/*      $NetBSD: mfc.c,v 1.62 2024/09/08 09:36:48 rillig Exp $ */

/*
 * Copyright (c) 1982, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * 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) 1994 Michael L. Hitch
 *
 * 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 AUTHOR ``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 AUTHOR 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 "opt_kgdb.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mfc.c,v 1.62 2024/09/08 09:36:48 rillig Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/conf.h>
#include <sys/kauth.h>
#include <machine/cpu.h>
#include <amiga/amiga/device.h>
#include <amiga/amiga/isr.h>
#include <amiga/amiga/custom.h>
#include <amiga/amiga/cia.h>
#include <amiga/amiga/cc.h>
#include <amiga/dev/zbusvar.h>

#include <dev/cons.h>

#include "mfcs.h"

#ifndef SEROBUF_SIZE
#define SEROBUF_SIZE    128
#endif
#ifndef SERIBUF_SIZE
#define SERIBUF_SIZE    1024
#endif

#define splser()        spl6()

/*
 * 68581 DUART registers
 */
struct mfc_regs {
        volatile u_char du_mr1a;
#define du_mr2a         du_mr1a
        u_char pad0;
        volatile u_char du_csra;
#define du_sra          du_csra
        u_char pad2;
        volatile u_char du_cra;
        u_char pad4;
        volatile u_char du_tba;
#define du_rba          du_tba
        u_char pad6;
        volatile u_char du_acr;
#define du_ipcr         du_acr
        u_char pad8;
        volatile u_char du_imr;
#define du_isr          du_imr
        u_char pad10;
        volatile u_char du_ctur;
#define du_cmsb         du_ctur
        u_char pad12;
        volatile u_char du_ctlr;
#define du_clsb         du_ctlr
        u_char pad14;
        volatile u_char du_mr1b;
#define du_mr2b         du_mr1b
        u_char pad16;
        volatile u_char du_csrb;
#define du_srb          du_csrb
        u_char pad18;
        volatile u_char du_crb;
        u_char pad20;
        volatile u_char du_tbb;
#define du_rbb          du_tbb
        u_char pad22;
        volatile u_char du_ivr;
        u_char pad24;
        volatile u_char du_opcr;
#define du_ip           du_opcr
        u_char pad26;
        volatile u_char du_btst;
#define du_strc         du_btst
        u_char pad28;
        volatile u_char du_btrst;
#define du_stpc         du_btrst
        u_char pad30;
};

/*
 * 68681 DUART serial port registers
 */
struct duart_regs {
        volatile u_char ch_mr1;
#define ch_mr2          ch_mr1
        u_char pad0;
        volatile u_char ch_csr;
#define ch_sr           ch_csr
        u_char pad1;
        volatile u_char ch_cr;
        u_char pad2;
        volatile u_char ch_tb;
#define ch_rb           ch_tb
        u_char pad3;
};

struct mfc_softc {
        device_t sc_dev;
        struct  isr sc_isr;
        struct  mfc_regs *sc_regs;
        u_long  clk_frq;
        u_short ct_val;
        u_char  ct_usecnt;
        u_char  imask;
        u_char  mfc_iii;
        u_char  last_ip;
};

#if NMFCS > 0
struct mfcs_softc {
        device_t sc_dev;
        struct  tty *sc_tty;
        struct  duart_regs *sc_duart;
        struct  mfc_regs *sc_regs;
        struct  mfc_softc *sc_mfc;
        int     swflags;
        long    flags;                  /* XXX */
#define CT_USED 1                       /* CT in use */
        u_short *rptr, *wptr, incnt, ovfl;
        u_short inbuf[SERIBUF_SIZE];
        char    *ptr, *end;
        char    outbuf[SEROBUF_SIZE];
        struct  vbl_node vbl_node;
        void    *mfcs_si;
};
#endif

#if NMFCP > 0
struct mfcp_softc {
};
#endif

struct mfc_args {
        struct zbus_args zargs;
        const char      *subdev;
        char    unit;
};

int     mfcprint(void *, const char *);
void    mfcattach(device_t, device_t, void *);
int     mfcmatch(device_t, cfdata_t, void *);

