* Streamer tape driver.

/* $NetBSD: wt.c,v 1.89 2022/09/25 17:11:48 thorpej Exp $ */

/*
* Streamer tape driver.
* Supports Archive and Wangtek compatible QIC-02/QIC-36 boards.
*
* Copyright (C) 1993 by:
* Sergey Ryzhkov <[email protected]>
* Serge Vakulenko <[email protected]>
*
* This software is distributed with NO WARRANTIES, not even the implied
* warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Authors grant any other persons or organisations permission to use
* or modify this software as long as this message is kept with the software,
* all derivative works or modified versions.
*
* This driver is derived from the old 386bsd Wangtek streamer tape driver,
* made by Robert Baron at CMU, based on Intel sources.
*/

/*
* Copyright (c) 1989 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Robert Baron
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or [email protected]
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/

/*
* Copyright 1988, 1989 by Intel Corporation
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: wt.c,v 1.89 2022/09/25 17:11:48 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/fcntl.h>
#include <sys/kmem.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/lwp.h>
#include <sys/conf.h>

#include <sys/intr.h>
#include <sys/bus.h>
#include <machine/pio.h>

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

/*
* Uncomment this to enable internal device tracing.
*/
#define WTDBPRINT(x) /* printf x */

#define WTPRI (PZERO+10) /* sleep priority */

#define WT_NPORT 2 /* 2 i/o ports */
#define AV_NPORT 4 /* 4 i/o ports */

enum wttype {
UNKNOWN = 0, /* unknown type, driver disabled */
ARCHIVE, /* Archive Viper SC499, SC402 etc */
WANGTEK, /* Wangtek */
};

static struct wtregs {
/* controller ports */
int DATAPORT, /* data, read only */
CMDPORT, /* command, write only */
STATPORT, /* status, read only */
CTLPORT, /* control, write only */
SDMAPORT, /* start DMA */
RDMAPORT; /* reset DMA */
/* status port bits */
u_char BUSY, /* not ready bit define */
NOEXCEP, /* no exception bit define */
RESETMASK, /* to check after reset */
RESETVAL, /* state after reset */
/* control port bits */
ONLINE, /* device selected */
RESET, /* reset command */
REQUEST, /* request command */
IEN; /* enable interrupts */
} wtregs = {
1, 1, 0, 0, 0, 0,
0x01, 0x02, 0x07, 0x05,
0x01, 0x02, 0x04, 0x08
}, avregs = {
0, 0, 1, 1, 2, 3,
0x40, 0x20, 0xf8, 0x50,
0, 0x80, 0x40, 0x20
};

struct wt_softc {
device_t sc_dev;
void *sc_ih;

bus_space_tag_t sc_iot;
bus_space_handle_t sc_ioh;
isa_chipset_tag_t sc_ic;

callout_t sc_timer_ch;

enum wttype type; /* type of controller */
int chan; /* DMA channel number, 1..3 */
int flags; /* state of tape drive */
unsigned dens; /* tape density */
int bsize; /* tape block size */
void *buf; /* internal i/o buffer */

void *dmavaddr; /* virtual address of DMA i/o buffer */
size_t dmatotal; /* size of i/o buffer */
int dmaflags; /* i/o direction */
size_t dmacount; /* resulting length of DMA i/o */

u_short error; /* code for error encountered */
u_short ercnt; /* number of error blocks */
u_short urcnt; /* number of underruns */

struct wtregs regs;
};

static dev_type_open(wtopen);
static dev_type_close(wtclose);
static dev_type_read(wtread);
static dev_type_write(wtwrite);
static dev_type_ioctl(wtioctl);
static dev_type_strategy(wtstrategy);
static dev_type_dump(wtdump);
static dev_type_size(wtsize);

const struct bdevsw wt_bdevsw = {
.d_open = wtopen,
.d_close = wtclose,
.d_strategy = wtstrategy,
.d_ioctl = wtioctl,
.d_dump = wtdump,
.d_psize = wtsize,
.d_discard = nodiscard,
.d_flag = D_TAPE
};

const struct cdevsw wt_cdevsw = {
.d_open = wtopen,
.d_close = wtclose,
.d_read = wtread,
.d_write = wtwrite,
.d_ioctl = wtioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_TAPE
};

