/*      $NetBSD: fd.c,v 1.89 2024/12/21 17:40:11 tsutsui Exp $  */

/*-
 * 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.
 *
 * 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
 */

/*-
 * Copyright (c) 1993, 1994, 1995 Charles M. Hannum.
 *
 * This code is derived from software contributed to Berkeley by
 * Don Ahn.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)fd.c        7.4 (Berkeley) 5/25/91
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.89 2024/12/21 17:40:11 tsutsui Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/fdio.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/kmem.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/conf.h>

#include <dev/cons.h>

#include <uvm/uvm_extern.h>

#include <machine/cpu.h>
#include <machine/autoconf.h>

#include <sun3/dev/fdreg.h>
#include <sun3/dev/fdvar.h>

#include "ioconf.h"

/*
 * Print a complaint when no fd children were specified
 * in the config file.  Better than a link error...
 *
 * XXX: Some folks say this driver should be split in two,
 * but that seems pointless with ONLY one type of child.
 * (Thankfully, no 3/80 boxes have floppy tapes!:)
 */
#include "fdc.h"
#if NFD == 0
#error "fdc but no fd?"
#endif

#define FDUNIT(dev)     (minor(dev) / 8)
#define FDTYPE(dev)     (minor(dev) % 8)

/* (mis)use device use flag to identify format operation */
#define B_FORMAT B_DEVPRIVATE

#ifdef FD_DEBUG
int     fdc_debug = 0;
#endif

enum fdc_state {
        DEVIDLE = 0,
        MOTORWAIT,
        DOSEEK,
        SEEKWAIT,
        SEEKTIMEDOUT,
        SEEKCOMPLETE,
        DOIO,
        IOCOMPLETE,
        IOTIMEDOUT,
        DORESET,
        RESETCOMPLETE,
        RESETTIMEDOUT,
        DORECAL,
        RECALWAIT,
        RECALTIMEDOUT,
        RECALCOMPLETE,
};

/* software state, per controller */
struct fdc_softc {
        device_t        sc_dev;         /* boilerplate */
        void *          sc_reg;

        struct callout sc_timo_ch;      /* timeout callout */
        struct callout sc_intr_ch;      /* pseudo-intr callout */

        struct fd_softc *sc_fd[4];      /* pointers to children */
        TAILQ_HEAD(drivehead, fd_softc) sc_drives;
        enum fdc_state  sc_state;
        int             sc_flags;
#define FDC_82077               0x01
#define FDC_NEEDHEADSETTLE      0x02
#define FDC_EIS                 0x04
        int             sc_errors;              /* number of retries so far */
        int             sc_overruns;            /* number of DMA overruns */
        int             sc_cfg;                 /* current configuration */
        int             sc_fcr;         /* current image of floppy ctrlr reg. */
        struct fdcio    sc_io;
#define sc_reg_msr      sc_io.fdcio_reg_msr
#define sc_reg_fifo     sc_io.fdcio_reg_fifo
#define sc_reg_fcr      sc_io.fdcio_reg_fcr
#define sc_reg_fvr      sc_io.fdcio_reg_fvr
#define sc_reg_drs      sc_io.fdcio_reg_msr
#define sc_istate       sc_io.fdcio_istate
#define sc_data         sc_io.fdcio_data
#define sc_tc           sc_io.fdcio_tc
#define sc_nstat        sc_io.fdcio_nstat
#define sc_status       sc_io.fdcio_status
#define sc_intrcnt      sc_io.fdcio_intrcnt
        void            *sc_si;                 /* softintr cookie */
};

/* controller driver configuration */
static int      fdcmatch(device_t, cfdata_t, void *);
static void     fdcattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(fdc, sizeof(struct fdc_softc),
    fdcmatch, fdcattach, NULL, NULL);

static struct fd_type *fd_dev_to_type(struct fd_softc *, dev_t);

/*
 * Floppies come in various flavors, e.g., 1.2MB vs 1.44MB; here is how
 * we tell them apart.
 */
struct fd_type {
        int     sectrac;        /* sectors per track */
        int     heads;          /* number of heads */
        int     seccyl;         /* sectors per cylinder */
        int     secsize;        /* size code for sectors */
        int     datalen;        /* data len when secsize = 0 */
        int     steprate;       /* step rate and head unload time */
        int     gap1;           /* gap len between sectors */
        int     gap2;           /* formatting gap */
        int     tracks;         /* total num of tracks */
        int     size;           /* size of disk in sectors */
        int     step;           /* steps per cylinder */
        int     rate;           /* transfer speed code */
        int     fillbyte;       /* format fill byte */
        int     interleave;     /* interleave factor (formatting) */
        const char *name;
};

/* The order of entries in the following table is important -- BEWARE! */
static struct fd_type fd_types[] = {
        { 18, 2, 36, 2, 0xff, 0xcf, 0x18, 0x50, 80, 2880, 1,
            FDC_500KBPS, 0xf6, 1, "1.44MB"    }, /* 1.44MB diskette */
        { 15, 2, 30, 2, 0xff, 0xdf, 0x1b, 0x54, 80, 2400, 1,
            FDC_500KBPS, 0xf6, 1, "1.2MB"    }, /* 1.2 MB AT-diskettes */
        {  9, 2, 18, 2, 0xff, 0xdf, 0x23, 0x50, 40,  720, 2,
            FDC_300KBPS, 0xf6, 1, "360KB/AT" }, /* 360kB in 1.2MB drive */
        {  9, 2, 18, 2, 0xff, 0xdf, 0x2a, 0x50, 40,  720, 1,
            FDC_250KBPS, 0xf6, 1, "360KB/PC" }, /* 360kB PC diskettes */
        {  9, 2, 18, 2, 0xff, 0xdf, 0x2a, 0x50, 80, 1440, 1,
            FDC_250KBPS, 0xf6, 1, "720KB"    }, /* 3.5" 720kB diskette */
        {  9, 2, 18, 2, 0xff, 0xdf, 0x23, 0x50, 80, 1440, 1,
            FDC_300KBPS, 0xf6, 1, "720KB/x"  }, /* 720kB in 1.2MB drive */
        {  9, 2, 18, 2, 0xff, 0xdf, 0x2a, 0x50, 40,  720, 2,
            FDC_250KBPS,0xf6,1, "360KB/x"  }, /* 360kB in 720kB drive */
};

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

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

        struct callout sc_motoron_ch;
        struct callout sc_motoroff_ch;

        daddr_t sc_blkno;       /* starting block number */
        int sc_bcount;          /* byte count left */
        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 */
        int sc_opts;            /* user-set options */

        TAILQ_ENTRY(fd_softc) sc_drivechain;
        int sc_ops;             /* I/O ops since last switch */
        struct bufq_state *sc_q;/* pending I/O requests */
        int sc_active;          /* number of active I/O operations */
};