#if NMFCS > 0
int     mfcsmatch(device_t, cfdata_t, void *);
void    mfcsattach(device_t, device_t, void *);
int     mfcsparam( struct tty *, struct termios *);
int     mfcshwiflow(struct tty *, int);
void    mfcsstart(struct tty *);
int     mfcsmctl(dev_t, int, int);
void    mfcsxintr(int);
void    mfcseint(int, int);
void    mfcsmint(register int);
void    mfcs_intr_soft(void *);
#endif

#if NMFCP > 0
void mfcpattach(device_t, device_t, void *);
int mfcpmatch(device_t, cfdata_t, void *);
#endif
int mfcintr(void *);

CFATTACH_DECL_NEW(mfc, sizeof(struct mfc_softc),
    mfcmatch, mfcattach, NULL, NULL);

#if NMFCS > 0
CFATTACH_DECL_NEW(mfcs, sizeof(struct mfcs_softc),
    mfcsmatch, mfcsattach, NULL, NULL);

extern struct cfdriver mfcs_cd;
#endif

#if NMFCP > 0
CFATTACH_DECL_NEW(mfcp, sizeof(struct mfcp_softc),
    mfcpmatch, mfcpattach, NULL, NULL);
#endif

dev_type_open(mfcsopen);
dev_type_close(mfcsclose);
dev_type_read(mfcsread);
dev_type_write(mfcswrite);
dev_type_ioctl(mfcsioctl);
dev_type_stop(mfcsstop);
dev_type_tty(mfcstty);
dev_type_poll(mfcspoll);

const struct cdevsw mfcs_cdevsw = {
        .d_open = mfcsopen,
        .d_close = mfcsclose,
        .d_read = mfcsread,
        .d_write = mfcswrite,
        .d_ioctl = mfcsioctl,
        .d_stop = mfcsstop,
        .d_tty = mfcstty,
        .d_poll = mfcspoll,
        .d_mmap = nommap,
        .d_kqfilter = ttykqfilter,
        .d_discard = nodiscard,
        .d_flag = D_TTY
};

int     mfcs_active;
int     mfcsdefaultrate = 38400 /*TTYDEF_SPEED*/;
#define SWFLAGS(dev) (sc->swflags | (((dev) & 0x80) == 0 ? TIOCFLAG_SOFTCAR : 0))

#ifdef notyet
/*
 * MultiFaceCard III, II+ (not supported yet), and
 * SerialMaster 500+ (not supported yet)
 * baud rate tables for BRG set 1 [not used yet]
 */

const struct speedtab mfcs3speedtab1[] = {
        { 0,            0       },
        { 100,          0x00    },
        { 220,          0x11    },
        { 600,          0x44    },
        { 1200,         0x55    },
        { 2400,         0x66    },
        { 4800,         0x88    },
        { 9600,         0x99    },
        { 19200,        0xbb    },
        { 115200,       0xcc    },
        { -1,           -1      }
};

/*
 * MultiFaceCard II, I, and SerialMaster 500
 * baud rate tables for BRG set 1 [not used yet]
 */

const struct speedtab mfcs2speedtab1[] = {
        { 0,            0       },
        { 50,           0x00    },
        { 110,          0x11    },
        { 300,          0x44    },
        { 600,          0x55    },
        { 1200,         0x66    },
        { 2400,         0x88    },
        { 4800,         0x99    },
        { 9600,         0xbb    },
        { 38400,        0xcc    },
        { -1,           -1      }
};
#endif

/*
 * MultiFaceCard III, II+ (not supported yet), and
 * SerialMaster 500+ (not supported yet)
 * baud rate tables for BRG set 2
 */

const struct speedtab mfcs3speedtab2[] = {
        { 0,            0       },
        { 150,          0x00    },
        { 200,          0x11    },
        { 300,          0x33    },
        { 600,          0x44    },
        { 1200,         0x55    },
        { 2400,         0x66    },
        { 4800,         0x88    },
        { 9600,         0x99    },
        { 19200,        0xbb    },
        { 38400,        0xcc    },
        { -1,           -1      }
};