static int wtwait(struct wt_softc *sc, int catch, const char *msg);
static int wtcmd(struct wt_softc *sc, int cmd);
static int wtstart(struct wt_softc *sc, int flag, void *vaddr, size_t len);
static void wtdma(struct wt_softc *sc);
static void wttimer(void *arg);
static void wtclock(struct wt_softc *sc);
static int wtreset(bus_space_tag_t, bus_space_handle_t, struct wtregs *);
static int wtsense(struct wt_softc *sc, int verbose, int ignore);
static int wtstatus(struct wt_softc *sc);
static void wtrewind(struct wt_softc *sc);
static int wtreadfm(struct wt_softc *sc);
static int wtwritefm(struct wt_softc *sc);
static u_char wtsoft(struct wt_softc *sc, int mask, int bits);
static int wtintr(void *sc);

int wtprobe(device_t, cfdata_t, void *);
void wtattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(wt, sizeof(struct wt_softc),
wtprobe, wtattach, NULL, NULL);

extern struct cfdriver wt_cd;

/*
* Probe for the presence of the device.
*/
int
wtprobe(device_t parent, cfdata_t match, void *aux)
{
struct isa_attach_args *ia = aux;
bus_space_tag_t iot = ia->ia_iot;
bus_space_handle_t ioh;
int rv = 0, iosize;

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

/* Disallow wildcarded i/o address. */
if (ia->ia_io[0].ir_addr == ISA_UNKNOWN_PORT)
return (0);
if (ia->ia_irq[0].ir_irq == ISA_UNKNOWN_IRQ)
return (0);

if (ia->ia_drq[0].ir_drq < 1 || ia->ia_drq[0].ir_drq > 3) {
printf("wtprobe: Bad drq=%d, should be 1..3\n",
ia->ia_drq[0].ir_drq);
return (0);
}

iosize = AV_NPORT;

/* Map i/o space */
if (bus_space_map(iot, ia->ia_io[0].ir_addr, iosize, 0, &ioh))
return 0;

/* Try Wangtek. */
if (wtreset(iot, ioh, &wtregs)) {
iosize = WT_NPORT; /* XXX misleading */
rv = 1;
goto done;
}

/* Try Archive. */
if (wtreset(iot, ioh, &avregs)) {
iosize = AV_NPORT;
rv = 1;
goto done;
}

done:
if (rv) {
ia->ia_nio = 1;
ia->ia_io[0].ir_size = iosize;

ia->ia_nirq = 1;
ia->ia_ndrq = 1;

ia->ia_niomem = 0;
}
bus_space_unmap(iot, ioh, AV_NPORT);
return rv;
}

/*
* Device is found, configure it.
*/
void
wtattach(device_t parent, device_t self, void *aux)
{
struct wt_softc *sc = device_private(self);
struct isa_attach_args *ia = aux;
bus_space_tag_t iot = ia->ia_iot;
bus_space_handle_t ioh;
bus_size_t maxsize;

sc->sc_dev = self;

/* Map i/o space */
if (bus_space_map(iot, ia->ia_io[0].ir_addr, AV_NPORT, 0, &ioh)) {
aprint_error(": can't map i/o space\n");
return;
}

sc->sc_iot = iot;
sc->sc_ioh = ioh;
sc->sc_ic = ia->ia_ic;

callout_init(&sc->sc_timer_ch, 0);

/* Try Wangtek. */
if (wtreset(iot, ioh, &wtregs)) {
sc->type = WANGTEK;
memcpy(&sc->regs, &wtregs, sizeof(sc->regs));
aprint_normal(": type <Wangtek>\n");
goto ok;
}

/* Try Archive. */
if (wtreset(iot, ioh, &avregs)) {
sc->type = ARCHIVE;
memcpy(&sc->regs, &avregs, sizeof(sc->regs));
aprint_normal(": type <Archive>\n");
/* Reset DMA. */
bus_space_write_1(iot, ioh, sc->regs.RDMAPORT, 0);
goto ok;
}

