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1da177e4 LT |
1 | /* |
2 | * ALSA sequencer Ports | |
3 | * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl> | |
4 | * Jaroslav Kysela <perex@suse.cz> | |
5 | * | |
6 | * | |
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. | |
11 | * | |
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. | |
16 | * | |
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 | |
20 | * | |
21 | */ | |
22 | ||
23 | #include <sound/driver.h> | |
24 | #include <sound/core.h> | |
25 | #include <linux/slab.h> | |
26 | #include "seq_system.h" | |
27 | #include "seq_ports.h" | |
28 | #include "seq_clientmgr.h" | |
29 | ||
30 | /* | |
31 | ||
32 | registration of client ports | |
33 | ||
34 | */ | |
35 | ||
36 | ||
37 | /* | |
38 | ||
39 | NOTE: the current implementation of the port structure as a linked list is | |
40 | not optimal for clients that have many ports. For sending messages to all | |
41 | subscribers of a port we first need to find the address of the port | |
42 | structure, which means we have to traverse the list. A direct access table | |
43 | (array) would be better, but big preallocated arrays waste memory. | |
44 | ||
45 | Possible actions: | |
46 | ||
47 | 1) leave it this way, a client does normaly does not have more than a few | |
48 | ports | |
49 | ||
50 | 2) replace the linked list of ports by a array of pointers which is | |
51 | dynamicly kmalloced. When a port is added or deleted we can simply allocate | |
52 | a new array, copy the corresponding pointers, and delete the old one. We | |
53 | then only need a pointer to this array, and an integer that tells us how | |
54 | much elements are in array. | |
55 | ||
56 | */ | |
57 | ||
58 | /* return pointer to port structure - port is locked if found */ | |
59 | client_port_t *snd_seq_port_use_ptr(client_t *client, int num) | |
60 | { | |
61 | struct list_head *p; | |
62 | client_port_t *port; | |
63 | ||
64 | if (client == NULL) | |
65 | return NULL; | |
66 | read_lock(&client->ports_lock); | |
67 | list_for_each(p, &client->ports_list_head) { | |
68 | port = list_entry(p, client_port_t, list); | |
69 | if (port->addr.port == num) { | |
70 | if (port->closing) | |
71 | break; /* deleting now */ | |
72 | snd_use_lock_use(&port->use_lock); | |
73 | read_unlock(&client->ports_lock); | |
74 | return port; | |
75 | } | |
76 | } | |
77 | read_unlock(&client->ports_lock); | |
78 | return NULL; /* not found */ | |
79 | } | |
80 | ||
81 | ||
82 | /* search for the next port - port is locked if found */ | |
83 | client_port_t *snd_seq_port_query_nearest(client_t *client, snd_seq_port_info_t *pinfo) | |
84 | { | |
85 | int num; | |
86 | struct list_head *p; | |
87 | client_port_t *port, *found; | |
88 | ||
89 | num = pinfo->addr.port; | |
90 | found = NULL; | |
91 | read_lock(&client->ports_lock); | |
92 | list_for_each(p, &client->ports_list_head) { | |
93 | port = list_entry(p, client_port_t, list); | |
94 | if (port->addr.port < num) | |
95 | continue; | |
96 | if (port->addr.port == num) { | |
97 | found = port; | |
98 | break; | |
99 | } | |
100 | if (found == NULL || port->addr.port < found->addr.port) | |
101 | found = port; | |
102 | } | |
103 | if (found) { | |
104 | if (found->closing) | |
105 | found = NULL; | |
106 | else | |
