NetBSD/sys/dev/midi.c

903 lines
19 KiB
C

/* $NetBSD: midi.c,v 1.43 2006/03/28 17:38:29 thorpej Exp $ */
/*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: midi.c,v 1.43 2006/03/28 17:38:29 thorpej Exp $");
#include "midi.h"
#include "sequencer.h"
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/vnode.h>
#include <sys/select.h>
#include <sys/poll.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/signalvar.h>
#include <sys/conf.h>
#include <sys/audioio.h>
#include <sys/midiio.h>
#include <sys/device.h>
#include <dev/audio_if.h>
#include <dev/midi_if.h>
#include <dev/midivar.h>
#if NMIDI > 0
#ifdef AUDIO_DEBUG
#define DPRINTF(x) if (mididebug) printf x
#define DPRINTFN(n,x) if (mididebug >= (n)) printf x
int mididebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif
int midi_wait;
void midi_in(void *, int);
void midi_out(void *);
int midi_start_output(struct midi_softc *, int);
int midi_sleep_timo(int *, const char *, int);
int midi_sleep(int *, const char *);
void midi_wakeup(int *);
void midi_initbuf(struct midi_buffer *);
void midi_timeout(void *);
int midiprobe(struct device *, struct cfdata *, void *);
void midiattach(struct device *, struct device *, void *);
int mididetach(struct device *, int);
int midiactivate(struct device *, enum devact);
dev_type_open(midiopen);
dev_type_close(midiclose);
dev_type_read(midiread);
dev_type_write(midiwrite);
dev_type_ioctl(midiioctl);
dev_type_poll(midipoll);
dev_type_kqfilter(midikqfilter);
const struct cdevsw midi_cdevsw = {
midiopen, midiclose, midiread, midiwrite, midiioctl,
nostop, notty, midipoll, nommap, midikqfilter,
};
CFATTACH_DECL(midi, sizeof(struct midi_softc),
midiprobe, midiattach, mididetach, midiactivate);
#ifdef MIDI_SAVE
#define MIDI_SAVE_SIZE 100000
int midicnt;
struct {
int cnt;
u_char buf[MIDI_SAVE_SIZE];
} midisave;
#define MIDI_GETSAVE _IOWR('m', 100, int)
#endif
extern struct cfdriver midi_cd;
int
midiprobe(struct device *parent, struct cfdata *match, void *aux)
{
struct audio_attach_args *sa = aux;
DPRINTFN(6,("midiprobe: type=%d sa=%p hw=%p\n",
sa->type, sa, sa->hwif));
return (sa->type == AUDIODEV_TYPE_MIDI);
}
void
midiattach(struct device *parent, struct device *self, void *aux)
{
struct midi_softc *sc = (void *)self;
struct audio_attach_args *sa = aux;
const struct midi_hw_if *hwp = sa->hwif;
void *hdlp = sa->hdl;
DPRINTFN(6, ("MIDI attach\n"));
#ifdef DIAGNOSTIC
if (hwp == 0 ||
hwp->open == 0 ||
hwp->close == 0 ||
hwp->output == 0 ||
hwp->getinfo == 0) {
printf("midi: missing method\n");
return;
}
#endif
callout_init(&sc->sc_callout);
sc->hw_if = hwp;
sc->hw_hdl = hdlp;
sc->dying = 0;
midi_attach(sc, parent);
}
int
midiactivate(struct device *self, enum devact act)
{
struct midi_softc *sc = (struct midi_softc *)self;
switch (act) {
case DVACT_ACTIVATE:
return (EOPNOTSUPP);
case DVACT_DEACTIVATE:
sc->dying = 1;
break;
}
return (0);
}
int
mididetach(struct device *self, int flags)
{
struct midi_softc *sc = (struct midi_softc *)self;
int maj, mn;
DPRINTF(("midi_detach: sc=%p flags=%d\n", sc, flags));
sc->dying = 1;
wakeup(&sc->wchan);
wakeup(&sc->rchan);
/* locate the major number */
maj = cdevsw_lookup_major(&midi_cdevsw);
/* Nuke the vnodes for any open instances (calls close). */
mn = device_unit(self);
vdevgone(maj, mn, mn, VCHR);
return (0);
}
void
midi_attach(struct midi_softc *sc, struct device *parent)
