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inotify: fix race
[linux-2.6.22.y-op.git] / sound / core / control.c
blob1f1ab9c1b668c5704badb84379f809439b085c09
1 /*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22 #include <sound/driver.h>
23 #include <linux/threads.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/time.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <sound/control.h>
32
33 /* max number of user-defined controls */
34 #define MAX_USER_CONTROLS 32
35
36 struct snd_kctl_ioctl {
37 struct list_head list; /* list of all ioctls */
38 snd_kctl_ioctl_func_t fioctl;
39 };
40
41 static DECLARE_RWSEM(snd_ioctl_rwsem);
42 static LIST_HEAD(snd_control_ioctls);
43 #ifdef CONFIG_COMPAT
44 static LIST_HEAD(snd_control_compat_ioctls);
45 #endif
46
47 static int snd_ctl_open(struct inode *inode, struct file *file)
48 {
49 unsigned long flags;
50 struct snd_card *card;
51 struct snd_ctl_file *ctl;
52 int err;
53
54 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
55 if (!card) {
56 err = -ENODEV;
57 goto __error1;
58 }
59 err = snd_card_file_add(card, file);
60 if (err < 0) {
61 err = -ENODEV;
62 goto __error1;
63 }
64 if (!try_module_get(card->module)) {
65 err = -EFAULT;
66 goto __error2;
67 }
68 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
69 if (ctl == NULL) {
70 err = -ENOMEM;
71 goto __error;
72 }
73 INIT_LIST_HEAD(&ctl->events);
74 init_waitqueue_head(&ctl->change_sleep);
75 spin_lock_init(&ctl->read_lock);
76 ctl->card = card;
77 ctl->prefer_pcm_subdevice = -1;
78 ctl->prefer_rawmidi_subdevice = -1;
79 ctl->pid = current->pid;
80 file->private_data = ctl;
81 write_lock_irqsave(&card->ctl_files_rwlock, flags);
82 list_add_tail(&ctl->list, &card->ctl_files);
83 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
84 return 0;
85
86 __error:
87 module_put(card->module);
88 __error2:
89 snd_card_file_remove(card, file);
90 __error1:
91 return err;
92 }
93
94 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
95 {
96 struct snd_kctl_event *cread;
97
98 spin_lock(&ctl->read_lock);
99 while (!list_empty(&ctl->events)) {
100 cread = snd_kctl_event(ctl->events.next);
101 list_del(&cread->list);
102 kfree(cread);
103 }
104 spin_unlock(&ctl->read_lock);
105 }
106
107 static int snd_ctl_release(struct inode *inode, struct file *file)
108 {
109 unsigned long flags;
110 struct snd_card *card;
111 struct snd_ctl_file *ctl;
112 struct snd_kcontrol *control;
113 unsigned int idx;
114
115 ctl = file->private_data;
116 fasync_helper(-1, file, 0, &ctl->fasync);
117 file->private_data = NULL;
118 card = ctl->card;
119 write_lock_irqsave(&card->ctl_files_rwlock, flags);
120 list_del(&ctl->list);
121 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
122 down_write(&card->controls_rwsem);
123 list_for_each_entry(control, &card->controls, list)
124 for (idx = 0; idx < control->count; idx++)
125 if (control->vd[idx].owner == ctl)
126 control->vd[idx].owner = NULL;
127 up_write(&card->controls_rwsem);
128 snd_ctl_empty_read_queue(ctl);
129 kfree(ctl);
130 module_put(card->module);
131 snd_card_file_remove(card, file);
132 return 0;
133 }
134
135 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
136 struct snd_ctl_elem_id *id)
137 {
138 unsigned long flags;
139 struct snd_ctl_file *ctl;
140 struct snd_kctl_event *ev;
141
142 snd_assert(card != NULL && id != NULL, return);
143 read_lock(&card->ctl_files_rwlock);
144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
145 card->mixer_oss_change_count++;
146 #endif
147 list_for_each_entry(ctl, &card->ctl_files, list) {
148 if (!ctl->subscribed)
149 continue;
150 spin_lock_irqsave(&ctl->read_lock, flags);
151 list_for_each_entry(ev, &ctl->events, list) {
152 if (ev->id.numid == id->numid) {
153 ev->mask |= mask;
154 goto _found;
155 }
156 }
157 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
158 if (ev) {
159 ev->id = *id;
160 ev->mask = mask;
161 list_add_tail(&ev->list, &ctl->events);
162 } else {
163 snd_printk(KERN_ERR "No memory available to allocate event\n");
164 }
165 _found:
166 wake_up(&ctl->change_sleep);
167 spin_unlock_irqrestore(&ctl->read_lock, flags);
168 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
169 }
170 read_unlock(&card->ctl_files_rwlock);
171 }
172
173 EXPORT_SYMBOL(snd_ctl_notify);
174
175 /**
176 * snd_ctl_new - create a control instance from the template
177 * @control: the control template
178 * @access: the default control access
179 *
180 * Allocates a new struct snd_kcontrol instance and copies the given template
181 * to the new instance. It does not copy volatile data (access).
182 *
183 * Returns the pointer of the new instance, or NULL on failure.
184 */
185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
186 unsigned int access)
187 {
188 struct snd_kcontrol *kctl;
189 unsigned int idx;
190
191 snd_assert(control != NULL, return NULL);
192 snd_assert(control->count > 0, return NULL);
193 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
194 if (kctl == NULL) {
195 snd_printk(KERN_ERR "Cannot allocate control instance\n");
196 return NULL;
197 }
198 *kctl = *control;
199 for (idx = 0; idx < kctl->count; idx++)
200 kctl->vd[idx].access = access;
201 return kctl;
202 }
203
204 /**
205 * snd_ctl_new1 - create a control instance from the template
206 * @ncontrol: the initialization record
207 * @private_data: the private data to set
208 *
209 * Allocates a new struct snd_kcontrol instance and initialize from the given
210 * template. When the access field of ncontrol is 0, it's assumed as
211 * READWRITE access. When the count field is 0, it's assumes as one.
