xref: /openbmc/linux/sound/core/control.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
1 /*
2  *  Routines for driver control interface
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/threads.h>
23 #include <linux/interrupt.h>
24 #include <linux/slab.h>
25 #include <linux/vmalloc.h>
26 #include <linux/time.h>
27 #include <sound/core.h>
28 #include <sound/minors.h>
29 #include <sound/info.h>
30 #include <sound/control.h>
31 
32 /* max number of user-defined controls */
33 #define MAX_USER_CONTROLS	32
34 
35 struct snd_kctl_ioctl {
36 	struct list_head list;		/* list of all ioctls */
37 	snd_kctl_ioctl_func_t fioctl;
38 };
39 
40 static DECLARE_RWSEM(snd_ioctl_rwsem);
41 static LIST_HEAD(snd_control_ioctls);
42 #ifdef CONFIG_COMPAT
43 static LIST_HEAD(snd_control_compat_ioctls);
44 #endif
45 
46 static int snd_ctl_open(struct inode *inode, struct file *file)
47 {
48 	unsigned long flags;
49 	struct snd_card *card;
50 	struct snd_ctl_file *ctl;
51 	int err;
52 
53 	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
54 	if (!card) {
55 		err = -ENODEV;
56 		goto __error1;
57 	}
58 	err = snd_card_file_add(card, file);
59 	if (err < 0) {
60 		err = -ENODEV;
61 		goto __error1;
62 	}
63 	if (!try_module_get(card->module)) {
64 		err = -EFAULT;
65 		goto __error2;
66 	}
67 	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
68 	if (ctl == NULL) {
69 		err = -ENOMEM;
70 		goto __error;
71 	}
72 	INIT_LIST_HEAD(&ctl->events);
73 	init_waitqueue_head(&ctl->change_sleep);
74 	spin_lock_init(&ctl->read_lock);
75 	ctl->card = card;
76 	ctl->prefer_pcm_subdevice = -1;
77 	ctl->prefer_rawmidi_subdevice = -1;
78 	ctl->pid = get_pid(task_pid(current));
79 	file->private_data = ctl;
80 	write_lock_irqsave(&card->ctl_files_rwlock, flags);
81 	list_add_tail(&ctl->list, &card->ctl_files);
82 	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
83 	return 0;
84 
85       __error:
86 	module_put(card->module);
87       __error2:
88 	snd_card_file_remove(card, file);
89       __error1:
90       	return err;
91 }
92 
93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
94 {
95 	unsigned long flags;
96 	struct snd_kctl_event *cread;
97 
98 	spin_lock_irqsave(&ctl->read_lock, flags);
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_irqrestore(&ctl->read_lock, flags);
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 	file->private_data = NULL;
117 	card = ctl->card;
118 	write_lock_irqsave(&card->ctl_files_rwlock, flags);
119 	list_del(&ctl->list);
120 	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
121 	down_write(&card->controls_rwsem);
122 	list_for_each_entry(control, &card->controls, list)
123 		for (idx = 0; idx < control->count; idx++)
124 			if (control->vd[idx].owner == ctl)
125 				control->vd[idx].owner = NULL;
126 	up_write(&card->controls_rwsem);
127 	snd_ctl_empty_read_queue(ctl);
128 	put_pid(ctl->pid);
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 	if (snd_BUG_ON(!card || !id))
143 		return;
144 	read_lock(&card->ctl_files_rwlock);
145 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
146 	card->mixer_oss_change_count++;
147 #endif
148 	list_for_each_entry(ctl, &card->ctl_files, list) {
149 		if (!ctl->subscribed)
150 			continue;
151 		spin_lock_irqsave(&ctl->read_lock, flags);
152 		list_for_each_entry(ev, &ctl->events, list) {
153 			if (ev->id.numid == id->numid) {
154 				ev->mask |= mask;
155 				goto _found;
156 			}
157 		}
158 		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
159 		if (ev) {
160 			ev->id = *id;
161 			ev->mask = mask;
162 			list_add_tail(&ev->list, &ctl->events);
163 		} else {
164 			snd_printk(KERN_ERR "No memory available to allocate event\n");
165 		}
166 	_found:
167 		wake_up(&ctl->change_sleep);
168 		spin_unlock_irqrestore(&ctl->read_lock, flags);
169 		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
170 	}
171 	read_unlock(&card->ctl_files_rwlock);
172 }
173 
174 EXPORT_SYMBOL(snd_ctl_notify);
175 
176 /**
177  * snd_ctl_new - create a control instance from the template
178  * @control: the control template
179  * @access: the default control access
180  *
181  * Allocates a new struct snd_kcontrol instance and copies the given template
182  * to the new instance. It does not copy volatile data (access).
