NetBSD/sys/dev/ic/z8530tty.c

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/* $NetBSD: z8530tty.c,v 1.9 1996/06/13 23:05:40 gwr Exp $ */
/*
* Copyright (c) 1994 Gordon W. Ross
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Lawrence Berkeley Laboratory.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)zs.c 8.1 (Berkeley) 7/19/93
*/
/*
* Zilog Z8530 Dual UART driver (tty interface)
*
* This is the "slave" driver that will be attached to
* the "zsc" driver for plain "tty" async. serial lines.
*
* Credits, history:
*
* The original version of this code was the sparc/dev/zs.c driver
* as distributed with the Berkeley 4.4 Lite release. Since then,
* Gordon Ross reorganized the code into the current parent/child
* driver scheme, separating the Sun keyboard and mouse support
* into independent child drivers.
*
* RTS/CTS flow-control support was a collaboration of:
* Gordon Ross <gwr@netbsd.org>,
* Bill Studenmund <wrstuden@loki.stanford.edu>
* Ian Dall <Ian.Dall@dsto.defence.gov.au>
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <dev/ic/z8530reg.h>
#include <machine/z8530var.h>
#ifdef KGDB
extern int zs_check_kgdb();
#endif
/*
* Allow the MD var.h to override the default CFLAG so that
* console messages during boot come out with correct parity.
*/
#ifndef ZSTTY_DEF_CFLAG
#define ZSTTY_DEF_CFLAG TTYDEF_CFLAG
#endif
/*
* How many input characters we can buffer.
* The port-specific var.h may override this.
* Note: must be a power of two!
*/
#ifndef ZSTTY_RING_SIZE
#define ZSTTY_RING_SIZE 2048
#endif
/*
* Make this an option variable one can patch.
* But be warned: this must be a power of 2!
*/
int zstty_rbuf_size = ZSTTY_RING_SIZE;
/* This should usually be 3/4 of ZSTTY_RING_SIZE */
int zstty_rbuf_hiwat = (ZSTTY_RING_SIZE - (ZSTTY_RING_SIZE >> 2));
struct zstty_softc {
struct device zst_dev; /* required first: base device */
struct tty *zst_tty;
struct zs_chanstate *zst_cs;
int zst_hwflags; /* see z8530var.h */
int zst_swflags; /* TIOCFLAG_SOFTCAR, ... <ttycom.h> */
/*
* Printing an overrun error message often takes long enough to
* cause another overrun, so we only print one per second.
*/
long zst_rotime; /* time of last ring overrun */
long zst_fotime; /* time of last fifo overrun */
/*
* The receive ring buffer.
*/
int zst_rbget; /* ring buffer `get' index */
volatile int zst_rbput; /* ring buffer `put' index */
int zst_ringmask;
int zst_rbhiwat;
u_short *zst_rbuf; /* rr1, data pairs */
/*
* The transmit byte count and address are used for pseudo-DMA
* output in the hardware interrupt code. PDMA can be suspended
* to get pending changes done; heldtbc is used for this. It can
* also be stopped for ^S; this sets TS_TTSTOP in tp->t_state.
*/
int zst_tbc; /* transmit byte count */
caddr_t zst_tba; /* transmit buffer address */
int zst_heldtbc; /* held tbc while xmission stopped */
/* Flags to communicate with zstty_softint() */
volatile char zst_rx_blocked; /* input block at ring */
volatile char zst_rx_overrun; /* ring overrun */
volatile char zst_tx_busy; /* working on an output chunk */
volatile char zst_tx_done; /* done with one output chunk */
volatile char zst_tx_stopped; /* H/W level stop (lost CTS) */
volatile char zst_st_check; /* got a status interrupt */
char pad[2];
};
/* Definition of the driver for autoconfig. */
static int zstty_match(struct device *, void *, void *);
static void zstty_attach(struct device *, struct device *, void *);
struct cfattach zstty_ca = {
sizeof(struct zstty_softc), zstty_match, zstty_attach
};
struct cfdriver zstty_cd = {
NULL, "zstty", DV_TTY
};
struct zsops zsops_tty;
/* Routines called from other code. */
cdev_decl(zs); /* open, close, read, write, ioctl, stop, ... */
static void zsstart(struct tty *);
static int zsparam(struct tty *, struct termios *);
static void zs_modem(struct zstty_softc *zst, int onoff);
static int zshwiflow(struct tty *, int);
static void zs_hwiflow(struct zstty_softc *, int);
/*
* zstty_match: how is this zs channel configured?