{
struct midi_info mi;
sc->isopen = 0;
midi_wait = MIDI_WAIT * hz / 1000000;
if (midi_wait == 0)
midi_wait = 1;
sc->sc_dev = parent;
sc->hw_if->getinfo(sc->hw_hdl, &mi);
sc->props = mi.props;
printf(": %s\n", mi.name);
}
int
midi_unit_count(void)
{
return midi_cd.cd_ndevs;
}
void
midi_initbuf(struct midi_buffer *mb)
{
mb->used = 0;
mb->usedhigh = MIDI_BUFSIZE;
mb->end = mb->start + mb->usedhigh;
mb->inp = mb->outp = mb->start;
}
int
midi_sleep_timo(int *chan, const char *label, int timo)
{
int st;
if (!label)
label = "midi";
DPRINTFN(5, ("midi_sleep_timo: %p %s %d\n", chan, label, timo));
*chan = 1;
st = tsleep(chan, PWAIT | PCATCH, label, timo);
*chan = 0;
#ifdef MIDI_DEBUG
if (st != 0)
printf("midi_sleep: %d\n", st);
#endif
return st;
}
int
midi_sleep(int *chan, const char *label)
{
return midi_sleep_timo(chan, label, 0);
}
void
midi_wakeup(int *chan)
{
if (*chan) {
DPRINTFN(5, ("midi_wakeup: %p\n", chan));
wakeup(chan);
*chan = 0;
}
}
static int midi_lengths[] = { 2,2,2,2,1,1,2,0 };
/* Number of bytes in a MIDI command */
#define MIDI_LENGTH(d) (midi_lengths[((d) >> 4) & 7])
void
midi_in(void *addr, int data)
{
struct midi_softc *sc = addr;
struct midi_buffer *mb = &sc->inbuf;
int i;
if (!sc->isopen)
return;
if (data == MIDI_ACK)
return;
DPRINTFN(3, ("midi_in: sc=%p data=0x%02x state=%d pos=%d\n",
sc, data, sc->in_state, sc->in_pos));
if (!(sc->flags & FREAD))
return; /* discard data if not reading */
switch(sc->in_state) {
case MIDI_IN_START:
if (MIDI_IS_STATUS(data)) {
switch(data) {
case 0xf0: /* Sysex */
sc->in_state = MIDI_IN_SYSEX;
sc->in_msg[0] = data;
sc->in_pos = 1;
sc->in_left = 0;
goto deliver_raw;
case 0xf1: /* MTC quarter frame */
case 0xf3: /* Song select */
sc->in_state = MIDI_IN_DATA;
sc->in_msg[0] = data;
sc->in_pos = 1;
sc->in_left = 1;
break;
case 0xf2: /* Song position pointer */
sc->in_state = MIDI_IN_DATA;
sc->in_msg[0] = data;
sc->in_pos = 1;
sc->in_left = 2;
break;
default:
if (MIDI_IS_COMMON(data)) {
sc->in_msg[0] = data;
sc->in_pos = 1;
goto deliver;
} else {
sc->in_state = MIDI_IN_DATA;
sc->in_msg[0] = sc->in_status = data;
sc->in_pos = 1;
sc->in_left = MIDI_LENGTH(data);
}
break;
}
} else {
if (MIDI_IS_STATUS(sc->in_status)) {
sc->in_state = MIDI_IN_DATA;
sc->in_msg[0] = sc->in_status;
sc->in_msg[1] = data;
sc->in_pos = 2;
sc->in_left = MIDI_LENGTH(sc->in_status) - 1;
if (sc->in_left == 0)
goto deliver;
}
}
return;
case MIDI_IN_DATA:
KASSERT(sc->in_left >= 1);
KASSERT(sc->in_pos < 3);
sc->in_msg[sc->in_pos++] = data;
if (--sc->in_left == 0)
break; /* deliver data */
return;
case MIDI_IN_SYSEX:
sc->in_msg[0] = data;
sc->in_pos = 1;
sc->in_left = 0;
if (data == MIDI_SYSEX_END)
sc->in_state = MIDI_IN_START;
goto deliver_raw;
}
deliver:
sc->in_state = MIDI_IN_START;
#if NSEQUENCER > 0
if (sc->seqopen) {
extern void midiseq_in(struct midi_dev *,u_char *,int);
midiseq_in(sc->seq_md, sc->in_msg, sc->in_pos);
return;
}
#endif
deliver_raw:
if (mb->used + sc->in_pos > mb->usedhigh) {
DPRINTF(("midi_in: buffer full, discard data=0x%02x\n",
sc->in_msg[0]));
return;
}
for (i = 0; i < sc->in_pos; i++) {
*mb->inp++ = sc->in_msg[i];
if (mb->inp >= mb->end)
mb->inp = mb->start;
mb->used++;
}
midi_wakeup(&sc->rchan);
selnotify(&sc->rsel, 0);
if (sc->async)
psignal(sc->async, SIGIO);
}
void
midi_out(void *addr)
{
struct midi_softc *sc = addr;
if (!sc->isopen)
return;
