dcm.c

早期freebsd实现

	register char *bp;
	register unsigned tail, next;
	register int port, nch;
	unsigned head;
	char buf[16];
	int s;
#ifdef DCMSTATS
	struct dcmstats *dsp = &dcmstats[BOARD(tp->t_dev)];
	int tch = 0;
#endif

	s = spltty();
#ifdef DCMSTATS
	dsp->xints++;
#endif
#ifdef DEBUG
	if (dcmdebug & DDB_OUTPUT)
		printf("dcmstart(%d): state %x flags %x outcc %d\n",
		       UNIT(tp->t_dev), tp->t_state, tp->t_flags,
		       tp->t_outq.c_cc);
#endif
	if (tp->t_state & (TS_TIMEOUT|TS_BUSY|TS_TTSTOP))
		goto out;
	if (tp->t_outq.c_cc <= tp->t_lowat) {
		if (tp->t_state&TS_ASLEEP) {
			tp->t_state &= ~TS_ASLEEP;
			wakeup((caddr_t)&tp->t_outq);
		}
		selwakeup(&tp->t_wsel);
	}
	if (tp->t_outq.c_cc == 0) {
#ifdef DCMSTATS
		dsp->xempty++;
#endif
		goto out;
	}

	dcm = dcm_addr[BOARD(tp->t_dev)];
	port = PORT(tp->t_dev);
	pp = dcm_preg(dcm, port);
	tail = pp->t_tail & TX_MASK;
	next = (tail + 1) & TX_MASK;
	head = pp->t_head & TX_MASK;
	if (head == next)
		goto out;
	fifo = &dcm->dcm_tfifos[3-port][tail];
again:
	nch = q_to_b(&tp->t_outq, buf, (head - next) & TX_MASK);
#ifdef DCMSTATS
	tch += nch;
#endif
#ifdef DEBUG
	if (dcmdebug & DDB_OUTPUT)
		printf("\thead %x tail %x nch %d\n", head, tail, nch);
#endif
	/*
	 * Loop transmitting all the characters we can.
	 */
	for (bp = buf; --nch >= 0; bp++) {
		fifo->data_char = *bp;
		pp->t_tail = next;
		/*
		 * If this is the first character,
		 * get the hardware moving right now.
		 */
		if (bp == buf) {
			tp->t_state |= TS_BUSY;
			SEM_LOCK(dcm);
			dcm->dcm_cmdtab[port].dcm_data |= CT_TX;
			dcm->dcm_cr |= (1 << port);
			SEM_UNLOCK(dcm);
		}
		tail = next;
		fifo = tail ? fifo+1 : &dcm->dcm_tfifos[3-port][0];
		next = (next + 1) & TX_MASK;
	}
	/*
	 * Head changed while we were loading the buffer,
	 * go back and load some more if we can.
	 */
	if (tp->t_outq.c_cc && head != (pp->t_head & TX_MASK)) {
#ifdef DCMSTATS
		dsp->xrestarts++;
#endif
		head = pp->t_head & TX_MASK;
		goto again;
	}

	/*
	 * Kick it one last time in case it finished while we were
	 * loading the last bunch.
	 */
	if (bp > &buf[1]) {
		tp->t_state |= TS_BUSY;
		SEM_LOCK(dcm);
		dcm->dcm_cmdtab[port].dcm_data |= CT_TX;
		dcm->dcm_cr |= (1 << port);
		SEM_UNLOCK(dcm);
	}
#ifdef DEBUG
	if (dcmdebug & DDB_INTR)
		printf("dcmstart(%d): head %x tail %x outqcc %d\n",
		       UNIT(tp->t_dev), head, tail, tp->t_outq.c_cc);
#endif
out:
#ifdef DCMSTATS
	dsp->xchars += tch;
	if (tch <= DCMXBSIZE)
		dsp->xsilo[tch]++;
	else
		dsp->xsilo[DCMXBSIZE+1]++;
#endif
	splx(s);
}
 
/*
 * Stop output on a line.
 */
dcmstop(tp, flag)
	register struct tty *tp;
	int flag;
{
	int s;

	s = spltty();
	if (tp->t_state & TS_BUSY) {
		/* XXX is there some way to safely stop transmission? */
		if ((tp->t_state&TS_TTSTOP) == 0)
			tp->t_state |= TS_FLUSH;
	}
	splx(s);
}
 