*/
int
zstty_match(parent, match, aux)
struct device *parent;
void *match, *aux;
{
struct cfdata *cf = match;
struct zsc_attach_args *args = aux;
/* Exact match is better than wildcard. */
if (cf->cf_loc[0] == args->channel)
return 2;
/* This driver accepts wildcard. */
if (cf->cf_loc[0] == -1)
return 1;
return 0;
}
void
zstty_attach(parent, self, aux)
struct device *parent, *self;
void *aux;
{
struct zsc_softc *zsc = (void *) parent;
struct zstty_softc *zst = (void *) self;
struct zsc_attach_args *args = aux;
struct zs_chanstate *cs;
struct cfdata *cf;
struct tty *tp;
int channel, tty_unit;
dev_t dev;
cf = zst->zst_dev.dv_cfdata;
tty_unit = zst->zst_dev.dv_unit;
channel = args->channel;
cs = &zsc->zsc_cs[channel];
cs->cs_private = zst;
cs->cs_ops = &zsops_tty;
zst->zst_cs = cs;
zst->zst_swflags = cf->cf_flags; /* softcar, etc. */
zst->zst_hwflags = args->hwflags;
dev = makedev(ZSTTY_MAJOR, tty_unit);
if (zst->zst_swflags)
printf(" flags 0x%x", zst->zst_swflags);
if (zst->zst_hwflags & ZS_HWFLAG_CONSOLE)
printf(" (console)");
else {
#ifdef KGDB
/*
* Allow kgdb to "take over" this port. If this port is
* NOT the kgdb port, zs_check_kgdb() will return zero.
* If it IS the kgdb port, it will print "kgdb,...\n"
* and then return non-zero.
*/
if (zs_check_kgdb(cs, dev)) {
/*
* This is the kgdb port (exclusive use)
* so skip the normal attach code.
*/
return;
}
#endif
}
printf("\n");
tp = ttymalloc();
tp->t_dev = dev;
tp->t_oproc = zsstart;
tp->t_param = zsparam;
tp->t_hwiflow = zshwiflow;
tty_attach(tp);
zst->zst_tty = tp;
zst->zst_rbhiwat = zstty_rbuf_size; /* impossible value */
zst->zst_ringmask = zstty_rbuf_size - 1;
zst->zst_rbuf = malloc(zstty_rbuf_size * sizeof(zst->zst_rbuf[0]),
M_DEVBUF, M_WAITOK);
/*
* Hardware init
*/
if (zst->zst_hwflags & ZS_HWFLAG_CONSOLE) {
/* This unit is the console. */
zst->zst_swflags |= TIOCFLAG_SOFTCAR;
/* Call _param so interrupts get enabled. */
cs->cs_defspeed = zs_getspeed(cs);
tp->t_ispeed = cs->cs_defspeed;
tp->t_ospeed = cs->cs_defspeed;
tp->t_cflag = ZSTTY_DEF_CFLAG;
(void) zsparam(tp, &tp->t_termios);
} else {
/* Not the console; may need reset. */
int reset, s;
reset = (channel == 0) ?
ZSWR9_A_RESET : ZSWR9_B_RESET;
s = splzs();
zs_write_reg(cs, 9, reset);
splx(s);
}
/*
* Initialize state of modem control lines (DTR).
* If softcar is set, turn on DTR now and leave it.
* otherwise, turn off DTR now, and raise in open.
* (Keeps modem from answering too early.)