/* what happened? */
aprint_error_dev(self, "lost controller\n");
return;

ok:
sc->flags = TPSTART; /* tape is rewound */
sc->dens = -1; /* unknown density */

sc->chan = ia->ia_drq[0].ir_drq;

if ((maxsize = isa_dmamaxsize(sc->sc_ic, sc->chan)) < MAXPHYS) {
aprint_error_dev(sc->sc_dev,
"max DMA size %lu is less than required %d\n",
(u_long)maxsize, MAXPHYS);
return;
}

if (isa_drq_alloc(sc->sc_ic, sc->chan) != 0) {
aprint_error_dev(sc->sc_dev, "can't reserve drq %d\n",
sc->chan);
return;
}

if (isa_dmamap_create(sc->sc_ic, sc->chan, MAXPHYS,
BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW)) {
aprint_error_dev(sc->sc_dev, "can't set up ISA DMA map\n");
return;
}

sc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq[0].ir_irq,
IST_EDGE, IPL_BIO, wtintr, sc);
}

static int
wtdump(dev_t dev, daddr_t blkno, void *va, size_t size)
{

/* Not implemented. */
return ENXIO;
}

static int
wtsize(dev_t dev)
{

/* Not implemented. */
return -1;
}

/*
* Open routine, called on every device open.
*/
static int
wtopen(dev_t dev, int flag, int mode, struct lwp *l)
{
int unit = minor(dev) & T_UNIT;
struct wt_softc *sc;
int error;

sc = device_lookup_private(&wt_cd, unit);
if (sc == NULL)
return (ENXIO);

/* Check that device is not in use */
if (sc->flags & TPINUSE)
return EBUSY;

/* If the tape is in rewound state, check the status and set density. */
if (sc->flags & TPSTART) {
/* If rewind is going on, wait */
if ((error = wtwait(sc, PCATCH, "wtrew")) != 0)
return error;

/* Check the controller status */
if (!wtsense(sc, 0, (flag & FWRITE) ? 0 : TP_WRP)) {
/* Bad status, reset the controller. */
if (!wtreset(sc->sc_iot, sc->sc_ioh, &sc->regs))
return EIO;
if (!wtsense(sc, 1, (flag & FWRITE) ? 0 : TP_WRP))
return EIO;
}

/* Set up tape density. */
if (sc->dens != (minor(dev) & WT_DENSEL)) {
int d = 0;

switch (minor(dev) & WT_DENSEL) {
case WT_DENSDFLT:
default:
break; /* default density */
case WT_QIC11:
d = QIC_FMT11; break; /* minor 010 */
case WT_QIC24:
d = QIC_FMT24; break; /* minor 020 */
case WT_QIC120:
d = QIC_FMT120; break; /* minor 030 */
case WT_QIC150:
d = QIC_FMT150; break; /* minor 040 */
case WT_QIC300:
d = QIC_FMT300; break; /* minor 050 */
case WT_QIC600:
d = QIC_FMT600; break; /* minor 060 */
}
if (d) {
/* Change tape density. */
if (!wtcmd(sc, d))
return EIO;
if (!wtsense(sc, 1, TP_WRP | TP_ILL))
return EIO;

/* Check the status of the controller. */
if (sc->error & TP_ILL) {
aprint_error_dev(sc->sc_dev,
"invalid tape density\n");
return ENODEV;
}
}
sc->dens = minor(dev) & WT_DENSEL;
}
sc->flags &= ~TPSTART;
} else if (sc->dens != (minor(dev) & WT_DENSEL))
return ENXIO;

sc->bsize = (minor(dev) & WT_BSIZE) ? 1024 : 512;
sc->buf = kmem_alloc(sc->bsize, KM_SLEEP);

sc->flags = TPINUSE;
if (flag & FREAD)
sc->flags |= TPREAD;
if (flag & FWRITE)
sc->flags |= TPWRITE;
return 0;
}

/*
* Close routine, called on last device close.
*/
static int
wtclose(dev_t dev, int flags, int mode, struct lwp *l)
{
struct wt_softc *sc;

sc = device_lookup_private(&wt_cd, minor(dev) & T_UNIT);

/* If rewind is pending, do nothing */
if (sc->flags & TPREW)
goto done;

/* If seek forward is pending and no rewind on close, do nothing */
if (sc->flags & TPRMARK) {
if (minor(dev) & T_NOREWIND)
goto done;

