zs.c

早期freebsd实现

	    zi->zi_dev.dv_xname, (unit & 1) + 'a', i ? (o ? "i/o" : i) : o);
	cs->cs_consio = 1;
	cs->cs_brkabort = 1;
	return (tp);
}

#ifdef KGDB
/*
 * The kgdb zs port, if any, was altered at boot time (see zs_kgdb_init).
 * Pick up the current speed and character size and restore the original
 * speed.
 */
static void
zs_checkkgdb(int unit, struct zs_chanstate *cs, struct tty *tp)
{

	if (kgdb_dev == makedev(ZSMAJOR, unit)) {
		tp->t_ispeed = tp->t_ospeed = kgdb_rate;
		tp->t_cflag = CS8;
		cs->cs_kgdb = 1;
		cs->cs_speed = zs_kgdb_savedspeed;
		(void) zsparam(tp, &tp->t_termios);
	}
}
#endif

/*
 * Compute the current baud rate given a ZSCC channel.
 */
static int
zs_getspeed(zc)
	register volatile struct zschan *zc;
{
	register int tconst;

	tconst = ZS_READ(zc, 12);
	tconst |= ZS_READ(zc, 13) << 8;
	return (TCONST_TO_BPS(PCLK / 16, tconst));
}


/*
 * Do an internal open.
 */
static void
zsiopen(struct tty *tp)
{

	(void) zsparam(tp, &tp->t_termios);
	ttsetwater(tp);
	tp->t_state = TS_ISOPEN | TS_CARR_ON;
}

/*
 * Do an internal close.  Eventually we should shut off the chip when both
 * ports on it are closed.
 */
static void
zsiclose(struct tty *tp)
{

	ttylclose(tp, 0);	/* ??? */
	ttyclose(tp);		/* ??? */
	tp->t_state = 0;
}


/*
 * Open a zs serial port.  This interface may not be used to open
 * the keyboard and mouse ports. (XXX)
 */
int
zsopen(dev_t dev, int flags, int mode, struct proc *p)
{
	register struct tty *tp;
	register struct zs_chanstate *cs;
	struct zsinfo *zi;
	int unit = minor(dev), zs = unit >> 1, error, s;

	if (zs >= zscd.cd_ndevs || (zi = zscd.cd_devs[zs]) == NULL ||
	    unit == ZS_KBD || unit == ZS_MOUSE)
		return (ENXIO);
	cs = &zi->zi_cs[unit & 1];
	if (cs->cs_consio)
		return (ENXIO);		/* ??? */
	tp = cs->cs_ttyp;
	s = spltty();
	if ((tp->t_state & TS_ISOPEN) == 0) {
		ttychars(tp);
		if (tp->t_ispeed == 0) {
			tp->t_iflag = TTYDEF_IFLAG;
			tp->t_oflag = TTYDEF_OFLAG;
			tp->t_cflag = TTYDEF_CFLAG;
			tp->t_lflag = TTYDEF_LFLAG;
			tp->t_ispeed = tp->t_ospeed = cs->cs_speed;
		}
		(void) zsparam(tp, &tp->t_termios);
		ttsetwater(tp);
	} else if (tp->t_state & TS_XCLUDE && p->p_ucred->cr_uid != 0) {
		splx(s);
		return (EBUSY);
	}
	error = 0;
	for (;;) {
		/* loop, turning on the device, until carrier present */
		zs_modem(cs, 1);
		if (cs->cs_softcar)
			tp->t_state |= TS_CARR_ON;
		if (flags & O_NONBLOCK || tp->t_cflag & CLOCAL ||
		    tp->t_state & TS_CARR_ON)
			break;
		tp->t_state |= TS_WOPEN;
		if (error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
		    ttopen, 0))
			break;
	}
	splx(s);
	if (error == 0)
		error = linesw[tp->t_line].l_open(dev, tp);
	if (error)
		zs_modem(cs, 0);
	return (error);
}

/*
 * Close a zs serial port.
 */
int
zsclose(dev_t dev, int flags, int mode, struct proc *p)
{
	register struct zs_chanstate *cs;
	register struct tty *tp;
	struct zsinfo *zi;
	int unit = minor(dev), s;

	zi = zscd.cd_devs[unit >> 1];
	cs = &zi->zi_cs[unit & 1];
	tp = cs->cs_ttyp;
	linesw[tp->t_line].l_close(tp, flags);
	if (tp->t_cflag & HUPCL || tp->t_state & TS_WOPEN ||
	    (tp->t_state & TS_ISOPEN) == 0) {
		zs_modem(cs, 0);
		/* hold low for 1 second */
		(void) tsleep((caddr_t)cs, TTIPRI, ttclos, hz);
	}
	ttyclose(tp);
#ifdef KGDB
	/* Reset the speed if we're doing kgdb on this port */
	if (cs->cs_kgdb) {
		tp->t_ispeed = tp->t_ospeed = kgdb_rate;
		(void) zsparam(tp, &tp->t_termios);
	}
#endif
	return (0);
}

