/*      $NetBSD: clmpcc.c,v 1.55 2026/03/18 05:09:12 thorpej Exp $ */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Steve C. Woodford.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Cirrus Logic CD2400/CD2401 Four Channel Multi-Protocol Comms. Controller.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: clmpcc.c,v 1.55 2026/03/18 05:09:12 thorpej Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/tty.h>
#include <sys/proc.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/malloc.h>
#include <sys/kauth.h>
#include <sys/intr.h>

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

#include <dev/ic/clmpccreg.h>
#include <dev/ic/clmpccvar.h>
#include <dev/cons.h>

#include "ioconf.h"

#if defined(CLMPCC_ONLY_BYTESWAP_LOW) && defined(CLMPCC_ONLY_BYTESWAP_HIGH)
#error  "CLMPCC_ONLY_BYTESWAP_LOW and CLMPCC_ONLY_BYTESWAP_HIGH are mutually exclusive."
#endif


static int      clmpcc_init(struct clmpcc_softc *sc);
static void     clmpcc_shutdown(struct clmpcc_chan *);
static int      clmpcc_speed(struct clmpcc_softc *, speed_t, int *, int *);
static int      clmpcc_param(struct tty *, struct termios *);
static void     clmpcc_set_params(struct clmpcc_chan *);
static void     clmpcc_start(struct tty *);
static int      clmpcc_modem_control(struct clmpcc_chan *, int, int);

#define CLMPCCUNIT(x)           (TTUNIT(x) & ~0x3)      // XXX >> 2? 
#define CLMPCCCHAN(x)           (TTUNIT(x) & 0x3)
#define CLMPCCDIALOUT(x)        TTDIALOUT(x)

/*
 * These should be in a header file somewhere...
 */
#define ISCLR(v, f)     (((v) & (f)) == 0)

dev_type_open(clmpccopen);
dev_type_close(clmpccclose);
dev_type_read(clmpccread);
dev_type_write(clmpccwrite);
dev_type_ioctl(clmpccioctl);
dev_type_stop(clmpccstop);
dev_type_tty(clmpcctty);
dev_type_poll(clmpccpoll);

const struct cdevsw clmpcc_cdevsw = {
        .d_open = clmpccopen,
        .d_close = clmpccclose,
        .d_read = clmpccread,
        .d_write = clmpccwrite,
        .d_ioctl = clmpccioctl,
        .d_stop = clmpccstop,
        .d_tty = clmpcctty,
        .d_poll = clmpccpoll,
        .d_mmap = nommap,
        .d_kqfilter = ttykqfilter,
        .d_discard = nodiscard,
        .d_flag = D_TTY
};

/*
 * Make this an option variable one can patch.
 */
u_int clmpcc_ibuf_size = CLMPCC_RING_SIZE;


/*
 * Things needed when the device is used as a console
 */
static struct clmpcc_softc *cons_sc = NULL;
static int cons_chan;
static int cons_rate;

static int      clmpcc_common_getc(struct clmpcc_softc *, int);
static void     clmpcc_common_putc(struct clmpcc_softc *, int, int);
int             clmpcccngetc(dev_t);
void            clmpcccnputc(dev_t, int);


/*
 * Convenience functions, inlined for speed
 */
#define integrate   static inline
integrate u_int8_t  clmpcc_rdreg(struct clmpcc_softc *, u_int);
integrate void      clmpcc_wrreg(struct clmpcc_softc *, u_int, u_int);
integrate u_int8_t  clmpcc_rdreg_odd(struct clmpcc_softc *, u_int);
integrate void      clmpcc_wrreg_odd(struct clmpcc_softc *, u_int, u_int);
integrate void      clmpcc_wrtx_multi(struct clmpcc_softc *, u_int8_t *,
                                        u_int);
integrate u_int8_t  clmpcc_select_channel(struct clmpcc_softc *, u_int);
integrate void      clmpcc_channel_cmd(struct clmpcc_softc *,int,int);
integrate void      clmpcc_enable_transmitter(struct clmpcc_chan *);

#define clmpcc_rd_msvr(s)       clmpcc_rdreg_odd(s,CLMPCC_REG_MSVR)
#define clmpcc_wr_msvr(s,r,v)   clmpcc_wrreg_odd(s,r,v)
#define clmpcc_wr_pilr(s,r,v)   clmpcc_wrreg_odd(s,r,v)
#define clmpcc_rd_rxdata(s)     clmpcc_rdreg_odd(s,CLMPCC_REG_RDR)
#define clmpcc_wr_txdata(s,v)   clmpcc_wrreg_odd(s,CLMPCC_REG_TDR,v)


integrate u_int8_t
clmpcc_rdreg(struct clmpcc_softc *sc, u_int offset)
{
#if !defined(CLMPCC_ONLY_BYTESWAP_LOW) && !defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= sc->sc_byteswap;
#elif defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= CLMPCC_BYTESWAP_HIGH;
#endif
        return bus_space_read_1(sc->sc_iot, sc->sc_ioh, offset);
}

integrate void
clmpcc_wrreg(struct clmpcc_softc *sc, u_int offset, u_int val)
{
#if !defined(CLMPCC_ONLY_BYTESWAP_LOW) && !defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= sc->sc_byteswap;
#elif defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= CLMPCC_BYTESWAP_HIGH;
#endif
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, offset, val);
}

integrate u_int8_t
clmpcc_rdreg_odd(struct clmpcc_softc *sc, u_int offset)
{
#if !defined(CLMPCC_ONLY_BYTESWAP_LOW) && !defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (sc->sc_byteswap & 2);
#elif defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (CLMPCC_BYTESWAP_HIGH & 2);
#endif
        return bus_space_read_1(sc->sc_iot, sc->sc_ioh, offset);
}

integrate void
clmpcc_wrreg_odd(struct clmpcc_softc *sc, u_int offset, u_int val)
{
#if !defined(CLMPCC_ONLY_BYTESWAP_LOW) && !defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (sc->sc_byteswap & 2);
#elif defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (CLMPCC_BYTESWAP_HIGH & 2);
#endif
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, offset, val);
}

integrate void
clmpcc_wrtx_multi(struct clmpcc_softc *sc, u_int8_t *buff, u_int count)
{
        u_int offset = CLMPCC_REG_TDR;