/*
 * MultiFaceCard II, I, and SerialMaster 500
 * baud rate tables for BRG set 2
 */

const struct speedtab mfcs2speedtab2[] = {
        { 0,            0       },
        { 75,           0x00    },
        { 100,          0x11    },
        { 150,          0x33    },
        { 300,          0x44    },
        { 600,          0x55    },
        { 1200,         0x66    },
        { 2400,         0x88    },
        { 4800,         0x99    },
        { 9600,         0xbb    },
        { 19200,        0xcc    },
        { -1,           -1      }
};

/*
 * if we are a bsc/Alf Data MultFaceCard (I, II, and III)
 */
int
mfcmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct zbus_args *zap;

        zap = aux;
        if (zap->manid == 2092 &&
            (zap->prodid == 16 || zap->prodid == 17 || zap->prodid == 18))

                return(1);
        return(0);
}

void
mfcattach(device_t parent, device_t self, void *aux)
{
        struct mfc_softc *scc;
        struct zbus_args *zap;
        struct mfc_args ma;
        int unit;
        struct mfc_regs *rp;

        zap = aux;

        printf ("\n");

        scc = device_private(self);
        scc->sc_dev = self;
        unit = device_unit(self);
        scc->sc_regs = rp = zap->va;
        if (zap->prodid == 18)
                scc->mfc_iii = 3;
        scc->clk_frq = scc->mfc_iii ? 230400 : 115200;

        rp->du_opcr = 0x00;             /* configure output port? */
        rp->du_btrst = 0x0f;            /* clear modem lines */
        rp->du_ivr = 0;                 /* IVR */
        rp->du_imr = 0;                 /* IMR */
        rp->du_acr = 0xe0;              /* baud rate generate set 2 */
        rp->du_ctur = 0;
        rp->du_ctlr = 4;
        rp->du_csra = 0xcc;             /* clock select = 38400 */
        rp->du_cra = 0x10;              /* reset mode register ptr */
        rp->du_cra = 0x20;
        rp->du_cra = 0x30;
        rp->du_cra = 0x40;
        rp->du_mr1a = 0x93;             /* MRA1 */
        rp->du_mr2a = 0x17;             /* MRA2 */
        rp->du_csrb = 0xcc;             /* clock select = 38400 */
        rp->du_crb = 0x10;              /* reset mode register ptr */
        rp->du_crb = 0x20;
        rp->du_crb = 0x30;
        rp->du_crb = 0x40;
        rp->du_mr1b = 0x93;             /* MRB1 */
        rp->du_mr2b = 0x17;             /* MRB2 */
        rp->du_cra = 0x05;              /* enable A Rx & Tx */
        rp->du_crb = 0x05;              /* enable B Rx & Tx */

        scc->sc_isr.isr_intr = mfcintr;
        scc->sc_isr.isr_arg = scc;
        scc->sc_isr.isr_ipl = 6;
        add_isr(&scc->sc_isr);

        /* configure ports */
        memcpy(&ma.zargs, zap, sizeof(struct zbus_args));

        ma.subdev = "mfcs";
        ma.unit = unit * 2;
        config_found(self, &ma, mfcprint, CFARGS_NONE);

        ma.unit = unit * 2 + 1;
        config_found(self, &ma, mfcprint, CFARGS_NONE);

        ma.subdev = "mfcp";
        ma.unit = unit;
        config_found(self, &ma, mfcprint, CFARGS_NONE);
}

/*
 *
 */
int
mfcsmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct mfc_args *ma;

        ma = aux;
        if (strcmp(ma->subdev, "mfcs") == 0)
                return (1);
        return (0);
}

void
mfcsattach(device_t parent, device_t self, void *aux)
{
        int unit;
        struct mfcs_softc *sc;
        struct mfc_softc *scc;
        struct mfc_args *ma;
        struct mfc_regs *rp;

        sc = device_private(self);
        sc->sc_dev = self;
        scc = device_private(parent);
        ma = aux;

        printf (": input fifo %d output fifo %d\n", SERIBUF_SIZE,
            SEROBUF_SIZE);

        unit = ma->unit;
        mfcs_active |= 1 << unit;
        sc->rptr = sc->wptr = sc->inbuf;
        sc->sc_mfc = scc;
        sc->sc_regs = rp = scc->sc_regs;
        sc->sc_duart = (struct duart_regs *) ((unit & 1) ? 
            __UNVOLATILE(&rp->du_mr1b) : __UNVOLATILE(&rp->du_mr1a));
        sc->mfcs_si = softint_establish(SOFTINT_SERIAL, mfcs_intr_soft, sc);
        /*
         * should have only one vbl routine to handle all ports?
         */
        sc->vbl_node.function = (void (*) (void *)) mfcsmint;
        sc->vbl_node.data = (void *) unit;
        add_vbl_function(&sc->vbl_node, 1, (void *) unit);
}