/* If read file mark is going on, wait */
wtwait(sc, 0, "wtrfm");
}

if (sc->flags & TPWANY) {
/* Tape was written. Write file mark. */
wtwritefm(sc);
}

if ((minor(dev) & T_NOREWIND) == 0) {
/* Rewind to beginning of tape. */
/* Don't wait until rewind, though. */
wtrewind(sc);
goto done;
}
if ((sc->flags & TPRANY) && (sc->flags & (TPVOL | TPWANY)) == 0) {
/* Space forward to after next file mark if no writing done. */
/* Don't wait for completion. */
wtreadfm(sc);
}

done:
sc->flags &= TPREW | TPRMARK | TPSTART | TPTIMER;
kmem_free(sc->buf, sc->bsize);
return 0;
}

/*
* Ioctl routine. Compatible with BSD ioctls.
* Direct QIC-02 commands ERASE and RETENSION added.
* There are three possible ioctls:
* ioctl(int fd, MTIOCGET, struct mtget *buf) -- get status
* ioctl(int fd, MTIOCTOP, struct mtop *buf) -- do BSD-like op
* ioctl(int fd, WTQICMD, int qicop) -- do QIC op
*/
static int
wtioctl(dev_t dev, unsigned long cmd, void *addr, int flag, struct lwp *l)
{
struct wt_softc *sc;
int error, count, op;

sc = device_lookup_private(&wt_cd, minor(dev) & T_UNIT);

switch (cmd) {
default:
return EINVAL;
case WTQICMD: /* direct QIC command */
op = *(int *)addr;
switch (op) {
default:
return EINVAL;
case QIC_ERASE: /* erase the whole tape */
if ((sc->flags & TPWRITE) == 0 || (sc->flags & TPWP))
return EACCES;
if ((error = wtwait(sc, PCATCH, "wterase")) != 0)
return error;
break;
case QIC_RETENS: /* retension the tape */
if ((error = wtwait(sc, PCATCH, "wtretens")) != 0)
return error;
break;
}
/* Both ERASE and RETENS operations work like REWIND. */
/* Simulate the rewind operation here. */
sc->flags &= ~(TPRO | TPWO | TPVOL);
if (!wtcmd(sc, op))
return EIO;
sc->flags |= TPSTART | TPREW;
if (op == QIC_ERASE)
sc->flags |= TPWANY;
wtclock(sc);
return 0;
case MTIOCIEOT: /* ignore EOT errors */
case MTIOCEEOT: /* enable EOT errors */
return 0;
case MTIOCGET:
((struct mtget*)addr)->mt_type =
sc->type == ARCHIVE ? MT_ISVIPER1 : 0x11;
((struct mtget*)addr)->mt_dsreg = sc->flags; /* status */
((struct mtget*)addr)->mt_erreg = sc->error; /* errors */
((struct mtget*)addr)->mt_resid = 0;
((struct mtget*)addr)->mt_fileno = 0; /* file */
((struct mtget*)addr)->mt_blkno = 0; /* block */
return 0;
case MTIOCTOP:
break;
}

switch ((short)((struct mtop*)addr)->mt_op) {
default:
#if 0
case MTFSR: /* forward space record */
case MTBSR: /* backward space record */
case MTBSF: /* backward space file */
#endif
return EINVAL;
case MTNOP: /* no operation, sets status only */
case MTCACHE: /* enable controller cache */
case MTNOCACHE: /* disable controller cache */
return 0;
case MTREW: /* rewind */
case MTOFFL: /* rewind and put the drive offline */
if (sc->flags & TPREW) /* rewind is running */
return 0;
if ((error = wtwait(sc, PCATCH, "wtorew")) != 0)
return error;
wtrewind(sc);
return 0;
case MTFSF: /* forward space file */
for (count = ((struct mtop*)addr)->mt_count; count > 0;
--count) {
if ((error = wtwait(sc, PCATCH, "wtorfm")) != 0)
return error;
if ((error = wtreadfm(sc)) != 0)
return error;
}
return 0;
case MTWEOF: /* write an end-of-file record */
if ((sc->flags & TPWRITE) == 0 || (sc->flags & TPWP))
return EACCES;
if ((error = wtwait(sc, PCATCH, "wtowfm")) != 0)
return error;
if ((error = wtwritefm(sc)) != 0)
return error;
return 0;
}

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

/*
* Strategy routine.
*/
static void
wtstrategy(struct buf *bp)
{
struct wt_softc *sc;
int s;

sc = device_lookup_private(&wt_cd, minor(bp->b_dev) & T_UNIT);

bp->b_resid = bp->b_bcount;