#if !defined(CLMPCC_ONLY_BYTESWAP_LOW) && !defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (sc->sc_byteswap & 2);
#elif defined(CLMPCC_ONLY_BYTESWAP_HIGH)
        offset ^= (CLMPCC_BYTESWAP_HIGH & 2);
#endif
        bus_space_write_multi_1(sc->sc_iot, sc->sc_ioh, offset, buff, count);
}

integrate u_int8_t
clmpcc_select_channel(struct clmpcc_softc *sc, u_int new_chan)
{
        u_int old_chan = clmpcc_rdreg_odd(sc, CLMPCC_REG_CAR);

        clmpcc_wrreg_odd(sc, CLMPCC_REG_CAR, new_chan);

        return old_chan;
}

integrate void
clmpcc_channel_cmd(struct clmpcc_softc *sc, int chan, int cmd)
{
        int i;

        for (i = 5000; i; i--) {
                if ( clmpcc_rdreg(sc, CLMPCC_REG_CCR) == 0 )
                        break;
                delay(1);
        }

        if ( i == 0 )
                printf("%s: channel %d command timeout (idle)\n",
                        device_xname(sc->sc_dev), chan);

        clmpcc_wrreg(sc, CLMPCC_REG_CCR, cmd);
}

integrate void
clmpcc_enable_transmitter(struct clmpcc_chan *ch)
{
        u_int old;
        int s;

        old = clmpcc_select_channel(ch->ch_sc, ch->ch_car);

        s = splserial();
        clmpcc_wrreg(ch->ch_sc, CLMPCC_REG_IER,
                clmpcc_rdreg(ch->ch_sc, CLMPCC_REG_IER) | CLMPCC_IER_TX_EMPTY);
        SET(ch->ch_tty->t_state, TS_BUSY);
        splx(s);

        clmpcc_select_channel(ch->ch_sc, old);
}

static int
clmpcc_speed(struct clmpcc_softc *sc, speed_t speed, int *cor, int *bpr)
{
        int c, co, br;

        for (co = 0, c = 8; c <= 2048; co++, c *= 4) {
                br = ((sc->sc_clk / c) / speed) - 1;
                if ( br < 0x100 ) {
                        *cor = co;
                        *bpr = br;
                        return 0;
                }
        }

        return -1;
}

void
clmpcc_attach(struct clmpcc_softc *sc)
{
        struct clmpcc_chan *ch;
        struct tty *tp;
        int chan;

        if ( cons_sc != NULL &&
             sc->sc_iot == cons_sc->sc_iot && sc->sc_ioh == cons_sc->sc_ioh )
                cons_sc = sc;

        /* Initialise the chip */
        clmpcc_init(sc);

        printf(": Cirrus Logic CD240%c Serial Controller\n",
                (clmpcc_rd_msvr(sc) & CLMPCC_MSVR_PORT_ID) ? '0' : '1');

        sc->sc_softintr_cookie =
            softint_establish(SOFTINT_SERIAL, clmpcc_softintr, sc);
        if (sc->sc_softintr_cookie == NULL)
                panic("clmpcc_attach: softintr_establish");
        memset(&(sc->sc_chans[0]), 0, sizeof(sc->sc_chans));

        for (chan = 0; chan < CLMPCC_NUM_CHANS; chan++) {
                ch = &sc->sc_chans[chan];

                ch->ch_sc = sc;
                ch->ch_car = chan;

                tp = tty_alloc();
                tp->t_oproc = clmpcc_start;
                tp->t_param = clmpcc_param;

                ch->ch_tty = tp;

                ch->ch_ibuf = malloc(clmpcc_ibuf_size * 2, M_DEVBUF, M_WAITOK);
                ch->ch_ibuf_end = &(ch->ch_ibuf[clmpcc_ibuf_size * 2]);
                ch->ch_ibuf_rd = ch->ch_ibuf_wr = ch->ch_ibuf;

                tty_attach(tp);
        }

        device_printf(sc->sc_dev, "%d channels available",
            CLMPCC_NUM_CHANS);
        if ( cons_sc == sc ) {
                printf(", console on channel %d.\n", cons_chan);
                SET(sc->sc_chans[cons_chan].ch_flags, CLMPCC_FLG_IS_CONSOLE);
                SET(sc->sc_chans[cons_chan].ch_openflags, TIOCFLAG_SOFTCAR);
        } else
                printf(".\n");
}

static int
clmpcc_init(struct clmpcc_softc *sc)
{
        u_int tcor = 0, tbpr = 0;
        u_int rcor = 0, rbpr = 0;
        u_int msvr_rts, msvr_dtr;
        u_int ccr;
        int is_console;
        int i;

        /*
         * All we're really concerned about here is putting the chip
         * into a quiescent state so that it won't do anything until
         * clmpccopen() is called. (Except the console channel.)
         */

        /*
         * If the chip is acting as console, set all channels to the supplied
         * console baud rate. Otherwise, plump for 9600.
         */
        if ( cons_sc &&
             sc->sc_ioh == cons_sc->sc_ioh && sc->sc_iot == cons_sc->sc_iot ) {
                clmpcc_speed(sc, cons_rate, &tcor, &tbpr);
                clmpcc_speed(sc, cons_rate, &rcor, &rbpr);
                is_console = 1;
        } else {
                clmpcc_speed(sc, 9600, &tcor, &tbpr);
                clmpcc_speed(sc, 9600, &rcor, &rbpr);
                is_console = 0;
        }

        /* Allow any pending output to be sent */
        delay(10000);

        /* Send the Reset All command  to channel 0 (resets all channels!) */
        clmpcc_channel_cmd(sc, 0, CLMPCC_CCR_T0_RESET_ALL);

        delay(1000);

        /*
         * The chip will set its firmware revision register to a non-zero
         * value to indicate completion of reset.
         */
        for (i = 10000; clmpcc_rdreg(sc, CLMPCC_REG_GFRCR) == 0 && i; i--)
                delay(1);

        if ( i == 0 ) {
                /*
                 * Watch out... If this chip is console, the message
                 * probably won't be sent since we just reset it!
                 */
                aprint_error_dev(sc->sc_dev, "Failed to reset chip\n");
                return -1;
        }

        for (i = 0; i < CLMPCC_NUM_CHANS; i++) {
                clmpcc_select_channel(sc, i);

                /* All interrupts are disabled to begin with */
                clmpcc_wrreg(sc, CLMPCC_REG_IER, 0);

                /* Make sure the channel interrupts on the correct vectors */
                clmpcc_wrreg(sc, CLMPCC_REG_LIVR, sc->sc_vector_base);
                clmpcc_wr_pilr(sc, CLMPCC_REG_RPILR, sc->sc_rpilr);
                clmpcc_wr_pilr(sc, CLMPCC_REG_TPILR, sc->sc_tpilr);
                clmpcc_wr_pilr(sc, CLMPCC_REG_MPILR, sc->sc_mpilr);

                /* Receive timer prescaler set to 1ms */
                clmpcc_wrreg(sc, CLMPCC_REG_TPR,
                                 CLMPCC_MSEC_TO_TPR(sc->sc_clk, 1));

                /* We support Async mode only */
                clmpcc_wrreg(sc, CLMPCC_REG_CMR, CLMPCC_CMR_ASYNC);

                /* Set the required baud rate */
                clmpcc_wrreg(sc, CLMPCC_REG_TCOR, CLMPCC_TCOR_CLK(tcor));
                clmpcc_wrreg(sc, CLMPCC_REG_TBPR, tbpr);
                clmpcc_wrreg(sc, CLMPCC_REG_RCOR, CLMPCC_RCOR_CLK(rcor));
                clmpcc_wrreg(sc, CLMPCC_REG_RBPR, rbpr);

