/*      $OpenBSD: fd.c,v 1.111 2025/11/17 14:27:43 jsg Exp $    */
/*      $NetBSD: fd.c,v 1.90 1996/05/12 23:12:03 mycroft Exp $  */

/*-
 * Copyright (c) 1993, 1994, 1995, 1996 Charles Hannum.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Don Ahn.
 *
 * Portions Copyright (c) 1993, 1994 by
 *  jc@irbs.UUCP (John Capo)
 *  vak@zebub.msk.su (Serge Vakulenko)
 *  ache@astral.msk.su (Andrew A. Chernov)
 *  joerg_wunsch@uriah.sax.de (Joerg Wunsch)
 *
 * 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.
 *
 *      @(#)fd.c        7.4 (Berkeley) 5/25/91
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/uio.h>
#include <sys/mtio.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/timeout.h>
#include <sys/dkio.h>

#include <machine/cpu.h>
#include <machine/bus.h>
#include <machine/intr.h>
#include <machine/ioctl_fd.h>

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

#if defined(__i386__) || defined(__amd64__)     /* XXX */
#include <i386/isa/nvram.h>
#endif

#include <dev/isa/fdlink.h>

/* XXX misuse a flag to identify format operation */
#define B_FORMAT B_XXX

/* fd_type struct now in ioctl_fd.h */

/* The order of entries in the following table is important -- BEWARE! */
struct fd_type fd_types[] = {
        { 18,2,36,2,0xff,0xcf,0x1b,0x6c,80,2880,1,FDC_500KBPS,"1.44MB"    }, /* 1.44MB diskette */
        { 15,2,30,2,0xff,0xdf,0x1b,0x54,80,2400,1,FDC_500KBPS, "1.2MB"    }, /* 1.2 MB AT-diskettes */
        {  9,2,18,2,0xff,0xdf,0x23,0x50,40, 720,2,FDC_300KBPS, "360KB/AT" }, /* 360kB in 1.2MB drive */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,40, 720,1,FDC_250KBPS, "360KB/PC" }, /* 360kB PC diskettes */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,80,1440,1,FDC_250KBPS, "720KB"    }, /* 3.5" 720kB diskette */
        {  9,2,18,2,0xff,0xdf,0x23,0x50,80,1440,1,FDC_300KBPS, "720KB/x"  }, /* 720kB in 1.2MB drive */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,40, 720,2,FDC_250KBPS, "360KB/x"  }, /* 360kB in 720kB drive */
        { 36,2,72,2,0xff,0xaf,0x1b,0x54,80,5760,1,FDC_500KBPS,"2.88MB"    },  /* 2.88MB diskette */
        {  8,2,16,3,0xff,0xdf,0x35,0x74,77,1232,1,FDC_500KBPS,"1.2MB/[1024bytes/sector]" }      /* 1.2 MB japanese format */
};

/* software state, per disk (with up to 4 disks per ctlr) */
struct fd_softc {
        struct device sc_dev;
        struct disk sc_dk;

        struct fd_type *sc_deftype;     /* default type descriptor */
        struct fd_type *sc_type;        /* current type descriptor */

        daddr_t sc_blkno;       /* starting block number */
        int sc_bcount;          /* byte count left */
        int sc_opts;                    /* user-set options */
        int sc_skip;            /* bytes already transferred */
        int sc_nblks;           /* number of blocks currently transferring */
        int sc_nbytes;          /* number of bytes currently transferring */

        int sc_drive;           /* physical unit number */
        int sc_flags;
#define FD_OPEN         0x01            /* it's open */
#define FD_MOTOR        0x02            /* motor should be on */
#define FD_MOTOR_WAIT   0x04            /* motor coming up */
        int sc_cylin;           /* where we think the head is */

        TAILQ_ENTRY(fd_softc) sc_drivechain;
        int sc_ops;             /* I/O ops since last switch */
        struct bufq sc_bufq;    /* pending I/O */
        struct buf *sc_bp;      /* the current I/O */
        struct timeout fd_motor_on_to;
        struct timeout fd_motor_off_to;
        struct timeout fdtimeout_to;
};