*/
zs_modem(zst, (zst->zst_swflags & TIOCFLAG_SOFTCAR) ? 1 : 0);
}
/*
* Return pointer to our tty.
*/
struct tty *
zstty(dev)
dev_t dev;
{
struct zstty_softc *zst;
int unit = minor(dev);
#ifdef DIAGNOSTIC
if (unit >= zstty_cd.cd_ndevs)
panic("zstty");
#endif
zst = zstty_cd.cd_devs[unit];
return (zst->zst_tty);
}
/*
* Open a zs serial (tty) port.
*/
int
zsopen(dev, flags, mode, p)
dev_t dev;
int flags;
int mode;
struct proc *p;
{
register struct tty *tp;
register struct zs_chanstate *cs;
struct zstty_softc *zst;
int error, s, unit;
unit = minor(dev);
if (unit >= zstty_cd.cd_ndevs)
return (ENXIO);
zst = zstty_cd.cd_devs[unit];
if (zst == NULL)
return (ENXIO);
tp = zst->zst_tty;
cs = zst->zst_cs;
/* If KGDB took the line, then tp==NULL */
if (tp == NULL)
return (EBUSY);
/* It's simpler to do this up here. */
if (((tp->t_state & (TS_ISOPEN | TS_XCLUDE))
== (TS_ISOPEN | TS_XCLUDE))
&& (p->p_ucred->cr_uid != 0) )
{
return (EBUSY);
}
s = spltty();
if ((tp->t_state & TS_ISOPEN) == 0) {
/* First open. */
ttychars(tp);
tp->t_iflag = TTYDEF_IFLAG;
tp->t_oflag = TTYDEF_OFLAG;
tp->t_cflag = ZSTTY_DEF_CFLAG;
if (zst->zst_swflags & TIOCFLAG_CLOCAL)
tp->t_cflag |= CLOCAL;
if (zst->zst_swflags & TIOCFLAG_CRTSCTS)
tp->t_cflag |= CRTSCTS;
if (zst->zst_swflags & TIOCFLAG_MDMBUF)
tp->t_cflag |= MDMBUF;
tp->t_lflag = TTYDEF_LFLAG;
tp->t_ispeed = tp->t_ospeed = cs->cs_defspeed;
(void) zsparam(tp, &tp->t_termios);
ttsetwater(tp);
/* Flush any pending input. */
zst->zst_rbget = zst->zst_rbput;
zs_iflush(cs); /* XXX */
/* Turn on DTR */
zs_modem(zst, 1);
if (zst->zst_swflags & TIOCFLAG_SOFTCAR) {
tp->t_state |= TS_CARR_ON;
}
}
error = 0;
/* Wait for carrier. */
for (;;) {
/* Might never get status intr if carrier already on. */
cs->cs_rr0 = zs_read_csr(cs);
if (cs->cs_rr0 & ZSRR0_DCD) {
tp->t_state |= TS_CARR_ON;
break;
}
if ((tp->t_state & TS_CARR_ON) ||
(tp->t_cflag & CLOCAL) ||
(flags & O_NONBLOCK) )
{
break;
}
tp->t_state |= TS_WOPEN;
error = ttysleep(tp, (caddr_t)&tp->t_rawq,
TTIPRI | PCATCH, ttopen, 0);
if (error) {
if ((tp->t_state & TS_ISOPEN) == 0) {
/* Never get here with softcar */
zs_modem(zst, 0);
tp->t_state &= ~TS_WOPEN;
ttwakeup(tp);
}
break;
}
}
splx(s);
if (error == 0)
error = linesw[tp->t_line].l_open(dev, tp);
return (error);
}
/*
* Close a zs serial port.