/*
 * Modem control
 */
dcmmctl(dev, bits, how)
	dev_t dev;
	int bits, how;
{
	register struct dcmdevice *dcm;
	int s, unit, brd, hit = 0;

	unit = UNIT(dev);
#ifdef DEBUG
	if (dcmdebug & DDB_MODEM)
		printf("dcmmctl(%d) unit %d  bits 0x%x how %x\n",
		       BOARD(unit), unit, bits, how);
#endif

	brd = BOARD(unit);
	dcm = dcm_addr[brd];
	s = spltty();
	switch (how) {

	case DMSET:
		dcm_modem[unit]->mdmout = bits;
		hit++;
		break;

	case DMBIS:
		dcm_modem[unit]->mdmout |= bits;
		hit++;
		break;

	case DMBIC:
		dcm_modem[unit]->mdmout &= ~bits;
		hit++;
		break;

	case DMGET:
		bits = dcm_modem[unit]->mdmin;
		if (dcmsoftCAR[brd] & FLAG_STDDCE)
			bits = hp2dce_in(bits);
		break;
	}
	if (hit) {
		SEM_LOCK(dcm);
		dcm->dcm_modemchng |= 1<<(unit & 3);
		dcm->dcm_cr |= CR_MODM;
		SEM_UNLOCK(dcm);
		DELAY(10); /* delay until done */
		(void) splx(s);
	}
	return (bits);
}

/*
 * Set board to either interrupt per-character or at a fixed interval.
 */
dcmsetischeme(brd, flags)
	int brd, flags;
{
	register struct dcmdevice *dcm = dcm_addr[brd];
	register struct dcmischeme *dis = &dcmischeme[brd];
	register int i;
	u_char mask;
	int perchar = flags & DIS_PERCHAR;

#ifdef DEBUG
	if (dcmdebug & DDB_INTSCHM)
		printf("dcmsetischeme(%d, %d): cur %d, ints %d, chars %d\n",
		       brd, perchar, dis->dis_perchar,
		       dis->dis_intr, dis->dis_char);
	if ((flags & DIS_RESET) == 0 && perchar == dis->dis_perchar) {
		printf("dcmsetischeme(%d):  redundent request %d\n",
		       brd, perchar);
		return;
	}
#endif
	/*
	 * If perchar is non-zero, we enable interrupts on all characters
	 * otherwise we disable perchar interrupts and use periodic
	 * polling interrupts.
	 */
	dis->dis_perchar = perchar;
	mask = perchar ? 0xf : 0x0;
	for (i = 0; i < 256; i++)
		dcm->dcm_bmap[i].data_data = mask;
	/*
	 * Don't slow down tandem mode, interrupt on flow control
	 * chars for any port on the board.
	 */
	if (!perchar) {
		register struct tty *tp = &dcm_tty[MKUNIT(brd, 0)];
		int c;

		for (i = 0; i < 4; i++, tp++) {
			if ((c = tp->t_cc[VSTART]) != _POSIX_VDISABLE)
				dcm->dcm_bmap[c].data_data |= (1 << i);
			if ((c = tp->t_cc[VSTOP]) != _POSIX_VDISABLE)
				dcm->dcm_bmap[c].data_data |= (1 << i);
		}
	}
	/*
	 * Board starts with timer disabled so if first call is to
	 * set perchar mode then we don't want to toggle the timer.
	 */
	if (flags == (DIS_RESET|DIS_PERCHAR))
		return;
	/*
	 * Toggle card 16.7ms interrupts (we first make sure that card
	 * has cleared the bit so it will see the toggle).
	 */
	while (dcm->dcm_cr & CR_TIMER)
		;
	SEM_LOCK(dcm);
	dcm->dcm_cr |= CR_TIMER;
	SEM_UNLOCK(dcm);
}

/*
 * Following are all routines needed for DCM to act as console
 */
#include <hp/dev/cons.h>

dcmcnprobe(cp)
	struct consdev *cp;
{
	register struct hp_hw *hw;
	int unit;

	/* locate the major number */
	for (dcmmajor = 0; dcmmajor < nchrdev; dcmmajor++)
		if (cdevsw[dcmmajor].d_open == dcmopen)
			break;

	/*
	 * Implicitly assigns the lowest select code DCM card found to be
	 * logical unit 0 (actually CONUNIT).  If your config file does
	 * anything different, you're screwed.
	 */
	for (hw = sc_table; hw->hw_type; hw++)
		if (HW_ISDEV(hw, D_COMMDCM) && !badaddr((short *)hw->hw_kva))
			break;
	if (!HW_ISDEV(hw, D_COMMDCM)) {
		cp->cn_pri = CN_DEAD;
		return;
	}
	unit = CONUNIT;
	dcm_addr[BOARD(CONUNIT)] = (struct dcmdevice *)hw->hw_kva;