/* floppy driver configuration */
int fdprobe(struct device *, void *, void *);
void fdattach(struct device *, struct device *, void *);
int fdactivate(struct device *, int);

const struct cfattach fd_ca = {
        sizeof(struct fd_softc), fdprobe, fdattach, NULL, fdactivate
};

struct cfdriver fd_cd = {
        NULL, "fd", DV_DISK
};

int fdgetdisklabel(dev_t, struct fd_softc *, struct disklabel *, int);
void fdstrategy(struct buf *);
void fdstart(struct fd_softc *);
int fdintr(struct fdc_softc *);

void fd_set_motor(struct fdc_softc *fdc, int reset);
void fd_motor_off(void *arg);
void fd_motor_on(void *arg);
void fdfinish(struct fd_softc *fd, struct buf *bp);
int fdformat(dev_t, struct fd_formb *, struct proc *);
static __inline struct fd_type *fd_dev_to_type(struct fd_softc *, dev_t);
void fdretry(struct fd_softc *);
void fdtimeout(void *);

int
fdgetdisklabel(dev_t dev, struct fd_softc *fd, struct disklabel *lp,
    int spoofonly)
{
        bzero(lp, sizeof(struct disklabel));

        lp->d_type = DTYPE_FLOPPY;
        lp->d_secsize = FD_BSIZE(fd);
        lp->d_secpercyl = fd->sc_type->seccyl;
        lp->d_nsectors = fd->sc_type->sectrac;
        lp->d_ncylinders = fd->sc_type->tracks;
        lp->d_ntracks = fd->sc_type->heads;     /* Go figure... */
        DL_SETDSIZE(lp, fd->sc_type->size);

        strncpy(lp->d_typename, "floppy disk", sizeof(lp->d_typename));
        strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
        lp->d_version = 1;

        lp->d_magic = DISKMAGIC;
        lp->d_magic2 = DISKMAGIC;
        lp->d_checksum = dkcksum(lp);

        /*
         * Call the generic disklabel extraction routine.  If there's
         * not a label there, fake it.
         */
        return readdisklabel(DISKLABELDEV(dev), fdstrategy, lp, spoofonly);
}

int
fdprobe(struct device *parent, void *match, void *aux)
{
        struct fdc_softc *fdc = (void *)parent;
        struct cfdata *cf = match;
        struct fdc_attach_args *fa = aux;
        int drive = fa->fa_drive;
        bus_space_tag_t iot = fdc->sc_iot;
        bus_space_handle_t ioh = fdc->sc_ioh;
        int n;

        if (cf->cf_loc[0] != -1 && cf->cf_loc[0] != drive)
                return 0;
        /*
         * XXX
         * This is to work around some odd interactions between this driver
         * and SMC Ethernet cards.
         */
        if (cf->cf_loc[0] == -1 && drive >= 2)
                return 0;

        /*
         * We want to keep the flags config gave us.
         */
        fa->fa_flags = cf->cf_flags;

        /* select drive and turn on motor */
        bus_space_write_1(iot, ioh, fdout, drive | FDO_FRST | FDO_MOEN(drive));
        /* wait for motor to spin up */
        tsleep_nsec(fdc, 0, "fdprobe", MSEC_TO_NSEC(250));
        out_fdc(iot, ioh, NE7CMD_RECAL);
        out_fdc(iot, ioh, drive);
        /* wait for recalibrate */
        tsleep_nsec(fdc, 0, "fdprobe", MSEC_TO_NSEC(2000));
        out_fdc(iot, ioh, NE7CMD_SENSEI);
        n = fdcresult(fdc);
#ifdef FD_DEBUG
        {
                int i;
                printf("fdprobe: status");
                for (i = 0; i < n; i++)
                        printf(" %x", fdc->sc_status[i]);
                printf("\n");
        }
#endif

        /* turn off motor */
        tsleep_nsec(fdc, 0, "fdprobe", MSEC_TO_NSEC(250));
        bus_space_write_1(iot, ioh, fdout, FDO_FRST);

        /* flags & 0x20 forces the drive to be found even if it won't probe */
        if (!(fa->fa_flags & 0x20) && (n != 2 || (fdc->sc_status[0] & 0xf8) != 0x20))
                return 0;

        return 1;
}

/*
 * Controller is working, and drive responded.  Attach it.
 */
void
fdattach(struct device *parent, struct device *self, void *aux)
{
        struct fdc_softc *fdc = (void *)parent;
        struct fd_softc *fd = (void *)self;
        struct fdc_attach_args *fa = aux;
        struct fd_type *type = fa->fa_deftype;
        int drive = fa->fa_drive;

        if (!type || (fa->fa_flags & 0x10)) {
                /* The config has overridden this. */
                switch (fa->fa_flags & 0x07) {
                case 1: /* 2.88MB */
                        type = &fd_types[7];
                        break;
                case 2: /* 1.44MB */
                        type = &fd_types[0];
                        break;
                case 3: /* 1.2MB */
                        type = &fd_types[1];
                        break;
                case 4: /* 720K */
                        type = &fd_types[4];
                        break;
                case 5: /* 360K */
                        type = &fd_types[3];
                        break;
                case 6: /* 1.2 MB japanese format */
                        type = &fd_types[8];
                        break;
#ifdef __alpha__
                default:
                        /* 1.44MB, how to detect others?
                         * idea from NetBSD -- jay@rootaction.net
                         */
                        type = &fd_types[0];
#endif
                }
        }

        if (type)
                printf(": %s %d cyl, %d head, %d sec\n", type->name,
                    type->tracks, type->heads, type->sectrac);
        else
                printf(": density unknown\n");

        fd->sc_cylin = -1;
        fd->sc_drive = drive;
        fd->sc_deftype = type;
        fdc->sc_type[drive] = FDC_TYPE_DISK;
        fdc->sc_link.fdlink.sc_fd[drive] = fd;