/*
 * print diag if pnp is NULL else just extra
 */
int
mfcprint(void *aux, const char *pnp)
{
        if (pnp == NULL)
                return(UNCONF);
        return(QUIET);
}

int
mfcsopen(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct tty *tp;
        struct mfcs_softc *sc;
        int unit, error;

        error = 0;
        unit = dev & 0x1f;

        sc = device_lookup_private(&mfcs_cd, unit);
        if (sc == NULL || (mfcs_active & (1 << unit)) == 0)
                return (ENXIO);

        if (sc->sc_tty)
                tp = sc->sc_tty;
        else {
                tp = sc->sc_tty = tty_alloc();
                tty_attach(tp);
        }

        tp->t_oproc = (void (*) (struct tty *)) mfcsstart;
        tp->t_param = mfcsparam;
        tp->t_dev = dev;
        tp->t_hwiflow = mfcshwiflow;

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

        ttylock(tp);
        if ((tp->t_state & TS_ISOPEN) == 0 && tp->t_wopen == 0) {
                ttychars(tp);
                if (tp->t_ispeed == 0) {
                        /*
                         * only when cleared do we reset to defaults.
                         */
                        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 = mfcsdefaultrate;
                }
                /*
                 * do these all the time
                 */
                if (sc->swflags & TIOCFLAG_CLOCAL)
                        tp->t_cflag |= CLOCAL;
                if (sc->swflags & TIOCFLAG_CRTSCTS)
                        tp->t_cflag |= CRTSCTS;
                if (sc->swflags & TIOCFLAG_MDMBUF)
                        tp->t_cflag |= MDMBUF;
                mfcsparam(tp, &tp->t_termios);
                ttsetwater(tp);

                (void)mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMSET);
                if ((SWFLAGS(dev) & TIOCFLAG_SOFTCAR) ||
                    (mfcsmctl(dev, 0, DMGET) & TIOCM_CD))
                        tp->t_state |= TS_CARR_ON;
                else
                        tp->t_state &= ~TS_CARR_ON;
        }

        /*
         * if NONBLOCK requested, ignore carrier
         */
        if (flag & O_NONBLOCK)
                goto done;

        /*
         * block waiting for carrier
         */
        while ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 0) {
                tp->t_wopen++;
                error = ttysleep(tp, &tp->t_rawcv, true, 0);
                tp->t_wopen--;
                if (error) {
                        ttyunlock(tp);
                        return(error);
                }
        }
done:
        /* This is a way to handle lost XON characters */
        if ((flag & O_TRUNC) && (tp->t_state & TS_TTSTOP)) {
                tp->t_state &= ~TS_TTSTOP;
                ttstart (tp);
        }
        /*
         * Reset the tty pointer, as there could have been a dialout
         * use of the tty with a dialin open waiting.
         */
        tp->t_dev = dev;
        ttyunlock(tp);
        return tp->t_linesw->l_open(dev, tp);
}

/*ARGSUSED*/
int
mfcsclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct tty *tp;
        int unit;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);
        struct mfc_softc *scc= sc->sc_mfc;

        unit = dev & 31;

        tp = sc->sc_tty;
        tp->t_linesw->l_close(tp, flag);
        sc->sc_duart->ch_cr = 0x70;                     /* stop break */

        scc->imask &= ~(0x7 << ((unit & 1) * 4));
        scc->sc_regs->du_imr = scc->imask;
        if (sc->flags & CT_USED) {
                --scc->ct_usecnt;
                sc->flags &= ~CT_USED;
        }

