* Copyright (c) 2003, Hugh Graham.

/* $NetBSD: dhu.c,v 1.58 2022/10/26 23:46:37 riastradh Exp $ */
/*
* Copyright (c) 2003, Hugh Graham.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell and Rick Macklem.
*
* 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. 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.
*/

/*
* Copyright (c) 1996 Ken C. Wellsch. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell and Rick Macklem.
*
* 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.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: dhu.c,v 1.58 2022/10/26 23:46:37 riastradh Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <sys/kauth.h>

#include <sys/bus.h>
#include <machine/scb.h>

#include <dev/qbus/ubavar.h>

#include <dev/qbus/dhureg.h>

#include "ioconf.h"

/* A DHU-11 has 16 ports while a DHV-11 has only 8. We use 16 by default */

#define NDHULINE 16

#define DHU_M2U(c) ((c)>>4) /* convert minor(dev) to unit # */
#define DHU_LINE(u) ((u)&0xF) /* extract line # from minor(dev) */

struct dhu_softc {
device_t sc_dev; /* Device struct used by config */
struct evcnt sc_rintrcnt; /* Interrupt statistics */
struct evcnt sc_tintrcnt; /* Interrupt statistics */
int sc_type; /* controller type, DHU or DHV */
int sc_lines; /* number of lines */
bus_space_tag_t sc_iot;
bus_space_handle_t sc_ioh;
bus_dma_tag_t sc_dmat;
struct {
struct tty *dhu_tty; /* what we work on */
bus_dmamap_t dhu_dmah;
int dhu_state; /* to manage TX output status */
short dhu_cc; /* character count on TX */
short dhu_modem; /* modem bits state */
} sc_dhu[NDHULINE];
};

#define IS_DHU 16 /* Unibus DHU-11 board linecount */
#define IS_DHV 8 /* Q-bus DHV-11 or DHQ-11 */

#define STATE_IDLE 000 /* no current output in progress */
#define STATE_DMA_RUNNING 001 /* DMA TX in progress */
#define STATE_DMA_STOPPED 002 /* DMA TX was aborted */
#define STATE_TX_ONE_CHAR 004 /* did a single char directly */

/* Flags used to monitor modem bits, make them understood outside driver */

#define DML_DTR TIOCM_DTR
#define DML_RTS TIOCM_RTS
#define DML_CTS TIOCM_CTS
#define DML_DCD TIOCM_CD
#define DML_RI TIOCM_RI
#define DML_DSR TIOCM_DSR
#define DML_BRK 0100000 /* no equivalent, we will mask */

#define DHU_READ_WORD(reg) \
bus_space_read_2(sc->sc_iot, sc->sc_ioh, reg)
#define DHU_WRITE_WORD(reg, val) \
bus_space_write_2(sc->sc_iot, sc->sc_ioh, reg, val)
#define DHU_READ_BYTE(reg) \
bus_space_read_1(sc->sc_iot, sc->sc_ioh, reg)
#define DHU_WRITE_BYTE(reg, val) \
bus_space_write_1(sc->sc_iot, sc->sc_ioh, reg, val)

/* On a stock DHV, channel pairs (0/1, 2/3, etc.) must use */
/* a baud rate from the same group. So limiting to B is likely */
/* best, although clone boards like the ABLE QHV allow all settings. */

static const struct speedtab dhuspeedtab[] = {
{ 0, 0 }, /* Groups */
{ 50, DHU_LPR_B50 }, /* A */
{ 75, DHU_LPR_B75 }, /* B */
{ 110, DHU_LPR_B110 }, /* A and B */
{ 134, DHU_LPR_B134 }, /* A and B */
{ 150, DHU_LPR_B150 }, /* B */
{ 300, DHU_LPR_B300 }, /* A and B */
{ 600, DHU_LPR_B600 }, /* A and B */
{ 1200, DHU_LPR_B1200 }, /* A and B */
{ 1800, DHU_LPR_B1800 }, /* B */
{ 2000, DHU_LPR_B2000 }, /* B */
{ 2400, DHU_LPR_B2400 }, /* A and B */
{ 4800, DHU_LPR_B4800 }, /* A and B */
{ 7200, DHU_LPR_B7200 }, /* A */
{ 9600, DHU_LPR_B9600 }, /* A and B */
{ 19200, DHU_LPR_B19200 }, /* B */
{ 38400, DHU_LPR_B38400 }, /* A */
{ -1, -1 }
};