/* at file marks and end of tape, we just return '0 bytes available' */
if (sc->flags & TPVOL)
goto xit;

if (bp->b_flags & B_READ) {
/* Check read access and no previous write to this tape. */
if ((sc->flags & TPREAD) == 0 || (sc->flags & TPWANY))
goto errxit;

/* For now, we assume that all data will be copied out */
/* If read command outstanding, just skip down */
if ((sc->flags & TPRO) == 0) {
if (!wtsense(sc, 1, TP_WRP)) {
/* Clear status. */
goto errxit;
}
if (!wtcmd(sc, QIC_RDDATA)) {
/* Set read mode. */
wtsense(sc, 1, TP_WRP);
goto errxit;
}
sc->flags |= TPRO | TPRANY;
}
} else {
/* Check write access and write protection. */
/* No previous read from this tape allowed. */
if ((sc->flags & TPWRITE) == 0 || (sc->flags & (TPWP | TPRANY)))
goto errxit;

/* If write command outstanding, just skip down */
if ((sc->flags & TPWO) == 0) {
if (!wtsense(sc, 1, 0)) {
/* Clear status. */
goto errxit;
}
if (!wtcmd(sc, QIC_WRTDATA)) {
/* Set write mode. */
wtsense(sc, 1, 0);
goto errxit;
}
sc->flags |= TPWO | TPWANY;
}
}

if (bp->b_bcount == 0)
goto xit;

sc->flags &= ~TPEXCEP;
s = splbio();
if (wtstart(sc, bp->b_flags, bp->b_data, bp->b_bcount)) {
wtwait(sc, 0, (bp->b_flags & B_READ) ? "wtread" : "wtwrite");
bp->b_resid -= sc->dmacount;
}
splx(s);

if (sc->flags & TPEXCEP) {
errxit:
bp->b_error = EIO;
}
xit:
biodone(bp);
return;
}

static int
wtread(dev_t dev, struct uio *uio, int flags)
{

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

static int
wtwrite(dev_t dev, struct uio *uio, int flags)
{

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

/*
* Interrupt routine.
*/
static int
wtintr(void *arg)
{
struct wt_softc *sc = arg;
u_char x;

/* get status */
x = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->regs.STATPORT);
WTDBPRINT(("wtintr() status=0x%x -- ", x));
if ((x & (sc->regs.BUSY | sc->regs.NOEXCEP))
== (sc->regs.BUSY | sc->regs.NOEXCEP)) {
WTDBPRINT(("busy\n"));
return 0; /* device is busy */
}

/*
* Check if rewind finished.
*/
if (sc->flags & TPREW) {
WTDBPRINT(((x & (sc->regs.BUSY | sc->regs.NOEXCEP))
== (sc->regs.BUSY | sc->regs.NOEXCEP) ?
"rewind busy?\n" : "rewind finished\n"));
sc->flags &= ~TPREW; /* rewind finished */
wtsense(sc, 1, TP_WRP);
wakeup((void *)sc);
return 1;
}

/*
* Check if writing/reading of file mark finished.
*/
if (sc->flags & (TPRMARK | TPWMARK)) {
WTDBPRINT(((x & (sc->regs.BUSY | sc->regs.NOEXCEP))
== (sc->regs.BUSY | sc->regs.NOEXCEP) ?
"marker r/w busy?\n" : "marker r/w finished\n"));
if ((x & sc->regs.NOEXCEP) == 0) /* operation failed */
wtsense(sc, 1, (sc->flags & TPRMARK) ? TP_WRP : 0);
sc->flags &= ~(TPRMARK | TPWMARK); /* operation finished */
wakeup((void *)sc);
return 1;
}

/*
* Do we started any i/o? If no, just return.
*/
if ((sc->flags & TPACTIVE) == 0) {
WTDBPRINT(("unexpected interrupt\n"));
return 0;
}
sc->flags &= ~TPACTIVE;
sc->dmacount += sc->bsize; /* increment counter */

