2 * Virtual Raw MIDI client on Sequencer
4 * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
5 * Jaroslav Kysela <perex@perex.cz>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 * Virtual Raw MIDI client
26 * The virtual rawmidi client is a sequencer client which associate
27 * a rawmidi device file. The created rawmidi device file can be
28 * accessed as a normal raw midi, but its MIDI source and destination
29 * are arbitrary. For example, a user-client software synth connected
30 * to this port can be used as a normal midi device as well.
32 * The virtual rawmidi device accepts also multiple opens. Each file
33 * has its own input buffer, so that no conflict would occur. The drain
34 * of input/output buffer acts only to the local buffer.
38 #include <linux/init.h>
39 #include <linux/wait.h>
40 #include <linux/module.h>
41 #include <linux/slab.h>
42 #include <sound/core.h>
43 #include <sound/rawmidi.h>
44 #include <sound/info.h>
45 #include <sound/control.h>
46 #include <sound/minors.h>
47 #include <sound/seq_kernel.h>
48 #include <sound/seq_midi_event.h>
49 #include <sound/seq_virmidi.h>
51 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
52 MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer");
53 MODULE_LICENSE("GPL");
56 * initialize an event record
58 static void snd_virmidi_init_event(struct snd_virmidi *vmidi,
59 struct snd_seq_event *ev)
61 memset(ev, 0, sizeof(*ev));
62 ev->source.port = vmidi->port;
63 switch (vmidi->seq_mode) {
64 case SNDRV_VIRMIDI_SEQ_DISPATCH:
65 ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
67 case SNDRV_VIRMIDI_SEQ_ATTACH:
68 /* FIXME: source and destination are same - not good.. */
69 ev->dest.client = vmidi->client;
70 ev->dest.port = vmidi->port;
73 ev->type = SNDRV_SEQ_EVENT_NONE;
77 * decode input event and put to read buffer of each opened file
80 /* callback for snd_seq_dump_var_event(), bridging to snd_rawmidi_receive() */
81 static int dump_to_rawmidi(void *ptr, void *buf, int count)
83 return snd_rawmidi_receive(ptr, buf, count);
86 static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
87 struct snd_seq_event *ev,
90 struct snd_virmidi *vmidi;
95 read_lock(&rdev->filelist_lock);
97 down_read(&rdev->filelist_sem);
98 list_for_each_entry(vmidi, &rdev->filelist, list) {
99 if (!READ_ONCE(vmidi->trigger))
101 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
102 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
104 snd_seq_dump_var_event(ev, dump_to_rawmidi, vmidi->substream);
105 snd_midi_event_reset_decode(vmidi->parser);
107 len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
109 snd_rawmidi_receive(vmidi->substream, msg, len);
113 read_unlock(&rdev->filelist_lock);
115 up_read(&rdev->filelist_sem);
121 * event handler of virmidi port
123 static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
124 void *private_data, int atomic, int hop)
126 struct snd_virmidi_dev *rdev;
129 if (!(rdev->flags & SNDRV_VIRMIDI_USE))
130 return 0; /* ignored */
131 return snd_virmidi_dev_receive_event(rdev, ev, atomic);
135 * trigger rawmidi stream for input
137 static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
139 struct snd_virmidi *vmidi = substream->runtime->private_data;
141 WRITE_ONCE(vmidi->trigger, !!up);
144 /* process rawmidi bytes and send events;
145 * we need no lock here for vmidi->event since it's handled only in this work
147 static void snd_vmidi_output_work(struct work_struct *work)
149 struct snd_virmidi *vmidi;
150 struct snd_rawmidi_substream *substream;
154 vmidi = container_of(work, struct snd_virmidi, output_work);
155 substream = vmidi->substream;
157 /* discard the outputs in dispatch mode unless subscribed */
158 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
159 !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
161 while (snd_rawmidi_transmit(substream, buf, sizeof(buf)) > 0)
166 while (READ_ONCE(vmidi->trigger)) {
167 if (snd_rawmidi_transmit(substream, &input, 1) != 1)
169 if (!snd_midi_event_encode_byte(vmidi->parser, input,
172 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
173 ret = snd_seq_kernel_client_dispatch(vmidi->client,
176 vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
180 /* rawmidi input might be huge, allow to have a break */
186 * trigger rawmidi stream for output
188 static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
190 struct snd_virmidi *vmidi = substream->runtime->private_data;
192 WRITE_ONCE(vmidi->trigger, !!up);
194 queue_work(system_highpri_wq, &vmidi->output_work);
198 * open rawmidi handle for input
200 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
202 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
203 struct snd_rawmidi_runtime *runtime = substream->runtime;
204 struct snd_virmidi *vmidi;
206 vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
209 vmidi->substream = substream;
210 if (snd_midi_event_new(0, &vmidi->parser) < 0) {
214 vmidi->seq_mode = rdev->seq_mode;
215 vmidi->client = rdev->client;
216 vmidi->port = rdev->port;
217 runtime->private_data = vmidi;
218 down_write(&rdev->filelist_sem);
219 write_lock_irq(&rdev->filelist_lock);
220 list_add_tail(&vmidi->list, &rdev->filelist);
221 write_unlock_irq(&rdev->filelist_lock);
222 up_write(&rdev->filelist_sem);
228 * open rawmidi handle for output
230 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
232 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
233 struct snd_rawmidi_runtime *runtime = substream->runtime;
234 struct snd_virmidi *vmidi;
236 vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
239 vmidi->substream = substream;
240 if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
244 vmidi->seq_mode = rdev->seq_mode;
245 vmidi->client = rdev->client;
246 vmidi->port = rdev->port;
247 snd_virmidi_init_event(vmidi, &vmidi->event);
249 INIT_WORK(&vmidi->output_work, snd_vmidi_output_work);
