	 */
	if (constty && unit == dcmconsole)
		constty = NULL;
	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}
 
dcmintr(brd)
	register int brd;
{
	register struct dcmdevice *dcm = dcm_addr[brd];
	register struct dcmischeme *dis;
	register int unit = MKUNIT(brd, 0);
	register int code, i;
	int pcnd[4], mcode, mcnd[4];

	/*
	 * Do all guarded register accesses right off to minimize
	 * block out of hardware.
	 */
	SEM_LOCK(dcm);
	if ((dcm->dcm_ic & IC_IR) == 0) {
		SEM_UNLOCK(dcm);
		return (0);
	}
	for (i = 0; i < 4; i++) {
		pcnd[i] = dcm->dcm_icrtab[i].dcm_data;
		dcm->dcm_icrtab[i].dcm_data = 0;
		code = dcm_modem[unit+i]->mdmin;
		if (dcmsoftCAR[brd] & FLAG_STDDCE)
			code = hp2dce_in(code);
		mcnd[i] = code;
	}
	code = dcm->dcm_iir & IIR_MASK;
	dcm->dcm_iir = 0;	/* XXX doc claims read clears interrupt?! */
	mcode = dcm->dcm_modemintr;
	dcm->dcm_modemintr = 0;
	SEM_UNLOCK(dcm);

#ifdef DEBUG
	if (dcmdebug & DDB_INTR) {
		printf("dcmintr(%d): iir %x pc %x/%x/%x/%x ",
		       brd, code, pcnd[0], pcnd[1], pcnd[2], pcnd[3]); 
		printf("miir %x mc %x/%x/%x/%x\n",
		       mcode, mcnd[0], mcnd[1], mcnd[2], mcnd[3]);
	}
#endif
	if (code & IIR_TIMEO)
		dcmrint(brd, dcm);
	if (code & IIR_PORT0)
		dcmpint(unit+0, pcnd[0], dcm);
	if (code & IIR_PORT1)
		dcmpint(unit+1, pcnd[1], dcm);
	if (code & IIR_PORT2)
		dcmpint(unit+2, pcnd[2], dcm);
	if (code & IIR_PORT3)
		dcmpint(unit+3, pcnd[3], dcm);
	if (code & IIR_MODM) {
		if (mcode == 0 || mcode & 0x1)	/* mcode==0 -> 98642 board */
			dcmmint(unit+0, mcnd[0], dcm);
		if (mcode & 0x2)
			dcmmint(unit+1, mcnd[1], dcm);
		if (mcode & 0x4)
			dcmmint(unit+2, mcnd[2], dcm);
		if (mcode & 0x8)
			dcmmint(unit+3, mcnd[3], dcm);
	}

	dis = &dcmischeme[brd];
	/*
	 * Chalk up a receiver interrupt if the timer running or one of
	 * the ports reports a special character interrupt.
	 */
	if ((code & IIR_TIMEO) ||
	    ((pcnd[0]|pcnd[1]|pcnd[2]|pcnd[3]) & IT_SPEC))
		dis->dis_intr++;
	/*
	 * See if it is time to check/change the interrupt rate.
	 */
	if (dcmistype < 0 &&
	    (i = time.tv_sec - dis->dis_time) >= dcminterval) {
		/*
		 * If currently per-character and averaged over 70 interrupts
		 * per-second (66 is threshold of 600 baud) in last interval,
		 * switch to timer mode.
		 *
		 * XXX decay counts ala load average to avoid spikes?
		 */
		if (dis->dis_perchar && dis->dis_intr > 70 * i)
			dcmsetischeme(brd, DIS_TIMER);
		/*
		 * If currently using timer and had more interrupts than
		 * received characters in the last interval, switch back
		 * to per-character.  Note that after changing to per-char
		 * we must process any characters already in the queue
		 * since they may have arrived before the bitmap was setup.
		 *
		 * XXX decay counts?
		 */
		else if (!dis->dis_perchar && dis->dis_intr > dis->dis_char) {
			dcmsetischeme(brd, DIS_PERCHAR);
			dcmrint(brd, dcm);
		}
		dis->dis_intr = dis->dis_char = 0;
		dis->dis_time = time.tv_sec;
	}
	return (1);
}

/*
 *  Port interrupt.  Can be two things:
 *	First, it might be a special character (exception interrupt);
 *	Second, it may be a buffer empty (transmit interrupt);
 */
dcmpint(unit, code, dcm)
	int unit, code;
	struct dcmdevice *dcm;
{
	struct tty *tp = &dcm_tty[unit];

	if (code & IT_SPEC)
		dcmreadbuf(unit, dcm, tp);
	if (code & IT_TX)
		dcmxint(unit, dcm, tp);
}

dcmrint(brd, dcm)
	int brd;
	register struct dcmdevice *dcm;
{
	register int i, unit;
	register struct tty *tp;

	unit = MKUNIT(brd, 0);
	tp = &dcm_tty[unit];
	for (i = 0; i < 4; i++, tp++, unit++)
		dcmreadbuf(unit, dcm, tp);
}