                /* Always default to 8N1 (XXX what about console?) */
                clmpcc_wrreg(sc, CLMPCC_REG_COR1, CLMPCC_COR1_CHAR_8BITS |
                                                  CLMPCC_COR1_NO_PARITY |
                                                  CLMPCC_COR1_IGNORE_PAR);

                clmpcc_wrreg(sc, CLMPCC_REG_COR2, 0);

                clmpcc_wrreg(sc, CLMPCC_REG_COR3, CLMPCC_COR3_STOP_1);

                clmpcc_wrreg(sc, CLMPCC_REG_COR4, CLMPCC_COR4_DSRzd |
                                                  CLMPCC_COR4_CDzd |
                                                  CLMPCC_COR4_CTSzd);

                clmpcc_wrreg(sc, CLMPCC_REG_COR5, CLMPCC_COR5_DSRod |
                                                  CLMPCC_COR5_CDod |
                                                  CLMPCC_COR5_CTSod |
                                                  CLMPCC_COR5_FLOW_NORM);

                clmpcc_wrreg(sc, CLMPCC_REG_COR6, 0);
                clmpcc_wrreg(sc, CLMPCC_REG_COR7, 0);

                /* Set the receive FIFO timeout */
                clmpcc_wrreg(sc, CLMPCC_REG_RTPRl, CLMPCC_RTPR_DEFAULT);
                clmpcc_wrreg(sc, CLMPCC_REG_RTPRh, 0);

                /* At this point, we set up the console differently */
                if ( is_console && i == cons_chan ) {
                        msvr_rts = CLMPCC_MSVR_RTS;
                        msvr_dtr = CLMPCC_MSVR_DTR;
                        ccr = CLMPCC_CCR_T0_RX_EN | CLMPCC_CCR_T0_TX_EN;
                } else {
                        msvr_rts = 0;
                        msvr_dtr = 0;
                        ccr = CLMPCC_CCR_T0_RX_DIS | CLMPCC_CCR_T0_TX_DIS;
                }

                clmpcc_wrreg(sc, CLMPCC_REG_MSVR_RTS, msvr_rts);
                clmpcc_wrreg(sc, CLMPCC_REG_MSVR_DTR, msvr_dtr);
                clmpcc_channel_cmd(sc, i, CLMPCC_CCR_T0_INIT | ccr);
                delay(100);
        }

        return 0;
}

static void
clmpcc_shutdown(struct clmpcc_chan *ch)
{
        int oldch;

        oldch = clmpcc_select_channel(ch->ch_sc, ch->ch_car);

        /* Turn off interrupts. */
        clmpcc_wrreg(ch->ch_sc, CLMPCC_REG_IER, 0);

        if ( ISCLR(ch->ch_flags, CLMPCC_FLG_IS_CONSOLE) ) {
                /* Disable the transmitter and receiver */
                clmpcc_channel_cmd(ch->ch_sc, ch->ch_car, CLMPCC_CCR_T0_RX_DIS |
                                                          CLMPCC_CCR_T0_TX_DIS);

                /* Drop RTS and DTR */
                clmpcc_modem_control(ch, TIOCM_RTS | TIOCM_DTR, DMBIS);
        }

        clmpcc_select_channel(ch->ch_sc, oldch);
}

int
clmpccopen(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct clmpcc_softc *sc;
        struct clmpcc_chan *ch;
        struct tty *tp;
        int oldch;
        int error;

        sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        ch = &sc->sc_chans[CLMPCCCHAN(dev)];

        tp = ch->ch_tty;

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

        /*
         * Do the following iff this is a first open.
         */
        if ( ISCLR(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0 ) {

                ttychars(tp);

                tp->t_dev = dev;
                tp->t_iflag = TTYDEF_IFLAG;
                tp->t_oflag = TTYDEF_OFLAG;
                tp->t_lflag = TTYDEF_LFLAG;
                tp->t_cflag = TTYDEF_CFLAG;
                tp->t_ospeed = tp->t_ispeed = TTYDEF_SPEED;

                if ( ISSET(ch->ch_openflags, TIOCFLAG_CLOCAL) )
                        SET(tp->t_cflag, CLOCAL);
                if ( ISSET(ch->ch_openflags, TIOCFLAG_CRTSCTS) )
                        SET(tp->t_cflag, CRTSCTS);
                if ( ISSET(ch->ch_openflags, TIOCFLAG_MDMBUF) )
                        SET(tp->t_cflag, MDMBUF);

                /*
                 * Override some settings if the channel is being
                 * used as the console.
                 */
                if ( ISSET(ch->ch_flags, CLMPCC_FLG_IS_CONSOLE) ) {
                        tp->t_ospeed = tp->t_ispeed = cons_rate;
                        SET(tp->t_cflag, CLOCAL);
                        CLR(tp->t_cflag, CRTSCTS);
                        CLR(tp->t_cflag, HUPCL);
                }

                ch->ch_control = 0;

                clmpcc_param(tp, &tp->t_termios);
                ttsetwater(tp);

                /* Clear the input ring */
                ch->ch_ibuf_rd = ch->ch_ibuf_wr = ch->ch_ibuf;

                /* Select the channel */
                oldch = clmpcc_select_channel(sc, ch->ch_car);

                /* Reset it */
                clmpcc_channel_cmd(sc, ch->ch_car, CLMPCC_CCR_T0_CLEAR |
                                                   CLMPCC_CCR_T0_RX_EN |
                                                   CLMPCC_CCR_T0_TX_EN);

                /* Enable receiver and modem change interrupts. */
                clmpcc_wrreg(sc, CLMPCC_REG_IER, CLMPCC_IER_MODEM |
                                                 CLMPCC_IER_RET |
                                                 CLMPCC_IER_RX_FIFO);

                /* Raise RTS and DTR */
                clmpcc_modem_control(ch, TIOCM_RTS | TIOCM_DTR, DMBIS);

                clmpcc_select_channel(sc, oldch);
        }

        error = ttyopen(tp, CLMPCCDIALOUT(dev), ISSET(flag, O_NONBLOCK));
        if (error)
                goto bad;

        error = (*tp->t_linesw->l_open)(dev, tp);
        if (error)
                goto bad;

        return 0;

bad:
        if ( ISCLR(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0 ) {
                /*
                 * We failed to open the device, and nobody else had it opened.
                 * Clean up the state as appropriate.
                 */
                clmpcc_shutdown(ch);
        }

        return error;
}

int
clmpccclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct clmpcc_softc     *sc =
                device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        struct clmpcc_chan      *ch = &sc->sc_chans[CLMPCCCHAN(dev)];
        struct tty              *tp = ch->ch_tty;
        int s;

        if ( ISCLR(tp->t_state, TS_ISOPEN) )
                return 0;