/*
* Clean up DMA.
*/
if ((sc->dmaflags & DMAMODE_READ) &&
(sc->dmatotal - sc->dmacount) < sc->bsize) {
/* If reading short block, copy the internal buffer
* to the user memory. */
isa_dmadone(sc->sc_ic, sc->chan);
memcpy(sc->dmavaddr, sc->buf, sc->dmatotal - sc->dmacount);
} else
isa_dmadone(sc->sc_ic, sc->chan);

/*
* On exception, check for end of file and end of volume.
*/
if ((x & sc->regs.NOEXCEP) == 0) {
WTDBPRINT(("i/o exception\n"));
wtsense(sc, 1, (sc->dmaflags & DMAMODE_READ) ? TP_WRP : 0);
if (sc->error & (TP_EOM | TP_FIL))
sc->flags |= TPVOL; /* end of file */
else
sc->flags |= TPEXCEP; /* i/o error */
wakeup((void *)sc);
return 1;
}

if (sc->dmacount < sc->dmatotal) {
/* Continue I/O. */
sc->dmavaddr = (char *)sc->dmavaddr + sc->bsize;
wtdma(sc);
WTDBPRINT(("continue i/o, %d\n", sc->dmacount));
return 1;
}
if (sc->dmacount > sc->dmatotal) /* short last block */
sc->dmacount = sc->dmatotal;
/* Wake up user level. */
wakeup((void *)sc);
WTDBPRINT(("i/o finished, %d\n", sc->dmacount));
return 1;
}

/* start the rewind operation */
static void
wtrewind(struct wt_softc *sc)
{
int rwmode = sc->flags & (TPRO | TPWO);

sc->flags &= ~(TPRO | TPWO | TPVOL);
/*
* Wangtek strictly follows QIC-02 standard:
* clearing ONLINE in read/write modes causes rewind.
* REWIND command is not allowed in read/write mode
* and gives `illegal command' error.
*/
if (sc->type == WANGTEK && rwmode) {
bus_space_write_1(sc->sc_iot, sc->sc_ioh, sc->regs.CTLPORT, 0);
} else if (!wtcmd(sc, QIC_REWIND))
return;
sc->flags |= TPSTART | TPREW;
wtclock(sc);
}

/*
* Start the `read marker' operation.
*/
static int
wtreadfm(struct wt_softc *sc)
{

sc->flags &= ~(TPRO | TPWO | TPVOL);
if (!wtcmd(sc, QIC_READFM)) {
wtsense(sc, 1, TP_WRP);
return EIO;
}
sc->flags |= TPRMARK | TPRANY;
wtclock(sc);
/* Don't wait for completion here. */
return 0;
}

/*
* Write marker to the tape.
*/
static int
wtwritefm(struct wt_softc *sc)
{

tsleep((void *)wtwritefm, WTPRI, "wtwfm", hz);
sc->flags &= ~(TPRO | TPWO);
if (!wtcmd(sc, QIC_WRITEFM)) {
wtsense(sc, 1, 0);
return EIO;
}
sc->flags |= TPWMARK | TPWANY;
wtclock(sc);
return wtwait(sc, 0, "wtwfm");
}

/*
* While controller status & mask == bits continue waiting.
*/
static u_char
wtsoft(struct wt_softc *sc, int mask, int bits)
{
bus_space_tag_t iot = sc->sc_iot;
bus_space_handle_t ioh = sc->sc_ioh;
u_char x;
int i;

/* Poll status port, waiting for specified bits. */
for (i = 0; i < 1000; ++i) { /* up to 1 msec */
x = bus_space_read_1(iot, ioh, sc->regs.STATPORT);
if ((x & mask) != bits)
return x;
delay(1);
}
for (i = 0; i < 100; ++i) { /* up to 10 msec */
x = bus_space_read_1(iot, ioh, sc->regs.STATPORT);
if ((x & mask) != bits)
return x;
delay(100);
}
for (;;) { /* forever */
x = bus_space_read_1(iot, ioh, sc->regs.STATPORT);
if ((x & mask) != bits)
return x;
tsleep((void *)wtsoft, WTPRI, "wtsoft", 1);
}
}

/*
* Execute QIC command.
*/
static int
wtcmd(struct wt_softc *sc, int cmd)
{
bus_space_tag_t iot = sc->sc_iot;
bus_space_handle_t ioh = sc->sc_ioh;
u_char x;
int s;