183  *
184  * Returns the pointer of the new instance, or NULL on failure.
185  */
186 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
187 					unsigned int access)
188 {
189 	struct snd_kcontrol *kctl;
190 	unsigned int idx;
191 
192 	if (snd_BUG_ON(!control || !control->count))
193 		return NULL;
194 	kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
195 	if (kctl == NULL) {
196 		snd_printk(KERN_ERR "Cannot allocate control instance\n");
197 		return NULL;
198 	}
199 	*kctl = *control;
200 	for (idx = 0; idx < kctl->count; idx++)
201 		kctl->vd[idx].access = access;
202 	return kctl;
203 }
204 
205 /**
206  * snd_ctl_new1 - create a control instance from the template
207  * @ncontrol: the initialization record
208  * @private_data: the private data to set
209  *
210  * Allocates a new struct snd_kcontrol instance and initialize from the given
211  * template.  When the access field of ncontrol is 0, it's assumed as
212  * READWRITE access. When the count field is 0, it's assumes as one.
213  *
214  * Returns the pointer of the newly generated instance, or NULL on failure.
215  */
216 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
217 				  void *private_data)
218 {
219 	struct snd_kcontrol kctl;
220 	unsigned int access;
221 
222 	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
223 		return NULL;
224 	memset(&kctl, 0, sizeof(kctl));
225 	kctl.id.iface = ncontrol->iface;
226 	kctl.id.device = ncontrol->device;
227 	kctl.id.subdevice = ncontrol->subdevice;
228 	if (ncontrol->name) {
229 		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
230 		if (strcmp(ncontrol->name, kctl.id.name) != 0)
231 			snd_printk(KERN_WARNING
232 				   "Control name '%s' truncated to '%s'\n",
233 				   ncontrol->name, kctl.id.name);
234 	}
235 	kctl.id.index = ncontrol->index;
236 	kctl.count = ncontrol->count ? ncontrol->count : 1;
237 	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
238 		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
239 				      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
240 		 		      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
241 		 		      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
242 	kctl.info = ncontrol->info;
243 	kctl.get = ncontrol->get;
244 	kctl.put = ncontrol->put;
245 	kctl.tlv.p = ncontrol->tlv.p;
246 	kctl.private_value = ncontrol->private_value;
247 	kctl.private_data = private_data;
248 	return snd_ctl_new(&kctl, access);
249 }
250 
251 EXPORT_SYMBOL(snd_ctl_new1);
252 
253 /**
254  * snd_ctl_free_one - release the control instance
255  * @kcontrol: the control instance
256  *
257  * Releases the control instance created via snd_ctl_new()
258  * or snd_ctl_new1().
259  * Don't call this after the control was added to the card.
260  */
261 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
262 {
263 	if (kcontrol) {
264 		if (kcontrol->private_free)
265 			kcontrol->private_free(kcontrol);
266 		kfree(kcontrol);
267 	}
268 }
269 
270 EXPORT_SYMBOL(snd_ctl_free_one);
271 
272 static unsigned int snd_ctl_hole_check(struct snd_card *card,
273 				       unsigned int count)
274 {
275 	struct snd_kcontrol *kctl;
276 
277 	list_for_each_entry(kctl, &card->controls, list) {
278 		if ((kctl->id.numid <= card->last_numid &&
279 		     kctl->id.numid + kctl->count > card->last_numid) ||
280 		    (kctl->id.numid <= card->last_numid + count - 1 &&
281 		     kctl->id.numid + kctl->count > card->last_numid + count - 1))
282 		    	return card->last_numid = kctl->id.numid + kctl->count - 1;
283 	}
284 	return card->last_numid;
285 }
286 
287 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
288 {
289 	unsigned int last_numid, iter = 100000;
290 
291 	last_numid = card->last_numid;
292 	while (last_numid != snd_ctl_hole_check(card, count)) {
293 		if (--iter == 0) {
294 			/* this situation is very unlikely */
295 			snd_printk(KERN_ERR "unable to allocate new control numid\n");
296 			return -ENOMEM;
297 		}
298 		last_numid = card->last_numid;
299 	}
300 	return 0;
301 }
302 
303 /**
304  * snd_ctl_add - add the control instance to the card
305  * @card: the card instance
306  * @kcontrol: the control instance to add
307  *
308  * Adds the control instance created via snd_ctl_new() or
309  * snd_ctl_new1() to the given card. Assigns also an unique
310  * numid used for fast search.