*/
int
zsclose(dev, flags, mode, p)
dev_t dev;
int flags;
int mode;
struct proc *p;
{
struct zstty_softc *zst;
register struct zs_chanstate *cs;
register struct tty *tp;
struct zsinfo *zi;
int hup, s;
zst = zstty_cd.cd_devs[minor(dev)];
cs = zst->zst_cs;
tp = zst->zst_tty;
/* XXX This is for cons.c. */
if ((tp->t_state & TS_ISOPEN) == 0)
return 0;
(*linesw[tp->t_line].l_close)(tp, flags);
hup = tp->t_cflag & HUPCL;
if (zst->zst_swflags & TIOCFLAG_SOFTCAR)
hup = 0;
if (hup) {
zs_modem(zst, 0);
/* hold low for 1 second */
(void) tsleep((caddr_t)cs, TTIPRI, ttclos, hz);
}
if (cs->cs_creg[5] & ZSWR5_BREAK) {
zs_break(cs, 0);
}
/* XXX - turn off interrupts? */
ttyclose(tp);
return (0);
}
/*
* Read/write zs serial port.
*/
int
zsread(dev, uio, flags)
dev_t dev;
struct uio *uio;
int flags;
{
register struct zstty_softc *zst;
register struct tty *tp;
zst = zstty_cd.cd_devs[minor(dev)];
tp = zst->zst_tty;
return (linesw[tp->t_line].l_read(tp, uio, flags));
}
int
zswrite(dev, uio, flags)
dev_t dev;
struct uio *uio;
int flags;
{
register struct zstty_softc *zst;
register struct tty *tp;
zst = zstty_cd.cd_devs[minor(dev)];
tp = zst->zst_tty;
return (linesw[tp->t_line].l_write(tp, uio, flags));
}
#define TIOCFLAG_ALL (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL | \
TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF )
int
zsioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
register struct zstty_softc *zst;
register struct zs_chanstate *cs;
register struct tty *tp;
register int error, tmp;
zst = zstty_cd.cd_devs[minor(dev)];
cs = zst->zst_cs;
tp = zst->zst_tty;
error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
if (error >= 0)
return (error);
error = ttioctl(tp, cmd, data, flag, p);
if (error >= 0)
return (error);
switch (cmd) {
case TIOCSBRK:
zs_break(cs, 1);
break;
case TIOCCBRK:
zs_break(cs, 0);
break;
case TIOCGFLAGS:
*(int *)data = zst->zst_swflags;
break;
case TIOCSFLAGS:
error = suser(p->p_ucred, &p->p_acflag);
if (error != 0)
return (EPERM);
tmp = *(int *)data;
/* Check for random bits... */
if (tmp & ~TIOCFLAG_ALL)
return(EINVAL);
/* Silently enforce softcar on the console. */
if (zst->zst_hwflags & ZS_HWFLAG_CONSOLE)
tmp |= TIOCFLAG_SOFTCAR;
/* These flags take effect during open. */
zst->zst_swflags = tmp;
break;
case TIOCSDTR:
zs_modem(zst, 1);
break;
case TIOCCDTR:
zs_modem(zst, 0);
break;
case TIOCMSET:
case TIOCMBIS:
case TIOCMBIC:
case TIOCMGET:
default:
return (ENOTTY);
}
return (0);
}
/*
* Start or restart transmission.
*/
static void
zsstart(tp)
register struct tty *tp;
{
register struct zstty_softc *zst;
register struct zs_chanstate *cs;
register int s, nch;
zst = zstty_cd.cd_devs[minor(tp->t_dev)];
cs = zst->zst_cs;
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 under CRTSCTS hfc and halted, do nothing
*/
if (tp->t_cflag & CRTSCTS)
if (zst->zst_tx_stopped)
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 */
(void) splzs();
if (nch) {
register char *p = tp->t_outq.c_cf;
/* mark busy, enable tx done interrupts, & send first byte */
tp->t_state |= TS_BUSY;
zst->zst_tx_busy = 1;
cs->cs_preg[1] |= ZSWR1_TIE;
cs->cs_creg[1] = cs->cs_preg[1];
zs_write_reg(cs, 1, cs->cs_creg[1]);
zs_write_data(cs, *p);
zst->zst_tba = p + 1;
zst->zst_tbc = nch - 1;
} else {
/*
* Nothing to send, turn off transmit done interrupts.
