/*      $NetBSD: cec.c,v 1.16 2021/08/07 16:19:12 thorpej Exp $ */

/*-
 * Copyright (c) 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gregory McGarry.
 *
 * 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cec.c,v 1.16 2021/08/07 16:19:12 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/kernel.h>

#include <sys/bus.h>

#include <dev/isa/isavar.h>
#include <dev/isa/isadmavar.h>

#include <dev/gpib/gpibvar.h>

#include <dev/ic/nec7210reg.h>

#ifndef DEBUG
#define DEBUG
#endif

#ifdef DEBUG
int cecdebug = 0x1f;
#define DPRINTF(flag, str)      if (cecdebug & (flag)) printf str
#define DBG_FOLLOW      0x01
#define DBG_CONFIG      0x02
#define DBG_INTR        0x04
#define DBG_REPORTTIME  0x08
#define DBG_FAIL        0x10
#define DBG_WAIT        0x20
#else
#define DPRINTF(flag, str)      /* nothing */
#endif

#define CEC_IOSIZE      8

struct cec_softc {
        device_t sc_dev;                /* generic device glue */

        bus_space_tag_t sc_iot;
        bus_space_handle_t sc_ioh;
        isa_chipset_tag_t sc_ic;
        int sc_drq;
        void *sc_ih;

        int sc_myaddr;                  /* my address */
        struct gpib_softc *sc_gpib;

        volatile int sc_flags;
#define CECF_IO         0x1
#define CECF_PPOLL      0x4
#define CECF_READ       0x8
#define CECF_TIMO       0x10
#define CECF_USEDMA     0x20
        int sc_ppoll_slave;             /* XXX stash our ppoll address */
        callout_t sc_timeout_ch;
};

int     cecprobe(device_t, cfdata_t, void *);
void    cecattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(cec, sizeof(struct cec_softc),
        cecprobe, cecattach, NULL, NULL);

void    cecreset(void *);
int     cecpptest(void *, int);
void    cecppwatch(void *, int);
void    cecppclear(void *);
void    cecxfer(void *, int, int, void *, int, int, int);
void    cecgo(void *v);
int     cecintr(void *);
int     cecsendcmds(void *, void *, int);
int     cecsenddata(void *, void *, int);
int     cecrecvdata(void *, void *, int);
int     cecgts(void *);
int     cectc(void *, int);
void    cecifc(void *);

static int      cecwait(struct cec_softc *, int, int);
static void     cectimeout(void *v);
static int      nec7210_setaddress(struct cec_softc *, int, int);
static void     nec7210_init(struct cec_softc *);
static void     nec7210_ifc(struct cec_softc *);

/*
 * Our chipset structure.
 */
struct gpib_chipset_tag cec_ic = {
        cecreset,
        NULL,
        NULL,
        cecpptest,
        cecppwatch,
        cecppclear,
        cecxfer,
        cectc,
        cecgts,
        cecifc,
        cecsendcmds,
        cecsenddata,
        cecrecvdata,
        NULL,
        NULL
};

int cecwtimeout = 0x10000;
int cecdmathresh = 3;

int
cecprobe(device_t parent, cfdata_t match, void *aux)
{
        struct isa_attach_args *ia = aux;
        bus_space_tag_t iot = ia->ia_iot;
        bus_space_handle_t ioh;

        DPRINTF(DBG_CONFIG, ("cecprobe: called\n"));

        if (ia->ia_nio < 1)
                return (0);
        if (ia->ia_nirq < 1)
                return (0);
        if (ia->ia_ndrq < 1)
                return (0);

        if (ISA_DIRECT_CONFIG(ia))
                return (0);

        if (ia->ia_io[0].ir_addr == ISA_UNKNOWN_PORT)
                return (0);

        if (ia->ia_ndrq > 0 && ia->ia_drq[0].ir_drq == ISA_UNKNOWN_DRQ)
                ia->ia_ndrq = 0;

        if (bus_space_map(iot, ia->ia_io[0].ir_addr, CEC_IOSIZE, 0, &ioh))
                return (0);

        /* XXX insert probe here */

        ia->ia_io[0].ir_size = CEC_IOSIZE;
        ia->ia_niomem = 0;

        bus_space_unmap(iot, ioh, CEC_IOSIZE);

        return (1);
}

void
cecattach(device_t parent, device_t self, void *aux)
{
        struct cec_softc *sc = device_private(self);
        struct isa_attach_args *ia = aux;
        struct gpibdev_attach_args ga;
        bus_size_t maxsize;

        printf("\n");