        /*
         * If the device is closed, it's close, no matter whether we deal with
         * modem control signals nor not.
         */
#if 0
        if (tp->t_cflag & HUPCL || tp->t_wopen != 0 ||
            (tp->t_state & TS_ISOPEN) == 0)
#endif
                (void) mfcsmctl(dev, 0, DMSET);
        ttyclose(tp);
#if not_yet
        if (tp != &mfcs_cons) {
                remove_vbl_function(&sc->vbl_node);
                tty_free(tp);
                sc->sc_tty = (struct tty *) NULL;
        }
#endif
        return (0);
}

int
mfcsread(dev_t dev, struct uio *uio, int flag)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);
        struct tty *tp = sc->sc_tty;
        if (tp == NULL)
                return(ENXIO);
        return tp->t_linesw->l_read(tp, uio, flag);
}

int
mfcswrite(dev_t dev, struct uio *uio, int flag)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);
        struct tty *tp = sc->sc_tty;

        if (tp == NULL)
                return(ENXIO);
        return tp->t_linesw->l_write(tp, uio, flag);
}

int
mfcspoll(dev_t dev, int events, struct lwp *l)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);
        struct tty *tp = sc->sc_tty;

        if (tp == NULL)
                return(ENXIO);
        return ((*tp->t_linesw->l_poll)(tp, events, l));
}

struct tty *
mfcstty(dev_t dev)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);

        return (sc->sc_tty);
}

int
mfcsioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        register struct tty *tp;
        register int error;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);

        tp = sc->sc_tty;
        if (!tp)
                return ENXIO;

        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:
                sc->sc_duart->ch_cr = 0x60;             /* start break */
                break;

        case TIOCCBRK:
                sc->sc_duart->ch_cr = 0x70;             /* stop break */
                break;

        case TIOCSDTR:
                (void) mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMBIS);
                break;

        case TIOCCDTR:
                (void) mfcsmctl(dev, TIOCM_DTR | TIOCM_RTS, DMBIC);
                break;

        case TIOCMSET:
                (void) mfcsmctl(dev, *(int *) data, DMSET);
                break;

        case TIOCMBIS:
                (void) mfcsmctl(dev, *(int *) data, DMBIS);
                break;

        case TIOCMBIC:
                (void) mfcsmctl(dev, *(int *) data, DMBIC);
                break;

        case TIOCMGET:
                *(int *)data = mfcsmctl(dev, 0, DMGET);
                break;
        case TIOCGFLAGS:
                *(int *)data = SWFLAGS(dev);
                break;
        case TIOCSFLAGS:
                error = kauth_authorize_device_tty(l->l_cred,
                    KAUTH_DEVICE_TTY_PRIVSET, tp);
                if (error != 0)
                        return(EPERM);

                sc->swflags = *(int *)data;
                sc->swflags &= /* only allow valid flags */
                  (TIOCFLAG_SOFTCAR | TIOCFLAG_CLOCAL | TIOCFLAG_CRTSCTS);
                /* XXXX need to change duart parameters? */
                break;
        default:
                return(EPASSTHROUGH);
        }

        return(0);
}

int
mfcsparam(struct tty *tp, struct termios *t)
{
        int cflag, unit, ospeed;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, tp->t_dev & 31);
        struct mfc_softc *scc= sc->sc_mfc;

        cflag = t->c_cflag;
        unit = tp->t_dev & 31;
        if (sc->flags & CT_USED) {
                --scc->ct_usecnt;
                sc->flags &= ~CT_USED;
        }
        ospeed = ttspeedtab(t->c_ospeed, scc->mfc_iii ? mfcs3speedtab2 :
            mfcs2speedtab2);

        /*
         * If Baud Rate Generator can't generate requested speed,
         * try to use the counter/timer.
         */
        if (ospeed < 0 && (scc->clk_frq % t->c_ospeed) == 0) {
                ospeed = scc->clk_frq / t->c_ospeed;    /* divisor */
                if (scc->ct_usecnt > 0 && scc->ct_val != ospeed)
                        ospeed = -1;
                else {
                        scc->sc_regs->du_ctur = ospeed >> 8;
                        scc->sc_regs->du_ctlr = ospeed;
                        scc->ct_val = ospeed;
                        ++scc->ct_usecnt;
                        sc->flags |= CT_USED;
                        ospeed = 0xdd;
                }
        }
        /* XXXX 68681 duart could handle split speeds */
        if (ospeed < 0 || (t->c_ispeed && t->c_ispeed != t->c_ospeed))
                return(EINVAL);