311  *
312  * Returns zero if successful, or a negative error code on failure.
313  *
314  * It frees automatically the control which cannot be added.
315  */
316 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
317 {
318 	struct snd_ctl_elem_id id;
319 	unsigned int idx;
320 	int err = -EINVAL;
321 
322 	if (! kcontrol)
323 		return err;
324 	if (snd_BUG_ON(!card || !kcontrol->info))
325 		goto error;
326 	id = kcontrol->id;
327 	down_write(&card->controls_rwsem);
328 	if (snd_ctl_find_id(card, &id)) {
329 		up_write(&card->controls_rwsem);
330 		snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
331 					id.iface,
332 					id.device,
333 					id.subdevice,
334 					id.name,
335 					id.index);
336 		err = -EBUSY;
337 		goto error;
338 	}
339 	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
340 		up_write(&card->controls_rwsem);
341 		err = -ENOMEM;
342 		goto error;
343 	}
344 	list_add_tail(&kcontrol->list, &card->controls);
345 	card->controls_count += kcontrol->count;
346 	kcontrol->id.numid = card->last_numid + 1;
347 	card->last_numid += kcontrol->count;
348 	up_write(&card->controls_rwsem);
349 	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
350 		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
351 	return 0;
352 
353  error:
354 	snd_ctl_free_one(kcontrol);
355 	return err;
356 }
357 
358 EXPORT_SYMBOL(snd_ctl_add);
359 
360 /**
361  * snd_ctl_remove - remove the control from the card and release it
362  * @card: the card instance
363  * @kcontrol: the control instance to remove
364  *
365  * Removes the control from the card and then releases the instance.
366  * You don't need to call snd_ctl_free_one(). You must be in
367  * the write lock - down_write(&card->controls_rwsem).
368  *
369  * Returns 0 if successful, or a negative error code on failure.
370  */
371 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
372 {
373 	struct snd_ctl_elem_id id;
374 	unsigned int idx;
375 
376 	if (snd_BUG_ON(!card || !kcontrol))
377 		return -EINVAL;
378 	list_del(&kcontrol->list);
379 	card->controls_count -= kcontrol->count;
380 	id = kcontrol->id;
381 	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
382 		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
383 	snd_ctl_free_one(kcontrol);
384 	return 0;
385 }
386 
387 EXPORT_SYMBOL(snd_ctl_remove);
388 
389 /**
390  * snd_ctl_remove_id - remove the control of the given id and release it
391  * @card: the card instance
392  * @id: the control id to remove
393  *
394  * Finds the control instance with the given id, removes it from the
395  * card list and releases it.
396  *
397  * Returns 0 if successful, or a negative error code on failure.
398  */
399 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
400 {
401 	struct snd_kcontrol *kctl;
402 	int ret;
403 
404 	down_write(&card->controls_rwsem);
405 	kctl = snd_ctl_find_id(card, id);
406 	if (kctl == NULL) {
407 		up_write(&card->controls_rwsem);
408 		return -ENOENT;
409 	}
410 	ret = snd_ctl_remove(card, kctl);
411 	up_write(&card->controls_rwsem);
412 	return ret;
413 }
414 
415 EXPORT_SYMBOL(snd_ctl_remove_id);
416 
417 /**
418  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
419  * @file: active control handle
420  * @id: the control id to remove
421  *
422  * Finds the control instance with the given id, removes it from the
423  * card list and releases it.
424  *
425  * Returns 0 if successful, or a negative error code on failure.
426  */
427 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
428 				   struct snd_ctl_elem_id *id)
429 {
430 	struct snd_card *card = file->card;
431 	struct snd_kcontrol *kctl;
432 	int idx, ret;
433 
434 	down_write(&card->controls_rwsem);
435 	kctl = snd_ctl_find_id(card, id);
436 	if (kctl == NULL) {
437 		ret = -ENOENT;
438 		goto error;
439 	}
440 	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
441 		ret = -EINVAL;
442 		goto error;
443 	}
444 	for (idx = 0; idx < kctl->count; idx++)
445 		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
446 			ret = -EBUSY;
447 			goto error;
448 		}
449 	ret = snd_ctl_remove(card, kctl);
450 	if (ret < 0)
451 		goto error;
452 	card->user_ctl_count--;
453 error:
454 	up_write(&card->controls_rwsem);
455 	return ret;
456 }
457 
458 /**
459  * snd_ctl_rename_id - replace the id of a control on the card
460  * @card: the card instance
461  * @src_id: the old id
462  * @dst_id: the new id
463  *
464  * Finds the control with the old id from the card, and replaces the
465  * id with the new one.
