/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 Mathew Kanner
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (augustss@netbsd.org).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/conf.h>
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/sx.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/poll.h>
#include <sys/sbuf.h>
#include <sys/kobj.h>
#include <sys/module.h>

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif

#include <dev/sound/midi/midi.h>
#include "mpu_if.h"

#include <dev/sound/midi/midiq.h>
MALLOC_DEFINE(M_MIDI, "midi buffers", "Midi data allocation area");

#ifndef KOBJMETHOD_END
#define KOBJMETHOD_END	{ NULL, NULL }
#endif

#define MIDI_DEV_MIDICTL 12

enum midi_states {
	MIDI_IN_START, MIDI_IN_SYSEX, MIDI_IN_DATA
};

#define MIDI_NAMELEN   16
struct snd_midi {
	KOBJ_FIELDS;
	struct mtx lock;		/* Protects all but queues */
	void   *cookie;

	int	unit;			/* Should only be used in midistat */
	int	channel;		/* Should only be used in midistat */

	int	busy;
	int	flags;			/* File flags */
	char	name[MIDI_NAMELEN];
	struct mtx qlock;		/* Protects inq, outq and flags */
	MIDIQ_HEAD(, char) inq, outq;
	int	rchan, wchan;
	struct selinfo rsel, wsel;
	int	hiwat;			/* QLEN(outq)>High-water -> disable
					 * writes from userland */
	enum midi_states inq_state;
	int	inq_status, inq_left;	/* Variables for the state machine in
					 * Midi_in, this is to provide that
					 * signals only get issued only
					 * complete command packets. */
	struct proc *async;
	struct cdev *dev;
	TAILQ_ENTRY(snd_midi) link;
};

TAILQ_HEAD(, snd_midi) midi_devs;

struct sx mstat_lock;

static d_open_t midi_open;
static d_close_t midi_close;
static d_ioctl_t midi_ioctl;
static d_read_t midi_read;
static d_write_t midi_write;
static d_poll_t midi_poll;

static struct cdevsw midi_cdevsw = {
	.d_version = D_VERSION,
	.d_open = midi_open,
	.d_close = midi_close,
	.d_read = midi_read,
	.d_write = midi_write,
	.d_ioctl = midi_ioctl,
	.d_poll = midi_poll,
	.d_name = "rmidi",
};

static int      midi_destroy(struct snd_midi *, int);
static int      midi_load(void);
static int      midi_unload(void);

SYSCTL_NODE(_hw, OID_AUTO, midi, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "Midi driver");

int             midi_debug;
/* XXX: should this be moved into debug.midi? */
SYSCTL_INT(_hw_midi, OID_AUTO, debug, CTLFLAG_RW, &midi_debug, 0, "");

#define MIDI_DEBUG(l,a)	if(midi_debug>=l) a

void
midistat_lock(void)
{
	sx_xlock(&mstat_lock);
}

void
midistat_unlock(void)
{
	sx_xunlock(&mstat_lock);
}

void
midistat_lockassert(void)
{
	sx_assert(&mstat_lock, SA_XLOCKED);
}

/*
 * Register a new rmidi device. cls midi_if interface unit == 0 means
 * auto-assign new unit number unit != 0 already assigned a unit number, eg.
 * not the first channel provided by this device. channel,	sub-unit
 * cookie is passed back on MPU calls Typical device drivers will call with
 * unit=0, channel=1..(number of channels) and cookie=soft_c and won't care
 * what unit number is used.
 *
 * It is an error to call midi_init with an already used unit/channel combo.
 */
struct snd_midi *
midi_init(kobj_class_t cls, int unit, int channel, void *cookie)
{
	struct snd_midi *m;
	int i;
	int inqsize, outqsize;
	uint8_t *buf;