static int dhu_match(device_t, cfdata_t, void *);
static void dhu_attach(device_t, device_t, void *);
static void dhurint(void *);
static void dhuxint(void *);
static void dhustart(struct tty *);
static int dhuparam(struct tty *, struct termios *);
static int dhuiflow(struct tty *, int);
static unsigned dhumctl(struct dhu_softc *,int, int, int);

CFATTACH_DECL_NEW(dhu, sizeof(struct dhu_softc),
dhu_match, dhu_attach, NULL, NULL);

static dev_type_open(dhuopen);
static dev_type_close(dhuclose);
static dev_type_read(dhuread);
static dev_type_write(dhuwrite);
static dev_type_ioctl(dhuioctl);
static dev_type_stop(dhustop);
static dev_type_tty(dhutty);
static dev_type_poll(dhupoll);

const struct cdevsw dhu_cdevsw = {
.d_open = dhuopen,
.d_close = dhuclose,
.d_read = dhuread,
.d_write = dhuwrite,
.d_ioctl = dhuioctl,
.d_stop = dhustop,
.d_tty = dhutty,
.d_poll = dhupoll,
.d_mmap = nommap,
.d_kqfilter = ttykqfilter,
.d_discard = nodiscard,
.d_flag = D_TTY
};

/* Autoconfig handles: setup the controller to interrupt, */
/* then complete the housecleaning for full operation */

static int
dhu_match(device_t parent, cfdata_t cf, void *aux)
{
struct uba_attach_args *ua = aux;
int n;

/* Reset controller to initialize, enable TX/RX interrupts */
/* to catch floating vector info elsewhere when completed */

bus_space_write_2(ua->ua_iot, ua->ua_ioh, DHU_UBA_CSR,
DHU_CSR_MASTER_RESET | DHU_CSR_RXIE | DHU_CSR_TXIE);

/* Now wait up to 3 seconds for self-test to complete. */

for (n = 0; n < 300; n++) {
DELAY(10000);
if ((bus_space_read_2(ua->ua_iot, ua->ua_ioh, DHU_UBA_CSR) &
DHU_CSR_MASTER_RESET) == 0)
break;
}

/* If the RESET did not clear after 3 seconds, */
/* the controller must be broken. */

if (n >= 300)
return 0;

/* Check whether diagnostic run has signalled a failure. */

if ((bus_space_read_2(ua->ua_iot, ua->ua_ioh, DHU_UBA_CSR) &
DHU_CSR_DIAG_FAIL) != 0)
return 0;

return 1;
}

static void
dhu_attach(device_t parent, device_t self, void *aux)
{
struct dhu_softc *sc = device_private(self);
struct uba_attach_args *ua = aux;
unsigned c;
int n, i;

sc->sc_dev = self;
sc->sc_iot = ua->ua_iot;
sc->sc_ioh = ua->ua_ioh;
sc->sc_dmat = ua->ua_dmat;
/* Process the 8 bytes of diagnostic info put into */
/* the FIFO following the master reset operation. */

aprint_normal("\n");
for (n = 0; n < 8; n++) {
c = DHU_READ_WORD(DHU_UBA_RBUF);

