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
79 static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
80 struct snd_seq_event *ev,
83 struct snd_virmidi *vmidi;
88 read_lock(&rdev->filelist_lock);
90 down_read(&rdev->filelist_sem);
91 list_for_each_entry(vmidi, &rdev->filelist, list) {
92 if (!READ_ONCE(vmidi->trigger))
94 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
95 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
97 snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
98 snd_midi_event_reset_decode(vmidi->parser);
100 len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
102 snd_rawmidi_receive(vmidi->substream, msg, len);
106 read_unlock(&rdev->filelist_lock);
108 up_read(&rdev->filelist_sem);
114 * event handler of virmidi port
116 static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
117 void *private_data, int atomic, int hop)
119 struct snd_virmidi_dev *rdev;
122 if (!(rdev->flags & SNDRV_VIRMIDI_USE))
123 return 0; /* ignored */
124 return snd_virmidi_dev_receive_event(rdev, ev, atomic);
128 * trigger rawmidi stream for input
130 static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
132 struct snd_virmidi *vmidi = substream->runtime->private_data;
134 WRITE_ONCE(vmidi->trigger, !!up);
137 /* process rawmidi bytes and send events;
138 * we need no lock here for vmidi->event since it's handled only in this work
140 static void snd_vmidi_output_work(struct work_struct *work)
142 struct snd_virmidi *vmidi;
143 struct snd_rawmidi_substream *substream;
147 vmidi = container_of(work, struct snd_virmidi, output_work);
148 substream = vmidi->substream;
150 /* discard the outputs in dispatch mode unless subscribed */
151 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
152 !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
154 while (snd_rawmidi_transmit(substream, buf, sizeof(buf)) > 0)
159 while (READ_ONCE(vmidi->trigger)) {
160 if (snd_rawmidi_transmit(substream, &input, 1) != 1)
162 if (!snd_midi_event_encode_byte(vmidi->parser, input,
165 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
166 ret = snd_seq_kernel_client_dispatch(vmidi->client,
169 vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
173 /* rawmidi input might be huge, allow to have a break */
179 * trigger rawmidi stream for output
181 static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
183 struct snd_virmidi *vmidi = substream->runtime->private_data;
185 WRITE_ONCE(vmidi->trigger, !!up);
187 queue_work(system_highpri_wq, &vmidi->output_work);
191 * open rawmidi handle for input
193 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
195 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
196 struct snd_rawmidi_runtime *runtime = substream->runtime;
197 struct snd_virmidi *vmidi;
199 vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
202 vmidi->substream = substream;
203 if (snd_midi_event_new(0, &vmidi->parser) < 0) {
207 vmidi->seq_mode = rdev->seq_mode;
208 vmidi->client = rdev->client;
209 vmidi->port = rdev->port;
210 runtime->private_data = vmidi;
211 down_write(&rdev->filelist_sem);
212 write_lock_irq(&rdev->filelist_lock);
213 list_add_tail(&vmidi->list, &rdev->filelist);
214 write_unlock_irq(&rdev->filelist_lock);
215 up_write(&rdev->filelist_sem);
221 * open rawmidi handle for output
223 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
225 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
226 struct snd_rawmidi_runtime *runtime = substream->runtime;
227 struct snd_virmidi *vmidi;
229 vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
232 vmidi->substream = substream;
233 if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
237 vmidi->seq_mode = rdev->seq_mode;
238 vmidi->client = rdev->client;
239 vmidi->port = rdev->port;
240 snd_virmidi_init_event(vmidi, &vmidi->event);
242 INIT_WORK(&vmidi->output_work, snd_vmidi_output_work);
243 runtime->private_data = vmidi;
248 * close rawmidi handle for input
250 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
252 struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
253 struct snd_virmidi *vmidi = substream->runtime->private_data;
255 down_write(&rdev->filelist_sem);
256 write_lock_irq(&rdev->filelist_lock);
257 list_del(&vmidi->list);
258 write_unlock_irq(&rdev->filelist_lock);
259 up_write(&rdev->filelist_sem);
260 snd_midi_event_free(vmidi->parser);
261 substream->runtime->private_data = NULL;
267 * close rawmidi handle for output
269 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
271 struct snd_virmidi *vmidi = substream->runtime->private_data;
273 WRITE_ONCE(vmidi->trigger, false); /* to be sure */
274 cancel_work_sync(&vmidi->output_work);
275 snd_midi_event_free(vmidi->parser);
276 substream->runtime->private_data = NULL;
282 * subscribe callback - allow output to rawmidi device
284 static int snd_virmidi_subscribe(void *private_data,