212 *
213 * Returns the pointer of the newly generated instance, or NULL on failure.
214 */
215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
216 void *private_data)
217 {
218 struct snd_kcontrol kctl;
219 unsigned int access;
220
221 snd_assert(ncontrol != NULL, return NULL);
222 snd_assert(ncontrol->info != NULL, return NULL);
223 memset(&kctl, 0, sizeof(kctl));
224 kctl.id.iface = ncontrol->iface;
225 kctl.id.device = ncontrol->device;
226 kctl.id.subdevice = ncontrol->subdevice;
227 if (ncontrol->name)
228 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
229 kctl.id.index = ncontrol->index;
230 kctl.count = ncontrol->count ? ncontrol->count : 1;
231 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
232 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
233 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
234 SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
235 SNDRV_CTL_ELEM_ACCESS_INDIRECT|
236 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
237 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
238 kctl.info = ncontrol->info;
239 kctl.get = ncontrol->get;
240 kctl.put = ncontrol->put;
241 kctl.tlv.p = ncontrol->tlv.p;
242 kctl.private_value = ncontrol->private_value;
243 kctl.private_data = private_data;
244 return snd_ctl_new(&kctl, access);
245 }
246
247 EXPORT_SYMBOL(snd_ctl_new1);
248
249 /**
250 * snd_ctl_free_one - release the control instance
251 * @kcontrol: the control instance
252 *
253 * Releases the control instance created via snd_ctl_new()
254 * or snd_ctl_new1().
255 * Don't call this after the control was added to the card.
256 */
257 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
258 {
259 if (kcontrol) {
260 if (kcontrol->private_free)
261 kcontrol->private_free(kcontrol);
262 kfree(kcontrol);
263 }
264 }
265
266 EXPORT_SYMBOL(snd_ctl_free_one);
267
268 static unsigned int snd_ctl_hole_check(struct snd_card *card,
269 unsigned int count)
270 {
271 struct snd_kcontrol *kctl;
272
273 list_for_each_entry(kctl, &card->controls, list) {
274 if ((kctl->id.numid <= card->last_numid &&
275 kctl->id.numid + kctl->count > card->last_numid) ||
276 (kctl->id.numid <= card->last_numid + count - 1 &&
277 kctl->id.numid + kctl->count > card->last_numid + count - 1))
278 return card->last_numid = kctl->id.numid + kctl->count - 1;
279 }
280 return card->last_numid;
281 }
282
283 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
284 {
285 unsigned int last_numid, iter = 100000;
286
287 last_numid = card->last_numid;
288 while (last_numid != snd_ctl_hole_check(card, count)) {
289 if (--iter == 0) {
290 /* this situation is very unlikely */
291 snd_printk(KERN_ERR "unable to allocate new control numid\n");
292 return -ENOMEM;
293 }
294 last_numid = card->last_numid;
295 }
296 return 0;
297 }
298
299 /**
300 * snd_ctl_add - add the control instance to the card
301 * @card: the card instance
302 * @kcontrol: the control instance to add
303 *
304 * Adds the control instance created via snd_ctl_new() or
305 * snd_ctl_new1() to the given card. Assigns also an unique
306 * numid used for fast search.
307 *
308 * Returns zero if successful, or a negative error code on failure.
309 *
310 * It frees automatically the control which cannot be added.
311 */
312 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
313 {
314 struct snd_ctl_elem_id id;
315 unsigned int idx;
316 int err = -EINVAL;
317
318 if (! kcontrol)
319 return err;
320 snd_assert(card != NULL, goto error);
321 snd_assert(kcontrol->info != NULL, goto error);
322 id = kcontrol->id;
323 down_write(&card->controls_rwsem);
324 if (snd_ctl_find_id(card, &id)) {
325 up_write(&card->controls_rwsem);
326 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
327 id.iface,
328 id.device,
329 id.subdevice,
330 id.name,
331 id.index);
332 err = -EBUSY;
333 goto error;
334 }
335 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
336 up_write(&card->controls_rwsem);
337 err = -ENOMEM;
338 goto error;
339 }
340 list_add_tail(&kcontrol->list, &card->controls);
341 card->controls_count += kcontrol->count;
342 kcontrol->id.numid = card->last_numid + 1;
343 card->last_numid += kcontrol->count;
344 up_write(&card->controls_rwsem);
345 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
346 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
347 return 0;
348
349 error:
350 snd_ctl_free_one(kcontrol);
351 return err;
352 }
353
354 EXPORT_SYMBOL(snd_ctl_add);
355
356 /**
357 * snd_ctl_remove - remove the control from the card and release it
358 * @card: the card instance
359 * @kcontrol: the control instance to remove
360 *
361 * Removes the control from the card and then releases the instance.
362 * You don't need to call snd_ctl_free_one(). You must be in
363 * the write lock - down_write(&card->controls_rwsem).
364 *
365 * Returns 0 if successful, or a negative error code on failure.
366 */
367 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
368 {
369 struct snd_ctl_elem_id id;
370 unsigned int idx;
371
372 snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
373 list_del(&kcontrol->list);
374 card->controls_count -= kcontrol->count;
375 id = kcontrol->id;
376 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
377 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
378 snd_ctl_free_one(kcontrol);
379 return 0;
380 }
381
382 EXPORT_SYMBOL(snd_ctl_remove);
383
384 /**
385 * snd_ctl_remove_id - remove the control of the given id and release it
386 * @card: the card instance
387 * @id: the control id to remove
388 *
389 * Finds the control instance with the given id, removes it from the
390 * card list and releases it.