	MIDI_DEBUG(1, printf("midiinit: unit %d/%d.\n", unit, channel));
	midistat_lock();
	/*
	 * Protect against call with existing unit/channel or auto-allocate a
	 * new unit number.
	 */
	i = -1;
	TAILQ_FOREACH(m, &midi_devs, link) {
		mtx_lock(&m->lock);
		if (unit != 0) {
			if (m->unit == unit && m->channel == channel) {
				mtx_unlock(&m->lock);
				goto err0;
			}
		} else {
			/*
			 * Find a better unit number
			 */
			if (m->unit > i)
				i = m->unit;
		}
		mtx_unlock(&m->lock);
	}

	if (unit == 0)
		unit = i + 1;

	MIDI_DEBUG(1, printf("midiinit #2: unit %d/%d.\n", unit, channel));
	m = malloc(sizeof(*m), M_MIDI, M_WAITOK | M_ZERO);
	kobj_init((kobj_t)m, cls);
	inqsize = MPU_INQSIZE(m, cookie);
	outqsize = MPU_OUTQSIZE(m, cookie);

	MIDI_DEBUG(1, printf("midiinit queues %d/%d.\n", inqsize, outqsize));
	if (!inqsize && !outqsize)
		goto err1;

	mtx_init(&m->lock, "raw midi", NULL, 0);
	mtx_init(&m->qlock, "q raw midi", NULL, 0);

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	if (inqsize)
		buf = malloc(sizeof(uint8_t) * inqsize, M_MIDI, M_NOWAIT);
	else
		buf = NULL;

	MIDIQ_INIT(m->inq, buf, inqsize);

	if (outqsize)
		buf = malloc(sizeof(uint8_t) * outqsize, M_MIDI, M_NOWAIT);
	else
		buf = NULL;
	m->hiwat = outqsize / 2;

	MIDIQ_INIT(m->outq, buf, outqsize);

	if ((inqsize && !MIDIQ_BUF(m->inq)) ||
	    (outqsize && !MIDIQ_BUF(m->outq)))
		goto err2;

	m->busy = 0;
	m->flags = 0;
	m->unit = unit;
	m->channel = channel;
	m->cookie = cookie;

	if (MPU_INIT(m, cookie))
		goto err2;

	mtx_unlock(&m->lock);
	mtx_unlock(&m->qlock);

	TAILQ_INSERT_TAIL(&midi_devs, m, link);

	midistat_unlock();

	m->dev = make_dev(&midi_cdevsw, unit, UID_ROOT, GID_WHEEL, 0666,
	    "midi%d.%d", unit, channel);
	m->dev->si_drv1 = m;

	return m;

err2:
	mtx_destroy(&m->qlock);
	mtx_destroy(&m->lock);

	if (MIDIQ_BUF(m->inq))
		free(MIDIQ_BUF(m->inq), M_MIDI);
	if (MIDIQ_BUF(m->outq))
		free(MIDIQ_BUF(m->outq), M_MIDI);
err1:
	free(m, M_MIDI);
err0:
	midistat_unlock();
	MIDI_DEBUG(1, printf("midi_init ended in error\n"));
	return NULL;
}

/*
 * midi_uninit does not call MIDI_UNINIT, as since this is the implementors
 * entry point. midi_uninit if fact, does not send any methods. A call to
 * midi_uninit is a defacto promise that you won't manipulate ch anymore
 */
int
midi_uninit(struct snd_midi *m)
{
	int err;

	err = EBUSY;
	midistat_lock();
	mtx_lock(&m->lock);
	if (m->busy) {
		if (!(m->rchan || m->wchan))
			goto err;

		if (m->rchan) {
			wakeup(&m->rchan);
			m->rchan = 0;
		}
		if (m->wchan) {
			wakeup(&m->wchan);
			m->wchan = 0;
		}
	}
	err = midi_destroy(m, 0);
	if (!err)
		goto exit;

err:
	mtx_unlock(&m->lock);
exit:
	midistat_unlock();
	return err;
}

#ifdef notdef
static int midi_lengths[] = {2, 2, 2, 2, 1, 1, 2, 0};