        /* XXXX handle parity, character size, stop bits, flow control */

        /*
         * copy to tty
         */
        tp->t_ispeed = t->c_ispeed;
        tp->t_ospeed = t->c_ospeed;
        tp->t_cflag = cflag;

        /*
         * enable interrupts
         */
        scc->imask |= (0x2 << ((unit & 1) * 4)) | 0x80;
        scc->sc_regs->du_imr = scc->imask;
#if defined(DEBUG) && 0
        printf("mfcsparam: speed %d => %x ct %d imask %x cflag %x\n",
            t->c_ospeed, ospeed, scc->ct_val, scc->imask, cflag);
#endif
        if (ospeed == 0)
                (void)mfcsmctl(tp->t_dev, 0, DMSET);    /* hang up line */
        else {
                /*
                 * (re)enable DTR
                 * and set baud rate. (8 bit mode)
                 */
                (void)mfcsmctl(tp->t_dev, TIOCM_DTR | TIOCM_RTS, DMSET);
                sc->sc_duart->ch_csr = ospeed;
        }
        return(0);
}

int
mfcshwiflow(struct tty *tp, int flag)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, tp->t_dev & 31);
        int unit = tp->t_dev & 1;

        if (flag)
                sc->sc_regs->du_btrst = 1 << unit;
        else
                sc->sc_regs->du_btst = 1 << unit;
        return 1;
}

void
mfcsstart(struct tty *tp)
{
        int cc, s, unit;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, tp->t_dev & 31);
        struct mfc_softc *scc= sc->sc_mfc;

        if ((tp->t_state & TS_ISOPEN) == 0)
                return;

        unit = tp->t_dev & 1;

        s = splser();
        if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP))
                goto out;

        cc = tp->t_outq.c_cc;
        if (!ttypull(tp) || (tp->t_state & TS_BUSY))
                goto out;

        /*
         * We only do bulk transfers if using CTSRTS flow control, not for
         * (probably sloooow) ixon/ixoff devices.
         */
        if ((tp->t_cflag & CRTSCTS) == 0)
                cc = 1;

        /*
         * Limit the amount of output we do in one burst
         * to prevent hogging the CPU.
         */
        if (cc > SEROBUF_SIZE)
                cc = SEROBUF_SIZE;
        cc = q_to_b(&tp->t_outq, sc->outbuf, cc);
        if (cc > 0) {
                tp->t_state |= TS_BUSY;

                sc->ptr = sc->outbuf;
                sc->end = sc->outbuf + cc;

                /*
                 * Get first character out, then have TBE-interrupts blow out
                 * further characters, until buffer is empty, and TS_BUSY gets
                 * cleared.
                 */
                sc->sc_duart->ch_tb = *sc->ptr++;
                scc->imask |= 1 << (unit * 4);
                sc->sc_regs->du_imr = scc->imask;
        }
out:
        splx(s);
}

/*
 * Stop output on a line.
 */
/*ARGSUSED*/
void
mfcsstop(struct tty *tp, int flag)
{
        int s;

        s = splser();
        if (tp->t_state & TS_BUSY) {
                if ((tp->t_state & TS_TTSTOP) == 0)
                        tp->t_state |= TS_FLUSH;
        }
        splx(s);
}

int
mfcsmctl(dev_t dev, int bits, int how)
{
        int unit, s;
        u_char ub = 0;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, dev & 31);

        unit = dev & 1;

        /*
         * convert TIOCM* mask into CIA mask
         * which is active low
         */
        if (how != DMGET) {
                /*
                 * need to save current state of DTR & RTS ?
                 */
                if (bits & TIOCM_DTR)
                        ub |= 0x04 << unit;
                if (bits & TIOCM_RTS)
                        ub |= 0x01 << unit;
        }
        s = splser();
        switch (how) {
        case DMSET:
                sc->sc_regs->du_btst = ub;
                sc->sc_regs->du_btrst = ub ^ (0x05 << unit);
                break;

        case DMBIC:
                sc->sc_regs->du_btrst = ub;
                ub = ~sc->sc_regs->du_ip;
                break;

        case DMBIS:
                sc->sc_regs->du_btst = ub;
                ub = ~sc->sc_regs->du_ip;
                break;

        case DMGET:
                ub = ~sc->sc_regs->du_ip;
                break;
        }
        (void)splx(s);