* This is useful if something is doing polled output.
*/
cs->cs_preg[1] &= ~ZSWR1_TIE;
cs->cs_creg[1] = cs->cs_preg[1];
zs_write_reg(cs, 1, cs->cs_creg[1]);
}
out:
splx(s);
}
/*
* Stop output, e.g., for ^S or output flush.
*/
int
zsstop(tp, flag)
struct tty *tp;
int flag;
{
register struct zstty_softc *zst;
register struct zs_chanstate *cs;
register int s;
zst = zstty_cd.cd_devs[minor(tp->t_dev)];
cs = zst->zst_cs;
s = splzs();
if (tp->t_state & TS_BUSY) {
/*
* Device is transmitting; must stop it.
* Also clear _heldtbc to prevent any
* flow-control event from resuming.
*/
zst->zst_tbc = 0;
zst->zst_heldtbc = 0;
if ((tp->t_state & TS_TTSTOP) == 0)
tp->t_state |= TS_FLUSH;
}
splx(s);
return (0);
}
/*
* Set ZS tty parameters from termios.
* XXX - Should just copy the whole termios after
* making sure all the changes could be done.
* XXX - Only whack the UART when params change...
*/
static int
zsparam(tp, t)
register struct tty *tp;
register struct termios *t;
{
register struct zstty_softc *zst;
register struct zs_chanstate *cs;
register int s, bps, cflag, tconst;
u_char tmp3, tmp4, tmp5, reset;
zst = zstty_cd.cd_devs[minor(tp->t_dev)];
cs = zst->zst_cs;
/* XXX: Need to use an MD function for this. */
bps = t->c_ospeed;
if (bps < 0 || (t->c_ispeed && t->c_ispeed != bps))
return (EINVAL);
if (bps == 0) {
/* stty 0 => drop DTR and RTS */
zs_modem(zst, 0);
return (0);
}
tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
if (tconst < 0)
return (EINVAL);
/* Convert back to make sure we can do it. */
bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
if (bps != t->c_ospeed)
return (EINVAL);
tp->t_ispeed = tp->t_ospeed = bps;
cflag = t->c_cflag;
tp->t_cflag = cflag;
/*
* Block interrupts so that state will not
* be altered until we are done setting it up.
*/
s = splzs();
/*
* Initial values in cs_preg are set before
* our attach routine is called. The master
* interrupt enable is handled by zsc.c
*/
cs->cs_preg[12] = tconst;
cs->cs_preg[13] = tconst >> 8;
switch (cflag & CSIZE) {
case CS5:
tmp3 = ZSWR3_RX_5;
tmp5 = ZSWR5_TX_5;
break;
case CS6:
tmp3 = ZSWR3_RX_6;
tmp5 = ZSWR5_TX_6;
break;
case CS7:
tmp3 = ZSWR3_RX_7;
tmp5 = ZSWR5_TX_7;
break;
case CS8:
default:
tmp3 = ZSWR3_RX_8;
tmp5 = ZSWR5_TX_8;
break;
}
cs->cs_preg[3] = tmp3 | ZSWR3_RX_ENABLE;
cs->cs_preg[5] = tmp5 | ZSWR5_TX_ENABLE | ZSWR5_DTR | ZSWR5_RTS;
tmp4 = ZSWR4_CLK_X16 | (cflag & CSTOPB ? ZSWR4_TWOSB : ZSWR4_ONESB);
if ((cflag & PARODD) == 0)
tmp4 |= ZSWR4_EVENP;
if (cflag & PARENB)
tmp4 |= ZSWR4_PARENB;
cs->cs_preg[4] = tmp4;
/*
* Output hardware flow control on the chip is horrendous:
* if carrier detect drops, the receiver is disabled.
* Therefore, NEVER set the HFC bit, and instead use
* the status interrupts to detect CTS changes.