DPRINTFN(3, ("midi_out: %p\n", sc));
midi_start_output(sc, 1);
}
int
midiopen(dev_t dev, int flags, int ifmt, struct lwp *l)
{
struct midi_softc *sc;
const struct midi_hw_if *hw;
int error;
sc = device_lookup(&midi_cd, MIDIUNIT(dev));
if (sc == NULL)
return (ENXIO);
if (sc->dying)
return (EIO);
DPRINTF(("midiopen %p\n", sc));
hw = sc->hw_if;
if (!hw)
return ENXIO;
if (sc->isopen)
return EBUSY;
sc->in_state = MIDI_IN_START;
sc->in_status = 0;
error = hw->open(sc->hw_hdl, flags, midi_in, midi_out, sc);
if (error)
return error;
sc->isopen++;
midi_initbuf(&sc->outbuf);
midi_initbuf(&sc->inbuf);
sc->flags = flags;
sc->rchan = 0;
sc->wchan = 0;
sc->pbus = 0;
sc->async = 0;
#ifdef MIDI_SAVE
if (midicnt != 0) {
midisave.cnt = midicnt;
midicnt = 0;
}
#endif
return 0;
}
int
midiclose(dev_t dev, int flags, int ifmt, struct lwp *l)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
const struct midi_hw_if *hw = sc->hw_if;
int s, error;
DPRINTF(("midiclose %p\n", sc));
midi_start_output(sc, 0);
error = 0;
s = splaudio();
while (sc->outbuf.used > 0 && !error) {
DPRINTFN(2,("midiclose sleep used=%d\n", sc->outbuf.used));
error = midi_sleep_timo(&sc->wchan, "mid_dr", 30*hz);
}
splx(s);
sc->isopen = 0;
hw->close(sc->hw_hdl);
#if NSEQUENCER > 0
sc->seqopen = 0;
sc->seq_md = 0;
#endif
return 0;
}
int
midiread(dev_t dev, struct uio *uio, int ioflag)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
struct midi_buffer *mb = &sc->inbuf;
int error;
u_char *outp;
int used, cc, n, resid;
int s;
DPRINTF(("midiread: %p, count=%lu\n", sc,
(unsigned long)uio->uio_resid));
if (sc->dying)
return EIO;
error = 0;
resid = uio->uio_resid;
while (uio->uio_resid == resid && !error) {
s = splaudio();
while (mb->used <= 0) {
if (ioflag & IO_NDELAY) {
splx(s);
return EWOULDBLOCK;
}
error = midi_sleep(&sc->rchan, "mid rd");
if (error) {
splx(s);
return error;
}
}
used = mb->used;
outp = mb->outp;
splx(s);
if (sc->dying)
return EIO;
cc = used; /* maximum to read */
n = mb->end - outp;
if (n < cc)
cc = n; /* don't read beyond end of buffer */
if (uio->uio_resid < cc)
cc = uio->uio_resid; /* and no more than we want */
DPRINTFN(3, ("midiread: uiomove cc=%d\n", cc));
error = uiomove(outp, cc, uio);
if (error)
break;
used -= cc;
outp += cc;
if (outp >= mb->end)
outp = mb->start;
s = splaudio();
mb->outp = outp;
mb->used = used;
splx(s);
}
return error;
}
void
midi_timeout(void *arg)
{
struct midi_softc *sc = arg;
DPRINTFN(3,("midi_timeout: %p\n", sc));
midi_start_output(sc, 1);
}
int
midi_start_output(struct midi_softc *sc, int intr)
{
struct midi_buffer *mb = &sc->outbuf;
u_char out;
int error;
int s;
int i;
error = 0;
if (sc->dying)
return EIO;
if (sc->pbus && !intr) {
DPRINTFN(4, ("midi_start_output: busy\n"));
return 0;
}
sc->pbus = (mb->used > 0)?1:0;
for (i = 0; i < MIDI_MAX_WRITE && mb->used > 0 &&
(!error || error==EINPROGRESS); i++) {
s = splaudio();
out = *mb->outp;
mb->outp++;
if (mb->outp >= mb->end)
mb->outp = mb->start;
mb->used--;
splx(s);
#ifdef MIDI_SAVE
midisave.buf[midicnt] = out;
midicnt = (midicnt + 1) % MIDI_SAVE_SIZE;
#endif
DPRINTFN(4, ("midi_start_output: %p i=%d, data=0x%02x\n",
sc, i, out));
error = sc->hw_if->output(sc->hw_hdl, out);
if ((sc->props & MIDI_PROP_OUT_INTR) && error!=EINPROGRESS)
/* If ointr is enabled, midi_start_output()
* normally writes only one byte,
* except hw_if->output() returns EINPROGRESS.