250 runtime->private_data = vmidi;
255 * close rawmidi handle for input
257 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
259 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
260 struct snd_virmidi *vmidi = substream->runtime->private_data;
262 down_write(&rdev->filelist_sem);
263 write_lock_irq(&rdev->filelist_lock);
264 list_del(&vmidi->list);
265 write_unlock_irq(&rdev->filelist_lock);
266 up_write(&rdev->filelist_sem);
267 snd_midi_event_free(vmidi->parser);
268 substream->runtime->private_data = NULL;
274 * close rawmidi handle for output
276 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
278 struct snd_virmidi *vmidi = substream->runtime->private_data;
280 WRITE_ONCE(vmidi->trigger, false); /* to be sure */
281 cancel_work_sync(&vmidi->output_work);
282 snd_midi_event_free(vmidi->parser);
283 substream->runtime->private_data = NULL;
289 * subscribe callback - allow output to rawmidi device
291 static int snd_virmidi_subscribe(void *private_data,
292 struct snd_seq_port_subscribe *info)
294 struct snd_virmidi_dev *rdev;
297 if (!try_module_get(rdev->card->module))
299 rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
304 * unsubscribe callback - disallow output to rawmidi device
306 static int snd_virmidi_unsubscribe(void *private_data,
307 struct snd_seq_port_subscribe *info)
309 struct snd_virmidi_dev *rdev;
312 rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
313 module_put(rdev->card->module);
319 * use callback - allow input to rawmidi device
321 static int snd_virmidi_use(void *private_data,
322 struct snd_seq_port_subscribe *info)
324 struct snd_virmidi_dev *rdev;
327 if (!try_module_get(rdev->card->module))
329 rdev->flags |= SNDRV_VIRMIDI_USE;
334 * unuse callback - disallow input to rawmidi device
336 static int snd_virmidi_unuse(void *private_data,
337 struct snd_seq_port_subscribe *info)
339 struct snd_virmidi_dev *rdev;
342 rdev->flags &= ~SNDRV_VIRMIDI_USE;
343 module_put(rdev->card->module);
352 static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
353 .open = snd_virmidi_input_open,
354 .close = snd_virmidi_input_close,
355 .trigger = snd_virmidi_input_trigger,
358 static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
359 .open = snd_virmidi_output_open,
360 .close = snd_virmidi_output_close,
361 .trigger = snd_virmidi_output_trigger,
365 * create a sequencer client and a port
367 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
370 struct snd_seq_port_callback pcallbacks;
371 struct snd_seq_port_info *pinfo;
374 if (rdev->client >= 0)
377 pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
383 client = snd_seq_create_kernel_client(rdev->card, rdev->device,
384 "%s %d-%d", rdev->rmidi->name,
391 rdev->client = client;
394 pinfo->addr.client = client;
395 sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
396 /* set all capabilities */
397 pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
398 pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
399 pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
400 pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
401 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
402 | SNDRV_SEQ_PORT_TYPE_PORT;
403 pinfo->midi_channels = 16;
404 memset(&pcallbacks, 0, sizeof(pcallbacks));
405 pcallbacks.owner = THIS_MODULE;
406 pcallbacks.private_data = rdev;
407 pcallbacks.subscribe = snd_virmidi_subscribe;
408 pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
409 pcallbacks.use = snd_virmidi_use;
410 pcallbacks.unuse = snd_virmidi_unuse;
411 pcallbacks.event_input = snd_virmidi_event_input;
412 pinfo->kernel = &pcallbacks;
413 err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
415 snd_seq_delete_kernel_client(client);
420 rdev->port = pinfo->addr.port;
421 err = 0; /* success */
430 * release the sequencer client
432 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
434 if (rdev->client >= 0) {
435 snd_seq_delete_kernel_client(rdev->client);
441 * register the device
443 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
445 struct snd_virmidi_dev *rdev = rmidi->private_data;
448 switch (rdev->seq_mode) {
449 case SNDRV_VIRMIDI_SEQ_DISPATCH:
450 err = snd_virmidi_dev_attach_seq(rdev);
454 case SNDRV_VIRMIDI_SEQ_ATTACH:
455 if (rdev->client == 0)
457 /* should check presence of port more strictly.. */
460 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
468 * unregister the device
470 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
472 struct snd_virmidi_dev *rdev = rmidi->private_data;
474 if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
475 snd_virmidi_dev_detach_seq(rdev);
482 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
483 .dev_register = snd_virmidi_dev_register,
484 .dev_unregister = snd_virmidi_dev_unregister,
490 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
492 struct snd_virmidi_dev *rdev = rmidi->private_data;
497 * create a new device
501 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
503 struct snd_rawmidi *rmidi;
504 struct snd_virmidi_dev *rdev;
508 if ((err = snd_rawmidi_new(card, "VirMidi", device,
509 16, /* may be configurable */
510 16, /* may be configurable */
513 strcpy(rmidi->name, rmidi->id);
514 rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
516 snd_device_free(card, rmidi);
521 rdev->device = device;
523 init_rwsem(&rdev->filelist_sem);
524 rwlock_init(&rdev->filelist_lock);
525 INIT_LIST_HEAD(&rdev->filelist);
526 rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
527 rmidi->private_data = rdev;
528 rmidi->private_free = snd_virmidi_free;
529 rmidi->ops = &snd_virmidi_global_ops;
530 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
531 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
532 rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
533 SNDRV_RAWMIDI_INFO_OUTPUT |
534 SNDRV_RAWMIDI_INFO_DUPLEX;
538 EXPORT_SYMBOL(snd_virmidi_new);