*/
if (cflag & CRTSCTS) {
zst->zst_rbhiwat = zstty_rbuf_hiwat;
cs->cs_preg[15] |= ZSWR15_CTS_IE;
} else {
zst->zst_rbhiwat = zstty_rbuf_size; /* impossible value */
cs->cs_preg[15] &= ~ZSWR15_CTS_IE;
}
/*
* If nothing is being transmitted, set up new current values,
* else mark them as pending.
*/
if (cs->cs_heldchange == 0) {
if (zst->zst_tx_busy) {
zst->zst_heldtbc = zst->zst_tbc;
zst->zst_tbc = 0;
cs->cs_heldchange = 0xFF; /* XXX */
} else {
zs_loadchannelregs(cs);
}
}
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(zst, onoff)
struct zstty_softc *zst;
int onoff;
{
struct zs_chanstate *cs;
struct tty *tp;
int s, bis, and;
cs = zst->zst_cs;
tp = zst->zst_tty;
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 (zst->zst_tx_busy) {
zst->zst_heldtbc = zst->zst_tbc;
zst->zst_tbc = 0;
cs->cs_heldchange = (1<<5);
} else {
cs->cs_creg[5] = cs->cs_preg[5];
zs_write_reg(cs, 5, cs->cs_creg[5]);
}
}
splx(s);
}
/*
* Try to block or unblock input using hardware flow-control.
* This is called by kern/tty.c if MDMBUF|CRTSCTS is set, and
* if this function returns non-zero, the TS_TBLOCK flag will
* be set or cleared according to the "stop" arg passed.
*/
int
zshwiflow(tp, stop)
struct tty *tp;
int stop;
{
register struct zstty_softc *zst;
int s;
zst = zstty_cd.cd_devs[minor(tp->t_dev)];
s = splzs();
if (stop) {
/*
* The tty layer is asking us to block input.
* If we already did it, just return TRUE.
*/
if (zst->zst_rx_blocked)
goto out;
zst->zst_rx_blocked = 1;
} else {
/*
* The tty layer is asking us to resume input.
* The input ring is always empty by now.
*/
zst->zst_rx_blocked = 0;
}
zs_hwiflow(zst, stop);
out:
splx(s);
return 1;
}
/*
* Internal version of zshwiflow
* called at splzs
*/
static void
zs_hwiflow(zst, stop)
register struct zstty_softc *zst;
int stop;
{
register struct zs_chanstate *cs;
register struct tty *tp;
register int bis, and;
cs = zst->zst_cs;
tp = zst->zst_tty;
if (stop) {
/* Block input (Lower RTS) */
bis = 0;
and = ~ZSWR5_RTS;
} else {
/* Unblock input (Raise RTS) */
bis = ZSWR5_RTS;
and = ~0;
}
cs->cs_preg[5] = (cs->cs_preg[5] | bis) & and;
if (cs->cs_heldchange == 0) {
if (zst->zst_tx_busy) {
zst->zst_heldtbc = zst->zst_tbc;
zst->zst_tbc = 0;
cs->cs_heldchange = (1<<5);
} else {
cs->cs_creg[5] = cs->cs_preg[5];
zs_write_reg(cs, 5, cs->cs_creg[5]);
}
}
}
/****************************************************************
* Interface to the lower layer (zscc)
****************************************************************/
/*
* receiver ready interrupt.
* called at splzs
*/
static void
zstty_rxint(cs)
register struct zs_chanstate *cs;
{
register struct zstty_softc *zst;
register int cc, put, put_next, ringmask;
register u_char c, rr0, rr1;
register u_short ch_rr1;
zst = cs->cs_private;
put = zst->zst_rbput;
ringmask = zst->zst_ringmask;
nextchar:
/*
* First read the status, because reading the received char
* destroys the status of this char.