        DPRINTF(DBG_CONFIG, ("cecattach: called\n"));

        sc->sc_dev = self;
        sc->sc_iot = ia->ia_iot;
        sc->sc_ic = ia->ia_ic;

        if (bus_space_map(sc->sc_iot, ia->ia_io[0].ir_addr, CEC_IOSIZE,
            0, &sc->sc_ioh) != 0) {
                aprint_error_dev(sc->sc_dev, "unable to map I/O space\n");
                return;
        }

        if (ia->ia_ndrq > 0) {
                sc->sc_flags |= CECF_USEDMA;
                sc->sc_drq = ia->ia_drq[0].ir_drq;

                (void) isa_drq_alloc(sc->sc_ic, sc->sc_drq);
                maxsize = isa_dmamaxsize(sc->sc_ic, sc->sc_drq);
                if (isa_dmamap_create(sc->sc_ic, sc->sc_drq,
                    maxsize, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW)) {
                        aprint_error_dev(sc->sc_dev,
                            "unable to create map for drq %d\n", sc->sc_drq);
                        sc->sc_flags &= ~CECF_USEDMA;
                }
        }

        sc->sc_myaddr = 15;             /* XXX */

        cecreset(sc);
        (void) nec7210_setaddress(sc, sc->sc_myaddr, -1);

        sc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq[0].ir_irq,
            IST_EDGE, IPL_BIO, cecintr, sc);
        if (sc->sc_ih == NULL) {
                aprint_error_dev(sc->sc_dev, "couldn't establish interrupt\n");
                return;
        }

        callout_init(&sc->sc_timeout_ch, 0);

        /* attach MI GPIB bus */
        cec_ic.cookie = (void *)sc;
        ga.ga_ic = &cec_ic;
        ga.ga_address = sc->sc_myaddr;
        sc->sc_gpib =
            (struct gpib_softc *)config_found(self, &ga, gpibdevprint,
            CFARGS_NONE);
}

int
cecintr(void *v)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        u_int8_t stat1, stat2;

        stat1 = bus_space_read_1(iot, ioh, NEC7210_ISR1);
        stat2 = bus_space_read_1(iot, ioh, NEC7210_ISR2);

        DPRINTF(DBG_INTR, ("cecintr: sc=%p stat1=0x%x stat2=0x%x\n",
            sc, stat1, stat2));

        if (sc->sc_flags & CECF_IO) {

                if (sc->sc_flags & CECF_TIMO)
                        callout_stop(&sc->sc_timeout_ch);

                bus_space_write_1(iot, ioh, NEC7210_IMR1, 0);
                bus_space_write_1(iot, ioh, NEC7210_IMR2, 0);
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_TCA);
                sc->sc_flags &= ~(CECF_IO | CECF_READ | CECF_TIMO);
                if (sc->sc_flags & CECF_USEDMA)
                        isa_dmadone(sc->sc_ic, sc->sc_drq);
                gpibintr(sc->sc_gpib);

        } else if (sc->sc_flags & CECF_PPOLL) {

                if (cecpptest(sc, sc->sc_ppoll_slave)) {
                        sc->sc_flags &= ~CECF_PPOLL;
                        bus_space_write_1(iot, ioh, NEC7210_IMR2, 0);
                        gpibintr(sc->sc_gpib);
                }

        }
        return (1);
}

void
cecreset(void *v)
{
        struct cec_softc *sc = v;
        u_int8_t cmd;

        DPRINTF(DBG_FOLLOW, ("cecreset: sc=%p\n", sc));

        nec7210_init(sc);
        nec7210_ifc(sc);
        /* we're now the system controller */

        /* XXX should be pushed higher */

        /* universal device clear */
        cmd = GPIBCMD_DCL;
        (void) cecsendcmds(sc, &cmd, 1);
        /* delay for devices to clear */
        DELAY(100000);
}

int
cecsendcmds(void *v, void *ptr, int origcnt)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int cnt = origcnt;
        u_int8_t *addr = ptr;