        /*
         * Initialize and attach the disk structure.
         */
        fd->sc_dk.dk_flags = DKF_NOLABELREAD;
        fd->sc_dk.dk_name = fd->sc_dev.dv_xname;
        bufq_init(&fd->sc_bufq, BUFQ_DEFAULT);
        disk_attach(&fd->sc_dev, &fd->sc_dk);

        /* Setup timeout structures */
        timeout_set(&fd->fd_motor_on_to, fd_motor_on, fd);
        timeout_set(&fd->fd_motor_off_to, fd_motor_off, fd);
        timeout_set(&fd->fdtimeout_to, fdtimeout, fd);
}

int
fdactivate(struct device *self, int act)
{
        struct fd_softc *fd = (void *)self;
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
        int rv = 0;

        switch (act) {
        case DVACT_SUSPEND:
                if (fdc->sc_state != DEVIDLE) {
                        timeout_del(&fd->fd_motor_on_to);
                        timeout_del(&fd->fd_motor_off_to);
                        timeout_del(&fd->fdtimeout_to);
                        fdc->sc_state = IOTIMEDOUT;
                        fdc->sc_errors = 4;
                }
                break;
        case DVACT_POWERDOWN:
                fd_motor_off(self);
                break;
        }

        return (rv);
}

/*
 * Translate nvram type into internal data structure.  Return NULL for
 * none/unknown/unusable.
 */
struct fd_type *
fd_nvtotype(char *fdc, int nvraminfo, int drive)
{
#ifdef __alpha__
        /* Alpha:  assume 1.44MB, idea from NetBSD sys/dev/isa/fd.c
         * -- jay@rootaction.net
         */
        return &fd_types[0]; /* 1.44MB */
#else
        int type;

        type = (drive == 0 ? nvraminfo : nvraminfo << 4) & 0xf0;
        switch (type) {
        case NVRAM_DISKETTE_NONE:
                return NULL;
        case NVRAM_DISKETTE_12M:
                return &fd_types[1];
        case NVRAM_DISKETTE_TYPE5:
        case NVRAM_DISKETTE_TYPE6:
                return &fd_types[7];
        case NVRAM_DISKETTE_144M:
                return &fd_types[0];
        case NVRAM_DISKETTE_360K:
                return &fd_types[3];
        case NVRAM_DISKETTE_720K:
                return &fd_types[4];
        default:
                printf("%s: drive %d: unknown device type 0x%x\n",
                    fdc, drive, type);
                return NULL;
        }
#endif
}

static __inline struct fd_type *
fd_dev_to_type(struct fd_softc *fd, dev_t dev)
{
        int type = FDTYPE(dev);

        if (type > (sizeof(fd_types) / sizeof(fd_types[0])))
                return NULL;
        return type ? &fd_types[type - 1] : fd->sc_deftype;
}

void
fdstrategy(struct buf *bp)
{
        struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(bp->b_dev)];
        int sz;
        int s;
        int fd_bsize = FD_BSIZE(fd);
        int bf = fd_bsize / DEV_BSIZE;

        /* Valid unit, controller, and request? */
        if (bp->b_blkno < 0 ||
            (((bp->b_blkno % bf) != 0 ||
              (bp->b_bcount % fd_bsize) != 0) &&
             (bp->b_flags & B_FORMAT) == 0)) {
                bp->b_error = EINVAL;
                goto bad;
        }

        /* If it's a null transfer, return immediately. */
        if (bp->b_bcount == 0)
                goto done;

        sz = howmany(bp->b_bcount, DEV_BSIZE);

        if (bp->b_blkno + sz > fd->sc_type->size * bf) {
                sz = fd->sc_type->size * bf - bp->b_blkno;
                if (sz == 0)
                        /* If exactly at end of disk, return EOF. */
                        goto done;
                if (sz < 0) {
                        /* If past end of disk, return EINVAL. */
                        bp->b_error = EINVAL;
                        goto bad;
                }
                /* Otherwise, truncate request. */
                bp->b_bcount = sz << DEV_BSHIFT;
        }

        bp->b_resid = bp->b_bcount;