WTDBPRINT(("wtcmd() cmd=0x%x\n", cmd));
s = splbio();
x = wtsoft(sc, sc->regs.BUSY | sc->regs.NOEXCEP,
sc->regs.BUSY | sc->regs.NOEXCEP); /* ready? */
if ((x & sc->regs.NOEXCEP) == 0) { /* error */
splx(s);
return 0;
}

/* output the command */
bus_space_write_1(iot, ioh, sc->regs.CMDPORT, cmd);

/* set request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT,
sc->regs.REQUEST | sc->regs.ONLINE);

/* wait for ready */
wtsoft(sc, sc->regs.BUSY, sc->regs.BUSY);

/* reset request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT,
sc->regs.IEN | sc->regs.ONLINE);

/* wait for not ready */
wtsoft(sc, sc->regs.BUSY, 0);
splx(s);
return 1;
}

/* wait for the end of i/o, seeking marker or rewind operation */
static int
wtwait(struct wt_softc *sc, int catch, const char *msg)
{
int error;

WTDBPRINT(("wtwait() `%s'\n", msg));
while (sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK))
if ((error = tsleep((void *)sc, WTPRI | catch, msg, 0)) != 0)
return error;
return 0;
}

/* initialize DMA for the i/o operation */
static void
wtdma(struct wt_softc *sc)
{
bus_space_tag_t iot = sc->sc_iot;
bus_space_handle_t ioh = sc->sc_ioh;

sc->flags |= TPACTIVE;
wtclock(sc);

if (sc->type == ARCHIVE) {
/* Set DMA. */
bus_space_write_1(iot, ioh, sc->regs.SDMAPORT, 0);
}

if ((sc->dmaflags & DMAMODE_READ) &&
(sc->dmatotal - sc->dmacount) < sc->bsize) {
/* Reading short block; do it through the internal buffer. */
isa_dmastart(sc->sc_ic, sc->chan, sc->buf,
sc->bsize, NULL, sc->dmaflags, BUS_DMA_NOWAIT);
} else
isa_dmastart(sc->sc_ic, sc->chan, sc->dmavaddr,
sc->bsize, NULL, sc->dmaflags, BUS_DMA_NOWAIT);
}

/* start i/o operation */
static int
wtstart(struct wt_softc *sc, int flag, void *vaddr, size_t len)
{
u_char x;

WTDBPRINT(("wtstart()\n"));
x = wtsoft(sc, sc->regs.BUSY | sc->regs.NOEXCEP,
sc->regs.BUSY | sc->regs.NOEXCEP); /* ready? */
if ((x & sc->regs.NOEXCEP) == 0) {
sc->flags |= TPEXCEP; /* error */
return 0;
}
sc->flags &= ~TPEXCEP; /* clear exception flag */
sc->dmavaddr = vaddr;
sc->dmatotal = len;
sc->dmacount = 0;
sc->dmaflags = flag & B_READ ? DMAMODE_READ : DMAMODE_WRITE;
wtdma(sc);
return 1;
}

/*
* Start timer.
*/
static void
wtclock(struct wt_softc *sc)
{

if (sc->flags & TPTIMER)
return;
sc->flags |= TPTIMER;
/*
* Some controllers seem to lose DMA interrupts too often. To make the
* tape stream we need 1 tick timeout.
*/
callout_reset(&sc->sc_timer_ch, (sc->flags & TPACTIVE) ? 1 : hz,
wttimer, sc);
}

/*
* Simulate an interrupt periodically while i/o is going.
* This is necessary in case interrupts get eaten due to
* multiple devices on a single IRQ line.
*/
static void
wttimer(void *arg)
{
register struct wt_softc *sc = (struct wt_softc *)arg;
int s;
u_char status;

sc->flags &= ~TPTIMER;
if ((sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK)) == 0)
return;

/* If i/o going, simulate interrupt. */
s = splbio();
status = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->regs.STATPORT);
if ((status & (sc->regs.BUSY | sc->regs.NOEXCEP))
!= (sc->regs.BUSY | sc->regs.NOEXCEP)) {
WTDBPRINT(("wttimer() -- "));
wtintr(sc);
}
splx(s);

/* Restart timer if i/o pending. */
if (sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK))
wtclock(sc);
}

/*
* Perform QIC-02 and QIC-36 compatible reset sequence.
*/
static int
wtreset(bus_space_tag_t iot, bus_space_handle_t ioh, struct wtregs *regs)
{
u_char x;
int i;