466  *
467  * Returns zero if successful, or a negative error code on failure.
468  */
469 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
470 		      struct snd_ctl_elem_id *dst_id)
471 {
472 	struct snd_kcontrol *kctl;
473 
474 	down_write(&card->controls_rwsem);
475 	kctl = snd_ctl_find_id(card, src_id);
476 	if (kctl == NULL) {
477 		up_write(&card->controls_rwsem);
478 		return -ENOENT;
479 	}
480 	kctl->id = *dst_id;
481 	kctl->id.numid = card->last_numid + 1;
482 	card->last_numid += kctl->count;
483 	up_write(&card->controls_rwsem);
484 	return 0;
485 }
486 
487 EXPORT_SYMBOL(snd_ctl_rename_id);
488 
489 /**
490  * snd_ctl_find_numid - find the control instance with the given number-id
491  * @card: the card instance
492  * @numid: the number-id to search
493  *
494  * Finds the control instance with the given number-id from the card.
495  *
496  * Returns the pointer of the instance if found, or NULL if not.
497  *
498  * The caller must down card->controls_rwsem before calling this function
499  * (if the race condition can happen).
500  */
501 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
502 {
503 	struct snd_kcontrol *kctl;
504 
505 	if (snd_BUG_ON(!card || !numid))
506 		return NULL;
507 	list_for_each_entry(kctl, &card->controls, list) {
508 		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
509 			return kctl;
510 	}
511 	return NULL;
512 }
513 
514 EXPORT_SYMBOL(snd_ctl_find_numid);
515 
516 /**
517  * snd_ctl_find_id - find the control instance with the given id
518  * @card: the card instance
519  * @id: the id to search
520  *
521  * Finds the control instance with the given id from the card.
522  *
523  * Returns the pointer of the instance if found, or NULL if not.
524  *
525  * The caller must down card->controls_rwsem before calling this function
526  * (if the race condition can happen).
527  */
528 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
529 				     struct snd_ctl_elem_id *id)
530 {
531 	struct snd_kcontrol *kctl;
532 
533 	if (snd_BUG_ON(!card || !id))
534 		return NULL;
535 	if (id->numid != 0)
536 		return snd_ctl_find_numid(card, id->numid);
537 	list_for_each_entry(kctl, &card->controls, list) {
538 		if (kctl->id.iface != id->iface)
539 			continue;
540 		if (kctl->id.device != id->device)
541 			continue;
542 		if (kctl->id.subdevice != id->subdevice)
543 			continue;
544 		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
545 			continue;
546 		if (kctl->id.index > id->index)
547 			continue;
548 		if (kctl->id.index + kctl->count <= id->index)
549 			continue;
550 		return kctl;
551 	}
552 	return NULL;
553 }
554 
555 EXPORT_SYMBOL(snd_ctl_find_id);
556 
557 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
558 			     unsigned int cmd, void __user *arg)
559 {
560 	struct snd_ctl_card_info *info;
561 
562 	info = kzalloc(sizeof(*info), GFP_KERNEL);
563 	if (! info)
564 		return -ENOMEM;
565 	down_read(&snd_ioctl_rwsem);
566 	info->card = card->number;
567 	strlcpy(info->id, card->id, sizeof(info->id));
568 	strlcpy(info->driver, card->driver, sizeof(info->driver));
569 	strlcpy(info->name, card->shortname, sizeof(info->name));
570 	strlcpy(info->longname, card->longname, sizeof(info->longname));
571 	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
572 	strlcpy(info->components, card->components, sizeof(info->components));
573 	up_read(&snd_ioctl_rwsem);
574 	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
575 		kfree(info);
576 		return -EFAULT;
577 	}
578 	kfree(info);
579 	return 0;
580 }
581 
582 static int snd_ctl_elem_list(struct snd_card *card,
583 			     struct snd_ctl_elem_list __user *_list)
584 {
585 	struct list_head *plist;
586 	struct snd_ctl_elem_list list;
587 	struct snd_kcontrol *kctl;
588 	struct snd_ctl_elem_id *dst, *id;
589 	unsigned int offset, space, first, jidx;
590 
591 	if (copy_from_user(&list, _list, sizeof(list)))
592 		return -EFAULT;
593 	offset = list.offset;
594 	space = list.space;
595 	first = 0;
596 	/* try limit maximum space */
597 	if (space > 16384)
598 		return -ENOMEM;
599 	if (space > 0) {