*/
rr1 = zs_read_reg(cs, 1);
c = zs_read_data(cs);
ch_rr1 = (c << 8) | rr1;
if (ch_rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
/* Clear the receive error. */
zs_write_csr(cs, ZSWR0_RESET_ERRORS);
}
/* XXX: Check for the stop character? */
zst->zst_rbuf[put] = ch_rr1;
put_next = (put + 1) & ringmask;
/* Would overrun if increment makes (put==get). */
if (put_next == zst->zst_rbget) {
zst->zst_rx_overrun = 1;
} else {
/* OK, really increment. */
put = put_next;
}
/* Keep reading until the FIFO is empty. */
rr0 = zs_read_csr(cs);
if (rr0 & ZSRR0_RX_READY)
goto nextchar;
/* Done reading. */
zst->zst_rbput = put;
/*
* If ring is getting too full, try to block input.
*/
cc = put - zst->zst_rbget;
if (cc < 0)
cc += zstty_rbuf_size;
if ((cc > zst->zst_rbhiwat) && (zst->zst_rx_blocked == 0)) {
zst->zst_rx_blocked = 1;
zs_hwiflow(zst, 1);
}
/* Ask for softint() call. */
cs->cs_softreq = 1;
}
/*
* transmitter ready interrupt. (splzs)
*/
static void
zstty_txint(cs)
register struct zs_chanstate *cs;
{
register struct zstty_softc *zst;
register int count;
zst = cs->cs_private;
/*
* If we suspended output for a "held" change,
* then handle that now and resume.
* Do flow-control changes ASAP.
* When the only change is for flow control,
* avoid hitting other registers, because that
* often makes the stupid zs drop input...
*/
if (cs->cs_heldchange) {
if (cs->cs_heldchange == (1<<5)) {
/* Avoid whacking the chip... */
cs->cs_creg[5] = cs->cs_preg[5];
zs_write_reg(cs, 5, cs->cs_creg[5]);
} else
zs_loadchannelregs(cs);
cs->cs_heldchange = 0;
count = zst->zst_heldtbc;
} else
count = zst->zst_tbc;
/*
* If our transmit buffer still has data,
* just send the next character.
*/
if (count > 0) {
/* Send the next char. */
zst->zst_tbc = --count;
zs_write_data(cs, *zst->zst_tba);
zst->zst_tba++;
return;
}
zs_write_csr(cs, ZSWR0_RESET_TXINT);
/* Ask the softint routine for more output. */
zst->zst_tx_busy = 0;
zst->zst_tx_done = 1;
cs->cs_softreq = 1;
}
/*
* status change interrupt. (splzs)
*/
static void
zstty_stint(cs)
register struct zs_chanstate *cs;
{
register struct zstty_softc *zst;
register struct tty *tp;
register u_char rr0;
zst = cs->cs_private;
tp = zst->zst_tty;
rr0 = zs_read_csr(cs);
zs_write_csr(cs, ZSWR0_RESET_STATUS);
/*
* Check here for console break, so that we can abort
* even when interrupts are locking up the machine.
*/
if ((rr0 & ZSRR0_BREAK) &&
(zst->zst_hwflags & ZS_HWFLAG_CONSOLE))
{
zs_abort();
return;
}
/*
* Need to handle CTS output flow control here.
* Output remains stopped as long as either the
* zst_tx_stopped or TS_TTSTOP flag is set.
* Never restart here; the softint routine will
* do that after things are ready to move.
*/
if (((rr0 & ZSRR0_CTS) == 0) && (tp->t_cflag & CRTSCTS)) {
zst->zst_tbc = 0;
zst->zst_heldtbc = 0;
zst->zst_tx_stopped = 1;
}
cs->cs_rr0_new = rr0;
zst->zst_st_check = 1;
/* Ask for softint() call. */
cs->cs_softreq = 1;
}
/*
* Print out a ring or fifo overrun error message.
*/
static void
zsoverrun(zst, ptime, what)
struct zstty_softc *zst;
long *ptime;
char *what;
{
if (*ptime != time.tv_sec) {
*ptime = time.tv_sec;
log(LOG_WARNING, "%s: %s overrun\n",
zst->zst_dev.dv_xname, what);
}
}
/*
* Software interrupt. Called at zssoft
*
* The main job to be done here is to empty the input ring
* by passing its contents up to the tty layer. The ring is
* always emptied during this operation, therefore the ring
* must not be larger than the space after "high water" in
* the tty layer, or the tty layer might drop our input.