107 | snd_use_lock_use(&found->use_lock); | |
108 | } | |
109 | read_unlock(&client->ports_lock); | |
110 | return found; | |
111 | } | |
112 | ||
113 | ||
114 | /* initialize port_subs_info_t */ | |
115 | static void port_subs_info_init(port_subs_info_t *grp) | |
116 | { | |
117 | INIT_LIST_HEAD(&grp->list_head); | |
118 | grp->count = 0; | |
119 | grp->exclusive = 0; | |
120 | rwlock_init(&grp->list_lock); | |
121 | init_rwsem(&grp->list_mutex); | |
122 | grp->open = NULL; | |
123 | grp->close = NULL; | |
124 | } | |
125 | ||
126 | ||
127 | /* create a port, port number is returned (-1 on failure) */ | |
128 | client_port_t *snd_seq_create_port(client_t *client, int port) | |
129 | { | |
130 | unsigned long flags; | |
131 | client_port_t *new_port; | |
132 | struct list_head *l; | |
133 | int num = -1; | |
134 | ||
135 | /* sanity check */ | |
136 | snd_assert(client, return NULL); | |
137 | ||
138 | if (client->num_ports >= SNDRV_SEQ_MAX_PORTS - 1) { | |
139 | snd_printk(KERN_WARNING "too many ports for client %d\n", client->number); | |
140 | return NULL; | |
141 | } | |
142 | ||
143 | /* create a new port */ | |
ecca82b4 | 144 | new_port = kzalloc(sizeof(*new_port), GFP_KERNEL); |
1da177e4 LT |
145 | if (! new_port) { |
146 | snd_printd("malloc failed for registering client port\n"); | |
147 | return NULL; /* failure, out of memory */ | |
148 | } | |
149 | /* init port data */ | |
150 | new_port->addr.client = client->number; | |
151 | new_port->addr.port = -1; | |
152 | new_port->owner = THIS_MODULE; | |
153 | sprintf(new_port->name, "port-%d", num); | |
154 | snd_use_lock_init(&new_port->use_lock); | |
155 | port_subs_info_init(&new_port->c_src); | |
156 | port_subs_info_init(&new_port->c_dest); | |
157 | ||
158 | num = port >= 0 ? port : 0; | |
159 | down(&client->ports_mutex); | |
160 | write_lock_irqsave(&client->ports_lock, flags); | |
161 | list_for_each(l, &client->ports_list_head) { | |
162 | client_port_t *p = list_entry(l, client_port_t, list); | |
163 | if (p->addr.port > num) | |
164 | break; | |
165 | if (port < 0) /* auto-probe mode */ | |
166 | num = p->addr.port + 1; | |
167 | } | |
168 | /* insert the new port */ | |
169 | list_add_tail(&new_port->list, l); | |
170 | client->num_ports++; | |
171 | new_port->addr.port = num; /* store the port number in the port */ | |
172 | write_unlock_irqrestore(&client->ports_lock, flags); | |
173 | up(&client->ports_mutex); | |
174 | sprintf(new_port->name, "port-%d", num); | |
175 | ||
176 | return new_port; | |
177 | } | |
178 | ||
179 | /* */ | |
180 | enum group_type_t { | |
181 | SRC_LIST, DEST_LIST | |
182 | }; | |
183 | ||
184 | static int subscribe_port(client_t *client, client_port_t *port, port_subs_info_t *grp, snd_seq_port_subscribe_t *info, int send_ack); | |
185 | static int unsubscribe_port(client_t *client, client_port_t *port, port_subs_info_t *grp, snd_seq_port_subscribe_t *info, int send_ack); | |
186 | ||
187 | ||
188 | static client_port_t *get_client_port(snd_seq_addr_t *addr, client_t **cp) | |
189 | { | |
190 | client_port_t *p; | |
191 | *cp = snd_seq_client_use_ptr(addr->client); | |
192 | if (*cp) { | |
193 | p = snd_seq_port_use_ptr(*cp, addr->port); | |
194 | if (! p) { | |
195 | snd_seq_client_unlock(*cp); | |
196 | *cp = NULL; | |
197 | } | |
198 | return p; | |
199 | } | |
200 | return NULL; | |