/* floppy driver configuration */
static int      fdmatch(device_t, cfdata_t, void *);
static void     fdattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(fd, sizeof(struct fd_softc),
    fdmatch, fdattach, NULL, NULL);

static dev_type_open(fdopen);
static dev_type_close(fdclose);
static dev_type_read(fdread);
static dev_type_write(fdwrite);
static dev_type_ioctl(fdioctl);
static dev_type_strategy(fdstrategy);

const struct bdevsw fd_bdevsw = {
        .d_open = fdopen,
        .d_close = fdclose,
        .d_strategy = fdstrategy,
        .d_ioctl = fdioctl,
        .d_dump = nodump,
        .d_psize = nosize,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

const struct cdevsw fd_cdevsw = {
        .d_open = fdopen,
        .d_close = fdclose,
        .d_read = fdread,
        .d_write = fdwrite,
        .d_ioctl = fdioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

static bool fd_shutdown(device_t, int);
static void fdgetdisklabel(dev_t);
static void fdstart(struct fd_softc *);
static int fdprint(void *, const char *);

struct dkdriver fddkdriver = {
        .d_strategy = fdstrategy
};

static void     fd_set_motor(struct fdc_softc *);
static void     fd_motor_off(void *);
static void     fd_motor_on(void *);
static int      fdcresult(struct fdc_softc *);
static int      out_fdc(struct fdc_softc *, u_char);
static void     fdcstart(struct fdc_softc *);
static void     fdcstatus(device_t, int, const char *);
static void     fdc_reset(struct fdc_softc *);
static void     fdctimeout(void *);
static void     fdcpseudointr(void *);
static int      fdchwintr(void *);
static void     fdcswintr(void *);
static int      fdcstate(struct fdc_softc *);
static void     fdcretry(struct fdc_softc *);
static void     fdfinish(struct fd_softc *, struct buf *);
static int      fdformat(dev_t, struct ne7_fd_formb *, struct proc *);
static void     fd_do_eject(struct fdc_softc *, int);
static void     fd_mountroot_hook(device_t);
static void     fdconf(struct fdc_softc *);

#define IPL_SOFTFD      IPL_BIO
#define FDC_SOFTPRI     2
#define FD_SET_SWINTR() softint_schedule(fdc->sc_si);

/*
 * The Floppy Control Register on the sun3x, not to be confused with the
 * Floppy ControllER Registers that this driver mostly insterfaces with,
 * controls some of the auxiliary functions of the floppy drive.  These
 * include asserting the floppy eject and terminal data count (or TC) pins
 * of the floppy drive and controller chip respectively.
 *
 * Often it is necessary to toggle individual bits within this register
 * while keeping the others untouched.  However, the register does not
 * present its latched data to the processor when read.  This prevents the
 * use of a read-modify-write cycle that would normally be used to modify
 * individual bits.  To get around this we must keep a copy of register's
 * current value and always insure that when we wish to modify the register,
 * we actually modify the copy and synchronize the register to it.
 */
#define FCR_REG_SYNC()  (*fdc->sc_reg_fcr = fdc->sc_fcr)

int
fdcmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct confargs *ca = aux;

        if (bus_peek(ca->ca_bustype, ca->ca_paddr, sizeof(uint8_t)) == -1)
                return 0;

        return 1;
}

/*
 * Arguments passed between fdcattach and fdprobe.
 */
struct fdc_attach_args {
        int fa_drive;
        struct bootpath *fa_bootpath;
        struct fd_type *fa_deftype;
};

/*
 * Print the location of a disk drive (called just before attaching the
 * the drive).  If `fdc' is not NULL, the drive was found but was not
 * in the system config file; print the drive name as well.
 * Return QUIET (config_find ignores this if the device was configured) to
 * avoid printing `fdN not configured' messages.
 */
int
fdprint(void *aux, const char *fdc)
{
        struct fdc_attach_args *fa = aux;

        if (fdc == NULL)
                aprint_normal(" drive %d", fa->fa_drive);
        return QUIET;
}

static void
fdconf(struct fdc_softc *fdc)
{
        int     vroom;

        if (out_fdc(fdc, NE7CMD_DUMPREG) || fdcresult(fdc) != 10)
                return;

        /*
         * dumpreg[7] seems to be a motor-off timeout; set it to whatever
         * the PROM thinks is appropriate.
         */
        if ((vroom = fdc->sc_status[7]) == 0)
                vroom = 0x64;

        /* Configure controller to use FIFO and Implied Seek */
        out_fdc(fdc, NE7CMD_CFG);
        out_fdc(fdc, vroom);
        out_fdc(fdc, fdc->sc_cfg);
        out_fdc(fdc, 0); /* PRETRK */
        /* No result phase */
}

void
fdcattach(device_t parent, device_t self, void *aux)
{
        struct confargs *ca = aux;
        struct fdc_softc *fdc = device_private(self);
        struct fdc_attach_args fa;
        int pri, vec;
        char code;

        fdc->sc_dev = self;

        fdc->sc_reg = (void *)bus_mapin(ca->ca_bustype, ca->ca_paddr,
            sizeof(union fdreg));

        callout_init(&fdc->sc_timo_ch, 0);
        callout_init(&fdc->sc_intr_ch, 0);

        fdc->sc_state = DEVIDLE;
        fdc->sc_istate = ISTATE_IDLE;
        fdc->sc_flags |= FDC_EIS;
        TAILQ_INIT(&fdc->sc_drives);

        /* Assume a 82072 */
        code = '2';

        if (code == '7') {
                panic("no 82077 fdc in this kernel");
                /* NOTREACHED */
        } else {
                fdc->sc_reg_msr = &((struct fdreg_72 *)fdc->sc_reg)->fd_msr;
                fdc->sc_reg_fifo = &((struct fdreg_72 *)fdc->sc_reg)->fd_fifo;

                fdc->sc_reg_fcr = ((volatile uint8_t *)fdc->sc_reg)
                    + FDC_FCR_OFFSET;
                fdc->sc_reg_fvr = ((volatile uint8_t *)fdc->sc_reg)
                    + FDC_FVR_OFFSET;
        }

        pri = ca->ca_intpri;
        vec = ca->ca_intvec;
        if (vec == -1) {
                /* Tell the FDC to fake an autovector. */
                vec = 0x18 + pri; /* XXX */
                isr_add_autovect(fdchwintr, fdc, pri);
        } else {
                /* An OBIO bus with vectors?  Weird exception. */
                isr_add_vectored(fdchwintr, fdc, pri, vec);
        }
        *fdc->sc_reg_fvr = vec; /* Program controller w/ interrupt vector */

        fdc->sc_si = softint_establish(SOFTINT_BIO, fdcswintr, fdc);
#if 0
        aprint_normal(": (softpri %d) chip 8207%c\n", FDC_SOFTPRI, code);
#else
        aprint_normal(": chip 8207%c\n", code);
#endif

#ifdef FD_DEBUG
        if (out_fdc(fdc, NE7CMD_VERSION) == 0 &&
            fdcresult(fdc) == 1 && fdc->sc_status[0] == 0x90) {
                if (fdc_debug)
                        aprint_debug("[version cmd]");
        }
#endif

        fdc_reset(fdc);
        /*
         * Configure controller; enable FIFO, Implied seek, no POLL mode?.
         * Note: CFG_EFIFO is active-low, initial threshold value: 8
         */
        fdc->sc_cfg = CFG_EIS|/*CFG_EFIFO|*/CFG_POLL|(8 & CFG_THRHLD_MASK);
        fdconf(fdc);

        evcnt_attach_dynamic(&fdc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
            device_xname(self), "intr");

        /* physical limit: four drives per controller. */
        for (fa.fa_drive = 0; fa.fa_drive < 4; fa.fa_drive++) {
                fa.fa_deftype = NULL;           /* unknown */
        fa.fa_deftype = &fd_types[0];           /* XXX */
                (void)config_found(self, (void *)&fa, fdprint, CFARGS_NONE);
        }
}

int
fdmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct fdc_softc *fdc = device_private(parent);
        struct fdc_attach_args *fa = aux;
        int drive = fa->fa_drive;
        int n, ok;

        if (drive > 0)
                /* XXX - for now, punt > 1 drives */
                return 0;