        DPRINTF(DBG_FOLLOW, ("cecsendcmds: sc=%p, ptr=%p cnt=%d\n",
            sc, ptr, origcnt));

        while (--cnt >= 0) {
                bus_space_write_1(iot, ioh, NEC7210_CDOR, *addr++);
                if (cecwait(sc, 0, ISR2_CO))
                        return (origcnt - cnt - 1);
        }
        return (origcnt);
}


int
cecrecvdata(void *v, void *ptr, int origcnt)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int cnt = origcnt;
        u_int8_t *addr = ptr;

        DPRINTF(DBG_FOLLOW, ("cecrecvdata: sc=%p, ptr=%p cnt=%d\n",
            sc, ptr, origcnt));

        /* XXX holdoff on end */
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, NEC7210_AUXMR, AUXCMD_RHDF);

        if (cnt) {
                while (--cnt >= 0) {
                        if (cecwait(sc, ISR1_DI, 0))
                                return (origcnt - cnt - 1);
                        *addr++ = bus_space_read_1(iot, ioh, NEC7210_DIR);
                }
        }
        return (origcnt);
}

int
cecsenddata(void *v, void *ptr, int origcnt)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int cnt = origcnt;
        u_int8_t *addr = ptr;

        DPRINTF(DBG_FOLLOW, ("cecdsenddata: sc=%p, ptr=%p cnt=%d\n",
            sc, ptr, origcnt));

        if (cnt) {
                while (--cnt > 0) {
                        bus_space_write_1(iot, ioh, NEC7210_CDOR, *addr++);
                        if (cecwait(sc, ISR1_DO, 0))
                                return (origcnt - cnt - 1);
                }
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_SEOI);
                bus_space_write_1(iot, ioh, NEC7210_CDOR, *addr);
                (void) cecwait(sc, ISR1_DO, 0);
        }
        return (origcnt);
}

int
cectc(void *v, int sync)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        u_int8_t adsr;
        int timo = cecwtimeout;

        DPRINTF(DBG_FOLLOW, ("cectc: sc=%p, sync=%d\n", sc, sync));

        adsr = bus_space_read_1(iot, ioh, NEC7210_ADSR);
#if 0
        if ((adsr & (ADSR_CIC | ADSR_NATN)) == ADSR_CIC) {
                DPRINTF(0xff, ("cectc: already CIC\n"));
                return (0);
        }
#endif

        if (sync) {
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_RHDF);
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_TCS);
        } else {
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_TCA);
        }

        /* wait until ATN is asserted */
        for (;;) {
                adsr = bus_space_read_1(iot, ioh, NEC7210_ADSR);
                if (--timo == 0) {
                        DPRINTF(DBG_REPORTTIME, ("cectc: timeout\n"));
                        return (1);
                }
                if ((adsr & ADSR_NATN) == 0)
                        break;
                DELAY(1);
        }

        return (0);
}

int
cecgts(void *v)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        u_int8_t adsr;
        int timo = cecwtimeout;

        DPRINTF(DBG_FOLLOW, ("cecgts: sc=%p\n", sc));

        adsr = bus_space_read_1(iot, ioh, NEC7210_ADSR);
#if 0
        if ((adsr & (ADSR_CIC | ADSR_NATN)) == ADSR_NATN) {
                DPRINTF(0xff, ("cecgts: already standby\n"));
                return (0);
        }
#endif

        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_GTS);

        /* wait unit ATN is released */
        for (;;) {
                adsr = bus_space_read_1(iot, ioh, NEC7210_ADSR);
                if (--timo == 0) {
                        DPRINTF(DBG_REPORTTIME, ("cecgts: timeout\n"));
                        return (1);
                }
                if ((adsr & ADSR_NATN) == ADSR_NATN)
                        break;
                DELAY(1);
        }

        return (0);
}

int
cecpptest(void *v, int slave)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int ppoll;

        DPRINTF(DBG_FOLLOW, ("cecpptest: sc=%p slave=%d\n", sc, slave));

        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_EPP);
        DELAY(25);
        ppoll = bus_space_read_1(iot, ioh, NEC7210_CPTR);
        DPRINTF(0xff, ("cecpptest: ppoll=%x\n", ppoll));
        return ((ppoll & (0x80 >> slave)) != 0);
}

void
cecppwatch(void *v, int slave)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        DPRINTF(DBG_FOLLOW, ("cecppwatch: sc=%p\n", sc));

        sc->sc_flags |= CECF_PPOLL;
        sc->sc_ppoll_slave = slave;
        bus_space_write_1(iot, ioh, NEC7210_IMR2, IMR2_CO);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_EPP);
}

void
cecppclear(void *v)
{
        struct cec_softc *sc = v;

