zs.c

早期freebsd实现

			c = cs->cs_rbuf[get++ & ZLRB_RING_MASK];
			switch (ZRING_TYPE(c)) {

			case ZRING_RINT:
				c = ZRING_VALUE(c);
				if (c & ZSRR1_DO)
					zsoverrun(unit, &cs->cs_fotime, "fifo");
				cc = c >> 8;
				if (c & ZSRR1_FE)
					cc |= TTY_FE;
				if (c & ZSRR1_PE)
					cc |= TTY_PE;
				/*
				 * this should be done through
				 * bstreams	XXX gag choke
				 */
				if (unit == ZS_KBD)
					kbd_rint(cc);
				else if (unit == ZS_MOUSE)
					ms_rint(cc);
				else
					line->l_rint(cc, tp);
				break;

			case ZRING_XINT:
				/*
				 * Transmit done: change registers and resume,
				 * or clear BUSY.
				 */
				if (cs->cs_heldchange) {
					s = splzs();
					c = zc->zc_csr;
					if ((c & ZSRR0_DCD) == 0)
						cs->cs_preg[3] &= ~ZSWR3_HFC;
					bcopy((caddr_t)cs->cs_preg,
					    (caddr_t)cs->cs_creg, 16);
					zs_loadchannelregs(zc, cs->cs_creg);
					splx(s);
					cs->cs_heldchange = 0;
					if (cs->cs_heldtbc &&
					    (tp->t_state & TS_TTSTOP) == 0) {
						cs->cs_tbc = cs->cs_heldtbc - 1;
						zc->zc_data = *cs->cs_tba++;
						goto again;
					}
				}
				tp->t_state &= ~TS_BUSY;
				if (tp->t_state & TS_FLUSH)
					tp->t_state &= ~TS_FLUSH;
				else
					ndflush(&tp->t_outq,
					    cs->cs_tba - tp->t_outq.c_cf);
				line->l_start(tp);
				break;

			case ZRING_SINT:
				/*
				 * Status line change.  HFC bit is run in
				 * hardware interrupt, to avoid locking
				 * at splzs here.
				 */
				c = ZRING_VALUE(c);
				if ((c ^ cs->cs_rr0) & ZSRR0_DCD) {
					cc = (c & ZSRR0_DCD) != 0;
					if (line->l_modem(tp, cc) == 0)
						zs_modem(cs, cc);
				}
				cs->cs_rr0 = c;
				break;

			default:
				log(LOG_ERR, "zs%d%c: bad ZRING_TYPE (%x)\n",
				    unit >> 1, (unit & 1) + 'a', c);
				break;
			}
		}
		cs->cs_rbget = get;
		goto again;
	}
	return (1);
}

int
zsioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
{
	int unit = minor(dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];
	register struct tty *tp = zi->zi_cs[unit & 1].cs_ttyp;
	register int error;

	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);

	switch (cmd) {

	case TIOCSBRK:
		/* FINISH ME ... need implicit TIOCCBRK in zsclose as well */

	case TIOCCBRK:

	case TIOCSDTR:

	case TIOCCDTR:

	case TIOCMSET:

	case TIOCMBIS:

	case TIOCMBIC:

	case TIOCMGET:

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

/*
 * Start or restart transmission.
 */
static void
zsstart(register struct tty *tp)
{
	register struct zs_chanstate *cs;
	register int s, nch;
	int unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];

	cs = &zi->zi_cs[unit & 1];
	s = spltty();

	/*
	 * If currently active or delaying, no need to do anything.
	 */
	if (tp->t_state & (TS_TIMEOUT | TS_BUSY | TS_TTSTOP))
		goto out;

	/*
	 * If there are sleepers, and output has drained below low
	 * water mark, awaken.
	 */
	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);
	}

	nch = ndqb(&tp->t_outq, 0);	/* XXX */
	if (nch) {
		register char *p = tp->t_outq.c_cf;

		/* mark busy, enable tx done interrupts, & send first byte */
		tp->t_state |= TS_BUSY;
		(void) splzs();
		cs->cs_preg[1] |= ZSWR1_TIE;
		cs->cs_creg[1] |= ZSWR1_TIE;
		ZS_WRITE(cs->cs_zc, 1, cs->cs_creg[1]);
		cs->cs_zc->zc_data = *p;
		cs->cs_tba = p + 1;
		cs->cs_tbc = nch - 1;
	} else {
		/*
		 * Nothing to send, turn off transmit done interrupts.
		 * This is useful if something is doing polled output.
		 */
		(void) splzs();
		cs->cs_preg[1] &= ~ZSWR1_TIE;
		cs->cs_creg[1] &= ~ZSWR1_TIE;
		ZS_WRITE(cs->cs_zc, 1, cs->cs_creg[1]);
	}
out:
	splx(s);
}