        /* XXXX should keep DTR & RTS states in softc? */
        bits = TIOCM_DTR | TIOCM_RTS;
        if (ub & (1 << unit))
                bits |= TIOCM_CTS;
        if (ub & (4 << unit))
                bits |= TIOCM_DSR;
        if (ub & (0x10 << unit))
                bits |= TIOCM_CD;
        /* XXXX RI is not supported on all boards */
        if (sc->sc_regs->pad26 & (1 << unit))
                bits |= TIOCM_RI;

        return(bits);
}

/*
 * Level 6 interrupt processing for the MultiFaceCard 68681 DUART
 */

int
mfcintr(void *arg)
{
        struct mfc_softc *scc = arg;
        struct mfcs_softc *sc;
        struct mfc_regs *regs;
        struct tty *tp;
        int istat, unit;
        u_short c;

        regs = scc->sc_regs;
        istat = regs->du_isr & scc->imask;
        if (istat == 0)
                return (0);
        unit = device_unit(scc->sc_dev) * 2;
        if (istat & 0x02) {             /* channel A receive interrupt */
                sc = device_lookup_private(&mfcs_cd, unit);
                while (1) {
                        c = regs->du_sra << 8;
                        if ((c & 0x0100) == 0)
                                break;
                        c |= regs->du_rba;
                        if (sc->incnt == SERIBUF_SIZE)
                                ++sc->ovfl;
                        else {
                                *sc->wptr++ = c;
                                if (sc->wptr == sc->inbuf + SERIBUF_SIZE)
                                        sc->wptr = sc->inbuf;
                                ++sc->incnt;
                                if (sc->incnt > SERIBUF_SIZE - 16)
                                        regs->du_btrst = 1;
                        }
                        if (c & 0x1000)
                                regs->du_cra = 0x40;
                }
        }
        if (istat & 0x20) {             /* channel B receive interrupt */
                sc = device_lookup_private(&mfcs_cd, unit + 1);
                while (1) {
                        c = regs->du_srb << 8;
                        if ((c & 0x0100) == 0)
                                break;
                        c |= regs->du_rbb;
                        if (sc->incnt == SERIBUF_SIZE)
                                ++sc->ovfl;
                        else {
                                *sc->wptr++ = c;
                                if (sc->wptr == sc->inbuf + SERIBUF_SIZE)
                                        sc->wptr = sc->inbuf;
                                ++sc->incnt;
                                if (sc->incnt > SERIBUF_SIZE - 16)
                                        regs->du_btrst = 2;
                        }
                        if (c & 0x1000)
                                regs->du_crb = 0x40;
                }
        }
        if (istat & 0x01) {             /* channel A transmit interrupt */
                sc = device_lookup_private(&mfcs_cd, unit);
                tp = sc->sc_tty;
                if (sc->ptr == sc->end) {
                        tp->t_state &= ~(TS_BUSY | TS_FLUSH);
                        scc->imask &= ~0x01;
                        regs->du_imr = scc->imask;
                        softint_schedule(sc->mfcs_si);
                }
                else
                        regs->du_tba = *sc->ptr++;
        }
        if (istat & 0x10) {             /* channel B transmit interrupt */
                sc = device_lookup_private(&mfcs_cd, unit + 1);
                tp = sc->sc_tty;
                if (sc->ptr == sc->end) {
                        tp->t_state &= ~(TS_BUSY | TS_FLUSH);
                        scc->imask &= ~0x10;
                        regs->du_imr = scc->imask;
                        softint_schedule(sc->mfcs_si);
                }
                else
                        regs->du_tbb = *sc->ptr++;
        }
        if (istat & 0x80) {             /* input port change interrupt */
                c = regs->du_ipcr;
                printf ("%s: ipcr %02x", device_xname(scc->sc_dev), c);
        }
        return(1);
}

void
mfcsxintr(int unit)
{
        int s1, s2, ovfl;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, unit);
        struct tty *tp = sc->sc_tty;