if ((c&DHU_DIAG_CODE) == DHU_DIAG_CODE) {
if ((c&0200) == 0000)
aprint_error_dev(self, "rom(%d) version %d\n",
((c>>1)&01), ((c>>2)&037));
else if (((c>>2)&07) != 0)
aprint_error_dev(self, "diag-error(proc%d)=%x\n",
((c>>1)&01), ((c>>2)&07));
}
}

c = DHU_READ_WORD(DHU_UBA_STAT);

sc->sc_type = (c & DHU_STAT_DHU)? IS_DHU: IS_DHV;

sc->sc_lines = 8; /* default */
if (sc->sc_type == IS_DHU && (c & DHU_STAT_MDL))
sc->sc_lines = 16;

aprint_normal_dev(self, "DH%s-11\n",
sc->sc_type == IS_DHU ? "U" : "V");

for (i = 0; i < sc->sc_lines; i++) {
struct tty *tp;

tp = sc->sc_dhu[i].dhu_tty = tty_alloc();
sc->sc_dhu[i].dhu_state = STATE_IDLE;
bus_dmamap_create(sc->sc_dmat, tp->t_outq.c_cn, 1,
tp->t_outq.c_cn, 0, BUS_DMA_ALLOCNOW|BUS_DMA_NOWAIT,
&sc->sc_dhu[i].dhu_dmah);
bus_dmamap_load(sc->sc_dmat, sc->sc_dhu[i].dhu_dmah,
tp->t_outq.c_cs, tp->t_outq.c_cn, 0, BUS_DMA_NOWAIT);

}

/* Now establish RX & TX interrupt handlers */

uba_intr_establish(ua->ua_icookie, ua->ua_cvec,
dhurint, sc, &sc->sc_rintrcnt);
uba_intr_establish(ua->ua_icookie, ua->ua_cvec + 4,
dhuxint, sc, &sc->sc_tintrcnt);
evcnt_attach_dynamic(&sc->sc_rintrcnt, EVCNT_TYPE_INTR, ua->ua_evcnt,
device_xname(sc->sc_dev), "rintr");
evcnt_attach_dynamic(&sc->sc_tintrcnt, EVCNT_TYPE_INTR, ua->ua_evcnt,
device_xname(sc->sc_dev), "tintr");
}

/* Receiver Interrupt */

static void
dhurint(void *arg)
{
struct dhu_softc *sc = arg;
struct tty *tp;
int cc, line;
unsigned c, delta;
int overrun = 0;

while ((c = DHU_READ_WORD(DHU_UBA_RBUF)) & DHU_RBUF_DATA_VALID) {

/* Ignore diagnostic FIFO entries. */

if ((c & DHU_DIAG_CODE) == DHU_DIAG_CODE)
continue;

cc = c & 0xFF;
line = DHU_LINE(c>>8);
tp = sc->sc_dhu[line].dhu_tty;

/* LINK.TYPE is set so we get modem control FIFO entries */

if ((c & DHU_DIAG_CODE) == DHU_MODEM_CODE) {
c = (c << 8);
/* Do MDMBUF flow control, wakeup sleeping opens */
if (c & DHU_STAT_DCD) {
if (!(tp->t_state & TS_CARR_ON))
(void)(*tp->t_linesw->l_modem)(tp, 1);
}
else if ((tp->t_state & TS_CARR_ON) &&
(*tp->t_linesw->l_modem)(tp, 0) == 0)
(void) dhumctl(sc, line, 0, DMSET);