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

        s = spltty();

        if ( ISCLR(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0 ) {
                /*
                 * Although we got a last close, the device may still be in
                 * use; e.g. if this was the dialout node, and there are still
                 * processes waiting for carrier on the non-dialout node.
                 */
                clmpcc_shutdown(ch);
        }

        ttyclose(tp);

        splx(s);

        return 0;
}

int
clmpccread(dev_t dev, struct uio *uio, int flag)
{
        struct clmpcc_softc *sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        struct tty *tp = sc->sc_chans[CLMPCCCHAN(dev)].ch_tty;

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

int
clmpccwrite(dev_t dev, struct uio *uio, int flag)
{
        struct clmpcc_softc *sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        struct tty *tp = sc->sc_chans[CLMPCCCHAN(dev)].ch_tty;

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

int
clmpccpoll(dev_t dev, int events, struct lwp *l)
{
        struct clmpcc_softc *sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        struct tty *tp = sc->sc_chans[CLMPCCCHAN(dev)].ch_tty;

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

struct tty *
clmpcctty(dev_t dev)
{
        struct clmpcc_softc *sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));

        return (sc->sc_chans[CLMPCCCHAN(dev)].ch_tty);
}

int
clmpccioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        struct clmpcc_softc *sc = device_lookup_private(&clmpcc_cd, CLMPCCUNIT(dev));
        struct clmpcc_chan *ch = &sc->sc_chans[CLMPCCCHAN(dev)];
        struct tty *tp = ch->ch_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;

        error = 0;

        switch (cmd) {
        case TIOCSBRK:
                SET(ch->ch_flags, CLMPCC_FLG_START_BREAK);
                clmpcc_enable_transmitter(ch);
                break;

        case TIOCCBRK:
                SET(ch->ch_flags, CLMPCC_FLG_END_BREAK);
                clmpcc_enable_transmitter(ch);
                break;

        case TIOCSDTR:
                clmpcc_modem_control(ch, TIOCM_DTR, DMBIS);
                break;

        case TIOCCDTR:
                clmpcc_modem_control(ch, TIOCM_DTR, DMBIC);
                break;

        case TIOCMSET:
                clmpcc_modem_control(ch, *((int *)data), DMSET);
                break;

        case TIOCMBIS:
                clmpcc_modem_control(ch, *((int *)data), DMBIS);
                break;

        case TIOCMBIC:
                clmpcc_modem_control(ch, *((int *)data), DMBIC);
                break;

        case TIOCMGET:
                *((int *)data) = clmpcc_modem_control(ch, 0, DMGET);
                break;

        case TIOCGFLAGS:
                *((int *)data) = ch->ch_openflags;
                break;

        case TIOCSFLAGS:
                error = kauth_authorize_device_tty(l->l_cred,
                    KAUTH_DEVICE_TTY_PRIVSET, tp);
                if ( error )
                        break;
                ch->ch_openflags = *((int *)data) &
                        (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL |
                         TIOCFLAG_CRTSCTS | TIOCFLAG_MDMBUF);
                if ( ISSET(ch->ch_flags, CLMPCC_FLG_IS_CONSOLE) )
                        SET(ch->ch_openflags, TIOCFLAG_SOFTCAR);
                break;

        default:
                error = EPASSTHROUGH;
                break;
        }

        return error;
}

int
clmpcc_modem_control(struct clmpcc_chan *ch, int bits, int howto)
{
        struct clmpcc_softc *sc = ch->ch_sc;
        struct tty *tp = ch->ch_tty;
        int oldch;
        int msvr;
        int rbits = 0;

        oldch = clmpcc_select_channel(sc, ch->ch_car);

        switch ( howto ) {
        case DMGET:
                msvr = clmpcc_rd_msvr(sc);

                if ( sc->sc_swaprtsdtr ) {
                        rbits |= (msvr & CLMPCC_MSVR_RTS) ? TIOCM_DTR : 0;
                        rbits |= (msvr & CLMPCC_MSVR_DTR) ? TIOCM_RTS : 0;
                } else {
                        rbits |= (msvr & CLMPCC_MSVR_RTS) ? TIOCM_RTS : 0;
                        rbits |= (msvr & CLMPCC_MSVR_DTR) ? TIOCM_DTR : 0;
                }

                rbits |= (msvr & CLMPCC_MSVR_CTS) ? TIOCM_CTS : 0;
                rbits |= (msvr & CLMPCC_MSVR_CD)  ? TIOCM_CD  : 0;
                rbits |= (msvr & CLMPCC_MSVR_DSR) ? TIOCM_DSR : 0;
                break;

        case DMSET:
                if ( sc->sc_swaprtsdtr ) {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_DTR,
                                        bits & TIOCM_RTS ? CLMPCC_MSVR_DTR : 0);
                    clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_RTS,
                                bits & TIOCM_DTR ? CLMPCC_MSVR_RTS : 0);
                } else {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_RTS,
                                        bits & TIOCM_RTS ? CLMPCC_MSVR_RTS : 0);
                    clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_DTR,
                                bits & TIOCM_DTR ? CLMPCC_MSVR_DTR : 0);
                }
                break;

        case DMBIS:
                if ( sc->sc_swaprtsdtr ) {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) && ISSET(bits, TIOCM_RTS) )
                        clmpcc_wr_msvr(sc,CLMPCC_REG_MSVR_DTR, CLMPCC_MSVR_DTR);
                    if ( ISSET(bits, TIOCM_DTR) )
                        clmpcc_wr_msvr(sc,CLMPCC_REG_MSVR_RTS, CLMPCC_MSVR_RTS);
                } else {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) && ISSET(bits, TIOCM_RTS) )
                        clmpcc_wr_msvr(sc,CLMPCC_REG_MSVR_RTS, CLMPCC_MSVR_RTS);
                    if ( ISSET(bits, TIOCM_DTR) )
                        clmpcc_wr_msvr(sc,CLMPCC_REG_MSVR_DTR, CLMPCC_MSVR_DTR);
                }
                break;

        case DMBIC:
                if ( sc->sc_swaprtsdtr ) {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) && ISCLR(bits, TIOCM_RTS) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_DTR, 0);
                    if ( ISCLR(bits, TIOCM_DTR) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_RTS, 0);
                } else {
                    if ( ISCLR(tp->t_cflag, CRTSCTS) && ISCLR(bits, TIOCM_RTS) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_RTS, 0);
                    if ( ISCLR(bits, TIOCM_DTR) )
                        clmpcc_wr_msvr(sc, CLMPCC_REG_MSVR_DTR, 0);
                }
                break;
        }

        clmpcc_select_channel(sc, oldch);

        return rbits;
}

static int
clmpcc_param(struct tty *tp, struct termios *t)
{
        struct clmpcc_softc *sc =
            device_lookup_private(&clmpcc_cd, CLMPCCUNIT(tp->t_dev));
        struct clmpcc_chan *ch = &sc->sc_chans[CLMPCCCHAN(tp->t_dev)];
        u_char cor;
        u_char oldch;
        int oclk = 0, obpr = 0;
        int iclk = 0, ibpr = 0;
        int s;