#ifdef FD_DEBUG
        printf("fdstrategy: b_blkno %lld b_bcount %d blkno %lld sz %d\n",
            (long long)bp->b_blkno, bp->b_bcount,
            (long long)fd->sc_blkno, sz);
#endif

        /* Queue I/O */
        bufq_queue(&fd->sc_bufq, bp);

        /* Queue transfer on drive, activate drive and controller if idle. */
        s = splbio();
        timeout_del(&fd->fd_motor_off_to); /* a good idea */
        if (fd->sc_bp == NULL)
                fdstart(fd);
#ifdef DIAGNOSTIC
        else {
                struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
                if (fdc->sc_state == DEVIDLE) {
                        printf("fdstrategy: controller inactive\n");
                        fdcstart(fdc);
                }
        }
#endif
        splx(s);
        return;

bad:
        bp->b_flags |= B_ERROR;
done:
        /* Toss transfer; we're done early. */
        bp->b_resid = bp->b_bcount;
        s = splbio();
        biodone(bp);
        splx(s);
}

void
fdstart(struct fd_softc *fd)
{
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
        int active = !TAILQ_EMPTY(&fdc->sc_link.fdlink.sc_drives);

        /* Link into controller queue. */
        fd->sc_bp = bufq_dequeue(&fd->sc_bufq);
        TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);

        /* If controller not already active, start it. */
        if (!active)
                fdcstart(fdc);
}

void
fdfinish(struct fd_softc *fd, struct buf *bp)
{
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;

        splassert(IPL_BIO);

        fd->sc_skip = 0;
        fd->sc_bp = bufq_dequeue(&fd->sc_bufq);

        /*
         * Move this drive to the end of the queue to give others a `fair'
         * chance.  We only force a switch if N operations are completed while
         * another drive is waiting to be serviced, since there is a long motor
         * startup delay whenever we switch.
         */
        if (TAILQ_NEXT(fd, sc_drivechain) != NULL && ++fd->sc_ops >= 8) {
                fd->sc_ops = 0;
                TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
                if (fd->sc_bp != NULL) {
                        TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd,
                                          sc_drivechain);
                }
        }

        biodone(bp);
        /* turn off motor 5s from now */
        timeout_add_sec(&fd->fd_motor_off_to, 5);
        fdc->sc_state = DEVIDLE;
}

int
fdread(dev_t dev, struct uio *uio, int flags)
{
        return (physio(fdstrategy, dev, B_READ, minphys, uio));
}

int
fdwrite(dev_t dev, struct uio *uio, int flags)
{
        return (physio(fdstrategy, dev, B_WRITE, minphys, uio));
}

void
fd_set_motor(struct fdc_softc *fdc, int reset)
{
        struct fd_softc *fd;
        u_char status;
        int n;

        if ((fd = TAILQ_FIRST(&fdc->sc_link.fdlink.sc_drives)) != NULL)
                status = fd->sc_drive;
        else
                status = 0;
        if (!reset)
                status |= FDO_FRST | FDO_FDMAEN;
        for (n = 0; n < 4; n++)
                if ((fd = fdc->sc_link.fdlink.sc_fd[n])
                    && (fd->sc_flags & FD_MOTOR))
                        status |= FDO_MOEN(n);
        bus_space_write_1(fdc->sc_iot, fdc->sc_ioh, fdout, status);
}

void
fd_motor_off(void *arg)
{
        struct fd_softc *fd = arg;
        int s;

        s = splbio();
        fd->sc_flags &= ~(FD_MOTOR | FD_MOTOR_WAIT);
        fd_set_motor((struct fdc_softc *)fd->sc_dev.dv_parent, 0);
        splx(s);
}

void
fd_motor_on(void *arg)
{
        struct fd_softc *fd = arg;
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
        int s;

        s = splbio();
        fd->sc_flags &= ~FD_MOTOR_WAIT;
        if ((TAILQ_FIRST(&fdc->sc_link.fdlink.sc_drives) == fd)
            && (fdc->sc_state == MOTORWAIT))
                (void) fdintr(fdc);
        splx(s);
}

int
fdopen(dev_t dev, int flags, int fmt, struct proc *p)
{
        uint64_t pmask;
        int unit;
        struct fd_softc *fd;
        struct fd_type *type;

        unit = FDUNIT(dev);
        if (unit >= fd_cd.cd_ndevs)
                return ENXIO;
        fd = fd_cd.cd_devs[unit];
        if (fd == 0)
                return ENXIO;
        type = fd_dev_to_type(fd, dev);
        if (type == NULL)
                return ENXIO;

        if ((fd->sc_flags & FD_OPEN) != 0 &&
            fd->sc_type != type)
                return EBUSY;

        fd->sc_type = type;
        fd->sc_cylin = -1;
        fd->sc_flags |= FD_OPEN;