/* send reset */
bus_space_write_1(iot, ioh, regs->CTLPORT, regs->RESET | regs->ONLINE);
delay(30);
/* turn off reset */
bus_space_write_1(iot, ioh, regs->CTLPORT, regs->ONLINE);
delay(30);

/* Read the controller status. */
x = bus_space_read_1(iot, ioh, regs->STATPORT);
if (x == 0xff) /* no port at this address? */
return 0;

/* Wait 3 sec for reset to complete. Needed for QIC-36 boards? */
for (i = 0; i < 3000; ++i) {
if ((x & regs->BUSY) == 0 || (x & regs->NOEXCEP) == 0)
break;
delay(1000);
x = bus_space_read_1(iot, ioh, regs->STATPORT);
}
return (x & regs->RESETMASK) == regs->RESETVAL;
}

/*
* Get controller status information. Return 0 if user i/o request should
* receive an i/o error code.
*/
static int
wtsense(struct wt_softc *sc, int verbose, int ignore)
{
const char *msg = 0;
int error;

WTDBPRINT(("wtsense() ignore=0x%x\n", ignore));
sc->flags &= ~(TPRO | TPWO);
if (!wtstatus(sc))
return 0;
if ((sc->error & TP_ST0) == 0)
sc->error &= ~TP_ST0MASK;
if ((sc->error & TP_ST1) == 0)
sc->error &= ~TP_ST1MASK;
sc->error &= ~ignore; /* ignore certain errors */
error = sc->error & (TP_FIL | TP_BNL | TP_UDA | TP_EOM | TP_WRP |
TP_USL | TP_CNI | TP_MBD | TP_NDT | TP_ILL);
if (!error)
return 1;
if (!verbose)
return 0;

/* lifted from tdriver.c from Wangtek */
if (error & TP_USL)
msg = "Drive not online";
else if (error & TP_CNI)
msg = "No cartridge";
else if ((error & TP_WRP) && (sc->flags & TPWP) == 0) {
msg = "Tape is write protected";
sc->flags |= TPWP;
} else if (error & TP_FIL)
msg = 0 /*"Filemark detected"*/;
else if (error & TP_EOM)
msg = 0 /*"End of tape"*/;
else if (error & TP_BNL)
msg = "Block not located";
else if (error & TP_UDA)
msg = "Unrecoverable data error";
else if (error & TP_NDT)
msg = "No data detected";
else if (error & TP_ILL)
msg = "Illegal command";
if (msg)
printf("%s: %s\n", device_xname(sc->sc_dev), msg);
return 0;
}

/*
* Get controller status information.
*/
static int
wtstatus(struct wt_softc *sc)
{
bus_space_tag_t iot = sc->sc_iot;
bus_space_handle_t ioh = sc->sc_ioh;
char *p;
int s;

s = splbio();
wtsoft(sc, sc->regs.BUSY | sc->regs.NOEXCEP,
sc->regs.BUSY | sc->regs.NOEXCEP); /* ready? */
/* send `read status' command */
bus_space_write_1(iot, ioh, sc->regs.CMDPORT, QIC_RDSTAT);

/* set request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT,
sc->regs.REQUEST | sc->regs.ONLINE);

/* wait for ready */
wtsoft(sc, sc->regs.BUSY, sc->regs.BUSY);
/* reset request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT, sc->regs.ONLINE);

/* wait for not ready */
wtsoft(sc, sc->regs.BUSY, 0);

p = (char *)&sc->error;
while (p < (char *)&sc->error + 6) {
u_char x = wtsoft(sc, sc->regs.BUSY | sc->regs.NOEXCEP,
sc->regs.BUSY | sc->regs.NOEXCEP);

if ((x & sc->regs.NOEXCEP) == 0) { /* error */
splx(s);
return 0;
}

/* read status byte */
*p++ = bus_space_read_1(iot, ioh, sc->regs.DATAPORT);

/* set request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT,
sc->regs.REQUEST | sc->regs.ONLINE);

/* wait for not ready */
wtsoft(sc, sc->regs.BUSY, 0);

/* unset request */
bus_space_write_1(iot, ioh, sc->regs.CTLPORT, sc->regs.ONLINE);
}
splx(s);
return 1;
}