        /* Check requested parameters. */
        if ( t->c_ospeed && clmpcc_speed(sc, t->c_ospeed, &oclk, &obpr) < 0 )
                return EINVAL;

        if ( t->c_ispeed && clmpcc_speed(sc, t->c_ispeed, &iclk, &ibpr) < 0 )
                return EINVAL;

        /*
         * For the console, always force CLOCAL and !HUPCL, so that the port
         * is always active.
         */
        if ( ISSET(ch->ch_openflags, TIOCFLAG_SOFTCAR) ||
             ISSET(ch->ch_flags, CLMPCC_FLG_IS_CONSOLE) ) {
                SET(t->c_cflag, CLOCAL);
                CLR(t->c_cflag, HUPCL);
        }

        CLR(ch->ch_flags, CLMPCC_FLG_UPDATE_PARMS);

        /* If ospeed it zero, hangup the line */
        clmpcc_modem_control(ch, TIOCM_DTR, t->c_ospeed == 0 ? DMBIC : DMBIS);

        if ( t->c_ospeed ) {
                ch->ch_tcor = CLMPCC_TCOR_CLK(oclk);
                ch->ch_tbpr = obpr;
        } else {
                ch->ch_tcor = 0;
                ch->ch_tbpr = 0;
        }

        if ( t->c_ispeed ) {
                ch->ch_rcor = CLMPCC_RCOR_CLK(iclk);
                ch->ch_rbpr = ibpr;
        } else {
                ch->ch_rcor = 0;
                ch->ch_rbpr = 0;
        }

        /* Work out value to use for COR1 */
        cor = 0;
        if ( ISSET(t->c_cflag, PARENB) ) {
                cor |= CLMPCC_COR1_NORM_PARITY;
                if ( ISSET(t->c_cflag, PARODD) )
                        cor |= CLMPCC_COR1_ODD_PARITY;
        }

        if ( ISCLR(t->c_cflag, INPCK) )
                cor |= CLMPCC_COR1_IGNORE_PAR;

        switch ( t->c_cflag & CSIZE ) {
          case CS5:
                cor |= CLMPCC_COR1_CHAR_5BITS;
                break;

          case CS6:
                cor |= CLMPCC_COR1_CHAR_6BITS;
                break;

          case CS7:
                cor |= CLMPCC_COR1_CHAR_7BITS;
                break;

          case CS8:
                cor |= CLMPCC_COR1_CHAR_8BITS;
                break;
        }

        ch->ch_cor1 = cor;

        /*
         * The only interesting bit in COR2 is 'CTS Automatic Enable'
         * when hardware flow control is in effect.
         */
        ch->ch_cor2 = ISSET(t->c_cflag, CRTSCTS) ? CLMPCC_COR2_CtsAE : 0;

        /* COR3 needs to be set to the number of stop bits... */
        ch->ch_cor3 = ISSET(t->c_cflag, CSTOPB) ? CLMPCC_COR3_STOP_2 :
                                                  CLMPCC_COR3_STOP_1;

        /*
         * COR4 contains the FIFO threshold setting.
         * We adjust the threshold depending on the input speed...
         */
        if ( t->c_ispeed <= 1200 )
                ch->ch_cor4 = CLMPCC_COR4_FIFO_LOW;
        else if ( t->c_ispeed <= 19200 )
                ch->ch_cor4 = CLMPCC_COR4_FIFO_MED;
        else
                ch->ch_cor4 = CLMPCC_COR4_FIFO_HIGH;

        /*
         * If chip is used with CTS and DTR swapped, we can enable
         * automatic hardware flow control.
         */
        if ( sc->sc_swaprtsdtr && ISSET(t->c_cflag, CRTSCTS) )
                ch->ch_cor5 = CLMPCC_COR5_FLOW_NORM;
        else
                ch->ch_cor5 = 0;

        s = splserial();
        oldch = clmpcc_select_channel(sc, ch->ch_car);

        /*
         * COR2 needs to be set immediately otherwise we might never get
         * a Tx EMPTY interrupt to change the other parameters.
         */
        if ( clmpcc_rdreg(sc, CLMPCC_REG_COR2) != ch->ch_cor2 )
                clmpcc_wrreg(sc, CLMPCC_REG_COR2, ch->ch_cor2);

        if ( ISCLR(ch->ch_tty->t_state, TS_BUSY) )
                clmpcc_set_params(ch);
        else
                SET(ch->ch_flags, CLMPCC_FLG_UPDATE_PARMS);

        clmpcc_select_channel(sc, oldch);

        splx(s);

        return 0;
}

static void
clmpcc_set_params(struct clmpcc_chan *ch)
{
        struct clmpcc_softc *sc = ch->ch_sc;
        u_char r1;
        u_char r2;

        if ( ch->ch_tcor || ch->ch_tbpr ) {
                r1 = clmpcc_rdreg(sc, CLMPCC_REG_TCOR);
                r2 = clmpcc_rdreg(sc, CLMPCC_REG_TBPR);
                /* Only write Tx rate if it really has changed */
                if ( ch->ch_tcor != r1 || ch->ch_tbpr != r2 ) {
                        clmpcc_wrreg(sc, CLMPCC_REG_TCOR, ch->ch_tcor);
                        clmpcc_wrreg(sc, CLMPCC_REG_TBPR, ch->ch_tbpr);
                }
        }

        if ( ch->ch_rcor || ch->ch_rbpr ) {
                r1 = clmpcc_rdreg(sc, CLMPCC_REG_RCOR);
                r2 = clmpcc_rdreg(sc, CLMPCC_REG_RBPR);
                /* Only write Rx rate if it really has changed */
                if ( ch->ch_rcor != r1 || ch->ch_rbpr != r2 ) {
                        clmpcc_wrreg(sc, CLMPCC_REG_RCOR, ch->ch_rcor);
                        clmpcc_wrreg(sc, CLMPCC_REG_RBPR, ch->ch_rbpr);
                }
        }

        if ( clmpcc_rdreg(sc, CLMPCC_REG_COR1) != ch->ch_cor1 ) {
                clmpcc_wrreg(sc, CLMPCC_REG_COR1, ch->ch_cor1);
                /* Any change to COR1 requires an INIT command */
                SET(ch->ch_flags, CLMPCC_FLG_NEED_INIT);
        }

        if ( clmpcc_rdreg(sc, CLMPCC_REG_COR3) != ch->ch_cor3 )
                clmpcc_wrreg(sc, CLMPCC_REG_COR3, ch->ch_cor3);