/*
 * Stop output, e.g., for ^S or output flush.
 */
static void
zsstop(register struct tty *tp, int flag)
{
	register struct zs_chanstate *cs;
	register int s, unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];

	cs = &zi->zi_cs[unit & 1];
	s = splzs();
	if (tp->t_state & TS_BUSY) {
		/*
		 * Device is transmitting; must stop it.
		 */
		cs->cs_tbc = 0;
		if ((tp->t_state & TS_TTSTOP) == 0)
			tp->t_state |= TS_FLUSH;
	}
	splx(s);
}

/*
 * Set ZS tty parameters from termios.
 *
 * This routine makes use of the fact that only registers
 * 1, 3, 4, 5, 9, 10, 11, 12, 13, 14, and 15 are written.
 */
static int
zsparam(register struct tty *tp, register struct termios *t)
{
	int unit = minor(tp->t_dev);
	struct zsinfo *zi = zscd.cd_devs[unit >> 1];
	register struct zs_chanstate *cs = &zi->zi_cs[unit & 1];
	register int tmp, tmp5, cflag, s;

	/*
	 * Because PCLK is only run at 4.9 MHz, the fastest we
	 * can go is 51200 baud (this corresponds to TC=1).
	 * This is somewhat unfortunate as there is no real
	 * reason we should not be able to handle higher rates.
	 */
	tmp = t->c_ospeed;
	if (tmp < 0 || (t->c_ispeed && t->c_ispeed != tmp))
		return (EINVAL);
	if (tmp == 0) {
		/* stty 0 => drop DTR and RTS */
		zs_modem(cs, 0);
		return (0);
	}
	tmp = BPS_TO_TCONST(PCLK / 16, tmp);
	if (tmp < 2)
		return (EINVAL);

	cflag = t->c_cflag;
	tp->t_ispeed = tp->t_ospeed = TCONST_TO_BPS(PCLK / 16, tmp);
	tp->t_cflag = cflag;

	/*
	 * Block interrupts so that state will not
	 * be altered until we are done setting it up.
	 */
	s = splzs();
	cs->cs_preg[12] = tmp;
	cs->cs_preg[13] = tmp >> 8;
	cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE;
	switch (cflag & CSIZE) {
	case CS5:
		tmp = ZSWR3_RX_5;
		tmp5 = ZSWR5_TX_5;
		break;
	case CS6:
		tmp = ZSWR3_RX_6;
		tmp5 = ZSWR5_TX_6;
		break;
	case CS7:
		tmp = ZSWR3_RX_7;
		tmp5 = ZSWR5_TX_7;
		break;
	case CS8:
	default:
		tmp = ZSWR3_RX_8;
		tmp5 = ZSWR5_TX_8;
		break;
	}

	/*
	 * Output hardware flow control on the chip is horrendous: if
	 * carrier detect drops, the receiver is disabled.  Hence we
	 * can only do this when the carrier is on.
	 */
	if (cflag & CCTS_OFLOW && cs->cs_zc->zc_csr & ZSRR0_DCD)
		tmp |= ZSWR3_HFC | ZSWR3_RX_ENABLE;
	else
		tmp |= ZSWR3_RX_ENABLE;
	cs->cs_preg[3] = tmp;
	cs->cs_preg[5] = tmp5 | ZSWR5_TX_ENABLE | ZSWR5_DTR | ZSWR5_RTS;

	tmp = ZSWR4_CLK_X16 | (cflag & CSTOPB ? ZSWR4_TWOSB : ZSWR4_ONESB);
	if ((cflag & PARODD) == 0)
		tmp |= ZSWR4_EVENP;
	if (cflag & PARENB)
		tmp |= ZSWR4_PARENB;
	cs->cs_preg[4] = tmp;
	cs->cs_preg[9] = ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR;
	cs->cs_preg[10] = ZSWR10_NRZ;
	cs->cs_preg[11] = ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD;
	cs->cs_preg[14] = ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA;
	cs->cs_preg[15] = ZSWR15_BREAK_IE | ZSWR15_DCD_IE;

	/*
	 * If nothing is being transmitted, set up new current values,
	 * else mark them as pending.
	 */
	if (cs->cs_heldchange == 0) {
		if (cs->cs_ttyp->t_state & TS_BUSY) {
			cs->cs_heldtbc = cs->cs_tbc;
			cs->cs_tbc = 0;
			cs->cs_heldchange = 1;
		} else {
			bcopy((caddr_t)cs->cs_preg, (caddr_t)cs->cs_creg, 16);
			zs_loadchannelregs(cs->cs_zc, cs->cs_creg);
		}
	}
	splx(s);
	return (0);
}