/* Do CRTSCTS flow control */
delta = c ^ sc->sc_dhu[line].dhu_modem;
sc->sc_dhu[line].dhu_modem = c;
if ((delta & DHU_STAT_CTS) &&
(tp->t_state & TS_ISOPEN) &&
(tp->t_cflag & CRTSCTS)) {
if (c & DHU_STAT_CTS) {
tp->t_state &= ~TS_TTSTOP;
ttstart(tp);
} else {
tp->t_state |= TS_TTSTOP;
dhustop(tp, 0);
}
}
continue;
}

if (!(tp->t_state & TS_ISOPEN)) {
cv_broadcast(&tp->t_rawcv);
continue;
}

if ((c & DHU_RBUF_OVERRUN_ERR) && overrun == 0) {
log(LOG_WARNING, "%s: silo overflow, line %d\n",
device_xname(sc->sc_dev), line);
overrun = 1;
}
/* A BREAK key will appear as a NULL with a framing error */
if (c & DHU_RBUF_FRAMING_ERR)
cc |= TTY_FE;
if (c & DHU_RBUF_PARITY_ERR)
cc |= TTY_PE;

(*tp->t_linesw->l_rint)(cc, tp);
}
}

/* Transmitter Interrupt */

static void
dhuxint(void *arg)
{
struct dhu_softc *sc = arg;
struct tty *tp;
int line, i;

while ((i = DHU_READ_BYTE(DHU_UBA_CSR_HI)) & (DHU_CSR_TX_ACTION >> 8)) {

line = DHU_LINE(i);
tp = sc->sc_dhu[line].dhu_tty;

if (i & (DHU_CSR_TX_DMA_ERROR >> 8))
printf("%s: DMA ERROR on line: %d\n",
device_xname(sc->sc_dev), line);
if (i & (DHU_CSR_DIAG_FAIL >> 8))
printf("%s: DIAG FAIL on line: %d\n",
device_xname(sc->sc_dev), line);

tp->t_state &= ~TS_BUSY;
if (tp->t_state & TS_FLUSH)
tp->t_state &= ~TS_FLUSH;
else {
if (sc->sc_dhu[line].dhu_state == STATE_DMA_STOPPED)
sc->sc_dhu[line].dhu_cc -=
DHU_READ_WORD(DHU_UBA_TBUFCNT);
ndflush(&tp->t_outq, sc->sc_dhu[line].dhu_cc);
sc->sc_dhu[line].dhu_cc = 0;
}

sc->sc_dhu[line].dhu_state = STATE_IDLE;

(*tp->t_linesw->l_start)(tp);
}
}

int
dhuopen(dev_t dev, int flag, int mode, struct lwp *l)
{
struct tty *tp;
int unit, line;
struct dhu_softc *sc;
int error = 0;

unit = DHU_M2U(minor(dev));
line = DHU_LINE(minor(dev));

sc = device_lookup_private(&dhu_cd, unit);
if (!sc)
return (ENXIO);

if (line >= sc->sc_lines)
return ENXIO;

tp = sc->sc_dhu[line].dhu_tty;
ttylock(tp);
if (sc->sc_type == IS_DHU) {
/* CSR 3:0 must be 0 */
DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE);
/* RX int delay 10ms */
DHU_WRITE_BYTE(DHU_UBA_RXTIME, 10);
}
DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE | line);
sc->sc_dhu[line].dhu_modem = DHU_READ_WORD(DHU_UBA_STAT);

if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
return (EBUSY);

tp->t_oproc = dhustart;
tp->t_param = dhuparam;
tp->t_hwiflow = dhuiflow;
tp->t_dev = dev;

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 = TTYDEF_SPEED;
}
(void) dhuparam(tp, &tp->t_termios);
ttsetwater(tp);
}
/* Use DMBIS and *not* DMSET or else we clobber incoming bits */
if (dhumctl(sc, line, DML_DTR|DML_RTS, DMBIS) & DML_DCD)
tp->t_state |= TS_CARR_ON;
while (!(flag & O_NONBLOCK) && !(tp->t_cflag & CLOCAL) &&
!(tp->t_state & TS_CARR_ON)) {
tp->t_wopen++;
error = ttysleep(tp, &tp->t_rawcv, true, 0);
tp->t_wopen--;
if (error)
break;
}
ttyunlock(tp);
if (error)
return (error);
return ((*tp->t_linesw->l_open)(dev, tp));
}