#endif					/* notdef */
/* Number of bytes in a MIDI command */
#define MIDI_LENGTH(d) (midi_lengths[((d) >> 4) & 7])
#define MIDI_ACK	0xfe
#define MIDI_IS_STATUS(d) ((d) >= 0x80)
#define MIDI_IS_COMMON(d) ((d) >= 0xf0)

#define MIDI_SYSEX_START	0xF0
#define MIDI_SYSEX_END	    0xF7

/*
 * midi_in: process all data until the queue is full, then discards the rest.
 * Since midi_in is a state machine, data discards can cause it to get out of
 * whack.  Process as much as possible.  It calls, wakeup, selnotify and
 * psignal at most once.
 */
int
midi_in(struct snd_midi *m, uint8_t *buf, int size)
{
	/* int             i, sig, enq; */
	int used;

	/* uint8_t       data; */
	MIDI_DEBUG(5, printf("midi_in: m=%p size=%d\n", m, size));

/*
 * XXX: locking flub
 */
	if (!(m->flags & M_RX))
		return size;

	used = 0;

	mtx_lock(&m->qlock);
#if 0
	/*
	 * Don't bother queuing if not in read mode.  Discard everything and
	 * return size so the caller doesn't freak out.
	 */

	if (!(m->flags & M_RX))
		return size;

	for (i = sig = 0; i < size; i++) {
		data = buf[i];
		enq = 0;
		if (data == MIDI_ACK)
			continue;

		switch (m->inq_state) {
		case MIDI_IN_START:
			if (MIDI_IS_STATUS(data)) {
				switch (data) {
				case 0xf0:	/* Sysex */
					m->inq_state = MIDI_IN_SYSEX;
					break;
				case 0xf1:	/* MTC quarter frame */
				case 0xf3:	/* Song select */
					m->inq_state = MIDI_IN_DATA;
					enq = 1;
					m->inq_left = 1;
					break;
				case 0xf2:	/* Song position pointer */
					m->inq_state = MIDI_IN_DATA;
					enq = 1;
					m->inq_left = 2;
					break;
				default:
					if (MIDI_IS_COMMON(data)) {
						enq = 1;
						sig = 1;
					} else {
						m->inq_state = MIDI_IN_DATA;
						enq = 1;
						m->inq_status = data;
						m->inq_left = MIDI_LENGTH(data);
					}
					break;
				}
			} else if (MIDI_IS_STATUS(m->inq_status)) {
				m->inq_state = MIDI_IN_DATA;
				if (!MIDIQ_FULL(m->inq)) {
					used++;
					MIDIQ_ENQ(m->inq, &m->inq_status, 1);
				}
				enq = 1;
				m->inq_left = MIDI_LENGTH(m->inq_status) - 1;
			}
			break;
			/*
			 * End of case MIDI_IN_START:
			 */

		case MIDI_IN_DATA:
			enq = 1;
			if (--m->inq_left <= 0)
				sig = 1;/* deliver data */
			break;
		case MIDI_IN_SYSEX:
			if (data == MIDI_SYSEX_END)
				m->inq_state = MIDI_IN_START;
			break;
		}

		if (enq)
			if (!MIDIQ_FULL(m->inq)) {
				MIDIQ_ENQ(m->inq, &data, 1);
				used++;
			}
		/*
	         * End of the state machines main "for loop"
	         */
	}
	if (sig) {
#endif
		MIDI_DEBUG(6, printf("midi_in: len %jd avail %jd\n",
		    (intmax_t)MIDIQ_LEN(m->inq),
		    (intmax_t)MIDIQ_AVAIL(m->inq)));
		if (MIDIQ_AVAIL(m->inq) > size) {
			used = size;
			MIDIQ_ENQ(m->inq, buf, size);
		} else {
			MIDI_DEBUG(4, printf("midi_in: Discarding data qu\n"));
			mtx_unlock(&m->qlock);
			return 0;
		}
		if (m->rchan) {
			wakeup(&m->rchan);
			m->rchan = 0;
		}
		selwakeup(&m->rsel);
		if (m->async) {
			PROC_LOCK(m->async);
			kern_psignal(m->async, SIGIO);
			PROC_UNLOCK(m->async);
		}
#if 0
	}
#endif
	mtx_unlock(&m->qlock);
	return used;
}