        /* select drive and turn on motor */
        fdc->sc_fcr |= FCR_DSEL(drive) | FCR_MTRON;
        FCR_REG_SYNC();
        /* wait for motor to spin up */
        delay(250000);

        fdc->sc_nstat = 0;
        out_fdc(fdc, NE7CMD_RECAL);
        out_fdc(fdc, drive);
        /* wait for recalibrate */
        for (n = 0; n < 10000; n++) {
                delay(1000);
                if ((*fdc->sc_reg_msr & (NE7_RQM|NE7_DIO|NE7_CB)) == NE7_RQM) {
                        /* wait a bit longer till device *really* is ready */
                        delay(100000);
                        if (out_fdc(fdc, NE7CMD_SENSEI))
                                break;
                        if (fdcresult(fdc) == 1 && fdc->sc_status[0] == 0x80)
                                /*
                                 * Got `invalid command'; we interpret it
                                 * to mean that the re-calibrate hasn't in
                                 * fact finished yet
                                 */
                                continue;
                        break;
                }
        }
        n = fdc->sc_nstat;
#ifdef FD_DEBUG
        if (fdc_debug) {
                int i;
                aprint_debug("%s: %d stati:", __func__, n);
                for (i = 0; i < n; i++)
                        aprint_debug(" %x", fdc->sc_status[i]);
                aprint_debug("\n");
        }
#endif
        ok = (n == 2 && (fdc->sc_status[0] & 0xf8) == 0x20) ? 1 : 0;

        /* turn off motor */
        fdc->sc_fcr &= ~(FCR_DSEL(drive)|FCR_MTRON);
        FCR_REG_SYNC();

        return ok;
}

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

        fd->sc_dv = self;

        callout_init(&fd->sc_motoron_ch, 0);
        callout_init(&fd->sc_motoroff_ch, 0);

        /* XXX Allow `flags' to override device type? */

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

        bufq_alloc(&fd->sc_q, "disksort", BUFQ_SORT_CYLINDER);
        fd->sc_cylin = -1;
        fd->sc_drive = drive;
        fd->sc_deftype = type;
        fdc->sc_fd[drive] = fd;

        /*
         * Initialize and attach the disk structure.
         */
        disk_init(&fd->sc_dk, device_xname(self), &fddkdriver);
        disk_attach(&fd->sc_dk);

#ifdef  sparc
        /*
         * We're told if we're the boot device in fdcattach().
         */
        if (fa->fa_bootpath)
                fa->fa_bootpath->dev = self;
#endif
#define OUT_FDC(sc, c)  do {                                            \
        if (out_fdc((sc), (c)) != 0)                                    \
                printf("fdc: specify command failed.\n");               \
        } while (/* CONSTCOND */ 0)

        /* specify command */
        OUT_FDC(fdc, NE7CMD_SPECIFY);
        OUT_FDC(fdc, type->steprate);
        /*
         * The '|1' in the following statement turns on the 'Non-DMA' bit
         * specifier in the last byte of the SPECIFY command as described in the
         * datasheet I have.  This is necessary for the driver to work on the
         * sun3x, because the system will not respond to the chip's requests
         * for DMA; there is no hardware on the motherboard to support it.
         * By enabling this bit, we will force the chip to interrupt when its
         * FIFO is full, at which point the interrupt handler will empty it and
         * continue.  This is ``pseudo-DMA''.
         * -J
         */
        OUT_FDC(fdc, 6|1);      /* XXX head load time == 6ms */
#undef  OUT_FDC

        /*
         * Establish a mountroot_hook anyway in case we booted
         * with RB_ASKNAME and get selected as the boot device.
         */
        mountroothook_establish(fd_mountroot_hook, self);

        /* Make sure the drive motor gets turned off at shutdown time. */
        if (!pmf_device_register1(self, NULL, NULL, fd_shutdown))
                aprint_error_dev(self, "couldn't establish power handler\n");
}

bool
fd_shutdown(device_t self, int howto)
{
        struct fd_softc *fd;

        fd = device_private(self);
        fd_motor_off(fd);

        return true;
}

static 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;
}

static void
fdstrategy(struct buf *bp)
{
        struct fd_softc *fd;
        int unit = FDUNIT(bp->b_dev);
        int sz;
        int s;

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

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

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

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

        bp->b_rawblkno = bp->b_blkno;
        bp->b_cylinder =
            bp->b_blkno / (FDC_BSIZE / DEV_BSIZE) / fd->sc_type->seccyl;

#ifdef FD_DEBUG
        if (fdc_debug > 1)
                printf("%s: b_blkno %d b_bcount %d blkno %d cylin %d\n",
                    __func__, (int)bp->b_blkno, bp->b_bcount,
                    (int)fd->sc_blkno, bp->b_cylinder);
#endif

        /* Queue transfer on drive, activate drive and controller if idle. */
        s = splbio();
        bufq_put(fd->sc_q, bp);
        callout_stop(&fd->sc_motoroff_ch);              /* a good idea */
        if (fd->sc_active == 0)
                fdstart(fd);
#ifdef DIAGNOSTIC
        else {
                struct fdc_softc *fdc;

                fdc = device_private(device_parent(fd->sc_dv));
                if (fdc->sc_state == DEVIDLE) {
                        printf("%s: controller inactive\n", __func__);
                        fdcstart(fdc);
                }
        }
#endif
        splx(s);
        return;

 done:
        /* Toss transfer; we're done early. */
        biodone(bp);
}

void
fdstart(struct fd_softc *fd)
{
        struct fdc_softc *fdc = device_private(device_parent(fd->sc_dv));
        bool active = fdc->sc_drives.tqh_first != 0;

        /* Link into controller queue. */
        fd->sc_active = 1;
        TAILQ_INSERT_TAIL(&fdc->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 = device_private(device_parent(fd->sc_dv));

        /*
         * 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.
         */
        (void)bufq_get(fd->sc_q);
        if (TAILQ_NEXT(fd, sc_drivechain) && ++fd->sc_ops >= 8) {
                fd->sc_ops = 0;
                TAILQ_REMOVE(&fdc->sc_drives, fd, sc_drivechain);
                if (bufq_peek(fd->sc_q) != NULL) {
                        TAILQ_INSERT_TAIL(&fdc->sc_drives, fd, sc_drivechain);
                } else
                        fd->sc_active = 0;
        }
        bp->b_resid = fd->sc_bcount;
        fd->sc_skip = 0;

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

void
fdc_reset(struct fdc_softc *fdc)
{

        fdc->sc_fcr = 0;
        FCR_REG_SYNC();

        *fdc->sc_reg_drs = DRS_RESET;
        delay(10);
        *fdc->sc_reg_drs = 0;

#ifdef FD_DEBUG
        if (fdc_debug)
                printf("fdc reset\n");
#endif
}

void
fd_set_motor(struct fdc_softc *fdc)
{
        struct fd_softc *fd;
        int n;

        int on = 0;

        for (n = 0; n < 4; n++)
                if ((fd = fdc->sc_fd[n]) && (fd->sc_flags & FD_MOTOR))
                        on = 1;
        if (on) {
                fdc->sc_fcr |= FCR_DSEL(0)|FCR_MTRON; /* XXX */
        } else {
                fdc->sc_fcr &= ~(FCR_DSEL(0)|FCR_MTRON); /* XXX */
        }
        FCR_REG_SYNC();
}