	/* initialize required fields */
	cp->cn_dev = makedev(dcmmajor, unit);
	cp->cn_tp = &dcm_tty[unit];
	switch (dcm_addr[BOARD(unit)]->dcm_rsid) {
	case DCMID:
		cp->cn_pri = CN_NORMAL;
		break;
	case DCMID|DCMCON:
		cp->cn_pri = CN_REMOTE;
		break;
	default:
		cp->cn_pri = CN_DEAD;
		return;
	}
	/*
	 * If dcmconsole is initialized, raise our priority.
	 */
	if (dcmconsole == UNIT(unit))
		cp->cn_pri = CN_REMOTE;
#ifdef KGDB_CHEAT
	/*
	 * This doesn't currently work, at least not with ite consoles;
	 * the console hasn't been initialized yet.
	 */
	if (major(kgdb_dev) == dcmmajor && BOARD(kgdb_dev) == BOARD(unit)) {
		(void) dcminit(kgdb_dev, kgdb_rate);
		if (kgdb_debug_init) {
			/*
			 * We assume that console is ready for us...
			 * this assumes that a dca or ite console
			 * has been selected already and will init
			 * on the first putc.
			 */
			printf("dcm%d: ", UNIT(kgdb_dev));
			kgdb_connect(1);
		}
	}
#endif
}

dcmcninit(cp)
	struct consdev *cp;
{
	dcminit(cp->cn_dev, dcmdefaultrate);
	dcmconsinit = 1;
	dcmconsole = UNIT(cp->cn_dev);
}

dcminit(dev, rate)
	dev_t dev;
	int rate;
{
	register struct dcmdevice *dcm = dcm_addr[BOARD(dev)];
	int s, mode, port;

	port = PORT(dev);
	mode = LC_8BITS | LC_1STOP;
	s = splhigh();
	/*
	 * Wait for transmitter buffer to empty.
	 */
	while (dcm->dcm_thead[port].ptr != dcm->dcm_ttail[port].ptr)
		DELAY(DCM_USPERCH(rate));
	/*
	 * Make changes known to hardware.
	 */
	dcm->dcm_data[port].dcm_baud = ttspeedtab(rate, dcmspeedtab);
	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(rate));
	splx(s);
}

dcmcngetc(dev)
	dev_t dev;
{
	register struct dcmdevice *dcm = dcm_addr[BOARD(dev)];
	register struct dcmrfifo *fifo;
	register struct dcmpreg *pp;
	register unsigned head;
	int s, c, stat, port;

	port = PORT(dev);
	pp = dcm_preg(dcm, port);
	s = splhigh();
	head = pp->r_head & RX_MASK;
	fifo = &dcm->dcm_rfifos[3-port][head>>1];
	while (head == (pp->r_tail & RX_MASK))
		;
	/*
	 * If board interrupts are enabled, just let our received char
	 * interrupt through in case some other port on the board was
	 * busy.  Otherwise we must clear the interrupt.
	 */
	SEM_LOCK(dcm);
	if ((dcm->dcm_ic & IC_IE) == 0)
		stat = dcm->dcm_iir;
	SEM_UNLOCK(dcm);
	c = fifo->data_char;
	stat = fifo->data_stat;
	pp->r_head = (head + 2) & RX_MASK;
	splx(s);
	return (c);
}

/*
 * Console kernel output character routine.
 */
dcmcnputc(dev, c)
	dev_t dev;
	int c;
{
	register struct dcmdevice *dcm = dcm_addr[BOARD(dev)];
	register struct dcmpreg *pp;
	unsigned tail;
	int s, port, stat;

	port = PORT(dev);
	pp = dcm_preg(dcm, port);
	s = splhigh();
#ifdef KGDB
	if (dev != kgdb_dev)
#endif
	if (dcmconsinit == 0) {
		(void) dcminit(dev, dcmdefaultrate);
		dcmconsinit = 1;
	}
	tail = pp->t_tail & TX_MASK;
	while (tail != (pp->t_head & TX_MASK))
		;
	dcm->dcm_tfifos[3-port][tail].data_char = c;
	pp->t_tail = tail = (tail + 1) & TX_MASK;
	SEM_LOCK(dcm);
	dcm->dcm_cmdtab[port].dcm_data |= CT_TX;
	dcm->dcm_cr |= (1 << port);
	SEM_UNLOCK(dcm);
	while (tail != (pp->t_head & TX_MASK))
		;
	/*
	 * If board interrupts are enabled, just let our completion
	 * interrupt through in case some other port on the board
	 * was busy.  Otherwise we must clear the interrupt.
	 */
	if ((dcm->dcm_ic & IC_IE) == 0) {
		SEM_LOCK(dcm);
		stat = dcm->dcm_iir;
		SEM_UNLOCK(dcm);
	}
	splx(s);
}
#endif