/*
 * midi_out: The only clearer of the M_TXEN flag.
 */
int
midi_out(struct snd_midi *m, uint8_t *buf, int size)
{
	int used;

/*
 * XXX: locking flub
 */
	if (!(m->flags & M_TXEN))
		return 0;

	MIDI_DEBUG(2, printf("midi_out: %p\n", m));
	mtx_lock(&m->qlock);
	used = MIN(size, MIDIQ_LEN(m->outq));
	MIDI_DEBUG(3, printf("midi_out: used %d\n", used));
	if (used)
		MIDIQ_DEQ(m->outq, buf, used);
	if (MIDIQ_EMPTY(m->outq)) {
		m->flags &= ~M_TXEN;
		MPU_CALLBACKP(m, m->cookie, m->flags);
	}
	if (used && MIDIQ_AVAIL(m->outq) > m->hiwat) {
		if (m->wchan) {
			wakeup(&m->wchan);
			m->wchan = 0;
		}
		selwakeup(&m->wsel);
		if (m->async) {
			PROC_LOCK(m->async);
			kern_psignal(m->async, SIGIO);
			PROC_UNLOCK(m->async);
		}
	}
	mtx_unlock(&m->qlock);
	return used;
}

int
midi_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
	struct snd_midi *m = i_dev->si_drv1;
	int retval;

	MIDI_DEBUG(1, printf("midiopen %p %s %s\n", td,
	    flags & FREAD ? "M_RX" : "", flags & FWRITE ? "M_TX" : ""));
	if (m == NULL)
		return ENXIO;

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	retval = 0;

	if (flags & FREAD) {
		if (MIDIQ_SIZE(m->inq) == 0)
			retval = ENXIO;
		else if (m->flags & M_RX)
			retval = EBUSY;
		if (retval)
			goto err;
	}
	if (flags & FWRITE) {
		if (MIDIQ_SIZE(m->outq) == 0)
			retval = ENXIO;
		else if (m->flags & M_TX)
			retval = EBUSY;
		if (retval)
			goto err;
	}
	m->busy++;

	m->rchan = 0;
	m->wchan = 0;
	m->async = 0;

	if (flags & FREAD) {
		m->flags |= M_RX | M_RXEN;
		/*
	         * Only clear the inq, the outq might still have data to drain
	         * from a previous session
	         */
		MIDIQ_CLEAR(m->inq);
	}

	if (flags & FWRITE)
		m->flags |= M_TX;

	MPU_CALLBACK(m, m->cookie, m->flags);

	MIDI_DEBUG(2, printf("midi_open: opened.\n"));

err:	mtx_unlock(&m->qlock);
	mtx_unlock(&m->lock);
	return retval;
}

int
midi_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
	struct snd_midi *m = i_dev->si_drv1;
	int retval;
	int oldflags;

	MIDI_DEBUG(1, printf("midi_close %p %s %s\n", td,
	    flags & FREAD ? "M_RX" : "", flags & FWRITE ? "M_TX" : ""));

	if (m == NULL)
		return ENXIO;

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	if ((flags & FREAD && !(m->flags & M_RX)) ||
	    (flags & FWRITE && !(m->flags & M_TX))) {
		retval = ENXIO;
		goto err;
	}
	m->busy--;

	oldflags = m->flags;

	if (flags & FREAD)
		m->flags &= ~(M_RX | M_RXEN);
	if (flags & FWRITE)
		m->flags &= ~M_TX;

	if ((m->flags & (M_TXEN | M_RXEN)) != (oldflags & (M_RXEN | M_TXEN)))
		MPU_CALLBACK(m, m->cookie, m->flags);