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(device_private(device_parent(fd->sc_dv)));
        splx(s);
}

void
fd_motor_on(void *arg)
{
        struct fd_softc *fd = arg;
        struct fdc_softc *fdc = device_private(device_parent(fd->sc_dv));
        int s;

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

int
fdcresult(struct fdc_softc *fdc)
{
        uint8_t i;
        int j, n = 0;

        for (j = 100000; j; j--) {
                i = *fdc->sc_reg_msr & (NE7_DIO | NE7_RQM | NE7_CB);
                if (i == NE7_RQM) {
                        fdc->sc_nstat = n;
                        return n;
                }
                if (i == (NE7_DIO | NE7_RQM | NE7_CB)) {
                        if (n >= sizeof(fdc->sc_status)) {
                                log(LOG_ERR, "fdcresult: overrun\n");
                                return -1;
                        }
                        fdc->sc_status[n++] = *fdc->sc_reg_fifo;
                } else
                        delay(10);
        }
        log(LOG_ERR, "fdcresult: timeout\n");
        fdc->sc_nstat = -1;
        return -1;
}

int
out_fdc(struct fdc_softc *fdc, u_char x)
{
        int i = 100000;

        while (((*fdc->sc_reg_msr & (NE7_DIO|NE7_RQM)) != NE7_RQM) && i-- > 0)
                delay(1);
        if (i <= 0)
                return -1;

        *fdc->sc_reg_fifo = x;
        return 0;
}

static int
fdopen(dev_t dev, int flags, int fmt, struct lwp *l)
{
        int unit, pmask;
        struct fd_softc *fd;
        struct fd_type *type;

        unit = FDUNIT(dev);
        fd = device_lookup_private(&fd_cd, unit);
        if (fd == NULL)
                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);

        pmask = (1 << DISKPART(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;
}

static int
fdclose(dev_t dev, int flags, int fmt, struct lwp *l)
{
        struct fd_softc *fd = device_lookup_private(&fd_cd, FDUNIT(dev));
        int pmask = (1 << DISKPART(dev));

        fd->sc_flags &= ~FD_OPEN;
        fd->sc_opts &= ~(FDOPT_NORETRY|FDOPT_SILENT);

        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;
}

static int
fdread(dev_t dev, struct uio *uio, int flag)
{

        return physio(fdstrategy, NULL, dev, B_READ, minphys, uio);
}

static int
fdwrite(dev_t dev, struct uio *uio, int flag)
{

        return physio(fdstrategy, NULL, dev, B_WRITE, minphys, uio);
}

void
fdcstart(struct fdc_softc *fdc)
{

#ifdef DIAGNOSTIC
        /* only got here if controller's drive queue was inactive; should
           be in idle state */
        if (fdc->sc_state != DEVIDLE) {
                printf("%s: not idle\n", __func__);
                return;
        }
#endif
        (void)fdcstate(fdc);
}

static void
fdcpstatus(int n, struct fdc_softc *fdc)
{
        char bits[64];

        switch (n) {
        case 0:
                printf("\n");
                break;
        case 2:
                snprintb(bits, sizeof(bits), NE7_ST0BITS, fdc->sc_status[0]);
                printf(" (st0 %s cyl %d)\n", bits, fdc->sc_status[1]);
                break;
        case 7:
                snprintb(bits, sizeof(bits), NE7_ST0BITS, fdc->sc_status[0]);
                printf(" (st0 %s", bits);
                snprintb(bits, sizeof(bits), NE7_ST1BITS, fdc->sc_status[1]);
                printf(" st1 %s", bits);
                snprintb(bits, sizeof(bits), NE7_ST2BITS, fdc->sc_status[2]);
                printf(" st2 %s", bits);
                printf(" cyl %d head %d sec %d)\n",
                    fdc->sc_status[3], fdc->sc_status[4], fdc->sc_status[5]);
                break;
#ifdef DIAGNOSTIC
        default:
                printf("\nfdcstatus: weird size");
                break;
#endif
        }
}

void
fdcstatus(device_t dv, int n, const char *s)
{
        struct fdc_softc *fdc = device_private(device_parent(dv));
#if 0
        /*
         * A 82072 seems to return <invalid command> on
         * gratuitous Sense Interrupt commands.
         */
        if (n == 0 && (fdc->sc_flags & FDC_82077)) {
                out_fdc(fdc, NE7CMD_SENSEI);
                (void)fdcresult(fdc);
                n = 2;
        }
#endif

        /* Just print last status */
        n = fdc->sc_nstat;

        printf("%s: %s: state %d", device_xname(dv), s, fdc->sc_state);

        fdcpstatus(n, fdc);
}

void
fdctimeout(void *arg)
{
        struct fdc_softc *fdc = arg;
        struct fd_softc *fd = TAILQ_FIRST(&fdc->sc_drives);
        int s;

        s = splbio();
        fdcstatus(fd->sc_dv, 0, "timeout");

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

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

void
fdcpseudointr(void *arg)
{
        struct fdc_softc *fdc = arg;
        int s;

        /* Just ensure it has the right spl. */
        s = splbio();
        (void)fdcstate(fdc);
        splx(s);
}


/*
 * hardware interrupt entry point: must be converted to `fast'
 * (in-window) handler.
 */
int
fdchwintr(void *arg)
{
        struct fdc_softc *fdc = arg;

        /*
         * This code was reverse engineered from the SPARC bsd_fdintr.s.
         */
        switch (fdc->sc_istate) {
        case ISTATE_IDLE:
                return 0;
        case ISTATE_SENSEI:
                out_fdc(fdc, NE7CMD_SENSEI);
                fdcresult(fdc);
                fdc->sc_istate = ISTATE_DONE;
                FD_SET_SWINTR();
                return 1;
        case ISTATE_DMA:
                break;
        default:
                log(LOG_ERR, "fdc: stray hard interrupt.\n");
                fdc->sc_fcr &= ~(FCR_DSEL(0));  /* Does this help? */
                fdc->sc_istate = ISTATE_SPURIOUS;
                FD_SET_SWINTR();
                return 1;
        }

        for (;;) {
                int msr;

                msr = *fdc->sc_reg_msr;

                if ((msr & NE7_RQM) == 0)
                        break;

                if ((msr & NE7_NDM) == 0) {
                        /* Execution phase finished, get result. */
                        fdcresult(fdc);
                        fdc->sc_istate = ISTATE_DONE;
                        FD_SET_SWINTR();
#ifdef FD_DEBUG
                        if (fdc_debug)
                                log(LOG_ERR, "fdc: overrun: tc = %d\n",
                                    fdc->sc_tc);
#endif
                        break;
                }

                if (msr & NE7_DIO) {
                        *fdc->sc_data++ = *fdc->sc_reg_fifo;
                } else {
                        *fdc->sc_reg_fifo = *fdc->sc_data++;
                }
                if (--fdc->sc_tc == 0) {
                        fdc->sc_fcr |= FCR_TC;
                        FCR_REG_SYNC();
                        delay(10);
                        fdc->sc_fcr &= ~FCR_TC;
                        FCR_REG_SYNC();
                        break;
                }
        }
        return 1;
}

void
fdcswintr(void *arg)
{
        struct fdc_softc *fdc = arg;
        int s;