        DPRINTF(DBG_FOLLOW, ("cecppclear: sc=%p\n", sc));

        sc->sc_flags &= ~CECF_PPOLL;
        bus_space_write_1(sc->sc_iot, sc->sc_ioh, NEC7210_IMR2, 0);
}

void
cecxfer(void *v, int slave, int sec, void *buf, int count, int dir, int timo)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        DPRINTF(DBG_FOLLOW,
            ("cecxfer: slave=%d sec=%d buf=%p count=%d dir=%x timo=%d\n",
            slave, sec, buf, count, dir, timo));

        sc->sc_flags |= CECF_IO;
        if (dir == GPIB_READ)
                sc->sc_flags |= CECF_READ;
        if (timo) {
                sc->sc_flags |= CECF_TIMO;
                callout_reset(&sc->sc_timeout_ch, 5*hz, cectimeout, sc);
        }

        if (sc->sc_flags & CECF_READ) {
                DPRINTF(DBG_FOLLOW, ("cecxfer: DMA read request\n"));
                if ((sc->sc_flags & CECF_USEDMA) != 0) {
                        isa_dmastart(sc->sc_ic, sc->sc_drq, buf, count, NULL,
                            DMAMODE_READ | DMAMODE_DEMAND, BUS_DMA_NOWAIT);
                        bus_space_write_1(iot, ioh, NEC7210_IMR2, IMR2_DMAI);
                        bus_space_write_1(iot, ioh, NEC7210_IMR1, IMR1_END);
                        // XXX (void) cecrecv(sc, slave, sec, NULL, 0);
                        (void) gpibrecv(&cec_ic, slave, sec, NULL, 0);
                } else {
                        /* XXX this doesn't work */
                        DPRINTF(DBG_FOLLOW, ("cecxfer: polling instead\n"));
                        bus_space_write_1(iot, ioh, NEC7210_IMR1, IMR1_END);
                        // XXX (void) cecrecv(sc, slave, sec, buf, count);
                        (void) gpibrecv(&cec_ic, slave, sec, buf, count);
                        bus_space_write_1(iot, ioh, NEC7210_IMR2, IMR2_CO);
                }
        } else {
                DPRINTF(DBG_FOLLOW, ("cecxfer: DMA write request\n"));
                bus_space_write_1(iot, ioh, NEC7210_IMR2, 0);
                if (count < cecdmathresh ||
                    (sc->sc_flags & CECF_USEDMA) == 0) {
                        DPRINTF(DBG_FOLLOW, ("cecxfer: polling instead\n"));
                        // XXX (void) cecsend(sc, slave, sec, buf, count);
                        (void) gpibsend(&cec_ic, slave, sec, buf, count);
                        bus_space_write_1(iot, ioh, NEC7210_IMR2, IMR2_CO);
                        return;
                }
                /* we send the last byte with EOI set */
                isa_dmastart(sc->sc_ic, sc->sc_drq, buf, count-1, NULL,
                    DMAMODE_WRITE | DMAMODE_DEMAND, BUS_DMA_NOWAIT);
                bus_space_write_1(iot, ioh, NEC7210_IMR2, IMR2_DMAO);
                // XXX (void) cecsend(sc, slave, sec, NULL, 0);
                (void) gpibsend(&cec_ic, slave, sec, NULL, 0);
                while (!isa_dmafinished(sc->sc_ic, sc->sc_drq))
                        DELAY(1);
                (void) cecwait(sc, ISR1_DO, 0);
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_SEOI);
                bus_space_write_1(iot, ioh, NEC7210_CDOR, *(char *)buf+count);
                /* generate interrupt */
                bus_space_write_1(iot, ioh, NEC7210_IMR1, IMR1_DO);
        }
}

void
cecifc(void *v)
{
        struct cec_softc *sc = v;

        nec7210_ifc(sc);
}

static int
nec7210_setaddress(struct cec_softc *sc, int pri, int sec)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        u_int8_t admr;

        /* assign our primary address */
        bus_space_write_1(iot, ioh, NEC7210_ADDR, (pri & ADDR_MASK));

        admr = ADMR_TRM0 | ADMR_TRM1;