        /*
         * Only update the disklabel if we're not open anywhere else.
         */
        if (fd->sc_dk.dk_openmask == 0)
                fdgetdisklabel(dev, fd, fd->sc_dk.dk_label, 0);

        pmask = (1ULL << FDPART(dev));

        switch (fmt) {
        case S_IFCHR:
                fd->sc_dk.dk_copenmask |= pmask;
                break;

        case S_IFBLK:
                fd->sc_dk.dk_bopenmask |= pmask;
                break;
        }
        fd->sc_dk.dk_openmask =
            fd->sc_dk.dk_copenmask | fd->sc_dk.dk_bopenmask;

        return 0;
}

int
fdclose(dev_t dev, int flags, int fmt, struct proc *p)
{
        struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
        uint64_t pmask = (1ULL << FDPART(dev));

        fd->sc_flags &= ~FD_OPEN;
        fd->sc_opts &= ~FDOPT_NORETRY;

        switch (fmt) {
        case S_IFCHR:
                fd->sc_dk.dk_copenmask &= ~pmask;
                break;

        case S_IFBLK:
                fd->sc_dk.dk_bopenmask &= ~pmask;
                break;
        }
        fd->sc_dk.dk_openmask =
            fd->sc_dk.dk_copenmask | fd->sc_dk.dk_bopenmask;

        return (0);
}

daddr_t
fdsize(dev_t dev)
{
        /* Swapping to floppies would not make sense. */
        return -1;
}

int
fddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
{
        /* Not implemented. */
        return ENXIO;
}

/*
 * Called from the controller.
 */
int
fdintr(struct fdc_softc *fdc)
{
#define st0     fdc->sc_status[0]
#define cyl     fdc->sc_status[1]
        struct fd_softc *fd;
        struct buf *bp;
        bus_space_tag_t iot = fdc->sc_iot;
        bus_space_handle_t ioh = fdc->sc_ioh;
        bus_space_handle_t ioh_ctl = fdc->sc_ioh_ctl;
        int read, head, sec, i, nblks, cylin;
        struct fd_type *type;
        struct fd_formb *finfo = NULL;
        int fd_bsize;

loop:
        /* Is there a transfer to this drive?  If not, deactivate drive. */
        fd = TAILQ_FIRST(&fdc->sc_link.fdlink.sc_drives);
        if (fd == NULL) {
                fdc->sc_state = DEVIDLE;
                return 1;
        }
        fd_bsize = FD_BSIZE(fd);

        bp = fd->sc_bp;
        if (bp == NULL) {
                fd->sc_ops = 0;
                TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
                goto loop;
        }

        if (bp->b_flags & B_FORMAT)
            finfo = (struct fd_formb *)bp->b_data;

        cylin = ((bp->b_blkno * DEV_BSIZE) + (bp->b_bcount - bp->b_resid)) /
            (fd_bsize * fd->sc_type->seccyl);

        switch (fdc->sc_state) {
        case DEVIDLE:
                fdc->sc_errors = 0;
                fd->sc_skip = 0;
                fd->sc_bcount = bp->b_bcount;
                fd->sc_blkno = bp->b_blkno / (fd_bsize / DEV_BSIZE);
                timeout_del(&fd->fd_motor_off_to);
                if ((fd->sc_flags & FD_MOTOR_WAIT) != 0) {
                        fdc->sc_state = MOTORWAIT;
                        return 1;
                }
                if ((fd->sc_flags & FD_MOTOR) == 0) {
                        /* Turn on the motor, being careful about pairing. */
                        struct fd_softc *ofd =
                                fdc->sc_link.fdlink.sc_fd[fd->sc_drive ^ 1];
                        if (ofd && ofd->sc_flags & FD_MOTOR) {
                                timeout_del(&ofd->fd_motor_off_to);
                                ofd->sc_flags &= ~(FD_MOTOR | FD_MOTOR_WAIT);
                        }
                        fd->sc_flags |= FD_MOTOR | FD_MOTOR_WAIT;
                        fd_set_motor(fdc, 0);
                        fdc->sc_state = MOTORWAIT;
                        /* Allow .25s for motor to stabilize. */
                        timeout_add_msec(&fd->fd_motor_on_to, 250);
                        return 1;
                }
                /* Make sure the right drive is selected. */
                fd_set_motor(fdc, 0);