        r1 = clmpcc_rdreg(sc, CLMPCC_REG_COR4);
        if ( ch->ch_cor4 != (r1 & CLMPCC_COR4_FIFO_MASK) ) {
                /*
                 * Note: If the FIFO has changed, we always set it to
                 * zero here and disable the Receive Timeout interrupt.
                 * It's up to the Rx Interrupt handler to pick the
                 * appropriate moment to write the new FIFO length.
                 */
                clmpcc_wrreg(sc, CLMPCC_REG_COR4, r1 & ~CLMPCC_COR4_FIFO_MASK);
                r1 = clmpcc_rdreg(sc, CLMPCC_REG_IER);
                clmpcc_wrreg(sc, CLMPCC_REG_IER, r1 & ~CLMPCC_IER_RET);
                SET(ch->ch_flags, CLMPCC_FLG_FIFO_CLEAR);
        }

        r1 = clmpcc_rdreg(sc, CLMPCC_REG_COR5);
        if ( ch->ch_cor5 != (r1 & CLMPCC_COR5_FLOW_MASK) ) {
                r1 &= ~CLMPCC_COR5_FLOW_MASK;
                clmpcc_wrreg(sc, CLMPCC_REG_COR5, r1 | ch->ch_cor5);
        }
}

static void
clmpcc_start(struct tty *tp)
{
        struct clmpcc_softc *sc =
            device_lookup_private(&clmpcc_cd, CLMPCCUNIT(tp->t_dev));
        struct clmpcc_chan *ch = &sc->sc_chans[CLMPCCCHAN(tp->t_dev)];
        u_int oldch;
        int s;

        s = spltty();

        if ( ISCLR(tp->t_state, TS_TTSTOP | TS_TIMEOUT | TS_BUSY) ) {
                ttypull(tp);
                if ( ISSET(ch->ch_flags, CLMPCC_FLG_START_BREAK |
                                         CLMPCC_FLG_END_BREAK) ||
                     tp->t_outq.c_cc > 0 ) {

                        if ( ISCLR(ch->ch_flags, CLMPCC_FLG_START_BREAK |
                                                 CLMPCC_FLG_END_BREAK) ) {
                                ch->ch_obuf_addr = tp->t_outq.c_cf;
                                ch->ch_obuf_size = ndqb(&tp->t_outq, 0);
                        }

                        /* Enable TX empty interrupts */
                        oldch = clmpcc_select_channel(ch->ch_sc, ch->ch_car);
                        clmpcc_wrreg(ch->ch_sc, CLMPCC_REG_IER,
                                clmpcc_rdreg(ch->ch_sc, CLMPCC_REG_IER) |
                                             CLMPCC_IER_TX_EMPTY);
                        clmpcc_select_channel(ch->ch_sc, oldch);
                        SET(tp->t_state, TS_BUSY);
                }
        }

        splx(s);
}

/*
 * Stop output on a line.
 */
void
clmpccstop(struct tty *tp, int flag)
{
        struct clmpcc_softc *sc =
            device_lookup_private(&clmpcc_cd, CLMPCCUNIT(tp->t_dev));
        struct clmpcc_chan *ch = &sc->sc_chans[CLMPCCCHAN(tp->t_dev)];
        int s;

        s = splserial();

        if ( ISSET(tp->t_state, TS_BUSY) ) {
                if ( ISCLR(tp->t_state, TS_TTSTOP) )
                        SET(tp->t_state, TS_FLUSH);
                ch->ch_obuf_size = 0;
        }
        splx(s);
}

/*
 * RX interrupt routine
 */
int
clmpcc_rxintr(void *arg)
{
        struct clmpcc_softc *sc = (struct clmpcc_softc *)arg;
        struct clmpcc_chan *ch;
        u_int8_t *put, *end, rxd;
        u_char errstat;
        u_char fc, tc;
        u_char risr;
        u_char rir;
#ifdef DDB
        int saw_break = 0;
#endif

        /* Receive interrupt active? */
        rir = clmpcc_rdreg(sc, CLMPCC_REG_RIR);

        /*
         * If we're using auto-vectored interrupts, we have to
         * verify if the chip is generating the interrupt.
         */
        if ( sc->sc_vector_base == 0 && (rir & CLMPCC_RIR_RACT) == 0 )
                return 0;

        /* Get pointer to interrupting channel's data structure */
        ch = &sc->sc_chans[rir & CLMPCC_RIR_RCN_MASK];

        /* Get the interrupt status register */
        risr = clmpcc_rdreg(sc, CLMPCC_REG_RISRl);
        if ( risr & CLMPCC_RISR_TIMEOUT ) {
                u_char reg;
                /*
                 * Set the FIFO threshold to zero, and disable
                 * further receive timeout interrupts.
                 */
                reg = clmpcc_rdreg(sc, CLMPCC_REG_COR4);
                clmpcc_wrreg(sc, CLMPCC_REG_COR4, reg & ~CLMPCC_COR4_FIFO_MASK);
                reg = clmpcc_rdreg(sc, CLMPCC_REG_IER);
                clmpcc_wrreg(sc, CLMPCC_REG_IER, reg & ~CLMPCC_IER_RET);
                clmpcc_wrreg(sc, CLMPCC_REG_REOIR, CLMPCC_REOIR_NO_TRANS);
                SET(ch->ch_flags, CLMPCC_FLG_FIFO_CLEAR);
                return 1;
        }

        /* How many bytes are waiting in the FIFO?  */
        fc = tc = clmpcc_rdreg(sc, CLMPCC_REG_RFOC) & CLMPCC_RFOC_MASK;

#ifdef DDB
        /*
         * Allow BREAK on the console to drop to the debugger.
         */
        if ( ISSET(ch->ch_flags, CLMPCC_FLG_IS_CONSOLE) &&
             risr & CLMPCC_RISR_BREAK ) {
                saw_break = 1;
        }
#endif

        if ( ISCLR(ch->ch_tty->t_state, TS_ISOPEN) && fc ) {
                /* Just get rid of the data */
                while ( fc-- )
                        (void) clmpcc_rd_rxdata(sc);
                goto rx_done;
        }

        put = ch->ch_ibuf_wr;
        end = ch->ch_ibuf_end;

        /*
         * Note: The chip is completely hosed WRT these error
         *       conditions; there seems to be no way to associate
         *       the error with the correct character in the FIFO.
         *       We compromise by tagging the first character we read
         *       with the error. Not perfect, but there's no other way.
         */
        errstat = 0;
        if ( risr & CLMPCC_RISR_PARITY )
                errstat |= TTY_PE;
        if ( risr & (CLMPCC_RISR_FRAMING | CLMPCC_RISR_BREAK) )
                errstat |= TTY_FE;

        /*
         * As long as there are characters in the FIFO, and we
         * have space for them...
         */
        while ( fc > 0 ) {

                *put++ = rxd = clmpcc_rd_rxdata(sc);
                *put++ = errstat;

                if ( put >= end )
                        put = ch->ch_ibuf;

                if ( put == ch->ch_ibuf_rd ) {
                        put -= 2;
                        if ( put < ch->ch_ibuf )
                                put = end - 2;
                }

                errstat = 0;
                fc--;
        }

        ch->ch_ibuf_wr = put;