/*ARGSUSED*/
int
dhuclose(dev_t dev, int flag, int mode, struct lwp *l)
{
const int unit = DHU_M2U(minor(dev));
const int line = DHU_LINE(minor(dev));
struct dhu_softc *sc = device_lookup_private(&dhu_cd, unit);
struct tty *tp = sc->sc_dhu[line].dhu_tty;

(*tp->t_linesw->l_close)(tp, flag);

/* Make sure a BREAK state is not left enabled. */

(void) dhumctl(sc, line, DML_BRK, DMBIC);

/* Do a hangup if so required. */

if ((tp->t_cflag & HUPCL) || tp->t_wopen || !(tp->t_state & TS_ISOPEN))
(void) dhumctl(sc, line, 0, DMSET);

return (ttyclose(tp));
}

int
dhuread(dev_t dev, struct uio *uio, int flag)
{
struct dhu_softc *sc = device_lookup_private(&dhu_cd, DHU_M2U(minor(dev)));
struct tty *tp = sc->sc_dhu[DHU_LINE(minor(dev))].dhu_tty;

return ((*tp->t_linesw->l_read)(tp, uio, flag));
}

int
dhuwrite(dev_t dev, struct uio *uio, int flag)
{
struct dhu_softc *sc = device_lookup_private(&dhu_cd, DHU_M2U(minor(dev)));
struct tty *tp = sc->sc_dhu[DHU_LINE(minor(dev))].dhu_tty;

return ((*tp->t_linesw->l_write)(tp, uio, flag));
}

int
dhupoll(dev_t dev, int events, struct lwp *l)
{
struct dhu_softc *sc = device_lookup_private(&dhu_cd, DHU_M2U(minor(dev)));
struct tty *tp = sc->sc_dhu[DHU_LINE(minor(dev))].dhu_tty;

return ((*tp->t_linesw->l_poll)(tp, events, l));
}

/*ARGSUSED*/
int
dhuioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
const int unit = DHU_M2U(minor(dev));
const int line = DHU_LINE(minor(dev));
struct dhu_softc *sc = device_lookup_private(&dhu_cd, unit);
struct tty *tp = sc->sc_dhu[line].dhu_tty;
int error;

error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
if (error != EPASSTHROUGH)
return (error);

error = ttioctl(tp, cmd, data, flag, l);
if (error != EPASSTHROUGH)
return (error);

switch (cmd) {

case TIOCSBRK:
(void) dhumctl(sc, line, DML_BRK, DMBIS);
break;

case TIOCCBRK:
(void) dhumctl(sc, line, DML_BRK, DMBIC);
break;

case TIOCSDTR:
(void) dhumctl(sc, line, DML_DTR|DML_RTS, DMBIS);
break;

case TIOCCDTR:
(void) dhumctl(sc, line, DML_DTR|DML_RTS, DMBIC);
break;

case TIOCMSET:
(void) dhumctl(sc, line, *(int *)data, DMSET);
break;

case TIOCMBIS:
(void) dhumctl(sc, line, *(int *)data, DMBIS);
break;

case TIOCMBIC:
(void) dhumctl(sc, line, *(int *)data, DMBIC);
break;

case TIOCMGET:
*(int *)data = (dhumctl(sc, line, 0, DMGET) & ~DML_BRK);
break;

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

struct tty *
dhutty(dev_t dev)
{
struct dhu_softc *sc = device_lookup_private(&dhu_cd, DHU_M2U(minor(dev)));

return sc->sc_dhu[DHU_LINE(minor(dev))].dhu_tty;
}

/*ARGSUSED*/
void
dhustop(struct tty *tp, int flag)
{
int s;

s = spltty();

if (tp->t_state & TS_BUSY) {
const int unit = DHU_M2U(minor(tp->t_dev));
const int line = DHU_LINE(minor(tp->t_dev));
struct dhu_softc *sc = device_lookup_private(&dhu_cd, unit);

if (sc->sc_dhu[line].dhu_state == STATE_DMA_RUNNING) {

sc->sc_dhu[line].dhu_state = STATE_DMA_STOPPED;

DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE | line);
DHU_WRITE_WORD(DHU_UBA_LNCTRL,
DHU_READ_WORD(DHU_UBA_LNCTRL) |
DHU_LNCTRL_DMA_ABORT);
}

if (!(tp->t_state & TS_TTSTOP))
tp->t_state |= TS_FLUSH;
}
(void) splx(s);
}

static void
dhustart(struct tty *tp)
{
struct dhu_softc *sc;
int line, cc;
int addr;
int s;

s = spltty();
if (tp->t_state & (TS_TIMEOUT|TS_BUSY|TS_TTSTOP))
goto out;
if (!ttypull(tp))
goto out;
cc = ndqb(&tp->t_outq, 0);
if (cc == 0)
goto out;

tp->t_state |= TS_BUSY;

sc = device_lookup_private(&dhu_cd,DHU_M2U(minor(tp->t_dev)));

line = DHU_LINE(minor(tp->t_dev));

DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE | line);

sc->sc_dhu[line].dhu_cc = cc;

if (cc == 1 && sc->sc_type == IS_DHV) {

sc->sc_dhu[line].dhu_state = STATE_TX_ONE_CHAR;

DHU_WRITE_WORD(DHU_UBA_TXCHAR,
DHU_TXCHAR_DATA_VALID | *tp->t_outq.c_cf);

} else {

sc->sc_dhu[line].dhu_state = STATE_DMA_RUNNING;

addr = sc->sc_dhu[line].dhu_dmah->dm_segs[0].ds_addr +
(tp->t_outq.c_cf - tp->t_outq.c_cs);

DHU_WRITE_WORD(DHU_UBA_TBUFCNT, cc);
DHU_WRITE_WORD(DHU_UBA_TBUFAD1, addr & 0xFFFF);
DHU_WRITE_WORD(DHU_UBA_TBUFAD2, ((addr>>16) & 0x3F) |
DHU_TBUFAD2_TX_ENABLE);
DHU_WRITE_WORD(DHU_UBA_LNCTRL,
DHU_READ_WORD(DHU_UBA_LNCTRL) & ~DHU_LNCTRL_DMA_ABORT);
DHU_WRITE_WORD(DHU_UBA_TBUFAD2,
DHU_READ_WORD(DHU_UBA_TBUFAD2) | DHU_TBUFAD2_DMA_START);
}
out:
(void) splx(s);
return;
}

static int
dhuparam(struct tty *tp, struct termios *t)
{
int cflag = t->c_cflag;
int ispeed = ttspeedtab(t->c_ispeed, dhuspeedtab);
int ospeed = ttspeedtab(t->c_ospeed, dhuspeedtab);
unsigned int lpr;
unsigned int lnctrl;
const int unit = DHU_M2U(minor(tp->t_dev));
const int line = DHU_LINE(minor(tp->t_dev));
struct dhu_softc * const sc = device_lookup_private(&dhu_cd, unit);
int s;

/* check requested parameters */
if (ospeed < 0 || ispeed < 0)
return (EINVAL);

tp->t_ispeed = t->c_ispeed;
tp->t_ospeed = t->c_ospeed;
tp->t_cflag = cflag;

if (ospeed == 0) {
(void) dhumctl(sc, line, 0, DMSET); /* hang up line */
return (0);
}

s = spltty();
DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE | line);

lpr = ((ispeed&017)<<8) | ((ospeed&017)<<12) ;

switch (cflag & CSIZE) {

case CS5:
lpr |= DHU_LPR_5_BIT_CHAR;
break;

case CS6:
lpr |= DHU_LPR_6_BIT_CHAR;
break;

case CS7:
lpr |= DHU_LPR_7_BIT_CHAR;
break;

default:
lpr |= DHU_LPR_8_BIT_CHAR;
break;
}

if (cflag & PARENB)
lpr |= DHU_LPR_PARENB;
if (!(cflag & PARODD))
lpr |= DHU_LPR_EPAR;
if (cflag & CSTOPB)
lpr |= DHU_LPR_2_STOP;