        if (fdc->sc_istate != ISTATE_DONE)
                return;

        fdc->sc_istate = ISTATE_IDLE;
        s = splbio();
        fdcstate(fdc);
        splx(s);
}

int
fdcstate(struct fdc_softc *fdc)
{
#define st0     fdc->sc_status[0]
#define st1     fdc->sc_status[1]
#define cyl     fdc->sc_status[1]
#define OUT_FDC(fdc, c, s)                                              \
        do {                                                            \
                if (out_fdc(fdc, (c))) {                                \
                        (fdc)->sc_state = (s);                          \
                        goto loop;                                      \
                }                                                       \
        } while (/* CONSTCOND */ 0)

        struct fd_softc *fd;
        struct buf *bp;
        int read, head, sec, nblks;
        struct fd_type *type;
        struct ne7_fd_formb *finfo = NULL;


        if (fdc->sc_istate != ISTATE_IDLE) {
                /* Trouble... */
                printf("fdc: spurious interrupt: state %d, istate=%d\n",
                    fdc->sc_state, fdc->sc_istate);
                fdc->sc_istate = ISTATE_IDLE;
                if (fdc->sc_state == RESETCOMPLETE ||
                    fdc->sc_state == RESETTIMEDOUT) {
                        panic("%s: spurious interrupt can't be cleared",
                            __func__);
                }
                goto doreset;
        }

 loop:
        /* Is there a drive for the controller to do a transfer with? */
        fd = TAILQ_FIRST(&fdc->sc_drives);
        if (fd == NULL) {
                fdc->sc_state = DEVIDLE;
                return 0;
        }

        /* Is there a transfer to this drive?  If not, deactivate drive. */
        bp = bufq_peek(fd->sc_q);
        if (bp == NULL) {
                fd->sc_ops = 0;
                TAILQ_REMOVE(&fdc->sc_drives, fd, sc_drivechain);
                fd->sc_active = 0;
                goto loop;
        }

        if (bp->b_flags & B_FORMAT)
                finfo = (struct ne7_fd_formb *)bp->b_data;

        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 / (FDC_BSIZE / DEV_BSIZE);
                callout_stop(&fd->sc_motoroff_ch);
                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_fd[fd->sc_drive ^ 1];
                        if (ofd && ofd->sc_flags & FD_MOTOR) {
                                callout_stop(&ofd->sc_motoroff_ch);
                                ofd->sc_flags &= ~(FD_MOTOR | FD_MOTOR_WAIT);
                        }
                        fd->sc_flags |= FD_MOTOR | FD_MOTOR_WAIT;
                        fd_set_motor(fdc);
                        fdc->sc_state = MOTORWAIT;
                        if (fdc->sc_flags & FDC_82077) { /* XXX */
                                /* Allow .25s for motor to stabilize. */
                                callout_reset(&fd->sc_motoron_ch, hz / 4,
                                    fd_motor_on, fd);
                        } else {
                                fd->sc_flags &= ~FD_MOTOR_WAIT;
                                goto loop;
                        }
                        return 1;
                }
                /* Make sure the right drive is selected. */
                fd_set_motor(fdc);

                /*FALLTHROUGH*/
        case DOSEEK:
        doseek:
                if ((fdc->sc_flags & FDC_EIS) &&
                    (bp->b_flags & B_FORMAT) == 0) {
                        fd->sc_cylin = bp->b_cylinder;
                        /* We use implied seek */
                        goto doio;
                }

                if (fd->sc_cylin == bp->b_cylinder)
                        goto doio;

                /* specify command */
                OUT_FDC(fdc, NE7CMD_SPECIFY, SEEKTIMEDOUT);
                OUT_FDC(fdc, fd->sc_type->steprate, SEEKTIMEDOUT);
                OUT_FDC(fdc, 6|1, SEEKTIMEDOUT); /* XXX head load time == 6ms */

                fdc->sc_istate = ISTATE_SENSEI;
                /* seek function */
                OUT_FDC(fdc, NE7CMD_SEEK, SEEKTIMEDOUT);
                OUT_FDC(fdc, fd->sc_drive, SEEKTIMEDOUT); /* drive number */
                OUT_FDC(fdc, bp->b_cylinder * fd->sc_type->step, SEEKTIMEDOUT);

                fd->sc_cylin = -1;
                fdc->sc_state = SEEKWAIT;
                fdc->sc_nstat = 0;

                iostat_seek(fd->sc_dk.dk_stats);
                disk_busy(&fd->sc_dk);

                callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
                return 1;

        case DOIO:
 doio:
#ifdef  NOTYET
                /* Check to see if the disk has changed */
                if (fdc->sc_reg_dir & FDI_DCHG) {
                        /*
                         * The disk in the drive has changed since
                         * the last transfer.  We need to see if its geometry
                         * has changed.
                         */
                }
#endif  /* NOTYET */

                if (finfo)
                        fd->sc_skip = (char *)&(finfo->fd_formb_cylno(0)) -
                                      (char *)finfo;
                type = fd->sc_type;
                sec = fd->sc_blkno % type->seccyl;
                nblks = type->seccyl - sec;
                nblks = uimin(nblks, fd->sc_bcount / FDC_BSIZE);
                nblks = uimin(nblks, FDC_MAXIOSIZE / FDC_BSIZE);
                fd->sc_nblks = nblks;
                fd->sc_nbytes = finfo ? bp->b_bcount : nblks * FDC_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) {
                                printf("%s: block %d != blkno %" PRIu64 "\n",
                                    device_xname(fdc->sc_dev), block,
                                    fd->sc_blkno);
#ifdef DDB
                                Debugger();
#endif
                        }
                }
#endif
                read = bp->b_flags & B_READ;

                /* Setup for pseudo DMA */
                fdc->sc_data = (char *)bp->b_data + fd->sc_skip;
                fdc->sc_tc = fd->sc_nbytes;

                *fdc->sc_reg_drs = type->rate;
#ifdef FD_DEBUG
                if (fdc_debug > 1)
                        printf("%s: %s drive %d track %d head %d sec %d "
                            "nblks %d\n", __func__,
                            read ? "read" : "write", fd->sc_drive,
                            fd->sc_cylin, head, sec, nblks);
#endif
                fdc->sc_state = IOCOMPLETE;
                fdc->sc_istate = ISTATE_DMA;
                fdc->sc_nstat = 0;
                if (finfo) {
                        /* formatting */
                        OUT_FDC(fdc, NE7CMD_FORMAT, IOTIMEDOUT);
                        OUT_FDC(fdc, (head << 2) | fd->sc_drive, IOTIMEDOUT);
                        OUT_FDC(fdc, finfo->fd_formb_secshift, IOTIMEDOUT);
                        OUT_FDC(fdc, finfo->fd_formb_nsecs, IOTIMEDOUT);
                        OUT_FDC(fdc, finfo->fd_formb_gaplen, IOTIMEDOUT);
                        OUT_FDC(fdc, finfo->fd_formb_fillbyte, IOTIMEDOUT);
                } else {
                        if (read)
                                OUT_FDC(fdc, NE7CMD_READ, IOTIMEDOUT);
                        else
                                OUT_FDC(fdc, NE7CMD_WRITE, IOTIMEDOUT);
                        OUT_FDC(fdc, (head << 2) | fd->sc_drive, IOTIMEDOUT);
                        OUT_FDC(fdc, fd->sc_cylin, IOTIMEDOUT); /*track*/
                        OUT_FDC(fdc, head, IOTIMEDOUT);
                        OUT_FDC(fdc, sec + 1, IOTIMEDOUT);      /*sector+1*/
                        OUT_FDC(fdc, type->secsize, IOTIMEDOUT);/*sector size*/
                        OUT_FDC(fdc, type->sectrac, IOTIMEDOUT);/*secs/track*/
                        OUT_FDC(fdc, type->gap1, IOTIMEDOUT);   /*gap1 size*/
                        OUT_FDC(fdc, type->datalen, IOTIMEDOUT);/*data length*/
                }

                disk_busy(&fd->sc_dk);