                /* FALLTHROUGH */
        case DOSEEK:
        doseek:
                if (fd->sc_cylin == cylin)
                        goto doio;

                out_fdc(iot, ioh, NE7CMD_SPECIFY);/* specify command */
                out_fdc(iot, ioh, fd->sc_type->steprate);
                out_fdc(iot, ioh, 6);           /* XXX head load time == 6ms */

                out_fdc(iot, ioh, NE7CMD_SEEK); /* seek function */
                out_fdc(iot, ioh, fd->sc_drive);        /* drive number */
                out_fdc(iot, ioh, cylin * fd->sc_type->step);

                fd->sc_cylin = -1;
                fdc->sc_state = SEEKWAIT;

                fd->sc_dk.dk_seek++;
                disk_busy(&fd->sc_dk);

                timeout_add_sec(&fd->fdtimeout_to, 4);
                return 1;

        case DOIO:
        doio:
                type = fd->sc_type;
                if (finfo)
                    fd->sc_skip = (char *)&(finfo->fd_formb_cylno(0)) -
                        (char *)finfo;
                sec = fd->sc_blkno % type->seccyl;
                nblks = type->seccyl - sec;
                nblks = min(nblks, fd->sc_bcount / fd_bsize);
                nblks = min(nblks, FDC_MAXIOSIZE / fd_bsize);
                fd->sc_nblks = nblks;
                fd->sc_nbytes = finfo ? bp->b_bcount : nblks * fd_bsize;
                head = sec / type->sectrac;
                sec -= head * type->sectrac;
#ifdef DIAGNOSTIC
                {int block;
                 block = (fd->sc_cylin * type->heads + head) * type->sectrac + sec;
                 if (block != fd->sc_blkno) {
                         panic("fdintr: block %d != blkno %llu", block, fd->sc_blkno);
                 }}
#endif
                read = bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE;
                isadma_start(bp->b_data + fd->sc_skip, fd->sc_nbytes,
                    fdc->sc_drq, read);
                bus_space_write_1(iot, ioh_ctl, fdctl, type->rate);
#ifdef FD_DEBUG
                printf("fdintr: %s drive %d track %d head %d sec %d nblks %d\n",
                    read ? "read" : "write", fd->sc_drive, fd->sc_cylin, head,
                    sec, nblks);
#endif
                if (finfo) {
                        /* formatting */
                        if (out_fdc(iot, ioh, NE7CMD_FORMAT) < 0) {
                            fdc->sc_errors = 4;
                            fdretry(fd);
                            goto loop;
                        }
                        out_fdc(iot, ioh, (head << 2) | fd->sc_drive);
                        out_fdc(iot, ioh, finfo->fd_formb_secshift);
                        out_fdc(iot, ioh, finfo->fd_formb_nsecs);
                        out_fdc(iot, ioh, finfo->fd_formb_gaplen);
                        out_fdc(iot, ioh, finfo->fd_formb_fillbyte);
                } else {
                        if (read)
                                out_fdc(iot, ioh, NE7CMD_READ); /* READ */
                        else
                                out_fdc(iot, ioh, NE7CMD_WRITE);/* WRITE */
                        out_fdc(iot, ioh, (head << 2) | fd->sc_drive);
                        out_fdc(iot, ioh, fd->sc_cylin);        /* track */
                        out_fdc(iot, ioh, head);
                        out_fdc(iot, ioh, sec + 1);             /* sec +1 */
                        out_fdc(iot, ioh, type->secsize);       /* sec size */
                        out_fdc(iot, ioh, type->sectrac);       /* secs/track */
                        out_fdc(iot, ioh, type->gap1);          /* gap1 size */
                        out_fdc(iot, ioh, type->datalen);       /* data len */
                }
                fdc->sc_state = IOCOMPLETE;

                disk_busy(&fd->sc_dk);

                /* allow 2 seconds for operation */
                timeout_add_sec(&fd->fdtimeout_to, 2);
                return 1;                               /* will return later */

        case SEEKWAIT:
                timeout_del(&fd->fdtimeout_to);
                fdc->sc_state = SEEKCOMPLETE;
                /* allow 1/50 second for heads to settle */
                timeout_add_msec(&fdc->fdcpseudointr_to, 20);
                return 1;

        case SEEKCOMPLETE:
                disk_unbusy(&fd->sc_dk, 0, 0, 0);       /* no data on seek */