/*
 * Raise or lower modem control (DTR/RTS) signals.  If a character is
 * in transmission, the change is deferred.
 */
static void
zs_modem(struct zs_chanstate *cs, int onoff)
{
	int s, bis, and;

	if (onoff) {
		bis = ZSWR5_DTR | ZSWR5_RTS;
		and = ~0;
	} else {
		bis = 0;
		and = ~(ZSWR5_DTR | ZSWR5_RTS);
	}
	s = splzs();
	cs->cs_preg[5] = (cs->cs_preg[5] | bis) & and;
	if (cs->cs_heldchange == 0) {
		if (cs->cs_ttyp->t_state & TS_BUSY) {
			cs->cs_heldtbc = cs->cs_tbc;
			cs->cs_tbc = 0;
			cs->cs_heldchange = 1;
		} else {
			cs->cs_creg[5] = (cs->cs_creg[5] | bis) & and;
			ZS_WRITE(cs->cs_zc, 5, cs->cs_creg[5]);
		}
	}
	splx(s);
}

/*
 * Write the given register set to the given zs channel in the proper order.
 * The channel must not be transmitting at the time.  The receiver will
 * be disabled for the time it takes to write all the registers.
 */
static void
zs_loadchannelregs(volatile struct zschan *zc, u_char *reg)
{
	int i;

	zc->zc_csr = ZSM_RESET_ERR;	/* reset error condition */
	i = zc->zc_data;		/* drain fifo */
	i = zc->zc_data;
	i = zc->zc_data;
	ZS_WRITE(zc, 4, reg[4]);
	ZS_WRITE(zc, 10, reg[10]);
	ZS_WRITE(zc, 3, reg[3] & ~ZSWR3_RX_ENABLE);
	ZS_WRITE(zc, 5, reg[5] & ~ZSWR5_TX_ENABLE);
	ZS_WRITE(zc, 1, reg[1]);
	ZS_WRITE(zc, 9, reg[9]);
	ZS_WRITE(zc, 11, reg[11]);
	ZS_WRITE(zc, 12, reg[12]);
	ZS_WRITE(zc, 13, reg[13]);
	ZS_WRITE(zc, 14, reg[14]);
	ZS_WRITE(zc, 15, reg[15]);
	ZS_WRITE(zc, 3, reg[3]);
	ZS_WRITE(zc, 5, reg[5]);
}

#ifdef KGDB
/*
 * Get a character from the given kgdb channel.  Called at splhigh().
 */
static int
zs_kgdb_getc(void *arg)
{
	register volatile struct zschan *zc = (volatile struct zschan *)arg;

	while ((zc->zc_csr & ZSRR0_RX_READY) == 0)
		continue;
	return (zc->zc_data);
}

/*
 * Put a character to the given kgdb channel.  Called at splhigh().
 */
static void
zs_kgdb_putc(void *arg, int c)
{
	register volatile struct zschan *zc = (volatile struct zschan *)arg;

	while ((zc->zc_csr & ZSRR0_TX_READY) == 0)
		continue;
	zc->zc_data = c;
}

/*
 * Set up for kgdb; called at boot time before configuration.
 * KGDB interrupts will be enabled later when zs0 is configured.
 */
void
zs_kgdb_init()
{
	volatile struct zsdevice *addr;
	volatile struct zschan *zc;
	int unit, zs;

	if (major(kgdb_dev) != ZSMAJOR)
		return;
	unit = minor(kgdb_dev);
	/*
	 * Unit must be 0 or 1 (zs0).
	 */
	if ((unsigned)unit >= ZS_KBD) {
		printf("zs_kgdb_init: bad minor dev %d\n", unit);
		return;
	}
	zs = unit >> 1;
	if ((addr = zsaddr[zs]) == NULL)
		addr = zsaddr[zs] = findzs(zs);
	unit &= 1;
	zc = unit == 0 ? &addr->zs_chan[CHAN_A] : &addr->zs_chan[CHAN_B];
	zs_kgdb_savedspeed = zs_getspeed(zc);
	printf("zs_kgdb_init: attaching zs%d%c at %d baud\n",
	    zs, unit + 'a', kgdb_rate);
	zs_reset(zc, 1, kgdb_rate);
	kgdb_attach(zs_kgdb_getc, zs_kgdb_putc, (void *)zc);
}
#endif /* KGDB */