                /* allow 2 seconds for operation */
                callout_reset(&fdc->sc_timo_ch, 2 * hz, fdctimeout, fdc);
                return 1;                               /* will return later */

        case SEEKWAIT:
                callout_stop(&fdc->sc_timo_ch);
                fdc->sc_state = SEEKCOMPLETE;
                if (fdc->sc_flags & FDC_NEEDHEADSETTLE) {
                        /* allow 1/50 second for heads to settle */
                        callout_reset(&fdc->sc_intr_ch, hz / 50,
                            fdcpseudointr, fdc);
                        return 1;               /* will return later */
                }
                /*FALLTHROUGH*/
        case SEEKCOMPLETE:
                /* no data on seek */
                disk_unbusy(&fd->sc_dk, 0, 0);

                /* Make sure seek really happened. */
                if (fdc->sc_nstat != 2 || (st0 & 0xf8) != 0x20 ||
                    cyl != bp->b_cylinder * fd->sc_type->step) {
#ifdef FD_DEBUG
                        if (fdc_debug)
                                fdcstatus(fd->sc_dv, 2, "seek failed");
#endif
                        fdcretry(fdc);
                        goto loop;
                }
                fd->sc_cylin = bp->b_cylinder;
                goto doio;

        case IOTIMEDOUT:
                fdc->sc_fcr |= FCR_TC;
                FCR_REG_SYNC();
                delay(10);
                fdc->sc_fcr &= ~FCR_TC;
                FCR_REG_SYNC();
                (void)fdcresult(fdc);
                /* FALLTHROUGH */
        case SEEKTIMEDOUT:
        case RECALTIMEDOUT:
        case RESETTIMEDOUT:
                fdcretry(fdc);
                goto loop;

        case IOCOMPLETE: /* IO DONE, post-analyze */
                callout_stop(&fdc->sc_timo_ch);

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

                if (fdc->sc_nstat != 7 || (st0 & 0xf8) != 0 || st1 != 0) {
#ifdef FD_DEBUG
                        if (fdc_debug) {
                                fdcstatus(fd->sc_dv, 7,
                                    bp->b_flags & B_READ
                                    ? "read failed" : "write failed");
                                printf("blkno %d nblks %d tc %d\n",
                                    (int)fd->sc_blkno, fd->sc_nblks,
                                    fdc->sc_tc);
                        }
#endif
                        if (fdc->sc_nstat == 7 &&
                            (st1 & ST1_OVERRUN) == ST1_OVERRUN) {

                                /*
                                 * Silently retry overruns if no other
                                 * error bit is set. Adjust threshold.
                                 */
                                int thr = fdc->sc_cfg & CFG_THRHLD_MASK;
                                if (thr < 15) {
                                        thr++;
                                        fdc->sc_cfg &= ~CFG_THRHLD_MASK;
                                        fdc->sc_cfg |= (thr & CFG_THRHLD_MASK);
#ifdef FD_DEBUG
                                        if (fdc_debug)
                                                printf("fdc: %d -> threshold\n",
                                                    thr);
#endif
                                        fdconf(fdc);
                                        fdc->sc_overruns = 0;
                                }
                                if (++fdc->sc_overruns < 3) {
                                        fdc->sc_state = DOIO;
                                        goto loop;
                                }
                        }
                        fdcretry(fdc);
                        goto loop;
                }
                if (fdc->sc_errors) {
                        diskerr(bp, "fd", "soft error", LOG_PRINTF,
                            fd->sc_skip / FDC_BSIZE, NULL);
                        printf("\n");
                        fdc->sc_errors = 0;
                } else {
                        if (--fdc->sc_overruns < -20) {
                                int thr = fdc->sc_cfg & CFG_THRHLD_MASK;
                                if (thr > 0) {
                                        thr--;
                                        fdc->sc_cfg &= ~CFG_THRHLD_MASK;
                                        fdc->sc_cfg |= (thr & CFG_THRHLD_MASK);
#ifdef FD_DEBUG
                                        if (fdc_debug)
                                                printf("fdc: %d -> threshold\n",
                                                    thr);
#endif
                                        fdconf(fdc);
                                }
                                fdc->sc_overruns = 0;
                        }
                }
                fd->sc_blkno += fd->sc_nblks;
                fd->sc_skip += fd->sc_nbytes;
                fd->sc_bcount -= fd->sc_nbytes;
                if (!finfo && fd->sc_bcount > 0) {
                        bp->b_cylinder = fd->sc_blkno / fd->sc_type->seccyl;
                        goto doseek;
                }
                fdfinish(fd, bp);
                goto loop;

        case DORESET:
 doreset:
                /* try a reset, keep motor on */
                fd_set_motor(fdc);
                delay(100);
                fdc_reset(fdc);
                fdc->sc_nstat = 0;
                fdc->sc_istate = ISTATE_SENSEI;
                fdc->sc_state = RESETCOMPLETE;
                callout_reset(&fdc->sc_timo_ch, hz / 2, fdctimeout, fdc);
                return 1;                       /* will return later */

        case RESETCOMPLETE:
                callout_stop(&fdc->sc_timo_ch);
                fdconf(fdc);

                /* FALLTHROUGH */
        case DORECAL:
                fdc->sc_state = RECALWAIT;
                fdc->sc_istate = ISTATE_SENSEI;
                fdc->sc_nstat = 0;
                /* recalibrate function */
                OUT_FDC(fdc, NE7CMD_RECAL, RECALTIMEDOUT);
                OUT_FDC(fdc, fd->sc_drive, RECALTIMEDOUT);
                callout_reset(&fdc->sc_timo_ch, 5 * hz, fdctimeout, fdc);
                return 1;                       /* will return later */

        case RECALWAIT:
                callout_stop(&fdc->sc_timo_ch);
                fdc->sc_state = RECALCOMPLETE;
                if (fdc->sc_flags & FDC_NEEDHEADSETTLE) {
                        /* allow 1/30 second for heads to settle */
                        callout_reset(&fdc->sc_intr_ch, hz / 30,
                            fdcpseudointr, fdc);
                        return 1;               /* will return later */
                }

        case RECALCOMPLETE:
                if (fdc->sc_nstat != 2 || (st0 & 0xf8) != 0x20 || cyl != 0) {
#ifdef FD_DEBUG
                        if (fdc_debug)
                                fdcstatus(fd->sc_dv, 2, "recalibrate failed");
#endif
                        fdcretry(fdc);
                        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_dv, 0, "stray interrupt");
                return 1;
        }
#ifdef DIAGNOSTIC
        panic("%s: impossible", __func__);
#endif
#undef  st0
#undef  st1
#undef  cyl
}

void
fdcretry(struct fdc_softc *fdc)
{
        struct fd_softc *fd;
        struct buf *bp;

        fd = fdc->sc_drives.tqh_first;
        bp = bufq_peek(fd->sc_q);

        fdc->sc_overruns = 0;
        if (fd->sc_opts & FDOPT_NORETRY)
                goto fail;

        switch (fdc->sc_errors) {
        case 0:
                /* try again */
                fdc->sc_state =
                        (fdc->sc_flags & FDC_EIS) ? DOIO : 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:
                if ((fd->sc_opts & FDOPT_SILENT) == 0) {
                        diskerr(bp, "fd", "hard error", LOG_PRINTF,
                            fd->sc_skip / FDC_BSIZE, NULL);