391 *
392 * Returns 0 if successful, or a negative error code on failure.
393 */
394 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
395 {
396 struct snd_kcontrol *kctl;
397 int ret;
398
399 down_write(&card->controls_rwsem);
400 kctl = snd_ctl_find_id(card, id);
401 if (kctl == NULL) {
402 up_write(&card->controls_rwsem);
403 return -ENOENT;
404 }
405 ret = snd_ctl_remove(card, kctl);
406 up_write(&card->controls_rwsem);
407 return ret;
408 }
409
410 EXPORT_SYMBOL(snd_ctl_remove_id);
411
412 /**
413 * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
414 * @file: active control handle
415 * @id: the control id to remove
416 *
417 * Finds the control instance with the given id, removes it from the
418 * card list and releases it.
419 *
420 * Returns 0 if successful, or a negative error code on failure.
421 */
422 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
423 struct snd_ctl_elem_id *id)
424 {
425 struct snd_card *card = file->card;
426 struct snd_kcontrol *kctl;
427 int idx, ret;
428
429 down_write(&card->controls_rwsem);
430 kctl = snd_ctl_find_id(card, id);
431 if (kctl == NULL) {
432 up_write(&card->controls_rwsem);
433 return -ENOENT;
434 }
435 for (idx = 0; idx < kctl->count; idx++)
436 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
437 up_write(&card->controls_rwsem);
438 return -EBUSY;
439 }
440 ret = snd_ctl_remove(card, kctl);
441 up_write(&card->controls_rwsem);
442 return ret;
443 }
444
445 /**
446 * snd_ctl_rename_id - replace the id of a control on the card
447 * @card: the card instance
448 * @src_id: the old id
449 * @dst_id: the new id
450 *
451 * Finds the control with the old id from the card, and replaces the
452 * id with the new one.
453 *
454 * Returns zero if successful, or a negative error code on failure.
455 */
456 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
457 struct snd_ctl_elem_id *dst_id)
458 {
459 struct snd_kcontrol *kctl;
460
461 down_write(&card->controls_rwsem);
462 kctl = snd_ctl_find_id(card, src_id);
463 if (kctl == NULL) {
464 up_write(&card->controls_rwsem);
465 return -ENOENT;
466 }
467 kctl->id = *dst_id;
468 kctl->id.numid = card->last_numid + 1;
469 card->last_numid += kctl->count;
470 up_write(&card->controls_rwsem);
471 return 0;
472 }
473
474 EXPORT_SYMBOL(snd_ctl_rename_id);
475
476 /**
477 * snd_ctl_find_numid - find the control instance with the given number-id
478 * @card: the card instance
479 * @numid: the number-id to search
480 *
481 * Finds the control instance with the given number-id from the card.
482 *
483 * Returns the pointer of the instance if found, or NULL if not.
484 *
485 * The caller must down card->controls_rwsem before calling this function
486 * (if the race condition can happen).
487 */
488 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
489 {
490 struct snd_kcontrol *kctl;
491
492 snd_assert(card != NULL && numid != 0, return NULL);
493 list_for_each_entry(kctl, &card->controls, list) {
494 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
495 return kctl;
496 }
497 return NULL;
498 }
499
500 EXPORT_SYMBOL(snd_ctl_find_numid);
501
502 /**
503 * snd_ctl_find_id - find the control instance with the given id
504 * @card: the card instance
505 * @id: the id to search
506 *
507 * Finds the control instance with the given id from the card.
508 *
509 * Returns the pointer of the instance if found, or NULL if not.
510 *
511 * The caller must down card->controls_rwsem before calling this function
512 * (if the race condition can happen).
513 */
514 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
515 struct snd_ctl_elem_id *id)
516 {
517 struct snd_kcontrol *kctl;
518
519 snd_assert(card != NULL && id != NULL, return NULL);
520 if (id->numid != 0)
521 return snd_ctl_find_numid(card, id->numid);
522 list_for_each_entry(kctl, &card->controls, list) {
523 if (kctl->id.iface != id->iface)
524 continue;
525 if (kctl->id.device != id->device)
526 continue;
527 if (kctl->id.subdevice != id->subdevice)
528 continue;
529 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
530 continue;
531 if (kctl->id.index > id->index)
532 continue;
533 if (kctl->id.index + kctl->count <= id->index)
534 continue;
535 return kctl;
536 }
537 return NULL;
538 }
539
540 EXPORT_SYMBOL(snd_ctl_find_id);
541
542 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
543 unsigned int cmd, void __user *arg)
544 {
545 struct snd_ctl_card_info *info;
546
547 info = kzalloc(sizeof(*info), GFP_KERNEL);
548 if (! info)
549 return -ENOMEM;
550 down_read(&snd_ioctl_rwsem);
551 info->card = card->number;
552 strlcpy(info->id, card->id, sizeof(info->id));
553 strlcpy(info->driver, card->driver, sizeof(info->driver));
554 strlcpy(info->name, card->shortname, sizeof(info->name));
555 strlcpy(info->longname, card->longname, sizeof(info->longname));
556 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
557 strlcpy(info->components, card->components, sizeof(info->components));
558 up_read(&snd_ioctl_rwsem);
559 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
560 kfree(info);
561 return -EFAULT;
562 }
563 kfree(info);
564 return 0;
565 }
566
567 static int snd_ctl_elem_list(struct snd_card *card,
568 struct snd_ctl_elem_list __user *_list)
569 {
570 struct list_head *plist;
571 struct snd_ctl_elem_list list;