201 | } | |
202 | ||
203 | /* | |
204 | * remove all subscribers on the list | |
205 | * this is called from port_delete, for each src and dest list. | |
206 | */ | |
207 | static void clear_subscriber_list(client_t *client, client_port_t *port, | |
208 | port_subs_info_t *grp, int grptype) | |
209 | { | |
210 | struct list_head *p, *n; | |
211 | ||
212 | down_write(&grp->list_mutex); | |
213 | list_for_each_safe(p, n, &grp->list_head) { | |
214 | subscribers_t *subs; | |
215 | client_t *c; | |
216 | client_port_t *aport; | |
217 | ||
218 | if (grptype == SRC_LIST) { | |
219 | subs = list_entry(p, subscribers_t, src_list); | |
220 | aport = get_client_port(&subs->info.dest, &c); | |
221 | } else { | |
222 | subs = list_entry(p, subscribers_t, dest_list); | |
223 | aport = get_client_port(&subs->info.sender, &c); | |
224 | } | |
225 | list_del(p); | |
226 | unsubscribe_port(client, port, grp, &subs->info, 0); | |
227 | if (!aport) { | |
228 | /* looks like the connected port is being deleted. | |
229 | * we decrease the counter, and when both ports are deleted | |
230 | * remove the subscriber info | |
231 | */ | |
232 | if (atomic_dec_and_test(&subs->ref_count)) | |
233 | kfree(subs); | |
234 | } else { | |
235 | /* ok we got the connected port */ | |
236 | port_subs_info_t *agrp; | |
237 | agrp = (grptype == SRC_LIST) ? &aport->c_dest : &aport->c_src; | |
238 | down_write(&agrp->list_mutex); | |
239 | if (grptype == SRC_LIST) | |
240 | list_del(&subs->dest_list); | |
241 | else | |
242 | list_del(&subs->src_list); | |
243 | unsubscribe_port(c, aport, agrp, &subs->info, 1); | |
244 | kfree(subs); | |
245 | up_write(&agrp->list_mutex); | |
246 | snd_seq_port_unlock(aport); | |
247 | snd_seq_client_unlock(c); | |
248 | } | |
249 | } | |
250 | up_write(&grp->list_mutex); | |
251 | } | |
252 | ||
253 | /* delete port data */ | |
254 | static int port_delete(client_t *client, client_port_t *port) | |
255 | { | |
256 | /* set closing flag and wait for all port access are gone */ | |
257 | port->closing = 1; | |
258 | snd_use_lock_sync(&port->use_lock); | |
259 | ||
260 | /* clear subscribers info */ | |
261 | clear_subscriber_list(client, port, &port->c_src, SRC_LIST); | |
262 | clear_subscriber_list(client, port, &port->c_dest, DEST_LIST); | |
263 | ||
264 | if (port->private_free) | |
265 | port->private_free(port->private_data); | |
266 | ||
267 | snd_assert(port->c_src.count == 0,); | |
268 | snd_assert(port->c_dest.count == 0,); | |
269 | ||
270 | kfree(port); | |
271 | return 0; | |
272 | } | |
273 | ||
274 | ||
275 | /* delete a port with the given port id */ | |
276 | int snd_seq_delete_port(client_t *client, int port) | |
277 | { | |
278 | unsigned long flags; | |
279 | struct list_head *l; | |
280 | client_port_t *found = NULL; | |
281 | ||
282 | down(&client->ports_mutex); | |
283 | write_lock_irqsave(&client->ports_lock, flags); | |
284 | list_for_each(l, &client->ports_list_head) { | |
285 | client_port_t *p = list_entry(l, client_port_t, list); | |
286 | if (p->addr.port == port) { | |
287 | /* ok found. delete from the list at first */ | |
288 | list_del(l); | |
289 | client->num_ports--; | |
290 | found = p; | |
291 | break; | |
292 | } | |
293 | } | |
294 | write_unlock_irqrestore(&client->ports_lock, flags); | |
295 | up(&client->ports_mutex); | |