*/
break;
}
midi_wakeup(&sc->wchan);
selnotify(&sc->wsel, 0);
if (sc->async)
psignal(sc->async, SIGIO);
if (!(sc->props & MIDI_PROP_OUT_INTR) || error==EINPROGRESS) {
if (mb->used > 0)
callout_reset(&sc->sc_callout, midi_wait,
midi_timeout, sc);
else
sc->pbus = 0;
}
if ((sc->props & MIDI_PROP_OUT_INTR) && error==EINPROGRESS)
error = 0;
return error;
}
int
midiwrite(dev_t dev, struct uio *uio, int ioflag)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
struct midi_buffer *mb = &sc->outbuf;
int error;
u_char *inp;
int used, cc, n;
int s;
DPRINTFN(2, ("midiwrite: %p, unit=%d, count=%lu\n", sc, unit,
(unsigned long)uio->uio_resid));
if (sc->dying)
return EIO;
error = 0;
while (uio->uio_resid > 0 && !error) {
s = splaudio();
if (mb->used >= mb->usedhigh) {
DPRINTFN(3,("midi_write: sleep used=%d hiwat=%d\n",
mb->used, mb->usedhigh));
if (ioflag & IO_NDELAY) {
splx(s);
return EWOULDBLOCK;
}
error = midi_sleep(&sc->wchan, "mid wr");
if (error) {
splx(s);
return error;
}
}
used = mb->used;
inp = mb->inp;
splx(s);
if (sc->dying)
return EIO;
cc = mb->usedhigh - used; /* maximum to write */
n = mb->end - inp;
if (n < cc)
cc = n; /* don't write beyond end of buffer */
if (uio->uio_resid < cc)
cc = uio->uio_resid; /* and no more than we have */
error = uiomove(inp, cc, uio);
#ifdef MIDI_DEBUG
if (error)
printf("midi_write:(1) uiomove failed %d; "
"cc=%d inp=%p\n",
error, cc, inp);
#endif
if (error)
break;
inp = mb->inp + cc;
if (inp >= mb->end)
inp = mb->start;
s = splaudio();
mb->inp = inp;
mb->used += cc;
splx(s);
error = midi_start_output(sc, 0);
}
return error;
}
/*
* This write routine is only called from sequencer code and expects
* a write that is smaller than the MIDI buffer.
*/
int
midi_writebytes(int unit, u_char *bf, int cc)
{
struct midi_softc *sc = midi_cd.cd_devs[unit];
struct midi_buffer *mb = &sc->outbuf;
int n, s;
DPRINTFN(2, ("midi_writebytes: %p, unit=%d, cc=%d\n", sc, unit, cc));
DPRINTFN(3, ("midi_writebytes: %x %x %x\n",bf[0],bf[1],bf[2]));
if (sc->dying)
return EIO;
s = splaudio();
if (mb->used + cc >= mb->usedhigh) {
splx(s);
return (EWOULDBLOCK);
}
n = mb->end - mb->inp;
if (cc < n)
n = cc;
mb->used += cc;
memcpy(mb->inp, bf, n);
mb->inp += n;
if (mb->inp >= mb->end) {
mb->inp = mb->start;
cc -= n;
if (cc > 0) {
memcpy(mb->inp, bf + n, cc);
mb->inp += cc;
}
}
splx(s);
return (midi_start_output(sc, 0));
}
int
midiioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct lwp *l)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
const struct midi_hw_if *hw = sc->hw_if;
int error;
DPRINTF(("midiioctl: %p cmd=0x%08lx\n", sc, cmd));
if (sc->dying)
return EIO;
error = 0;
switch (cmd) {
case FIONBIO:
/* All handled in the upper FS layer. */
break;
case FIOASYNC:
if (*(int *)addr) {
if (sc->async)
return EBUSY;
sc->async = l->l_proc;
DPRINTF(("midi_ioctl: FIOASYNC %p\n", l->l_proc));
} else
sc->async = 0;
break;
#if 0
case MIDI_PRETIME:
/* XXX OSS
* This should set up a read timeout, but that's
* why we have poll(), so there's nothing yet. */