572 struct snd_kcontrol *kctl;
573 struct snd_ctl_elem_id *dst, *id;
574 unsigned int offset, space, first, jidx;
575
576 if (copy_from_user(&list, _list, sizeof(list)))
577 return -EFAULT;
578 offset = list.offset;
579 space = list.space;
580 first = 0;
581 /* try limit maximum space */
582 if (space > 16384)
583 return -ENOMEM;
584 if (space > 0) {
585 /* allocate temporary buffer for atomic operation */
586 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
587 if (dst == NULL)
588 return -ENOMEM;
589 down_read(&card->controls_rwsem);
590 list.count = card->controls_count;
591 plist = card->controls.next;
592 while (plist != &card->controls) {
593 if (offset == 0)
594 break;
595 kctl = snd_kcontrol(plist);
596 if (offset < kctl->count)
597 break;
598 offset -= kctl->count;
599 plist = plist->next;
600 }
601 list.used = 0;
602 id = dst;
603 while (space > 0 && plist != &card->controls) {
604 kctl = snd_kcontrol(plist);
605 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
606 snd_ctl_build_ioff(id, kctl, jidx);
607 id++;
608 space--;
609 list.used++;
610 }
611 plist = plist->next;
612 offset = 0;
613 }
614 up_read(&card->controls_rwsem);
615 if (list.used > 0 &&
616 copy_to_user(list.pids, dst,
617 list.used * sizeof(struct snd_ctl_elem_id))) {
618 vfree(dst);
619 return -EFAULT;
620 }
621 vfree(dst);
622 } else {
623 down_read(&card->controls_rwsem);
624 list.count = card->controls_count;
625 up_read(&card->controls_rwsem);
626 }
627 if (copy_to_user(_list, &list, sizeof(list)))
628 return -EFAULT;
629 return 0;
630 }
631
632 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
633 struct snd_ctl_elem_info *info)
634 {
635 struct snd_card *card = ctl->card;
636 struct snd_kcontrol *kctl;
637 struct snd_kcontrol_volatile *vd;
638 unsigned int index_offset;
639 int result;
640
641 down_read(&card->controls_rwsem);
642 kctl = snd_ctl_find_id(card, &info->id);
643 if (kctl == NULL) {
644 up_read(&card->controls_rwsem);
645 return -ENOENT;
646 }
647 #ifdef CONFIG_SND_DEBUG
648 info->access = 0;
649 #endif
650 result = kctl->info(kctl, info);
651 if (result >= 0) {
652 snd_assert(info->access == 0, );
653 index_offset = snd_ctl_get_ioff(kctl, &info->id);
654 vd = &kctl->vd[index_offset];
655 snd_ctl_build_ioff(&info->id, kctl, index_offset);
656 info->access = vd->access;
657 if (vd->owner) {
658 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
659 if (vd->owner == ctl)
660 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
661 info->owner = vd->owner_pid;
662 } else {
663 info->owner = -1;
664 }
665 }
666 up_read(&card->controls_rwsem);
667 return result;
668 }
669
670 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
671 struct snd_ctl_elem_info __user *_info)
672 {
673 struct snd_ctl_elem_info info;
674 int result;
675
676 if (copy_from_user(&info, _info, sizeof(info)))
677 return -EFAULT;
678 snd_power_lock(ctl->card);
679 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
680 if (result >= 0)
681 result = snd_ctl_elem_info(ctl, &info);
682 snd_power_unlock(ctl->card);
683 if (result >= 0)
684 if (copy_to_user(_info, &info, sizeof(info)))
685 return -EFAULT;
686 return result;
687 }
688
689 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
690 {
691 struct snd_kcontrol *kctl;
692 struct snd_kcontrol_volatile *vd;
693 unsigned int index_offset;
694 int result, indirect;
695
696 down_read(&card->controls_rwsem);
697 kctl = snd_ctl_find_id(card, &control->id);
698 if (kctl == NULL) {
699 result = -ENOENT;
700 } else {
701 index_offset = snd_ctl_get_ioff(kctl, &control->id);
702 vd = &kctl->vd[index_offset];
703 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
704 if (control->indirect != indirect) {
705 result = -EACCES;
706 } else {
707 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
708 snd_ctl_build_ioff(&control->id, kctl, index_offset);
709 result = kctl->get(kctl, control);
710 } else {
711 result = -EPERM;
712 }
713 }
714 }
715 up_read(&card->controls_rwsem);
716 return result;
717 }
718
719 EXPORT_SYMBOL(snd_ctl_elem_read);
720
721 static int snd_ctl_elem_read_user(struct snd_card *card,
722 struct snd_ctl_elem_value __user *_control)
723 {
724 struct snd_ctl_elem_value *control;
725 int result;
726
727 control = kmalloc(sizeof(*control), GFP_KERNEL);
728 if (control == NULL)
729 return -ENOMEM;
730 if (copy_from_user(control, _control, sizeof(*control))) {
731 kfree(control);
732 return -EFAULT;
733 }
734 snd_power_lock(card);
735 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
736 if (result >= 0)
737 result = snd_ctl_elem_read(card, control);
738 snd_power_unlock(card);
739 if (result >= 0)
740 if (copy_to_user(_control, control, sizeof(*control)))
741 result = -EFAULT;
742 kfree(control);
743 return result;
744 }
745
746 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
747 struct snd_ctl_elem_value *control)
748 {
749 struct snd_kcontrol *kctl;
750 struct snd_kcontrol_volatile *vd;
751 unsigned int index_offset;
752 int result, indirect;
753
754 down_read(&card->controls_rwsem);
755 kctl = snd_ctl_find_id(card, &control->id);
756 if (kctl == NULL) {
757 result = -ENOENT;
758 } else {
759 index_offset = snd_ctl_get_ioff(kctl, &control->id);
760 vd = &kctl->vd[index_offset];
761 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