296 | if (found) | |
297 | return port_delete(client, found); | |
298 | else | |
299 | return -ENOENT; | |
300 | } | |
301 | ||
302 | /* delete the all ports belonging to the given client */ | |
303 | int snd_seq_delete_all_ports(client_t *client) | |
304 | { | |
305 | unsigned long flags; | |
306 | struct list_head deleted_list, *p, *n; | |
307 | ||
308 | /* move the port list to deleted_list, and | |
309 | * clear the port list in the client data. | |
310 | */ | |
311 | down(&client->ports_mutex); | |
312 | write_lock_irqsave(&client->ports_lock, flags); | |
313 | if (! list_empty(&client->ports_list_head)) { | |
314 | __list_add(&deleted_list, | |
315 | client->ports_list_head.prev, | |
316 | client->ports_list_head.next); | |
317 | INIT_LIST_HEAD(&client->ports_list_head); | |
318 | } else { | |
319 | INIT_LIST_HEAD(&deleted_list); | |
320 | } | |
321 | client->num_ports = 0; | |
322 | write_unlock_irqrestore(&client->ports_lock, flags); | |
323 | ||
324 | /* remove each port in deleted_list */ | |
325 | list_for_each_safe(p, n, &deleted_list) { | |
326 | client_port_t *port = list_entry(p, client_port_t, list); | |
327 | list_del(p); | |
328 | snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port); | |
329 | port_delete(client, port); | |
330 | } | |
331 | up(&client->ports_mutex); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | /* set port info fields */ | |
336 | int snd_seq_set_port_info(client_port_t * port, snd_seq_port_info_t * info) | |
337 | { | |
338 | snd_assert(port && info, return -EINVAL); | |
339 | ||
340 | /* set port name */ | |
341 | if (info->name[0]) | |
342 | strlcpy(port->name, info->name, sizeof(port->name)); | |
343 | ||
344 | /* set capabilities */ | |
345 | port->capability = info->capability; | |
346 | ||
347 | /* get port type */ | |
348 | port->type = info->type; | |
349 | ||
350 | /* information about supported channels/voices */ | |
351 | port->midi_channels = info->midi_channels; | |
352 | port->midi_voices = info->midi_voices; | |
353 | port->synth_voices = info->synth_voices; | |
354 | ||
355 | /* timestamping */ | |
356 | port->timestamping = (info->flags & SNDRV_SEQ_PORT_FLG_TIMESTAMP) ? 1 : 0; | |
357 | port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0; | |
358 | port->time_queue = info->time_queue; | |
359 | ||
360 | return 0; | |
361 | } | |
362 | ||
363 | /* get port info fields */ | |
364 | int snd_seq_get_port_info(client_port_t * port, snd_seq_port_info_t * info) | |
365 | { | |
366 | snd_assert(port && info, return -EINVAL); | |
367 | ||
368 | /* get port name */ | |
369 | strlcpy(info->name, port->name, sizeof(info->name)); | |
370 | ||
371 | /* get capabilities */ | |
372 | info->capability = port->capability; | |
373 | ||
374 | /* get port type */ | |
375 | info->type = port->type; | |
376 | ||
377 | /* information about supported channels/voices */ | |
378 | info->midi_channels = port->midi_channels; | |
379 | info->midi_voices = port->midi_voices; | |
380 | info->synth_voices = port->synth_voices; | |
381 | ||
382 | /* get subscriber counts */ | |
383 | info->read_use = port->c_src.count; | |
384 | info->write_use = port->c_dest.count; | |
385 | ||
386 | /* timestamping */ | |
387 | info->flags = 0; | |
388 | if (port->timestamping) { | |
389 | info->flags |= SNDRV_SEQ_PORT_FLG_TIMESTAMP; | |