dcmreadbuf(unit, dcm, tp)
	int unit;
	register struct dcmdevice *dcm;
	register struct tty *tp;
{
	int port = PORT(unit);
	register struct dcmpreg *pp = dcm_preg(dcm, port);
	register struct dcmrfifo *fifo;
	register int c, stat;
	register unsigned head;
	int nch = 0;
#ifdef DCMSTATS
	struct dcmstats *dsp = &dcmstats[BOARD(unit)];

	dsp->rints++;
#endif
	if ((tp->t_state & TS_ISOPEN) == 0) {
#ifdef KGDB
		if ((makedev(dcmmajor, unit) == kgdb_dev) &&
		    (head = pp->r_head & RX_MASK) != (pp->r_tail & RX_MASK) &&
		    dcm->dcm_rfifos[3-port][head>>1].data_char == FRAME_START) {
			pp->r_head = (head + 2) & RX_MASK;
			kgdb_connect(0);	/* trap into kgdb */
			return;
		}
#endif /* KGDB */
		pp->r_head = pp->r_tail & RX_MASK;
		return;
	}

	head = pp->r_head & RX_MASK;
	fifo = &dcm->dcm_rfifos[3-port][head>>1];
	/*
	 * XXX upper bound on how many chars we will take in one swallow?
	 */
	while (head != (pp->r_tail & RX_MASK)) {
		/*
		 * Get character/status and update head pointer as fast
		 * as possible to make room for more characters.
		 */
		c = fifo->data_char;
		stat = fifo->data_stat;
		head = (head + 2) & RX_MASK;
		pp->r_head = head;
		fifo = head ? fifo+1 : &dcm->dcm_rfifos[3-port][0];
		nch++;

#ifdef DEBUG
		if (dcmdebug & DDB_INPUT)
			printf("dcmreadbuf(%d): c%x('%c') s%x f%x h%x t%x\n",
			       unit, c&0xFF, c, stat&0xFF,
			       tp->t_flags, head, pp->r_tail);
#endif
		/*
		 * Check for and handle errors
		 */
		if (stat & RD_MASK) {
#ifdef DEBUG
			if (dcmdebug & (DDB_INPUT|DDB_SIOERR))
				printf("dcmreadbuf(%d): err: c%x('%c') s%x\n",
				       unit, stat, c&0xFF, c);
#endif
			if (stat & (RD_BD | RD_FE))
				c |= TTY_FE;
			else if (stat & RD_PE)
				c |= TTY_PE;
			else if (stat & RD_OVF)
				log(LOG_WARNING,
				    "dcm%d: silo overflow\n", unit);
			else if (stat & RD_OE)
				log(LOG_WARNING,
				    "dcm%d: uart overflow\n", unit);
		}
		(*linesw[tp->t_line].l_rint)(c, tp);
	}
	dcmischeme[BOARD(unit)].dis_char += nch;
#ifdef DCMSTATS
	dsp->rchars += nch;
	if (nch <= DCMRBSIZE)
		dsp->rsilo[nch]++;
	else
		dsp->rsilo[DCMRBSIZE+1]++;
#endif
}

dcmxint(unit, dcm, tp)
	int unit;
	struct dcmdevice *dcm;
	register struct tty *tp;
{
	tp->t_state &= ~TS_BUSY;
	if (tp->t_state & TS_FLUSH)
		tp->t_state &= ~TS_FLUSH;
	(*linesw[tp->t_line].l_start)(tp);
}

dcmmint(unit, mcnd, dcm)
	register int unit;
	register struct dcmdevice *dcm;
        int mcnd;
{
	register struct tty *tp;
	int delta;

#ifdef DEBUG
	if (dcmdebug & DDB_MODEM)
		printf("dcmmint: port %d mcnd %x mcndlast %x\n",
		       unit, mcnd, mcndlast[unit]);
#endif
	tp = &dcm_tty[unit];
	delta = mcnd ^ mcndlast[unit];
	mcndlast[unit] = mcnd;
	if ((delta & MI_CTS) && (tp->t_state & TS_ISOPEN) &&
	    (tp->t_flags & CCTS_OFLOW)) {
		if (mcnd & MI_CTS) {
			tp->t_state &= ~TS_TTSTOP;
			ttstart(tp);
		} else
			tp->t_state |= TS_TTSTOP;	/* inline dcmstop */
	}
	if (delta & MI_CD) {
		if (mcnd & MI_CD)
			(void)(*linesw[tp->t_line].l_modem)(tp, 1);
		else if ((dcmsoftCAR[BOARD(unit)] & (1 << PORT(unit))) == 0 &&
		    (*linesw[tp->t_line].l_modem)(tp, 0) == 0) {
			dcm_modem[unit]->mdmout = MO_OFF;
			SEM_LOCK(dcm);
			dcm->dcm_modemchng |= 1<<(unit & 3);
			dcm->dcm_cr |= CR_MODM;
			SEM_UNLOCK(dcm);
			DELAY(10); /* time to change lines */
		}
	}
}

dcmioctl(dev, cmd, data, flag, p)
	dev_t dev;
	int cmd;
	caddr_t data;
	int flag;
	struct proc *p;
{
	register struct tty *tp;
	register int unit = UNIT(dev);
	register struct dcmdevice *dcm;
	register int port;
	int error, s;
 