762 if (control->indirect != indirect) {
763 result = -EACCES;
764 } else {
765 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
766 kctl->put == NULL ||
767 (file && vd->owner != NULL && vd->owner != file)) {
768 result = -EPERM;
769 } else {
770 snd_ctl_build_ioff(&control->id, kctl, index_offset);
771 result = kctl->put(kctl, control);
772 }
773 if (result > 0) {
774 up_read(&card->controls_rwsem);
775 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
776 return 0;
777 }
778 }
779 }
780 up_read(&card->controls_rwsem);
781 return result;
782 }
783
784 EXPORT_SYMBOL(snd_ctl_elem_write);
785
786 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
787 struct snd_ctl_elem_value __user *_control)
788 {
789 struct snd_ctl_elem_value *control;
790 struct snd_card *card;
791 int result;
792
793 control = kmalloc(sizeof(*control), GFP_KERNEL);
794 if (control == NULL)
795 return -ENOMEM;
796 if (copy_from_user(control, _control, sizeof(*control))) {
797 kfree(control);
798 return -EFAULT;
799 }
800 card = file->card;
801 snd_power_lock(card);
802 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
803 if (result >= 0)
804 result = snd_ctl_elem_write(card, file, control);
805 snd_power_unlock(card);
806 if (result >= 0)
807 if (copy_to_user(_control, control, sizeof(*control)))
808 result = -EFAULT;
809 kfree(control);
810 return result;
811 }
812
813 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
814 struct snd_ctl_elem_id __user *_id)
815 {
816 struct snd_card *card = file->card;
817 struct snd_ctl_elem_id id;
818 struct snd_kcontrol *kctl;
819 struct snd_kcontrol_volatile *vd;
820 int result;
821
822 if (copy_from_user(&id, _id, sizeof(id)))
823 return -EFAULT;
824 down_write(&card->controls_rwsem);
825 kctl = snd_ctl_find_id(card, &id);
826 if (kctl == NULL) {
827 result = -ENOENT;
828 } else {
829 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
830 if (vd->owner != NULL)
831 result = -EBUSY;
832 else {
833 vd->owner = file;
834 vd->owner_pid = current->pid;
835 result = 0;
836 }
837 }
838 up_write(&card->controls_rwsem);
839 return result;
840 }
841
842 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
843 struct snd_ctl_elem_id __user *_id)
844 {
845 struct snd_card *card = file->card;
846 struct snd_ctl_elem_id id;
847 struct snd_kcontrol *kctl;
848 struct snd_kcontrol_volatile *vd;
849 int result;
850
851 if (copy_from_user(&id, _id, sizeof(id)))
852 return -EFAULT;
853 down_write(&card->controls_rwsem);
854 kctl = snd_ctl_find_id(card, &id);
855 if (kctl == NULL) {
856 result = -ENOENT;
857 } else {
858 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
859 if (vd->owner == NULL)
860 result = -EINVAL;
861 else if (vd->owner != file)
862 result = -EPERM;
863 else {
864 vd->owner = NULL;
865 vd->owner_pid = 0;
866 result = 0;
867 }
868 }
869 up_write(&card->controls_rwsem);
870 return result;
871 }
872
873 struct user_element {
874 struct snd_ctl_elem_info info;
875 void *elem_data; /* element data */
876 unsigned long elem_data_size; /* size of element data in bytes */
877 void *tlv_data; /* TLV data */
878 unsigned long tlv_data_size; /* TLV data size */
879 void *priv_data; /* private data (like strings for enumerated type) */
880 unsigned long priv_data_size; /* size of private data in bytes */
881 };
882
883 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
884 struct snd_ctl_elem_info *uinfo)
885 {
886 struct user_element *ue = kcontrol->private_data;
887
888 *uinfo = ue->info;
889 return 0;
890 }
891
892 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
893 struct snd_ctl_elem_value *ucontrol)
894 {
895 struct user_element *ue = kcontrol->private_data;
896
897 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
898 return 0;
899 }
900
901 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
902 struct snd_ctl_elem_value *ucontrol)
903 {
904 int change;
905 struct user_element *ue = kcontrol->private_data;
906
907 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
908 if (change)
909 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
910 return change;
911 }
912
913 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
914 int op_flag,
915 unsigned int size,
916 unsigned int __user *tlv)
917 {
918 struct user_element *ue = kcontrol->private_data;
919 int change = 0;
920 void *new_data;
921
922 if (op_flag > 0) {
923 if (size > 1024 * 128) /* sane value */
924 return -EINVAL;
925 new_data = kmalloc(size, GFP_KERNEL);
926 if (new_data == NULL)
927 return -ENOMEM;
928 if (copy_from_user(new_data, tlv, size)) {
929 kfree(new_data);
930 return -EFAULT;
931 }
932 change = ue->tlv_data_size != size;
933 if (!change)
934 change = memcmp(ue->tlv_data, new_data, size);
935 kfree(ue->tlv_data);
936 ue->tlv_data = new_data;
937 ue->tlv_data_size = size;
938 } else {
939 if (! ue->tlv_data_size || ! ue->tlv_data)
940 return -ENXIO;
941 if (size < ue->tlv_data_size)
942 return -ENOSPC;
943 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
944 return -EFAULT;
945 }
946 return change;
947 }
948
949 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
950 {
951 struct user_element *ue = kcontrol->private_data;
952 if (ue->tlv_data)
953 kfree(ue->tlv_data);
954 kfree(ue);
955 }
956