/*
 * Read/write zs serial port.
 */
int
zsread(dev_t dev, struct uio *uio, int flags)
{
	register struct tty *tp = &zs_tty[minor(dev)];

	return (linesw[tp->t_line].l_read(tp, uio, flags));
}

int
zswrite(dev_t dev, struct uio *uio, int flags)
{
	register struct tty *tp = &zs_tty[minor(dev)];

	return (linesw[tp->t_line].l_write(tp, uio, flags));
}

/*
 * ZS hardware interrupt.  Scan all ZS channels.  NB: we know here that
 * channels are kept in (A,B) pairs.
 *
 * Do just a little, then get out; set a software interrupt if more
 * work is needed.
 *
 * We deliberately ignore the vectoring Zilog gives us, and match up
 * only the number of `reset interrupt under service' operations, not
 * the order.
 */
/* ARGSUSED */
int
zshard(void *intrarg)
{
	register struct zs_chanstate *a;
#define	b (a + 1)
	register volatile struct zschan *zc;
	register int rr3, intflags = 0, v, i;
	static int zsrint(struct zs_chanstate *, volatile struct zschan *);
	static int zsxint(struct zs_chanstate *, volatile struct zschan *);
	static int zssint(struct zs_chanstate *, volatile struct zschan *);

	for (a = zslist; a != NULL; a = b->cs_next) {
		rr3 = ZS_READ(a->cs_zc, 3);
		if (rr3 & (ZSRR3_IP_A_RX|ZSRR3_IP_A_TX|ZSRR3_IP_A_STAT)) {
			intflags |= 2;
			zc = a->cs_zc;
			i = a->cs_rbput;
			if (rr3 & ZSRR3_IP_A_RX && (v = zsrint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_A_TX && (v = zsxint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_A_STAT && (v = zssint(a, zc)) != 0) {
				a->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			a->cs_rbput = i;
		}
		if (rr3 & (ZSRR3_IP_B_RX|ZSRR3_IP_B_TX|ZSRR3_IP_B_STAT)) {
			intflags |= 2;
			zc = b->cs_zc;
			i = b->cs_rbput;
			if (rr3 & ZSRR3_IP_B_RX && (v = zsrint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_B_TX && (v = zsxint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			if (rr3 & ZSRR3_IP_B_STAT && (v = zssint(b, zc)) != 0) {
				b->cs_rbuf[i++ & ZLRB_RING_MASK] = v;
				intflags |= 1;
			}
			b->cs_rbput = i;
		}
	}
#undef b
	if (intflags & 1) {
#if sun4c /* XXX -- but this will go away when zshard moves to locore.s */
		struct clockframe *p = intrarg;

		if ((p->psr & PSR_PIL) < (PIL_TTY << 8)) {
			zsshortcuts++;
			(void) spltty();
			if (zshardscope) {
				LED_ON;
				LED_OFF;
			}
			return (zssoft(intrarg));
		}
#endif
		ienab_bis(IE_ZSSOFT);
	}
	return (intflags & 2);
}

static int
zsrint(register struct zs_chanstate *cs, register volatile struct zschan *zc)
{
	register int c = zc->zc_data;

	if (cs->cs_conk) {
		register struct conk_state *conk = &zsconk_state;

		/*
		 * Check here for console abort function, so that we
		 * can abort even when interrupts are locking up the
		 * machine.
		 */
		if (c == KBD_RESET) {
			conk->conk_id = 1;	/* ignore next byte */
			conk->conk_l1 = 0;
		} else if (conk->conk_id)
			conk->conk_id = 0;	/* stop ignoring bytes */
		else if (c == KBD_L1)
			conk->conk_l1 = 1;	/* L1 went down */
		else if (c == (KBD_L1|KBD_UP))
			conk->conk_l1 = 0;	/* L1 went up */
		else if (c == KBD_A && conk->conk_l1) {
			zsabort();
			conk->conk_l1 = 0;	/* we never see the up */
			goto clearit;		/* eat the A after L1-A */
		}
	}
#ifdef KGDB
	if (c == FRAME_START && cs->cs_kgdb && 
	    (cs->cs_ttyp->t_state & TS_ISOPEN) == 0) {
		zskgdb(cs->cs_unit);
		goto clearit;
	}
#endif
	/* compose receive character and status */
	c <<= 8;
	c |= ZS_READ(zc, 1);