390 | if (port->time_real) | |
391 | info->flags |= SNDRV_SEQ_PORT_FLG_TIME_REAL; | |
392 | info->time_queue = port->time_queue; | |
393 | } | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | ||
399 | ||
400 | /* | |
401 | * call callback functions (if any): | |
402 | * the callbacks are invoked only when the first (for connection) or | |
403 | * the last subscription (for disconnection) is done. Second or later | |
404 | * subscription results in increment of counter, but no callback is | |
405 | * invoked. | |
406 | * This feature is useful if these callbacks are associated with | |
407 | * initialization or termination of devices (see seq_midi.c). | |
408 | * | |
409 | * If callback_all option is set, the callback function is invoked | |
410 | * at each connnection/disconnection. | |
411 | */ | |
412 | ||
413 | static int subscribe_port(client_t *client, client_port_t *port, port_subs_info_t *grp, | |
414 | snd_seq_port_subscribe_t *info, int send_ack) | |
415 | { | |
416 | int err = 0; | |
417 | ||
418 | if (!try_module_get(port->owner)) | |
419 | return -EFAULT; | |
420 | grp->count++; | |
421 | if (grp->open && (port->callback_all || grp->count == 1)) { | |
422 | err = grp->open(port->private_data, info); | |
423 | if (err < 0) { | |
424 | module_put(port->owner); | |
425 | grp->count--; | |
426 | } | |
427 | } | |
428 | if (err >= 0 && send_ack && client->type == USER_CLIENT) | |
429 | snd_seq_client_notify_subscription(port->addr.client, port->addr.port, | |
430 | info, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED); | |
431 | ||
432 | return err; | |
433 | } | |
434 | ||
435 | static int unsubscribe_port(client_t *client, client_port_t *port, | |
436 | port_subs_info_t *grp, | |
437 | snd_seq_port_subscribe_t *info, int send_ack) | |
438 | { | |
439 | int err = 0; | |
440 | ||
441 | if (! grp->count) | |
442 | return -EINVAL; | |
443 | grp->count--; | |
444 | if (grp->close && (port->callback_all || grp->count == 0)) | |
445 | err = grp->close(port->private_data, info); | |
446 | if (send_ack && client->type == USER_CLIENT) | |
447 | snd_seq_client_notify_subscription(port->addr.client, port->addr.port, | |
448 | info, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED); | |
449 | module_put(port->owner); | |
450 | return err; | |
451 | } | |
452 | ||
453 | ||
454 | ||
455 | /* check if both addresses are identical */ | |
456 | static inline int addr_match(snd_seq_addr_t *r, snd_seq_addr_t *s) | |
457 | { | |
458 | return (r->client == s->client) && (r->port == s->port); | |
459 | } | |
460 | ||
461 | /* check the two subscribe info match */ | |
462 | /* if flags is zero, checks only sender and destination addresses */ | |
463 | static int match_subs_info(snd_seq_port_subscribe_t *r, | |
464 | snd_seq_port_subscribe_t *s) | |
465 | { | |
466 | if (addr_match(&r->sender, &s->sender) && | |
467 | addr_match(&r->dest, &s->dest)) { | |
468 | if (r->flags && r->flags == s->flags) | |
469 | return r->queue == s->queue; | |
470 | else if (! r->flags) | |
471 | return 1; | |
472 | } | |
473 | return 0; | |
474 | } | |
475 | ||
476 | ||
477 | /* connect two ports */ | |
478 | int snd_seq_port_connect(client_t *connector, | |
479 | client_t *src_client, client_port_t *src_port, | |
480 | client_t *dest_client, client_port_t *dest_port, | |