                /* Make sure seek really happened. */
                out_fdc(iot, ioh, NE7CMD_SENSEI);
                if (fdcresult(fdc) != 2 || (st0 & 0xf8) != 0x20 ||
                    cyl != cylin * fd->sc_type->step) {
#ifdef FD_DEBUG
                        fdcstatus(&fd->sc_dev, 2, "seek failed");
#endif
                        fdretry(fd);
                        goto loop;
                }
                fd->sc_cylin = cylin;
                goto doio;

        case IOTIMEDOUT:
                isadma_abort(fdc->sc_drq);
        case SEEKTIMEDOUT:
        case RECALTIMEDOUT:
        case RESETTIMEDOUT:
                fdretry(fd);
                goto loop;

        case IOCOMPLETE: /* IO DONE, post-analyze */
                timeout_del(&fd->fdtimeout_to);

                disk_unbusy(&fd->sc_dk, (bp->b_bcount - bp->b_resid),
                    fd->sc_blkno, (bp->b_flags & B_READ));

                if (fdcresult(fdc) != 7 || (st0 & 0xf8) != 0) {
                        isadma_abort(fdc->sc_drq);
#ifdef FD_DEBUG
                        fdcstatus(&fd->sc_dev, 7, bp->b_flags & B_READ ?
                            "read failed" : "write failed");
                        printf("blkno %lld nblks %d\n",
                            (long long)fd->sc_blkno, fd->sc_nblks);
#endif
                        fdretry(fd);
                        goto loop;
                }
                read = bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE;
                isadma_done(fdc->sc_drq);
                if (fdc->sc_errors) {
                        diskerr(bp, "fd", "soft error", LOG_PRINTF,
                            fd->sc_skip / fd_bsize, (struct disklabel *)NULL);
                        printf("\n");
                        fdc->sc_errors = 0;
                }

                fd->sc_blkno += fd->sc_nblks;
                fd->sc_skip += fd->sc_nbytes;
                fd->sc_bcount -= fd->sc_nbytes;
                bp->b_resid -= fd->sc_nbytes;
                if (!finfo && fd->sc_bcount > 0) {
                        cylin = fd->sc_blkno / fd->sc_type->seccyl;
                        goto doseek;
                }
                fdfinish(fd, bp);
                goto loop;

        case DORESET:
                /* try a reset, keep motor on */
                fd_set_motor(fdc, 1);
                delay(100);
                fd_set_motor(fdc, 0);
                fdc->sc_state = RESETCOMPLETE;
                timeout_add_msec(&fd->fdtimeout_to, 500);
                return 1;                       /* will return later */

        case RESETCOMPLETE:
                timeout_del(&fd->fdtimeout_to);
                /* clear the controller output buffer */
                for (i = 0; i < 4; i++) {
                        out_fdc(iot, ioh, NE7CMD_SENSEI);
                        (void) fdcresult(fdc);
                }

                /* FALLTHROUGH */
        case DORECAL:
                out_fdc(iot, ioh, NE7CMD_RECAL);        /* recal function */
                out_fdc(iot, ioh, fd->sc_drive);
                fdc->sc_state = RECALWAIT;
                timeout_add_sec(&fd->fdtimeout_to, 5);
                return 1;                       /* will return later */

        case RECALWAIT:
                timeout_del(&fd->fdtimeout_to);
                fdc->sc_state = RECALCOMPLETE;
                /* allow 1/30 second for heads to settle */
                timeout_add_msec(&fdc->fdcpseudointr_to, 1000 / 30);
                return 1;                       /* will return later */

        case RECALCOMPLETE:
                out_fdc(iot, ioh, NE7CMD_SENSEI);
                if (fdcresult(fdc) != 2 || (st0 & 0xf8) != 0x20 || cyl != 0) {
#ifdef FD_DEBUG
                        fdcstatus(&fd->sc_dev, 2, "recalibrate failed");
#endif
                        fdretry(fd);
                        goto loop;
                }
                fd->sc_cylin = 0;
                goto doseek;

        case MOTORWAIT:
                if (fd->sc_flags & FD_MOTOR_WAIT)
                        return 1;               /* time's not up yet */
                goto doseek;

        default:
                fdcstatus(&fd->sc_dev, 0, "stray interrupt");
                return 1;
        }
#ifdef DIAGNOSTIC
        panic("fdintr: impossible");
#endif
#undef  st0
#undef  cyl
}

void
fdtimeout(void *arg)
{
        struct fd_softc *fd = arg;
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
        int s;

        s = splbio();
#ifdef DEBUG
        log(LOG_ERR,"fdtimeout: state %d\n", fdc->sc_state);
#endif
        fdcstatus(&fd->sc_dev, 0, "timeout");

        if (fd->sc_bp != NULL)
                fdc->sc_state++;
        else
                fdc->sc_state = DEVIDLE;