        /*
         * Make sure we're not interrupted by another
         * vbl, but allow level6 ints
         */
        s1 = spltty();

        /*
         * pass along any accumulated information
         * while input is not blocked
         */
        while (sc->incnt && (tp->t_state & TS_TBLOCK) == 0) {
                /*
                 * no collision with ser_fastint()
                 */
                mfcseint(unit, *sc->rptr++);

                ovfl = 0;
                /* lock against mfcs_fastint() */
                s2 = splser();
                --sc->incnt;
                if (sc->rptr == sc->inbuf + SERIBUF_SIZE)
                        sc->rptr = sc->inbuf;
                if (sc->ovfl != 0) {
                        ovfl = sc->ovfl;
                        sc->ovfl = 0;
                }
                splx(s2);
                if (ovfl != 0)
                        log(LOG_WARNING, "%s: %d buffer overflow!\n",
                            device_xname(sc->sc_dev), ovfl);
        }
        if (sc->incnt == 0 && (tp->t_state & TS_TBLOCK) == 0) {
                sc->sc_regs->du_btst = 1 << unit;       /* XXXX */
        }
        splx(s1);
}

void
mfcseint(int unit, int stat)
{
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, unit);
        struct tty *tp;
        u_char ch;
        int c;

        tp = sc->sc_tty;
        ch = stat & 0xff;
        c = ch;

        if ((tp->t_state & TS_ISOPEN) == 0) {
#ifdef KGDB
                extern const struct cdevsw ser_cdevsw;
                int maj;

                /* we don't care about parity errors */
                maj = cdevsw_lookup_major(&ser_cdevsw);
                if (kgdb_dev == makedev(maj, unit) && c == FRAME_END)
                        kgdb_connect(0);        /* trap into kgdb */
#endif
                return;
        }

        /*
         * Check for break and (if enabled) parity error.
         */
        if (stat & 0xc000)
                c |= TTY_FE;
        else if (stat & 0x2000)
                        c |= TTY_PE;

        if (stat & 0x1000)
                log(LOG_WARNING, "%s: fifo overflow\n",
                    device_xname(device_lookup_private(&mfcs_cd, unit)));

        tp->t_linesw->l_rint(c, tp);
}

/*
 * This interrupt is periodically invoked in the vertical blank
 * interrupt.  It's used to keep track of the modem control lines
 * and (new with the fast_int code) to move accumulated data
 * up into the tty layer.
 */
void
mfcsmint(int unit)
{
        struct tty *tp;
        struct mfcs_softc *sc = device_lookup_private(&mfcs_cd, unit);
        u_char stat, last, istat;

        tp = sc->sc_tty;
        if (!tp)
                return;

        if ((tp->t_state & TS_ISOPEN) == 0 && tp->t_wopen == 0) {
                sc->rptr = sc->wptr = sc->inbuf;
                sc->incnt = 0;
                return;
        }
        /*
         * empty buffer
         */
        mfcsxintr(unit);

        stat = ~sc->sc_regs->du_ip;
        last = sc->sc_mfc->last_ip;
        sc->sc_mfc->last_ip = stat;

        /*
         * check whether any interesting signal changed state
         */
        istat = stat ^ last;

        if ((istat & (0x10 << (unit & 1))) &&           /* CD changed */
            (SWFLAGS(tp->t_dev) & TIOCFLAG_SOFTCAR) == 0) {
                if (stat & (0x10 << (unit & 1)))
                        tp->t_linesw->l_modem(tp, 1);
                else if (tp->t_linesw->l_modem(tp, 0) == 0) {
                        sc->sc_regs->du_btrst = 0x0a << (unit & 1);
                }
        }
}

void
mfcs_intr_soft(void *arg)
{
        struct mfcs_softc *sc = (struct mfcs_softc *)arg;
        struct tty *tp = sc->sc_tty;

        if (tp->t_linesw)
                tp->t_linesw->l_start(tp);
        else
                mfcsstart(tp);
}