DHU_WRITE_WORD(DHU_UBA_LPR, lpr);

DHU_WRITE_WORD(DHU_UBA_TBUFAD2,
DHU_READ_WORD(DHU_UBA_TBUFAD2) | DHU_TBUFAD2_TX_ENABLE);

lnctrl = DHU_READ_WORD(DHU_UBA_LNCTRL);

/* Setting LINK.TYPE enables modem signal change interrupts. */

lnctrl |= (DHU_LNCTRL_RX_ENABLE | DHU_LNCTRL_LINK_TYPE);

/* Enable the auto XON/XOFF feature on the controller */

if (t->c_iflag & IXON)
lnctrl |= DHU_LNCTRL_OAUTO;
else
lnctrl &= ~DHU_LNCTRL_OAUTO;

if (t->c_iflag & IXOFF)
lnctrl |= DHU_LNCTRL_IAUTO;
else
lnctrl &= ~DHU_LNCTRL_IAUTO;

DHU_WRITE_WORD(DHU_UBA_LNCTRL, lnctrl);

(void) splx(s);
return (0);
}

static int
dhuiflow(struct tty *tp, int flag)
{

if (tp->t_cflag & CRTSCTS) {
const int unit = DHU_M2U(minor(tp->t_dev));
const int line = DHU_LINE(minor(tp->t_dev));
struct dhu_softc * const sc = device_lookup_private(&dhu_cd, unit);
(void) dhumctl(sc, line, DML_RTS, ((flag)? DMBIC: DMBIS));
return (1);
}
return (0);
}

static unsigned int
dhumctl(struct dhu_softc *sc, int line, int bits, int how)
{
unsigned status;
unsigned lnctrl;
unsigned mbits;
int s;

s = spltty();

DHU_WRITE_BYTE(DHU_UBA_CSR, DHU_CSR_RXIE | line);

mbits = 0;

/* external signals as seen from the port */

status = DHU_READ_WORD(DHU_UBA_STAT);

if (status & DHU_STAT_CTS)
mbits |= DML_CTS;

if (status & DHU_STAT_DCD)
mbits |= DML_DCD;

if (status & DHU_STAT_DSR)
mbits |= DML_DSR;

if (status & DHU_STAT_RI)
mbits |= DML_RI;

/* internal signals/state delivered to port */

lnctrl = DHU_READ_WORD(DHU_UBA_LNCTRL);

if (lnctrl & DHU_LNCTRL_RTS)
mbits |= DML_RTS;

if (lnctrl & DHU_LNCTRL_DTR)
mbits |= DML_DTR;

if (lnctrl & DHU_LNCTRL_BREAK)
mbits |= DML_BRK;

switch (how) {

case DMSET:
mbits = bits;
break;

case DMBIS:
mbits |= bits;
break;

case DMBIC:
mbits &= ~bits;
break;

case DMGET:
(void) splx(s);
return (mbits);
}

if (mbits & DML_RTS)
lnctrl |= DHU_LNCTRL_RTS;
else
lnctrl &= ~DHU_LNCTRL_RTS;

if (mbits & DML_DTR)
lnctrl |= DHU_LNCTRL_DTR;
else
lnctrl &= ~DHU_LNCTRL_DTR;

if (mbits & DML_BRK)
lnctrl |= DHU_LNCTRL_BREAK;
else
lnctrl &= ~DHU_LNCTRL_BREAK;

DHU_WRITE_WORD(DHU_UBA_LNCTRL, lnctrl);

(void) splx(s);
return (mbits);
}