#ifdef DEBUG
	if (dcmdebug & DDB_IOCTL)
		printf("dcmioctl: unit %d cmd %x data %x flag %x\n",
		       unit, cmd, *data, flag);
#endif
	tp = &dcm_tty[unit];
	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
	if (error >= 0)
		return (error);
	error = ttioctl(tp, cmd, data, flag);
	if (error >= 0)
		return (error);

	port = PORT(unit);
	dcm = dcm_addr[BOARD(unit)];
	switch (cmd) {
	case TIOCSBRK:
		/*
		 * Wait for transmitter buffer to empty
		 */
		s = spltty();
		while (dcm->dcm_thead[port].ptr != dcm->dcm_ttail[port].ptr)
			DELAY(DCM_USPERCH(tp->t_ospeed));
		SEM_LOCK(dcm);
		dcm->dcm_cmdtab[port].dcm_data |= CT_BRK;
		dcm->dcm_cr |= (1 << port);	/* start break */
		SEM_UNLOCK(dcm);
		splx(s);
		break;

	case TIOCCBRK:
		SEM_LOCK(dcm);
		dcm->dcm_cmdtab[port].dcm_data |= CT_BRK;
		dcm->dcm_cr |= (1 << port);	/* end break */
		SEM_UNLOCK(dcm);
		break;

	case TIOCSDTR:
		(void) dcmmctl(dev, MO_ON, DMBIS);
		break;

	case TIOCCDTR:
		(void) dcmmctl(dev, MO_ON, DMBIC);
		break;

	case TIOCMSET:
		(void) dcmmctl(dev, *(int *)data, DMSET);
		break;

	case TIOCMBIS:
		(void) dcmmctl(dev, *(int *)data, DMBIS);
		break;

	case TIOCMBIC:
		(void) dcmmctl(dev, *(int *)data, DMBIC);
		break;

	case TIOCMGET:
		*(int *)data = dcmmctl(dev, 0, DMGET);
		break;

	default:
		return (ENOTTY);
	}
	return (0);
}

dcmparam(tp, t)
	register struct tty *tp;
	register struct termios *t;
{
	register struct dcmdevice *dcm;
	register int port, mode, cflag = t->c_cflag;
	int ospeed = ttspeedtab(t->c_ospeed, dcmspeedtab);

	/* check requested parameters */
        if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
                return (EINVAL);
        /* and copy to tty */
        tp->t_ispeed = t->c_ispeed;
        tp->t_ospeed = t->c_ospeed;
        tp->t_cflag = cflag;
	if (ospeed == 0) {
		(void) dcmmctl(UNIT(tp->t_dev), MO_OFF, DMSET);
		return (0);
	}

	mode = 0;
	switch (cflag&CSIZE) {
	case CS5:
		mode = LC_5BITS; break;
	case CS6:
		mode = LC_6BITS; break;
	case CS7:
		mode = LC_7BITS; break;
	case CS8:
		mode = LC_8BITS; break;
	}
	if (cflag&PARENB) {
		if (cflag&PARODD)
			mode |= LC_PODD;
		else
			mode |= LC_PEVEN;
	}
	if (cflag&CSTOPB)
		mode |= LC_2STOP;
	else
		mode |= LC_1STOP;
#ifdef DEBUG
	if (dcmdebug & DDB_PARAM)
		printf("dcmparam(%d): cflag %x mode %x speed %d uperch %d\n",
		       UNIT(tp->t_dev), cflag, mode, tp->t_ospeed,
		       DCM_USPERCH(tp->t_ospeed));
#endif

	port = PORT(tp->t_dev);
	dcm = dcm_addr[BOARD(tp->t_dev)];
	/*
	 * Wait for transmitter buffer to empty.
	 */
	while (dcm->dcm_thead[port].ptr != dcm->dcm_ttail[port].ptr)
		DELAY(DCM_USPERCH(tp->t_ospeed));
	/*
	 * Make changes known to hardware.
	 */
	dcm->dcm_data[port].dcm_baud = ospeed;
	dcm->dcm_data[port].dcm_conf = mode;
	SEM_LOCK(dcm);
	dcm->dcm_cmdtab[port].dcm_data |= CT_CON;
	dcm->dcm_cr |= (1 << port);
	SEM_UNLOCK(dcm);
	/*
	 * Delay for config change to take place. Weighted by baud.
	 * XXX why do we do this?
	 */
	DELAY(16 * DCM_USPERCH(tp->t_ospeed));
	return (0);
}
 
void
dcmstart(tp)
	register struct tty *tp;
{
	register struct dcmdevice *dcm;
	register struct dcmpreg *pp;
	register struct dcmtfifo *fifo;