957 static int snd_ctl_elem_add(struct snd_ctl_file *file,
958 struct snd_ctl_elem_info *info, int replace)
959 {
960 struct snd_card *card = file->card;
961 struct snd_kcontrol kctl, *_kctl;
962 unsigned int access;
963 long private_size;
964 struct user_element *ue;
965 int idx, err;
966
967 if (card->user_ctl_count >= MAX_USER_CONTROLS)
968 return -ENOMEM;
969 if (info->count > 1024)
970 return -EINVAL;
971 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
972 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
973 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
974 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
975 info->id.numid = 0;
976 memset(&kctl, 0, sizeof(kctl));
977 down_write(&card->controls_rwsem);
978 _kctl = snd_ctl_find_id(card, &info->id);
979 err = 0;
980 if (_kctl) {
981 if (replace)
982 err = snd_ctl_remove(card, _kctl);
983 else
984 err = -EBUSY;
985 } else {
986 if (replace)
987 err = -ENOENT;
988 }
989 up_write(&card->controls_rwsem);
990 if (err < 0)
991 return err;
992 memcpy(&kctl.id, &info->id, sizeof(info->id));
993 kctl.count = info->owner ? info->owner : 1;
994 access |= SNDRV_CTL_ELEM_ACCESS_USER;
995 kctl.info = snd_ctl_elem_user_info;
996 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
997 kctl.get = snd_ctl_elem_user_get;
998 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
999 kctl.put = snd_ctl_elem_user_put;
1000 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1001 kctl.tlv.c = snd_ctl_elem_user_tlv;
1002 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1003 }
1004 switch (info->type) {
1005 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1006 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1007 private_size = sizeof(long);
1008 if (info->count > 128)
1009 return -EINVAL;
1010 break;
1011 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1012 private_size = sizeof(long long);
1013 if (info->count > 64)
1014 return -EINVAL;
1015 break;
1016 case SNDRV_CTL_ELEM_TYPE_BYTES:
1017 private_size = sizeof(unsigned char);
1018 if (info->count > 512)
1019 return -EINVAL;
1020 break;
1021 case SNDRV_CTL_ELEM_TYPE_IEC958:
1022 private_size = sizeof(struct snd_aes_iec958);
1023 if (info->count != 1)
1024 return -EINVAL;
1025 break;
1026 default:
1027 return -EINVAL;
1028 }
1029 private_size *= info->count;
1030 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1031 if (ue == NULL)
1032 return -ENOMEM;
1033 ue->info = *info;
1034 ue->info.access = 0;
1035 ue->elem_data = (char *)ue + sizeof(*ue);
1036 ue->elem_data_size = private_size;
1037 kctl.private_free = snd_ctl_elem_user_free;
1038 _kctl = snd_ctl_new(&kctl, access);
1039 if (_kctl == NULL) {
1040 kfree(ue);
1041 return -ENOMEM;
1042 }
1043 _kctl->private_data = ue;
1044 for (idx = 0; idx < _kctl->count; idx++)
1045 _kctl->vd[idx].owner = file;
1046 err = snd_ctl_add(card, _kctl);
1047 if (err < 0)
1048 return err;
1049
1050 down_write(&card->controls_rwsem);
1051 card->user_ctl_count++;
1052 up_write(&card->controls_rwsem);
1053
1054 return 0;
1055 }
1056
1057 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1058 struct snd_ctl_elem_info __user *_info, int replace)
1059 {
1060 struct snd_ctl_elem_info info;
1061 if (copy_from_user(&info, _info, sizeof(info)))
1062 return -EFAULT;
1063 return snd_ctl_elem_add(file, &info, replace);
1064 }
1065
1066 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1067 struct snd_ctl_elem_id __user *_id)
1068 {
1069 struct snd_ctl_elem_id id;
1070 int err;
1071
1072 if (copy_from_user(&id, _id, sizeof(id)))
1073 return -EFAULT;
1074 err = snd_ctl_remove_unlocked_id(file, &id);
1075 if (! err) {
1076 struct snd_card *card = file->card;
1077 down_write(&card->controls_rwsem);
1078 card->user_ctl_count--;
1079 up_write(&card->controls_rwsem);
1080 }
1081 return err;
1082 }
1083
1084 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1085 {
1086 int subscribe;
1087 if (get_user(subscribe, ptr))
1088 return -EFAULT;
1089 if (subscribe < 0) {
1090 subscribe = file->subscribed;
1091 if (put_user(subscribe, ptr))
1092 return -EFAULT;
1093 return 0;
1094 }
1095 if (subscribe) {
1096 file->subscribed = 1;
1097 return 0;
1098 } else if (file->subscribed) {
1099 snd_ctl_empty_read_queue(file);
1100 file->subscribed = 0;
1101 }
1102 return 0;
1103 }
1104
1105 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1106 struct snd_ctl_tlv __user *_tlv,
1107 int op_flag)
1108 {
1109 struct snd_card *card = file->card;
1110 struct snd_ctl_tlv tlv;
1111 struct snd_kcontrol *kctl;
1112 struct snd_kcontrol_volatile *vd;
1113 unsigned int len;
1114 int err = 0;
1115
1116 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1117 return -EFAULT;
1118 if (tlv.length < sizeof(unsigned int) * 3)
1119 return -EINVAL;
1120 down_read(&card->controls_rwsem);
1121 kctl = snd_ctl_find_numid(card, tlv.numid);
1122 if (kctl == NULL) {
1123 err = -ENOENT;
1124 goto __kctl_end;
1125 }
1126 if (kctl->tlv.p == NULL) {
1127 err = -ENXIO;
1128 goto __kctl_end;
1129 }
1130 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1131 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1132 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1133 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1134 err = -ENXIO;
1135 goto __kctl_end;
1136 }