481 | snd_seq_port_subscribe_t *info) | |
482 | { | |
483 | port_subs_info_t *src = &src_port->c_src; | |
484 | port_subs_info_t *dest = &dest_port->c_dest; | |
485 | subscribers_t *subs; | |
486 | struct list_head *p; | |
487 | int err, src_called = 0; | |
488 | unsigned long flags; | |
489 | int exclusive; | |
490 | ||
ecca82b4 | 491 | subs = kzalloc(sizeof(*subs), GFP_KERNEL); |
1da177e4 LT |
492 | if (! subs) |
493 | return -ENOMEM; | |
494 | ||
495 | subs->info = *info; | |
496 | atomic_set(&subs->ref_count, 2); | |
497 | ||
498 | down_write(&src->list_mutex); | |
499 | down_write(&dest->list_mutex); | |
500 | ||
501 | exclusive = info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE ? 1 : 0; | |
502 | err = -EBUSY; | |
503 | if (exclusive) { | |
504 | if (! list_empty(&src->list_head) || ! list_empty(&dest->list_head)) | |
505 | goto __error; | |
506 | } else { | |
507 | if (src->exclusive || dest->exclusive) | |
508 | goto __error; | |
509 | /* check whether already exists */ | |
510 | list_for_each(p, &src->list_head) { | |
511 | subscribers_t *s = list_entry(p, subscribers_t, src_list); | |
512 | if (match_subs_info(info, &s->info)) | |
513 | goto __error; | |
514 | } | |
515 | list_for_each(p, &dest->list_head) { | |
516 | subscribers_t *s = list_entry(p, subscribers_t, dest_list); | |
517 | if (match_subs_info(info, &s->info)) | |
518 | goto __error; | |
519 | } | |
520 | } | |
521 | ||
522 | if ((err = subscribe_port(src_client, src_port, src, info, | |
523 | connector->number != src_client->number)) < 0) | |
524 | goto __error; | |
525 | src_called = 1; | |
526 | ||
527 | if ((err = subscribe_port(dest_client, dest_port, dest, info, | |
528 | connector->number != dest_client->number)) < 0) | |
529 | goto __error; | |
530 | ||
531 | /* add to list */ | |
532 | write_lock_irqsave(&src->list_lock, flags); | |
533 | // write_lock(&dest->list_lock); // no other lock yet | |
534 | list_add_tail(&subs->src_list, &src->list_head); | |
535 | list_add_tail(&subs->dest_list, &dest->list_head); | |
536 | // write_unlock(&dest->list_lock); // no other lock yet | |
537 | write_unlock_irqrestore(&src->list_lock, flags); | |
538 | ||
539 | src->exclusive = dest->exclusive = exclusive; | |
540 | ||
541 | up_write(&dest->list_mutex); | |
542 | up_write(&src->list_mutex); | |
543 | return 0; | |
544 | ||
545 | __error: | |
546 | if (src_called) | |
547 | unsubscribe_port(src_client, src_port, src, info, | |
548 | connector->number != src_client->number); | |
549 | kfree(subs); | |
550 | up_write(&dest->list_mutex); | |
551 | up_write(&src->list_mutex); | |
552 | return err; | |
553 | } | |
554 | ||
555 | ||
556 | /* remove the connection */ | |
557 | int snd_seq_port_disconnect(client_t *connector, | |
558 | client_t *src_client, client_port_t *src_port, | |
559 | client_t *dest_client, client_port_t *dest_port, | |
560 | snd_seq_port_subscribe_t *info) | |
561 | { | |
562 | port_subs_info_t *src = &src_port->c_src; | |
563 | port_subs_info_t *dest = &dest_port->c_dest; | |
564 | subscribers_t *subs; | |
565 | struct list_head *p; | |
566 | int err = -ENOENT; | |
567 | unsigned long flags; | |
568 | ||
569 | down_write(&src->list_mutex); | |
570 | down_write(&dest->list_mutex); | |
571 | ||
572 | /* look for the connection */ | |
573 | list_for_each(p, &src->list_head) { | |