error = EINVAL;
break;
#endif
#ifdef MIDI_SAVE
case MIDI_GETSAVE:
error = copyout(&midisave, *(void **)addr, sizeof midisave);
break;
#endif
default:
if (hw->ioctl)
error = hw->ioctl(sc->hw_hdl, cmd, addr, flag, l);
else
error = EINVAL;
break;
}
return error;
}
int
midipoll(dev_t dev, int events, struct lwp *l)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
int revents = 0;
int s;
DPRINTF(("midipoll: %p events=0x%x\n", sc, events));
if (sc->dying)
return POLLHUP;
s = splaudio();
if (events & (POLLIN | POLLRDNORM))
if (sc->inbuf.used > 0)
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (sc->outbuf.used < sc->outbuf.usedhigh)
revents |= events & (POLLOUT | POLLWRNORM);
if (revents == 0) {
if (events & (POLLIN | POLLRDNORM))
selrecord(l, &sc->rsel);
if (events & (POLLOUT | POLLWRNORM))
selrecord(l, &sc->wsel);
}
splx(s);
return revents;
}
static void
filt_midirdetach(struct knote *kn)
{
struct midi_softc *sc = kn->kn_hook;
int s;
s = splaudio();
SLIST_REMOVE(&sc->rsel.sel_klist, kn, knote, kn_selnext);
splx(s);
}
static int
filt_midiread(struct knote *kn, long hint)
{
struct midi_softc *sc = kn->kn_hook;
/* XXXLUKEM (thorpej): please make sure this is correct. */
kn->kn_data = sc->inbuf.used;
return (kn->kn_data > 0);
}
static const struct filterops midiread_filtops =
{ 1, NULL, filt_midirdetach, filt_midiread };
static void
filt_midiwdetach(struct knote *kn)
{
struct midi_softc *sc = kn->kn_hook;
int s;
s = splaudio();
SLIST_REMOVE(&sc->wsel.sel_klist, kn, knote, kn_selnext);
splx(s);
}
static int
filt_midiwrite(struct knote *kn, long hint)
{
struct midi_softc *sc = kn->kn_hook;
/* XXXLUKEM (thorpej): please make sure this is correct. */
kn->kn_data = sc->outbuf.usedhigh - sc->outbuf.used;
return (kn->kn_data > 0);
}
static const struct filterops midiwrite_filtops =
{ 1, NULL, filt_midiwdetach, filt_midiwrite };
int
midikqfilter(dev_t dev, struct knote *kn)
{
int unit = MIDIUNIT(dev);
struct midi_softc *sc = midi_cd.cd_devs[unit];
struct klist *klist;
int s;
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &sc->rsel.sel_klist;
kn->kn_fop = &midiread_filtops;
break;
case EVFILT_WRITE:
klist = &sc->wsel.sel_klist;
kn->kn_fop = &midiwrite_filtops;
break;
default:
return (1);
}
kn->kn_hook = sc;
s = splaudio();
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
splx(s);
return (0);
}
void
midi_getinfo(dev_t dev, struct midi_info *mi)
{
struct midi_softc *sc;
sc = device_lookup(&midi_cd, MIDIUNIT(dev));
if (sc == NULL)
return;
if (sc->dying)
return;
sc->hw_if->getinfo(sc->hw_hdl, mi);
}
#endif /* NMIDI > 0 */
#if NMIDI > 0 || NMIDIBUS > 0
int audioprint(void *, const char *);
struct device *
midi_attach_mi(const struct midi_hw_if *mhwp, void *hdlp, struct device *dev)
{
struct audio_attach_args arg;
#ifdef DIAGNOSTIC
if (mhwp == NULL) {
aprint_error("midi_attach_mi: NULL\n");
return (0);
}
#endif
arg.type = AUDIODEV_TYPE_MIDI;
arg.hwif = mhwp;
arg.hdl = hdlp;
return (config_found(dev, &arg, audioprint));
}
#endif /* NMIDI > 0 || NMIDIBUS > 0 */