        /* assign our secondary address */
        if (sec != -1) {
                bus_space_write_1(iot, ioh, NEC7210_ADDR,
                    (ADDR_ARS | (sec & ADDR_MASK)));
                admr |= ADMR_ADM1;
        } else {
                /* disable secondary address */
                bus_space_write_1(iot, ioh, NEC7210_ADDR,
                    (ADDR_ARS | ADDR_DT | ADDR_DL));
                admr |= ADMR_ADM0;
        }
        bus_space_write_1(iot, ioh, NEC7210_ADMR, admr);

        return (0);
}

static void
nec7210_init(struct cec_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        /* reset chip */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_CRST);

        /* clear interrupts */
        bus_space_read_1(iot, ioh, NEC7210_CPTR);
        bus_space_read_1(iot, ioh, NEC7210_ISR1);
        bus_space_read_1(iot, ioh, NEC7210_ISR2);

        /* initialise interrupts */
        bus_space_write_1(iot, ioh, NEC7210_IMR1, 0);
        bus_space_write_1(iot, ioh, NEC7210_IMR2, 0);
        bus_space_write_1(iot, ioh, NEC7210_SPMR, 0);
        bus_space_write_1(iot, ioh, NEC7210_EOSR, 0);

        /* set internal clock to 8MHz */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, (AUXMR_ICR | 0x8));
        /* parallel poll unconfigure */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, (AUXMR_PPOLL | PPOLL_PPU));

        /* assign our address */
        bus_space_write_1(iot, ioh, NEC7210_ADDR, 0);
        /* disable secondary address */
        bus_space_write_1(iot, ioh, NEC7210_ADDR,
            (ADDR_ARS | ADDR_DT | ADDR_DL));

        /* setup transceivers */
        bus_space_write_1(iot, ioh, NEC7210_ADMR,
            (ADMR_ADM0 | ADMR_TRM0 | ADMR_TRM1));
        bus_space_write_1(iot, ioh, NEC7210_AUXMR,
            (AUXMR_REGA | AUX_A_HSNORM));

        /* set INT pin to active high */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXMR_REGB);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXMR_REGE);

        /* holdoff on end condition */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, (AUXMR_REGA | AUX_A_HLDE));

        /* reconnect to bus */
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, (AUXMR_CMD | AUXCMD_IEPON));
}

/*
 * Place all devices on the bus into quiescient state ready for
 * remote programming.
 * Obviously, we're the system controller upon exit.
 */
void
nec7210_ifc(struct cec_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

/*XXX*/ bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_TCA);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_CREN);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_SIFC);
        /* wait for devices to enter quiescient state */
        DELAY(100);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_CIFC);
        bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_SREN);
}

static int
cecwait(struct cec_softc *sc, int x1, int x2)
{
        int timo = cecwtimeout;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        u_int8_t stat1, stat2;

        DPRINTF(DBG_WAIT, ("cecwait: sc=%p, x1=0x%x x2=0x%x\n", sc, x1, x2));

        for (;;) {
                stat1 = bus_space_read_1(iot, ioh, NEC7210_ISR1);
                stat2 = bus_space_read_1(iot, ioh, NEC7210_ISR2);
#if 0
                if ((stat1 & ISR1_ERR)) {
                        DPRINTF(DBG_WAIT, ("cecwait: got ERR\n"));
                        return (1);
                }
#endif
                if (--timo == 0) {
                        DPRINTF(DBG_REPORTTIME,
                            ("cecwait: timeout x1=0x%x x2=0x%x\n", x1, x2));
                        return (1);
                }
                if ((stat1 & x1) || (stat2 & x2))
                        break;
                DELAY(1);
        }
        return (0);
}

static void
cectimeout(void *v)
{
        struct cec_softc *sc = v;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int s;

        DPRINTF(DBG_FOLLOW, ("cectimeout: sc=%p\n", sc));

        s = splbio();
        if (sc->sc_flags & CECF_IO) {
                bus_space_write_1(iot, ioh, NEC7210_IMR1, 0);
                bus_space_write_2(iot, ioh, NEC7210_IMR2, 0);
                bus_space_write_1(iot, ioh, NEC7210_AUXMR, AUXCMD_TCA);
                sc->sc_flags &= ~(CECF_IO | CECF_READ | CECF_TIMO);
                isa_dmaabort(sc->sc_ic, sc->sc_drq);
                aprint_error_dev(sc->sc_dev, "%s timeout\n",
                    sc->sc_flags & CECF_READ ? "read" : "write");
                gpibintr(sc->sc_gpib);
        }
        splx(s);
}