                        fdcpstatus(7, fdc);
                }

                bp->b_error = EIO;
                fdfinish(fd, bp);
        }
        fdc->sc_errors++;
}

static int
fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
{
        struct fd_softc *fd = device_lookup_private(&fd_cd, FDUNIT(dev));
        struct fdformat_parms *form_parms;
        struct fdformat_cmd *form_cmd;
        struct ne7_fd_formb *fd_formb;
        int il[FD_MAX_NSEC + 1];
        int i, j;
        int error;

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

        case DIOCWLABEL:
                if ((flag & FWRITE) == 0)
                        return EBADF;
                /* XXX do something */
                return 0;

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

                error = setdisklabel(fd->sc_dk.dk_label,
                    (struct disklabel *)addr, 0, fd->sc_dk.dk_cpulabel);
                if (error)
                        return error;

                error = writedisklabel(dev, fdstrategy, fd->sc_dk.dk_label,
                    fd->sc_dk.dk_cpulabel);
                return error;

        case DIOCLOCK:
                /*
                 * Nothing to do here, really.
                 */
                return 0;

        case DIOCEJECT:
                if (*(int *)addr == 0) {
                        int part = DISKPART(dev);
                        /*
                         * Don't force eject: check that we are the only
                         * partition open. If so, unlock it.
                         */
                        if ((fd->sc_dk.dk_openmask & ~(1 << part)) != 0 ||
                            fd->sc_dk.dk_bopenmask + fd->sc_dk.dk_copenmask !=
                            fd->sc_dk.dk_openmask) {
                                return EBUSY;
                        }
                }
                /* FALLTHROUGH */
        case ODIOCEJECT:
                fd_do_eject(device_private(device_parent(fd->sc_dv)),
                    fd->sc_drive);
                return 0;

        case FDIOCGETFORMAT:
                form_parms = (struct fdformat_parms *)addr;
                form_parms->fdformat_version = FDFORMAT_VERSION;
                form_parms->nbps = 128 * (1 << fd->sc_type->secsize);
                form_parms->ncyl = fd->sc_type->tracks;
                form_parms->nspt = fd->sc_type->sectrac;
                form_parms->ntrk = fd->sc_type->heads;
                form_parms->stepspercyl = fd->sc_type->step;
                form_parms->gaplen = fd->sc_type->gap2;
                form_parms->fillbyte = fd->sc_type->fillbyte;
                form_parms->interleave = fd->sc_type->interleave;
                switch (fd->sc_type->rate) {
                case FDC_500KBPS:
                        form_parms->xfer_rate = 500 * 1024;
                        break;
                case FDC_300KBPS:
                        form_parms->xfer_rate = 300 * 1024;
                        break;
                case FDC_250KBPS:
                        form_parms->xfer_rate = 250 * 1024;
                        break;
                default:
                        return EINVAL;
                }
                return 0;

        case FDIOCSETFORMAT:
                if ((flag & FWRITE) == 0)
                        return EBADF;   /* must be opened for writing */

                form_parms = (struct fdformat_parms *)addr;
                if (form_parms->fdformat_version != FDFORMAT_VERSION)
                        return EINVAL; /* wrong version of formatting prog */

                i = form_parms->nbps >> 7;
                if ((form_parms->nbps & 0x7f) || ffs(i) == 0 ||
                    i & ~(1 << (ffs(i) - 1)))
                        /* not a power-of-two multiple of 128 */
                        return EINVAL;

                switch (form_parms->xfer_rate) {
                case 500 * 1024:
                        fd->sc_type->rate = FDC_500KBPS;
                        break;
                case 300 * 1024:
                        fd->sc_type->rate = FDC_300KBPS;
                        break;
                case 250 * 1024:
                        fd->sc_type->rate = FDC_250KBPS;
                        break;
                default:
                        return EINVAL;
                }

                if (form_parms->nspt > FD_MAX_NSEC ||
                    form_parms->fillbyte > 0xff ||
                    form_parms->interleave > 0xff)
                        return EINVAL;
                fd->sc_type->sectrac = form_parms->nspt;
                if (form_parms->ntrk != 2 && form_parms->ntrk != 1)
                        return EINVAL;
                fd->sc_type->heads = form_parms->ntrk;
                fd->sc_type->seccyl = form_parms->nspt * form_parms->ntrk;
                fd->sc_type->secsize = ffs(i) - 1;
                fd->sc_type->gap2 = form_parms->gaplen;
                fd->sc_type->tracks = form_parms->ncyl;
                fd->sc_type->size = fd->sc_type->seccyl * form_parms->ncyl *
                    form_parms->nbps / DEV_BSIZE;
                fd->sc_type->step = form_parms->stepspercyl;
                fd->sc_type->fillbyte = form_parms->fillbyte;
                fd->sc_type->interleave = form_parms->interleave;
                return 0;

        case FDIOCFORMAT_TRACK:
                if((flag & FWRITE) == 0)
                        /* must be opened for writing */
                        return EBADF;
                form_cmd = (struct fdformat_cmd *)addr;
                if (form_cmd->formatcmd_version != FDFORMAT_VERSION)
                        /* wrong version of formatting prog */
                        return EINVAL;

                if (form_cmd->head >= fd->sc_type->heads ||
                    form_cmd->cylinder >= fd->sc_type->tracks) {
                        return EINVAL;
                }

                fd_formb = kmem_alloc(sizeof(*fd_formb), KM_SLEEP);
                fd_formb->head = form_cmd->head;
                fd_formb->cyl = form_cmd->cylinder;
                fd_formb->transfer_rate = fd->sc_type->rate;
                fd_formb->fd_formb_secshift = fd->sc_type->secsize;
                fd_formb->fd_formb_nsecs = fd->sc_type->sectrac;
                fd_formb->fd_formb_gaplen = fd->sc_type->gap2;
                fd_formb->fd_formb_fillbyte = fd->sc_type->fillbyte;

                memset(il, 0, sizeof(il));
                for (j = 0, i = 1; i <= fd_formb->fd_formb_nsecs; i++) {
                        while (il[(j%fd_formb->fd_formb_nsecs) + 1])
                                j++;
                        il[(j % fd_formb->fd_formb_nsecs) + 1] = i;
                        j += fd->sc_type->interleave;
                }
                for (i = 0; i < fd_formb->fd_formb_nsecs; i++) {
                        fd_formb->fd_formb_cylno(i) = form_cmd->cylinder;
                        fd_formb->fd_formb_headno(i) = form_cmd->head;
                        fd_formb->fd_formb_secno(i) = il[i+1];
                        fd_formb->fd_formb_secsize(i) = fd->sc_type->secsize;
                }

                error = fdformat(dev, fd_formb, l->l_proc);
                kmem_free(fd_formb, sizeof(*fd_formb));
                return error;