        (void) fdintr(fdc);
        splx(s);
}

void
fdretry(struct fd_softc *fd)
{
        struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
        struct buf *bp = fd->sc_bp;

        if (fd->sc_opts & FDOPT_NORETRY)
            goto fail;
        switch (fdc->sc_errors) {
        case 0:
                /* try again */
                fdc->sc_state = DOSEEK;
                break;

        case 1: case 2: case 3:
                /* didn't work; try recalibrating */
                fdc->sc_state = DORECAL;
                break;

        case 4:
                /* still no go; reset the bastard */
                fdc->sc_state = DORESET;
                break;

        default:
        fail:
                diskerr(bp, "fd", "hard error", LOG_PRINTF,
                    fd->sc_skip / FD_BSIZE(fd), (struct disklabel *)NULL);
                printf(" (st0 %b st1 %b st2 %b cyl %d head %d sec %d)\n",
                    fdc->sc_status[0], NE7_ST0BITS,
                    fdc->sc_status[1], NE7_ST1BITS,
                    fdc->sc_status[2], NE7_ST2BITS,
                    fdc->sc_status[3], fdc->sc_status[4], fdc->sc_status[5]);

                bp->b_flags |= B_ERROR;
                bp->b_error = EIO;
                bp->b_resid = bp->b_bcount;
                fdfinish(fd, bp);
        }
        fdc->sc_errors++;
}

int
fdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
        struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
        struct disklabel *lp;
        int error;

        switch (cmd) {
        case MTIOCTOP:
                if (((struct mtop *)addr)->mt_op != MTOFFL)
                        return EIO;
                return (0);

        case DIOCRLDINFO:
                lp = malloc(sizeof(*lp), M_TEMP, M_WAITOK);
                fdgetdisklabel(dev, fd, lp, 0);
                bcopy(lp, fd->sc_dk.dk_label, sizeof(*lp));
                free(lp, M_TEMP, sizeof(*lp));
                return 0;

        case DIOCGPDINFO:
                fdgetdisklabel(dev, fd, (struct disklabel *)addr, 1);
                return 0;

        case DIOCGDINFO:
                *(struct disklabel *)addr = *(fd->sc_dk.dk_label);
                return 0;

        case DIOCGPART:
                ((struct partinfo *)addr)->disklab = fd->sc_dk.dk_label;
                ((struct partinfo *)addr)->part =
                    &fd->sc_dk.dk_label->d_partitions[FDPART(dev)];
                return 0;

        case DIOCWDINFO:
        case DIOCSDINFO:
                if ((flag & FWRITE) == 0)
                        return EBADF;

                error = setdisklabel(fd->sc_dk.dk_label,
                    (struct disklabel *)addr, 0);
                if (error == 0) {
                        if (cmd == DIOCWDINFO)
                                error = writedisklabel(DISKLABELDEV(dev),
                                    fdstrategy, fd->sc_dk.dk_label);
                }
                return error;

        case FD_FORM:
                if((flag & FWRITE) == 0)
                        return EBADF;  /* must be opened for writing */
                else if(((struct fd_formb *)addr)->format_version !=
                        FD_FORMAT_VERSION)
                        return EINVAL; /* wrong version of formatting prog */
                else
                        return fdformat(dev, (struct fd_formb *)addr, p);
                break;

        case FD_GTYPE:                  /* get drive type */
                *(struct fd_type *)addr = *fd->sc_type;
                return 0;

        case FD_GOPTS:                  /* get drive options */
                *(int *)addr = fd->sc_opts;
                return 0;
                
        case FD_SOPTS:                  /* set drive options */
                fd->sc_opts = *(int *)addr;
                return 0;

        default:
                return ENOTTY;
        }

#ifdef DIAGNOSTIC
        panic("fdioctl: impossible");
#endif
}

int
fdformat(dev_t dev, struct fd_formb *finfo, struct proc *p)
{
        int rv = 0;
        struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
        struct fd_type *type = fd->sc_type;
        struct buf *bp;
        int fd_bsize = FD_BSIZE(fd);

        /* set up a buffer header for fdstrategy() */
        bp = malloc(sizeof(*bp), M_TEMP, M_NOWAIT | M_ZERO);
        if (bp == NULL)
                return ENOBUFS;

        bp->b_flags = B_BUSY | B_PHYS | B_FORMAT | B_RAW;
        bp->b_proc = p;
        bp->b_dev = dev;

        /*
         * calculate a fake blkno, so fdstrategy() would initiate a
         * seek to the requested cylinder
         */
        bp->b_blkno = (finfo->cyl * (type->sectrac * type->heads)
                + finfo->head * type->sectrac) * fd_bsize / DEV_BSIZE;

        bp->b_bcount = sizeof(struct fd_idfield_data) * finfo->fd_formb_nsecs;
        bp->b_data = (caddr_t)finfo;
        
#ifdef DEBUG
        printf("fdformat: blkno %llx count %lx\n", bp->b_blkno, bp->b_bcount);
#endif

        /* now do the format */
        fdstrategy(bp);

        /* ...and wait for it to complete */
        rv = biowait(bp);
        free(bp, M_TEMP, sizeof(*bp));
        return (rv);
}