1137 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1138 if (file && vd->owner != NULL && vd->owner != file) {
1139 err = -EPERM;
1140 goto __kctl_end;
1141 }
1142 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1143 if (err > 0) {
1144 up_read(&card->controls_rwsem);
1145 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1146 return 0;
1147 }
1148 } else {
1149 if (op_flag) {
1150 err = -ENXIO;
1151 goto __kctl_end;
1152 }
1153 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1154 if (tlv.length < len) {
1155 err = -ENOMEM;
1156 goto __kctl_end;
1157 }
1158 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1159 err = -EFAULT;
1160 }
1161 __kctl_end:
1162 up_read(&card->controls_rwsem);
1163 return err;
1164 }
1165
1166 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1167 {
1168 struct snd_ctl_file *ctl;
1169 struct snd_card *card;
1170 struct snd_kctl_ioctl *p;
1171 void __user *argp = (void __user *)arg;
1172 int __user *ip = argp;
1173 int err;
1174
1175 ctl = file->private_data;
1176 card = ctl->card;
1177 snd_assert(card != NULL, return -ENXIO);
1178 switch (cmd) {
1179 case SNDRV_CTL_IOCTL_PVERSION:
1180 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1181 case SNDRV_CTL_IOCTL_CARD_INFO:
1182 return snd_ctl_card_info(card, ctl, cmd, argp);
1183 case SNDRV_CTL_IOCTL_ELEM_LIST:
1184 return snd_ctl_elem_list(card, argp);
1185 case SNDRV_CTL_IOCTL_ELEM_INFO:
1186 return snd_ctl_elem_info_user(ctl, argp);
1187 case SNDRV_CTL_IOCTL_ELEM_READ:
1188 return snd_ctl_elem_read_user(card, argp);
1189 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1190 return snd_ctl_elem_write_user(ctl, argp);
1191 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1192 return snd_ctl_elem_lock(ctl, argp);
1193 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1194 return snd_ctl_elem_unlock(ctl, argp);
1195 case SNDRV_CTL_IOCTL_ELEM_ADD:
1196 return snd_ctl_elem_add_user(ctl, argp, 0);
1197 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1198 return snd_ctl_elem_add_user(ctl, argp, 1);
1199 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1200 return snd_ctl_elem_remove(ctl, argp);
1201 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1202 return snd_ctl_subscribe_events(ctl, ip);
1203 case SNDRV_CTL_IOCTL_TLV_READ:
1204 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1205 case SNDRV_CTL_IOCTL_TLV_WRITE:
1206 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1207 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1208 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1209 case SNDRV_CTL_IOCTL_POWER:
1210 return -ENOPROTOOPT;
1211 case SNDRV_CTL_IOCTL_POWER_STATE:
1212 #ifdef CONFIG_PM
1213 return put_user(card->power_state, ip) ? -EFAULT : 0;
1214 #else
1215 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1216 #endif
1217 }
1218 down_read(&snd_ioctl_rwsem);
1219 list_for_each_entry(p, &snd_control_ioctls, list) {
1220 err = p->fioctl(card, ctl, cmd, arg);
1221 if (err != -ENOIOCTLCMD) {
1222 up_read(&snd_ioctl_rwsem);
1223 return err;
1224 }
1225 }
1226 up_read(&snd_ioctl_rwsem);
1227 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1228 return -ENOTTY;
1229 }
1230
1231 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1232 size_t count, loff_t * offset)
1233 {
1234 struct snd_ctl_file *ctl;
1235 int err = 0;
1236 ssize_t result = 0;
1237
1238 ctl = file->private_data;
1239 snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1240 if (!ctl->subscribed)
1241 return -EBADFD;
1242 if (count < sizeof(struct snd_ctl_event))
1243 return -EINVAL;
1244 spin_lock_irq(&ctl->read_lock);
1245 while (count >= sizeof(struct snd_ctl_event)) {
1246 struct snd_ctl_event ev;
1247 struct snd_kctl_event *kev;
1248 while (list_empty(&ctl->events)) {
1249 wait_queue_t wait;
1250 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1251 err = -EAGAIN;
1252 goto __end_lock;
1253 }
1254 init_waitqueue_entry(&wait, current);
1255 add_wait_queue(&ctl->change_sleep, &wait);
1256 set_current_state(TASK_INTERRUPTIBLE);
1257 spin_unlock_irq(&ctl->read_lock);
1258 schedule();
1259 remove_wait_queue(&ctl->change_sleep, &wait);
1260 if (signal_pending(current))
1261 return -ERESTARTSYS;
1262 spin_lock_irq(&ctl->read_lock);
1263 }
1264 kev = snd_kctl_event(ctl->events.next);
1265 ev.type = SNDRV_CTL_EVENT_ELEM;
1266 ev.data.elem.mask = kev->mask;
1267 ev.data.elem.id = kev->id;
1268 list_del(&kev->list);
1269 spin_unlock_irq(&ctl->read_lock);
1270 kfree(kev);
1271 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1272 err = -EFAULT;
1273 goto __end;
1274 }
1275 spin_lock_irq(&ctl->read_lock);
1276 buffer += sizeof(struct snd_ctl_event);
1277 count -= sizeof(struct snd_ctl_event);
1278 result += sizeof(struct snd_ctl_event);
1279 }
1280 __end_lock:
1281 spin_unlock_irq(&ctl->read_lock);
1282 __end:
1283 return result > 0 ? result : err;
1284 }
1285
1286 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1287 {
1288 unsigned int mask;
1289 struct snd_ctl_file *ctl;
1290
1291 ctl = file->private_data;
1292 if (!ctl->subscribed)
1293 return 0;
1294 poll_wait(file, &ctl->change_sleep, wait);
1295
1296 mask = 0;
1297 if (!list_empty(&ctl->events))
1298 mask |= POLLIN | POLLRDNORM;
1299
1300 return mask;
1301 }
1302
1303 /*
1304 * register the device-specific control-ioctls.