	MIDI_DEBUG(1, printf("midi_close: closed, busy = %d.\n", m->busy));

	mtx_unlock(&m->qlock);
	mtx_unlock(&m->lock);
	retval = 0;
err:	return retval;
}

/*
 * TODO: midi_read, per oss programmer's guide pg. 42 should return as soon
 * as data is available.
 */
int
midi_read(struct cdev *i_dev, struct uio *uio, int ioflag)
{
#define MIDI_RSIZE 32
	struct snd_midi *m = i_dev->si_drv1;
	int retval;
	int used;
	char buf[MIDI_RSIZE];

	MIDI_DEBUG(5, printf("midiread: count=%lu\n",
	    (unsigned long)uio->uio_resid));

	retval = EIO;

	if (m == NULL)
		goto err0;

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	if (!(m->flags & M_RX))
		goto err1;

	while (uio->uio_resid > 0) {
		while (MIDIQ_EMPTY(m->inq)) {
			retval = EWOULDBLOCK;
			if (ioflag & O_NONBLOCK)
				goto err1;
			mtx_unlock(&m->lock);
			m->rchan = 1;
			retval = msleep(&m->rchan, &m->qlock,
			    PCATCH | PDROP, "midi RX", 0);
			/*
			 * We slept, maybe things have changed since last
			 * dying check
			 */
			if (retval == EINTR)
				goto err0;
			if (m != i_dev->si_drv1)
				retval = ENXIO;
			/* if (retval && retval != ERESTART) */
			if (retval)
				goto err0;
			mtx_lock(&m->lock);
			mtx_lock(&m->qlock);
			m->rchan = 0;
			if (!m->busy)
				goto err1;
		}
		MIDI_DEBUG(6, printf("midi_read start\n"));
		/*
	         * At this point, it is certain that m->inq has data
	         */

		used = MIN(MIDIQ_LEN(m->inq), uio->uio_resid);
		used = MIN(used, MIDI_RSIZE);

		MIDI_DEBUG(6, printf("midiread: uiomove cc=%d\n", used));
		MIDIQ_DEQ(m->inq, buf, used);
		retval = uiomove(buf, used, uio);
		if (retval)
			goto err1;
	}

	/*
	 * If we Made it here then transfer is good
	 */
	retval = 0;
err1:	mtx_unlock(&m->qlock);
	mtx_unlock(&m->lock);
err0:	MIDI_DEBUG(4, printf("midi_read: ret %d\n", retval));
	return retval;
}

/*
 * midi_write: The only setter of M_TXEN
 */

int
midi_write(struct cdev *i_dev, struct uio *uio, int ioflag)
{
#define MIDI_WSIZE 32
	struct snd_midi *m = i_dev->si_drv1;
	int retval;
	int used;
	char buf[MIDI_WSIZE];

	MIDI_DEBUG(4, printf("midi_write\n"));
	retval = 0;
	if (m == NULL)
		goto err0;

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	if (!(m->flags & M_TX))
		goto err1;

	while (uio->uio_resid > 0) {
		while (MIDIQ_AVAIL(m->outq) == 0) {
			retval = EWOULDBLOCK;
			if (ioflag & O_NONBLOCK)
				goto err1;
			mtx_unlock(&m->lock);
			m->wchan = 1;
			MIDI_DEBUG(3, printf("midi_write msleep\n"));
			retval = msleep(&m->wchan, &m->qlock,
			    PCATCH | PDROP, "midi TX", 0);
			/*
			 * We slept, maybe things have changed since last
			 * dying check
			 */
			if (retval == EINTR)
				goto err0;
			if (m != i_dev->si_drv1)
				retval = ENXIO;
			if (retval)
				goto err0;
			mtx_lock(&m->lock);
			mtx_lock(&m->qlock);
			m->wchan = 0;
			if (!m->busy)
				goto err1;
		}

		/*
	         * We are certain than data can be placed on the queue
	         */

		used = MIN(MIDIQ_AVAIL(m->outq), uio->uio_resid);
		used = MIN(used, MIDI_WSIZE);
		MIDI_DEBUG(5, printf("midiout: resid %zd len %jd avail %jd\n",
		    uio->uio_resid, (intmax_t)MIDIQ_LEN(m->outq),
		    (intmax_t)MIDIQ_AVAIL(m->outq)));