285 struct snd_seq_port_subscribe *info)
287 struct snd_virmidi_dev *rdev;
290 if (!try_module_get(rdev->card->module))
292 rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
297 * unsubscribe callback - disallow output to rawmidi device
299 static int snd_virmidi_unsubscribe(void *private_data,
300 struct snd_seq_port_subscribe *info)
302 struct snd_virmidi_dev *rdev;
305 rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
306 module_put(rdev->card->module);
312 * use callback - allow input to rawmidi device
314 static int snd_virmidi_use(void *private_data,
315 struct snd_seq_port_subscribe *info)
317 struct snd_virmidi_dev *rdev;
320 if (!try_module_get(rdev->card->module))
322 rdev->flags |= SNDRV_VIRMIDI_USE;
327 * unuse callback - disallow input to rawmidi device
329 static int snd_virmidi_unuse(void *private_data,
330 struct snd_seq_port_subscribe *info)
332 struct snd_virmidi_dev *rdev;
335 rdev->flags &= ~SNDRV_VIRMIDI_USE;
336 module_put(rdev->card->module);
345 static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
346 .open = snd_virmidi_input_open,
347 .close = snd_virmidi_input_close,
348 .trigger = snd_virmidi_input_trigger,
351 static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
352 .open = snd_virmidi_output_open,
353 .close = snd_virmidi_output_close,
354 .trigger = snd_virmidi_output_trigger,
358 * create a sequencer client and a port
360 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
363 struct snd_seq_port_callback pcallbacks;
364 struct snd_seq_port_info *pinfo;
367 if (rdev->client >= 0)
370 pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
376 client = snd_seq_create_kernel_client(rdev->card, rdev->device,
377 "%s %d-%d", rdev->rmidi->name,
384 rdev->client = client;
387 pinfo->addr.client = client;
388 sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
389 /* set all capabilities */
390 pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
391 pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
392 pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
393 pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
394 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
395 | SNDRV_SEQ_PORT_TYPE_PORT;
396 pinfo->midi_channels = 16;
397 memset(&pcallbacks, 0, sizeof(pcallbacks));
398 pcallbacks.owner = THIS_MODULE;
399 pcallbacks.private_data = rdev;
400 pcallbacks.subscribe = snd_virmidi_subscribe;
401 pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
402 pcallbacks.use = snd_virmidi_use;
403 pcallbacks.unuse = snd_virmidi_unuse;
404 pcallbacks.event_input = snd_virmidi_event_input;
405 pinfo->kernel = &pcallbacks;
406 err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
408 snd_seq_delete_kernel_client(client);
413 rdev->port = pinfo->addr.port;
414 err = 0; /* success */
423 * release the sequencer client
425 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
427 if (rdev->client >= 0) {
428 snd_seq_delete_kernel_client(rdev->client);
434 * register the device
436 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
438 struct snd_virmidi_dev *rdev = rmidi->private_data;
441 switch (rdev->seq_mode) {
442 case SNDRV_VIRMIDI_SEQ_DISPATCH:
443 err = snd_virmidi_dev_attach_seq(rdev);
447 case SNDRV_VIRMIDI_SEQ_ATTACH:
448 if (rdev->client == 0)
450 /* should check presence of port more strictly.. */
453 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
461 * unregister the device
463 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
465 struct snd_virmidi_dev *rdev = rmidi->private_data;
467 if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
468 snd_virmidi_dev_detach_seq(rdev);
475 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
476 .dev_register = snd_virmidi_dev_register,
477 .dev_unregister = snd_virmidi_dev_unregister,
483 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
485 struct snd_virmidi_dev *rdev = rmidi->private_data;
490 * create a new device
494 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
496 struct snd_rawmidi *rmidi;
497 struct snd_virmidi_dev *rdev;
501 if ((err = snd_rawmidi_new(card, "VirMidi", device,
502 16, /* may be configurable */
503 16, /* may be configurable */
506 strcpy(rmidi->name, rmidi->id);
507 rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
509 snd_device_free(card, rmidi);
514 rdev->device = device;
516 init_rwsem(&rdev->filelist_sem);
517 rwlock_init(&rdev->filelist_lock);
518 INIT_LIST_HEAD(&rdev->filelist);
519 rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
520 rmidi->private_data = rdev;
521 rmidi->private_free = snd_virmidi_free;
522 rmidi->ops = &snd_virmidi_global_ops;
523 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
524 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
525 rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
526 SNDRV_RAWMIDI_INFO_OUTPUT |
527 SNDRV_RAWMIDI_INFO_DUPLEX;
531 EXPORT_SYMBOL(snd_virmidi_new);