1305 * called from each device manager like pcm.c, hwdep.c, etc.
1306 */
1307 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1308 {
1309 struct snd_kctl_ioctl *pn;
1310
1311 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1312 if (pn == NULL)
1313 return -ENOMEM;
1314 pn->fioctl = fcn;
1315 down_write(&snd_ioctl_rwsem);
1316 list_add_tail(&pn->list, lists);
1317 up_write(&snd_ioctl_rwsem);
1318 return 0;
1319 }
1320
1321 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1322 {
1323 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1324 }
1325
1326 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1327
1328 #ifdef CONFIG_COMPAT
1329 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1330 {
1331 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1332 }
1333
1334 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1335 #endif
1336
1337 /*
1338 * de-register the device-specific control-ioctls.
1339 */
1340 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1341 struct list_head *lists)
1342 {
1343 struct snd_kctl_ioctl *p;
1344
1345 snd_assert(fcn != NULL, return -EINVAL);
1346 down_write(&snd_ioctl_rwsem);
1347 list_for_each_entry(p, lists, list) {
1348 if (p->fioctl == fcn) {
1349 list_del(&p->list);
1350 up_write(&snd_ioctl_rwsem);
1351 kfree(p);
1352 return 0;
1353 }
1354 }
1355 up_write(&snd_ioctl_rwsem);
1356 snd_BUG();
1357 return -EINVAL;
1358 }
1359
1360 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1361 {
1362 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1363 }
1364
1365 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1366
1367 #ifdef CONFIG_COMPAT
1368 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1369 {
1370 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1371 }
1372
1373 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1374 #endif
1375
1376 static int snd_ctl_fasync(int fd, struct file * file, int on)
1377 {
1378 struct snd_ctl_file *ctl;
1379 int err;
1380 ctl = file->private_data;
1381 err = fasync_helper(fd, file, on, &ctl->fasync);
1382 if (err < 0)
1383 return err;
1384 return 0;
1385 }
1386
1387 /*
1388 * ioctl32 compat
1389 */
1390 #ifdef CONFIG_COMPAT
1391 #include "control_compat.c"
1392 #else
1393 #define snd_ctl_ioctl_compat NULL
1394 #endif
1395
1396 /*
1397 * INIT PART
1398 */
1399
1400 static const struct file_operations snd_ctl_f_ops =
1401 {
1402 .owner = THIS_MODULE,
1403 .read = snd_ctl_read,
1404 .open = snd_ctl_open,
1405 .release = snd_ctl_release,
1406 .poll = snd_ctl_poll,
1407 .unlocked_ioctl = snd_ctl_ioctl,
1408 .compat_ioctl = snd_ctl_ioctl_compat,
1409 .fasync = snd_ctl_fasync,
1410 };
1411
1412 /*
1413 * registration of the control device
1414 */
1415 static int snd_ctl_dev_register(struct snd_device *device)
1416 {
1417 struct snd_card *card = device->device_data;
1418 int err, cardnum;
1419 char name[16];
1420
1421 snd_assert(card != NULL, return -ENXIO);
1422 cardnum = card->number;
1423 snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1424 sprintf(name, "controlC%i", cardnum);
1425 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1426 &snd_ctl_f_ops, card, name)) < 0)
1427 return err;
1428 return 0;
1429 }
1430
1431 /*
1432 * disconnection of the control device
1433 */
1434 static int snd_ctl_dev_disconnect(struct snd_device *device)
1435 {
1436 struct snd_card *card = device->device_data;
1437 struct snd_ctl_file *ctl;
1438 int err, cardnum;
1439
1440 snd_assert(card != NULL, return -ENXIO);
1441 cardnum = card->number;
1442 snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1443
1444 down_read(&card->controls_rwsem);
1445 list_for_each_entry(ctl, &card->ctl_files, list) {
1446 wake_up(&ctl->change_sleep);
1447 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1448 }
1449 up_read(&card->controls_rwsem);
1450
1451 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1452 card, -1)) < 0)
1453 return err;
1454 return 0;
1455 }
1456
1457 /*
1458 * free all controls
1459 */
1460 static int snd_ctl_dev_free(struct snd_device *device)
1461 {
1462 struct snd_card *card = device->device_data;
1463 struct snd_kcontrol *control;
1464
1465 down_write(&card->controls_rwsem);
1466 while (!list_empty(&card->controls)) {
1467 control = snd_kcontrol(card->controls.next);
1468 snd_ctl_remove(card, control);
1469 }
1470 up_write(&card->controls_rwsem);
1471 return 0;
1472 }
1473
1474 /*
1475 * create control core:
1476 * called from init.c
1477 */
1478 int snd_ctl_create(struct snd_card *card)
1479 {
1480 static struct snd_device_ops ops = {
1481 .dev_free = snd_ctl_dev_free,
1482 .dev_register = snd_ctl_dev_register,
1483 .dev_disconnect = snd_ctl_dev_disconnect,
1484 };
1485
1486 snd_assert(card != NULL, return -ENXIO);
1487 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1488 }
linux v2.6.22.y-op