*
* Note: an "input blockage" condition is assumed to exist if
* EITHER the TS_TBLOCK flag or zst_rx_blocked flag is set.
*/
static void
zstty_softint(cs)
struct zs_chanstate *cs;
{
register struct zstty_softc *zst;
register struct linesw *line;
register struct tty *tp;
register int get, c, s;
int ringmask, overrun;
register u_short ring_data;
register u_char rr0, rr1, delta;
zst = cs->cs_private;
tp = zst->zst_tty;
line = &linesw[tp->t_line];
ringmask = zst->zst_ringmask;
overrun = 0;
/*
* Raise to tty priority while servicing the ring.
*/
s = spltty();
if (zst->zst_rx_overrun) {
zst->zst_rx_overrun = 0;
zsoverrun(zst, &zst->zst_rotime, "ring");
}
/*
* Copy data from the receive ring into the tty layer.
*/
get = zst->zst_rbget;
while (get != zst->zst_rbput) {
ring_data = zst->zst_rbuf[get];
get = (get + 1) & ringmask;
if (ring_data & ZSRR1_DO)
overrun++;
/* low byte of ring_data is rr1 */
c = (ring_data >> 8) & 0xff;
if (ring_data & ZSRR1_FE)
c |= TTY_FE;
if (ring_data & ZSRR1_PE)
c |= TTY_PE;
line->l_rint(c, tp);
}
zst->zst_rbget = get;
/*
* If the overrun flag is set now, it was set while
* copying char/status pairs from the ring, which
* means this was a hardware (fifo) overrun.
*/
if (overrun) {
zsoverrun(zst, &zst->zst_fotime, "fifo");
}
/*
* We have emptied the input ring. Maybe unblock input.
* Note: an "input blockage" condition is assumed to exist
* when EITHER zst_rx_blocked or the TS_TBLOCK flag is set,
* so unblock here ONLY if TS_TBLOCK has not been set.
*/
if (zst->zst_rx_blocked && ((tp->t_state & TS_TBLOCK) == 0)) {
(void) splzs();
zst->zst_rx_blocked = 0;
zs_hwiflow(zst, 0); /* unblock input */
(void) spltty();
}
/*
* Do any deferred work for status interrupts.
* The rr0 was saved in the h/w interrupt to
* avoid another splzs in here.
*/
if (zst->zst_st_check) {
zst->zst_st_check = 0;
rr0 = cs->cs_rr0_new;
delta = rr0 ^ cs->cs_rr0;
cs->cs_rr0 = rr0;
if (delta & ZSRR0_DCD) {
c = ((rr0 & ZSRR0_DCD) != 0);
if (line->l_modem(tp, c) == 0)
zs_modem(zst, c);
}
if ((delta & ZSRR0_CTS) && (tp->t_cflag & CRTSCTS)) {
/*
* Only do restart here. Stop is handled
* at the h/w interrupt level.
*/
if (rr0 & ZSRR0_CTS) {
zst->zst_tx_stopped = 0;
tp->t_state &= ~TS_TTSTOP;
(*line->l_start)(tp);
}
}
}
if (zst->zst_tx_done) {
zst->zst_tx_done = 0;
tp->t_state &= ~TS_BUSY;
if (tp->t_state & TS_FLUSH)
tp->t_state &= ~TS_FLUSH;
else
ndflush(&tp->t_outq, zst->zst_tba -
(caddr_t) tp->t_outq.c_cf);
line->l_start(tp);
}
splx(s);
}
struct zsops zsops_tty = {
zstty_rxint, /* receive char available */
zstty_stint, /* external/status */
zstty_txint, /* xmit buffer empty */
zstty_softint, /* process software interrupt */
};