#if 0
        if ( sc->sc_swaprtsdtr == 0 &&
             ISSET(cy->cy_tty->t_cflag, CRTSCTS) && cc < ch->ch_r_hiwat) {
                /*
                 * If RTS/DTR are not physically swapped, we have to
                 * do hardware flow control manually
                 */
                clmpcc_wr_msvr(sc, CLMPCC_MSVR_RTS, 0);
        }
#endif

rx_done:
        if ( fc != tc ) {
                if ( ISSET(ch->ch_flags, CLMPCC_FLG_FIFO_CLEAR) ) {
                        u_char reg;
                        /*
                         * Set the FIFO threshold to the preset value,
                         * and enable receive timeout interrupts.
                         */
                        reg = clmpcc_rdreg(sc, CLMPCC_REG_COR4);
                        reg = (reg & ~CLMPCC_COR4_FIFO_MASK) | ch->ch_cor4;
                        clmpcc_wrreg(sc, CLMPCC_REG_COR4, reg);
                        reg = clmpcc_rdreg(sc, CLMPCC_REG_IER);
                        clmpcc_wrreg(sc, CLMPCC_REG_IER, reg | CLMPCC_IER_RET);
                        CLR(ch->ch_flags, CLMPCC_FLG_FIFO_CLEAR);
                }

                clmpcc_wrreg(sc, CLMPCC_REG_REOIR, 0);
                softint_schedule(sc->sc_softintr_cookie);
        } else
                clmpcc_wrreg(sc, CLMPCC_REG_REOIR, CLMPCC_REOIR_NO_TRANS);

#ifdef DDB
        /*
         * Only =after= we write REOIR is it safe to drop to the debugger.
         */
        if ( saw_break )
                Debugger();
#endif

        return 1;
}

/*
 * Tx interrupt routine
 */
int
clmpcc_txintr(void *arg)
{
        struct clmpcc_softc *sc = (struct clmpcc_softc *)arg;
        struct clmpcc_chan *ch;
        u_char ftc, oftc;
        u_char tir, teoir;
        int etcmode = 0;

        /* Tx interrupt active? */
        tir = clmpcc_rdreg(sc, CLMPCC_REG_TIR);

        /*
         * If we're using auto-vectored interrupts, we have to
         * verify if the chip is generating the interrupt.
         */
        if ( sc->sc_vector_base == 0 && (tir & CLMPCC_TIR_TACT) == 0 )
                return 0;

        /* Get pointer to interrupting channel's data structure */
        ch = &sc->sc_chans[tir & CLMPCC_TIR_TCN_MASK];

        /* Dummy read of the interrupt status register */
        (void) clmpcc_rdreg(sc, CLMPCC_REG_TISR);

        /* Make sure embedded transmit commands are disabled */
        clmpcc_wrreg(sc, CLMPCC_REG_COR2, ch->ch_cor2);

        ftc = oftc = clmpcc_rdreg(sc, CLMPCC_REG_TFTC);

        /* Handle a delayed parameter change */
        if ( ISSET(ch->ch_flags, CLMPCC_FLG_UPDATE_PARMS) ) {
                CLR(ch->ch_flags, CLMPCC_FLG_UPDATE_PARMS);
                clmpcc_set_params(ch);
        }

        if ( ch->ch_obuf_size > 0 ) {
                u_int n = uimin(ch->ch_obuf_size, ftc);

                clmpcc_wrtx_multi(sc, ch->ch_obuf_addr, n);

                ftc -= n;
                ch->ch_obuf_size -= n;
                ch->ch_obuf_addr += n;

        } else {
                /*
                 * Check if we should start/stop a break
                 */
                if ( ISSET(ch->ch_flags, CLMPCC_FLG_START_BREAK) ) {
                        CLR(ch->ch_flags, CLMPCC_FLG_START_BREAK);
                        /* Enable embedded transmit commands */
                        clmpcc_wrreg(sc, CLMPCC_REG_COR2,
                                        ch->ch_cor2 | CLMPCC_COR2_ETC);
                        clmpcc_wr_txdata(sc, CLMPCC_ETC_MAGIC);
                        clmpcc_wr_txdata(sc, CLMPCC_ETC_SEND_BREAK);
                        ftc -= 2;
                        etcmode = 1;
                }

                if ( ISSET(ch->ch_flags, CLMPCC_FLG_END_BREAK) ) {
                        CLR(ch->ch_flags, CLMPCC_FLG_END_BREAK);
                        /* Enable embedded transmit commands */
                        clmpcc_wrreg(sc, CLMPCC_REG_COR2,
                                        ch->ch_cor2 | CLMPCC_COR2_ETC);
                        clmpcc_wr_txdata(sc, CLMPCC_ETC_MAGIC);
                        clmpcc_wr_txdata(sc, CLMPCC_ETC_STOP_BREAK);
                        ftc -= 2;
                        etcmode = 1;
                }
        }

        tir = clmpcc_rdreg(sc, CLMPCC_REG_IER);

        if ( ftc != oftc ) {
                /*
                 * Enable/disable the Tx FIFO threshold interrupt
                 * according to how much data is in the FIFO.
                 * However, always disable the FIFO threshold if
                 * we've left the channel in 'Embedded Transmit
                 * Command' mode.
                 */
                if ( etcmode || ftc >= ch->ch_cor4 )
                        tir &= ~CLMPCC_IER_TX_FIFO;
                else
                        tir |= CLMPCC_IER_TX_FIFO;
                teoir = 0;
        } else {
                /*
                 * No data was sent.
                 * Disable transmit interrupt.
                 */
                tir &= ~(CLMPCC_IER_TX_EMPTY|CLMPCC_IER_TX_FIFO);
                teoir = CLMPCC_TEOIR_NO_TRANS;

                /*
                 * Request Tx processing in the soft interrupt handler
                 */
                ch->ch_tx_done = 1;
                softint_schedule(sc->sc_softintr_cookie);
        }

        clmpcc_wrreg(sc, CLMPCC_REG_IER, tir);
        clmpcc_wrreg(sc, CLMPCC_REG_TEOIR, teoir);

        return 1;
}

/*
 * Modem change interrupt routine
 */
int
clmpcc_mdintr(void *arg)
{
        struct clmpcc_softc *sc = (struct clmpcc_softc *)arg;
        u_char mir;

        /* Modem status interrupt active? */
        mir = clmpcc_rdreg(sc, CLMPCC_REG_MIR);

        /*
         * If we're using auto-vectored interrupts, we have to
         * verify if the chip is generating the interrupt.
         */
        if ( sc->sc_vector_base == 0 && (mir & CLMPCC_MIR_MACT) == 0 )
                return 0;

        /* Dummy read of the interrupt status register */
        (void) clmpcc_rdreg(sc, CLMPCC_REG_MISR);