		MIDI_DEBUG(5, printf("midi_write: uiomove cc=%d\n", used));
		retval = uiomove(buf, used, uio);
		if (retval)
			goto err1;
		MIDIQ_ENQ(m->outq, buf, used);
		/*
	         * Inform the bottom half that data can be written
	         */
		if (!(m->flags & M_TXEN)) {
			m->flags |= M_TXEN;
			MPU_CALLBACK(m, m->cookie, m->flags);
		}
	}
	/*
	 * If we Made it here then transfer is good
	 */
	retval = 0;
err1:	mtx_unlock(&m->qlock);
	mtx_unlock(&m->lock);
err0:	return retval;
}

int
midi_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode,
    struct thread *td)
{
	return ENXIO;
}

int
midi_poll(struct cdev *i_dev, int events, struct thread *td)
{
	struct snd_midi *m = i_dev->si_drv1;
	int revents;

	if (m == NULL)
		return 0;

	revents = 0;

	mtx_lock(&m->lock);
	mtx_lock(&m->qlock);

	if (events & (POLLIN | POLLRDNORM))
		if (!MIDIQ_EMPTY(m->inq))
			events |= events & (POLLIN | POLLRDNORM);

	if (events & (POLLOUT | POLLWRNORM))
		if (MIDIQ_AVAIL(m->outq) < m->hiwat)
			events |= events & (POLLOUT | POLLWRNORM);

	if (revents == 0) {
		if (events & (POLLIN | POLLRDNORM))
			selrecord(td, &m->rsel);

		if (events & (POLLOUT | POLLWRNORM))
			selrecord(td, &m->wsel);
	}
	mtx_unlock(&m->lock);
	mtx_unlock(&m->qlock);

	return (revents);
}

/*
 * Single point of midi destructions.
 */
static int
midi_destroy(struct snd_midi *m, int midiuninit)
{
	midistat_lockassert();
	mtx_assert(&m->lock, MA_OWNED);

	MIDI_DEBUG(3, printf("midi_destroy\n"));
	m->dev->si_drv1 = NULL;
	mtx_unlock(&m->lock);	/* XXX */
	destroy_dev(m->dev);
	TAILQ_REMOVE(&midi_devs, m, link);
	if (midiuninit)
		MPU_UNINIT(m, m->cookie);
	free(MIDIQ_BUF(m->inq), M_MIDI);
	free(MIDIQ_BUF(m->outq), M_MIDI);
	mtx_destroy(&m->qlock);
	mtx_destroy(&m->lock);
	free(m, M_MIDI);
	return 0;
}

static int
midi_load(void)
{
	sx_init(&mstat_lock, "midistat lock");
	TAILQ_INIT(&midi_devs);

	return 0;
}

static int
midi_unload(void)
{
	struct snd_midi *m, *tmp;
	int retval;

	MIDI_DEBUG(1, printf("midi_unload()\n"));
	retval = EBUSY;
	midistat_lock();
	TAILQ_FOREACH_SAFE(m, &midi_devs, link, tmp) {
		mtx_lock(&m->lock);
		if (m->busy)
			retval = EBUSY;
		else
			retval = midi_destroy(m, 1);
		if (retval)
			goto exit;
	}
	midistat_unlock();

	sx_destroy(&mstat_lock);
	return 0;

exit:
	mtx_unlock(&m->lock);
	midistat_unlock();
	if (retval)
		MIDI_DEBUG(2, printf("midi_unload: failed\n"));
	return retval;
}

static int
midi_modevent(module_t mod, int type, void *data)
{
	int retval;

	retval = 0;

	switch (type) {
	case MOD_LOAD:
		retval = midi_load();
		break;

	case MOD_UNLOAD:
		retval = midi_unload();
		break;

	default:
		break;
	}

	return retval;
}

DEV_MODULE(midi, midi_modevent, NULL);
MODULE_VERSION(midi, 1);