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

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

#ifdef DEBUG
        case _IO('f', 100):
                {
                int k;
                struct fdc_softc *fdc =
                    device_private(device_parent(fd->sc_dv));

                out_fdc(fdc, NE7CMD_DUMPREG);
                fdcresult(fdc);
                printf("dumpreg(%d regs): <", fdc->sc_nstat);
                for (k = 0; k < fdc->sc_nstat; k++)
                        printf(" %x", fdc->sc_status[k]);
                printf(">\n");
                return 0;
                }

        case _IOW('f', 101, int):
                {
                struct fdc_softc *fdc =
                    device_private(device_parent(fd->sc_dv));

                fdc->sc_cfg &= ~CFG_THRHLD_MASK;
                fdc->sc_cfg |= (*(int *)addr & CFG_THRHLD_MASK);
                fdconf(fdc);
                return 0;
                }

        case _IO('f', 102):
                {
                int k;
                struct fdc_softc *fdc =
                    device_private(device_parent(fd->sc_dv));

                out_fdc(fdc, NE7CMD_SENSEI);
                fdcresult(fdc);
                printf("sensei(%d regs): <", fdc->sc_nstat);
                for (k=0; k < fdc->sc_nstat; k++)
                        printf(" 0x%x", fdc->sc_status[k]);
                printf(">\n");
                return 0;
                }
#endif

        default:
                return ENOTTY;
        }

#ifdef DIAGNOSTIC
        panic("%s: impossible", __func__);
#endif
}

int
fdformat(dev_t dev, struct ne7_fd_formb *finfo, struct proc *p)
{
        int rv = 0;
        struct fd_softc *fd = device_lookup_private(&fd_cd, FDUNIT(dev));
        struct fd_type *type = fd->sc_type;
        struct buf *bp;

        /* set up a buffer header for fdstrategy() */
        bp = getiobuf(NULL, false);
        if (bp == NULL)
                return ENOBUFS;

        bp->b_vp = NULL;
        bp->b_cflags = BC_BUSY;
        bp->b_flags = B_PHYS | B_FORMAT;
        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) * FDC_BSIZE / DEV_BSIZE;

        bp->b_bcount = sizeof(struct fd_idfield_data) * finfo->fd_formb_nsecs;
        bp->b_data = (void *)finfo;

#ifdef FD_DEBUG
        if (fdc_debug)
                printf("%s: blkno %x count %d\n",
                    __func__, (int)bp->b_blkno, bp->b_bcount);
#endif

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

        /* ...and wait for it to complete */
        rv = biowait(bp);
        putiobuf(bp);
        return rv;
}

void
fdgetdisklabel(dev_t dev)
{
        int unit = FDUNIT(dev), i;
        struct fd_softc *fd = device_lookup_private(&fd_cd, unit);
        struct disklabel *lp = fd->sc_dk.dk_label;
        struct cpu_disklabel *clp = fd->sc_dk.dk_cpulabel;

        memset(lp, 0, sizeof(struct disklabel));
        memset(clp, 0, sizeof(struct cpu_disklabel));

        lp->d_type = DKTYPE_FLOPPY;
        lp->d_secsize = FDC_BSIZE;
        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... */
        lp->d_rpm = 3600;       /* XXX like it matters... */

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

        lp->d_partitions[RAW_PART].p_offset = 0;
        lp->d_partitions[RAW_PART].p_size = lp->d_secpercyl * lp->d_ncylinders;
        lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
        lp->d_npartitions = RAW_PART + 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.
         */
        if (readdisklabel(dev, fdstrategy, lp, clp) != NULL) {
                strncpy(lp->d_packname, "default label",
                    sizeof(lp->d_packname));
                /*
                 * Reset the partition info; it might have gotten
                 * trashed in readdisklabel().
                 *
                 * XXX Why do we have to do this?  readdisklabel()
                 * should be safe...
                 */
                for (i = 0; i < MAXPARTITIONS; ++i) {
                        lp->d_partitions[i].p_offset = 0;
                        if (i == RAW_PART) {
                                lp->d_partitions[i].p_size =
                                    lp->d_secpercyl * lp->d_ncylinders;
                                lp->d_partitions[i].p_fstype = FS_BSDFFS;
                        } else {
                                lp->d_partitions[i].p_size = 0;
                                lp->d_partitions[i].p_fstype = FS_UNUSED;
                        }
                }
                lp->d_npartitions = RAW_PART + 1;
        }
}

void
fd_do_eject(struct fdc_softc *fdc, int unit)
{

        fdc->sc_fcr |= FCR_DSEL(unit)|FCR_EJECT;
        FCR_REG_SYNC();
        delay(10);
        fdc->sc_fcr &= ~(FCR_DSEL(unit)|FCR_EJECT);
        FCR_REG_SYNC();
}

#ifdef MEMORY_DISK_HOOKS_sun3x_not_yet
int     fd_read_md_image(size_t *, void **);
#endif

/* ARGSUSED */
void
fd_mountroot_hook(device_t dev)
{
        struct fd_softc *fd;
        struct fdc_softc *fdc;
        int c;

        fd = device_private(dev);
        fdc = device_private(device_parent(dev));
        fd_do_eject(fdc, fd->sc_drive);
        printf("Insert filesystem floppy and press return.");
        for (;;) {
                c = cngetc();
                if ((c == '\r') || (c == '\n')) {
                        printf("\n");
                        break;
                }
        }
#ifdef MEMORY_DISK_HOOKS_sun3x_not_yet
        {
                extern int (*md_read_image)(size_t *, void **);

                md_read_image = fd_read_md_image;
        }
#endif
}

#ifdef MEMORY_DISK_HOOKS_sun3x_not_yet

#define FDMICROROOTSIZE ((2*18*80) << DEV_BSHIFT)

int
fd_read_md_image(size_t *sizep, void **addrp)
{
        struct fdc_softc *fdc;
        struct fd_softc *fd;
        struct buf buf, *bp = &buf;
        dev_t dev;
        off_t offset;
        void *addr;

        dev = makedev(cdevsw_lookup_major(&fd_cdevsw), 0);      /* XXX */

        addr = kmem_alloc(FDMICROROOTSIZE, KM_SLEEP);
        *addrp = addr;

        if (fdopen(dev, 0, S_IFCHR, NULL))
                panic("fd: mountroot: fdopen");

        offset = 0;

        for (;;) {
                bp->b_dev = dev;
                bp->b_error = 0;
                bp->b_resid = 0;
                bp->b_proc = NULL;
                bp->b_flags = B_PHYS | B_RAW | B_READ;
                bp->b_cflags = BC_BUSY;
                bp->b_blkno = btodb(offset);
                bp->b_bcount = DEV_BSIZE;
                bp->b_data = addr;
                fdstrategy(bp);
                biowait(bp);
                if (bp->b_error)
                        panic("fd: mountroot: fdread error %d", bp->b_error);

                if (bp->b_resid != 0)
                        break;

                addr += DEV_BSIZE;
                offset += DEV_BSIZE;
                if (offset + DEV_BSIZE > FDMICROROOTSIZE)
                        break;
        }
        (void)fdclose(dev, 0, S_IFCHR, NULL);
        *sizep = offset;
        fd = device_lookup_private(&fd_cd, 0);
        fdc = device_private(device_parent(fd->sc_dv));
        fd_do_eject(fdc, 0); /* XXX */
        return 0;
}
#endif