        /* Retrieve current status of modem lines. */
        sc->sc_chans[mir & CLMPCC_MIR_MCN_MASK].ch_control |=
                clmpcc_rd_msvr(sc) & CLMPCC_MSVR_CD;

        clmpcc_wrreg(sc, CLMPCC_REG_MEOIR, 0);
        softint_schedule(sc->sc_softintr_cookie);

        return 1;
}

void
clmpcc_softintr(void *arg)
{
        struct clmpcc_softc *sc = (struct clmpcc_softc *)arg;
        struct clmpcc_chan *ch;
        struct tty *tp;
        int (*rint)(int, struct tty *);
        u_char *get;
        u_char reg;
        u_int c;
        int chan;

        /* Handle Modem state changes too... */

        for (chan = 0; chan < CLMPCC_NUM_CHANS; chan++) {
                ch = &sc->sc_chans[chan];
                tp = ch->ch_tty;

                get = ch->ch_ibuf_rd;
                rint = tp->t_linesw->l_rint;

                /* Squirt buffered incoming data into the tty layer */
                while ( get != ch->ch_ibuf_wr ) {
                        c = get[0];
                        c |= ((u_int)get[1]) << 8;
                        if ( (rint)(c, tp) == -1 ) {
                                ch->ch_ibuf_rd = ch->ch_ibuf_wr;
                                break;
                        }

                        get += 2;
                        if ( get == ch->ch_ibuf_end )
                                get = ch->ch_ibuf;

                        ch->ch_ibuf_rd = get;
                }

                /*
                 * Is the transmitter idle and in need of attention?
                 */
                if ( ch->ch_tx_done ) {
                        ch->ch_tx_done = 0;

                        if ( ISSET(ch->ch_flags, CLMPCC_FLG_NEED_INIT) ) {
                                clmpcc_channel_cmd(sc, ch->ch_car,
                                                       CLMPCC_CCR_T0_INIT  |
                                                       CLMPCC_CCR_T0_RX_EN |
                                                       CLMPCC_CCR_T0_TX_EN);
                                CLR(ch->ch_flags, CLMPCC_FLG_NEED_INIT);

                                /*
                                 * Allow time for the channel to initialise.
                                 * (Empirically derived duration; there must
                                 * be another way to determine the command
                                 * has completed without busy-waiting...)
                                 */
                                delay(800);

                                /*
                                 * Update the tty layer's idea of the carrier
                                 * bit, in case we changed CLOCAL or MDMBUF.
                                 * We don't hang up here; we only do that by
                                 * explicit request.
                                 */
                                reg = clmpcc_rd_msvr(sc) & CLMPCC_MSVR_CD;
                                (*tp->t_linesw->l_modem)(tp, reg != 0);
                        }

                        CLR(tp->t_state, TS_BUSY);
                        if ( ISSET(tp->t_state, TS_FLUSH) )
                                CLR(tp->t_state, TS_FLUSH);
                        else
                                ndflush(&tp->t_outq,
                                     (int)(ch->ch_obuf_addr - tp->t_outq.c_cf));

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


/*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX*/
/*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX*/
/*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX*/
/*
 * Following are all routines needed for a cd240x channel to act as console
 */
int
clmpcc_cnattach(struct clmpcc_softc *sc, int chan, int rate)
{
        cons_sc = sc;
        cons_chan = chan;
        cons_rate = rate;

        return (clmpcc_init(sc));
}

/*
 * The following functions are polled getc and putc routines, for console use.
 */
static int
clmpcc_common_getc(struct clmpcc_softc *sc, int chan)
{
        u_char old_chan;
        u_char old_ier;
        u_char ch, rir, risr;
        int s;

        s = splhigh();

        /* Save the currently active channel */
        old_chan = clmpcc_select_channel(sc, chan);

        /*
         * We have to put the channel into RX interrupt mode before
         * trying to read the Rx data register. So save the previous
         * interrupt mode.
         */
        old_ier = clmpcc_rdreg(sc, CLMPCC_REG_IER);
        clmpcc_wrreg(sc, CLMPCC_REG_IER, CLMPCC_IER_RX_FIFO);

        /* Loop until we get a character */
        for (;;) {
                /*
                 * The REN bit will be set in the Receive Interrupt Register
                 * when the CD240x has a character to process. Remember,
                 * the RACT bit won't be set until we generate an interrupt
                 * acknowledge cycle via the MD front-end.
                 */
                rir = clmpcc_rdreg(sc, CLMPCC_REG_RIR);
                if ( (rir & CLMPCC_RIR_REN) == 0 )
                        continue;

                /* Acknowledge the request */
                if ( sc->sc_iackhook )
                        (sc->sc_iackhook)(sc, CLMPCC_IACK_RX);

                /*
                 * Determine if the interrupt is for the required channel
                 * and if valid data is available.
                 */
                rir = clmpcc_rdreg(sc, CLMPCC_REG_RIR);
                risr = clmpcc_rdreg(sc, CLMPCC_REG_RISR);
                if ( (rir & CLMPCC_RIR_RCN_MASK) != chan ||
                     risr != 0 ) {
                        /* Rx error, or BREAK */
                        clmpcc_wrreg(sc, CLMPCC_REG_REOIR,
                                         CLMPCC_REOIR_NO_TRANS);
                } else {
                        /* Dummy read of the FIFO count register */
                        (void) clmpcc_rdreg(sc, CLMPCC_REG_RFOC);

                        /* Fetch the received character */
                        ch = clmpcc_rd_rxdata(sc);

                        clmpcc_wrreg(sc, CLMPCC_REG_REOIR, 0);
                        break;
                }
        }

        /* Restore the original IER and CAR register contents */
        clmpcc_wrreg(sc, CLMPCC_REG_IER, old_ier);
        clmpcc_select_channel(sc, old_chan);

        splx(s);
        return ch;
}


static void
clmpcc_common_putc(struct clmpcc_softc *sc, int chan, int c)
{
        u_char old_chan;
        int s = splhigh();

        /* Save the currently active channel */
        old_chan = clmpcc_select_channel(sc, chan);

        /*
         * Since we can only access the Tx Data register from within
         * the interrupt handler, the easiest way to get console data
         * onto the wire is using one of the Special Transmit Character
         * registers.
         */
        clmpcc_wrreg(sc, CLMPCC_REG_SCHR4, c);
        clmpcc_wrreg(sc, CLMPCC_REG_STCR, CLMPCC_STCR_SSPC(4) |
                                          CLMPCC_STCR_SND_SPC);

        /* Wait until the "Send Special Character" command is accepted */
        while ( clmpcc_rdreg(sc, CLMPCC_REG_STCR) != 0 )
                ;

        /* Restore the previous channel selected */
        clmpcc_select_channel(sc, old_chan);

        splx(s);
}

int
clmpcccngetc(dev_t dev)
{
        return clmpcc_common_getc(cons_sc, cons_chan);
}

/*
 * Console kernel output character routine.
 */
void
clmpcccnputc(dev_t dev, int c)
{
        if ( c == '\n' )
                clmpcc_common_putc(cons_sc, cons_chan, '\r');

        clmpcc_common_putc(cons_sc, cons_chan, c);
}