574 | subs = list_entry(p, subscribers_t, src_list); | |
575 | if (match_subs_info(info, &subs->info)) { | |
576 | write_lock_irqsave(&src->list_lock, flags); | |
577 | // write_lock(&dest->list_lock); // no lock yet | |
578 | list_del(&subs->src_list); | |
579 | list_del(&subs->dest_list); | |
580 | // write_unlock(&dest->list_lock); | |
581 | write_unlock_irqrestore(&src->list_lock, flags); | |
582 | src->exclusive = dest->exclusive = 0; | |
583 | unsubscribe_port(src_client, src_port, src, info, | |
584 | connector->number != src_client->number); | |
585 | unsubscribe_port(dest_client, dest_port, dest, info, | |
586 | connector->number != dest_client->number); | |
587 | kfree(subs); | |
588 | err = 0; | |
589 | break; | |
590 | } | |
591 | } | |
592 | ||
593 | up_write(&dest->list_mutex); | |
594 | up_write(&src->list_mutex); | |
595 | return err; | |
596 | } | |
597 | ||
598 | ||
599 | /* get matched subscriber */ | |
600 | subscribers_t *snd_seq_port_get_subscription(port_subs_info_t *src_grp, | |
601 | snd_seq_addr_t *dest_addr) | |
602 | { | |
603 | struct list_head *p; | |
604 | subscribers_t *s, *found = NULL; | |
605 | ||
606 | down_read(&src_grp->list_mutex); | |
607 | list_for_each(p, &src_grp->list_head) { | |
608 | s = list_entry(p, subscribers_t, src_list); | |
609 | if (addr_match(dest_addr, &s->info.dest)) { | |
610 | found = s; | |
611 | break; | |
612 | } | |
613 | } | |
614 | up_read(&src_grp->list_mutex); | |
615 | return found; | |
616 | } | |
617 | ||
618 | /* | |
619 | * Attach a device driver that wants to receive events from the | |
620 | * sequencer. Returns the new port number on success. | |
621 | * A driver that wants to receive the events converted to midi, will | |
622 | * use snd_seq_midisynth_register_port(). | |
623 | */ | |
624 | /* exported */ | |
625 | int snd_seq_event_port_attach(int client, | |
626 | snd_seq_port_callback_t *pcbp, | |
627 | int cap, int type, int midi_channels, | |
628 | int midi_voices, char *portname) | |
629 | { | |
630 | snd_seq_port_info_t portinfo; | |
631 | int ret; | |
632 | ||
633 | /* Set up the port */ | |
634 | memset(&portinfo, 0, sizeof(portinfo)); | |
635 | portinfo.addr.client = client; | |
636 | strlcpy(portinfo.name, portname ? portname : "Unamed port", | |
637 | sizeof(portinfo.name)); | |
638 | ||
639 | portinfo.capability = cap; | |
640 | portinfo.type = type; | |
641 | portinfo.kernel = pcbp; | |
642 | portinfo.midi_channels = midi_channels; | |
643 | portinfo.midi_voices = midi_voices; | |
644 | ||
645 | /* Create it */ | |
646 | ret = snd_seq_kernel_client_ctl(client, | |
647 | SNDRV_SEQ_IOCTL_CREATE_PORT, | |
648 | &portinfo); | |
649 | ||
650 | if (ret >= 0) | |
651 | ret = portinfo.addr.port; | |
652 | ||
653 | return ret; | |
654 | } | |
655 | ||
656 | ||
657 | /* | |
658 | * Detach the driver from a port. | |
659 | */ | |
660 | /* exported */ | |
661 | int snd_seq_event_port_detach(int client, int port) | |
662 | { | |
663 | snd_seq_port_info_t portinfo; | |
664 | int err; | |
665 | ||
666 | memset(&portinfo, 0, sizeof(portinfo)); | |
667 | portinfo.addr.client = client; | |
668 | portinfo.addr.port = port; | |
669 | err = snd_seq_kernel_client_ctl(client, | |
670 | SNDRV_SEQ_IOCTL_DELETE_PORT, | |
671 | &portinfo); | |
672 | ||
673 | return err; | |
674 | } |