	/* clear receive error & interrupt condition */
	zc->zc_csr = ZSWR0_RESET_ERRORS;
	zc->zc_csr = ZSWR0_CLR_INTR;

	return (ZRING_MAKE(ZRING_RINT, c));

clearit:
	zc->zc_csr = ZSWR0_RESET_ERRORS;
	zc->zc_csr = ZSWR0_CLR_INTR;
	return (0);
}

static int
zsxint(register struct zs_chanstate *cs, register volatile struct zschan *zc)
{
	register int i = cs->cs_tbc;

	if (i == 0) {
		zc->zc_csr = ZSWR0_RESET_TXINT;
		zc->zc_csr = ZSWR0_CLR_INTR;
		return (ZRING_MAKE(ZRING_XINT, 0));
	}
	cs->cs_tbc = i - 1;
	zc->zc_data = *cs->cs_tba++;
	zc->zc_csr = ZSWR0_CLR_INTR;
	return (0);
}

static int
zssint(register struct zs_chanstate *cs, register volatile struct zschan *zc)
{
	register int rr0;

	rr0 = zc->zc_csr;
	zc->zc_csr = ZSWR0_RESET_STATUS;
	zc->zc_csr = ZSWR0_CLR_INTR;
	/*
	 * The chip's hardware flow control is, as noted in zsreg.h,
	 * busted---if the DCD line goes low the chip shuts off the
	 * receiver (!).  If we want hardware CTS flow control but do
	 * not have it, and carrier is now on, turn HFC on; if we have
	 * HFC now but carrier has gone low, turn it off.
	 */
	if (rr0 & ZSRR0_DCD) {
		if (cs->cs_ttyp->t_cflag & CCTS_OFLOW &&
		    (cs->cs_creg[3] & ZSWR3_HFC) == 0) {
			cs->cs_creg[3] |= ZSWR3_HFC;
			ZS_WRITE(zc, 3, cs->cs_creg[3]);
		}
	} else {
		if (cs->cs_creg[3] & ZSWR3_HFC) {
			cs->cs_creg[3] &= ~ZSWR3_HFC;
			ZS_WRITE(zc, 3, cs->cs_creg[3]);
		}
	}
	if ((rr0 & ZSRR0_BREAK) && cs->cs_brkabort) {
		zsabort();
		return (0);
	}
	return (ZRING_MAKE(ZRING_SINT, rr0));
}

zsabort()
{

	printf("stopping on keyboard abort\n");
	callrom();
}

#ifdef KGDB
/*
 * KGDB framing character received: enter kernel debugger.  This probably
 * should time out after a few seconds to avoid hanging on spurious input.
 */
zskgdb(int unit)
{

	printf("zs%d%c: kgdb interrupt\n", unit >> 1, (unit & 1) + 'a');
	kgdb_connect(1);
}
#endif

/*
 * Print out a ring or fifo overrun error message.
 */
static void
zsoverrun(int unit, long *ptime, char *what)
{

	if (*ptime != time.tv_sec) {
		*ptime = time.tv_sec;
		log(LOG_WARNING, "zs%d%c: %s overrun\n", unit >> 1,
		    (unit & 1) + 'a', what);
	}
}

/*
 * ZS software interrupt.  Scan all channels for deferred interrupts.
 */
int
zssoft(void *arg)
{
	register struct zs_chanstate *cs;
	register volatile struct zschan *zc;
	register struct linesw *line;
	register struct tty *tp;
	register int get, n, c, cc, unit, s;

	for (cs = zslist; cs != NULL; cs = cs->cs_next) {
		get = cs->cs_rbget;
again:
		n = cs->cs_rbput;	/* atomic */
		if (get == n)		/* nothing more on this line */
			continue;
		unit = cs->cs_unit;	/* set up to handle interrupts */
		zc = cs->cs_zc;
		tp = cs->cs_ttyp;
		line = &linesw[tp->t_line];
		/*
		 * Compute the number of interrupts in the receive ring.
		 * If the count is overlarge, we lost some events, and
		 * must advance to the first valid one.  It may get
		 * overwritten if more data are arriving, but this is
		 * too expensive to check and gains nothing (we already
		 * lost out; all we can do at this point is trade one
		 * kind of loss for another).
		 */
		n -= get;
		if (n > ZLRB_RING_SIZE) {
			zsoverrun(unit, &cs->cs_rotime, "ring");
			get += n - ZLRB_RING_SIZE;
			n = ZLRB_RING_SIZE;
		}
		while (--n >= 0) {
			/* race to keep ahead of incoming interrupts */