600 		/* allocate temporary buffer for atomic operation */
601 		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
602 		if (dst == NULL)
603 			return -ENOMEM;
604 		down_read(&card->controls_rwsem);
605 		list.count = card->controls_count;
606 		plist = card->controls.next;
607 		while (plist != &card->controls) {
608 			if (offset == 0)
609 				break;
610 			kctl = snd_kcontrol(plist);
611 			if (offset < kctl->count)
612 				break;
613 			offset -= kctl->count;
614 			plist = plist->next;
615 		}
616 		list.used = 0;
617 		id = dst;
618 		while (space > 0 && plist != &card->controls) {
619 			kctl = snd_kcontrol(plist);
620 			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
621 				snd_ctl_build_ioff(id, kctl, jidx);
622 				id++;
623 				space--;
624 				list.used++;
625 			}
626 			plist = plist->next;
627 			offset = 0;
628 		}
629 		up_read(&card->controls_rwsem);
630 		if (list.used > 0 &&
631 		    copy_to_user(list.pids, dst,
632 				 list.used * sizeof(struct snd_ctl_elem_id))) {
633 			vfree(dst);
634 			return -EFAULT;
635 		}
636 		vfree(dst);
637 	} else {
638 		down_read(&card->controls_rwsem);
639 		list.count = card->controls_count;
640 		up_read(&card->controls_rwsem);
641 	}
642 	if (copy_to_user(_list, &list, sizeof(list)))
643 		return -EFAULT;
644 	return 0;
645 }
646 
647 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
648 			     struct snd_ctl_elem_info *info)
649 {
650 	struct snd_card *card = ctl->card;
651 	struct snd_kcontrol *kctl;
652 	struct snd_kcontrol_volatile *vd;
653 	unsigned int index_offset;
654 	int result;
655 
656 	down_read(&card->controls_rwsem);
657 	kctl = snd_ctl_find_id(card, &info->id);
658 	if (kctl == NULL) {
659 		up_read(&card->controls_rwsem);
660 		return -ENOENT;
661 	}
662 #ifdef CONFIG_SND_DEBUG
663 	info->access = 0;
664 #endif
665 	result = kctl->info(kctl, info);
666 	if (result >= 0) {
667 		snd_BUG_ON(info->access);
668 		index_offset = snd_ctl_get_ioff(kctl, &info->id);
669 		vd = &kctl->vd[index_offset];
670 		snd_ctl_build_ioff(&info->id, kctl, index_offset);
671 		info->access = vd->access;
672 		if (vd->owner) {
673 			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
674 			if (vd->owner == ctl)
675 				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
676 			info->owner = pid_vnr(vd->owner->pid);
677 		} else {
678 			info->owner = -1;
679 		}
680 	}
681 	up_read(&card->controls_rwsem);
682 	return result;
683 }
684 
685 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
686 				  struct snd_ctl_elem_info __user *_info)
687 {
688 	struct snd_ctl_elem_info info;
689 	int result;
690 
691 	if (copy_from_user(&info, _info, sizeof(info)))
692 		return -EFAULT;
693 	snd_power_lock(ctl->card);
694 	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
695 	if (result >= 0)
696 		result = snd_ctl_elem_info(ctl, &info);
697 	snd_power_unlock(ctl->card);
698 	if (result >= 0)
699 		if (copy_to_user(_info, &info, sizeof(info)))
700 			return -EFAULT;
701 	return result;
702 }
703 
704 static int snd_ctl_elem_read(struct snd_card *card,
705 			     struct snd_ctl_elem_value *control)
706 {
707 	struct snd_kcontrol *kctl;
708 	struct snd_kcontrol_volatile *vd;
709 	unsigned int index_offset;
710 	int result;
711 
712 	down_read(&card->controls_rwsem);
713 	kctl = snd_ctl_find_id(card, &control->id);
714 	if (kctl == NULL) {
715 		result = -ENOENT;
716 	} else {
717 		index_offset = snd_ctl_get_ioff(kctl, &control->id);
718 		vd = &kctl->vd[index_offset];
719 		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
720 		    kctl->get != NULL) {
721 			snd_ctl_build_ioff(&control->id, kctl, index_offset);
722 			result = kctl->get(kctl, control);
723 		} else
724 			result = -EPERM;
725 	}
726 	up_read(&card->controls_rwsem);
727 	return result;
728 }
729 
730 static int snd_ctl_elem_read_user(struct snd_card *card,
731 				  struct snd_ctl_elem_value __user *_control)
732 {
733 	struct snd_ctl_elem_value *control;
734 	int result;
735 
736 	control = memdup_user(_control, sizeof(*control));
737 	if (IS_ERR(control))
738 		return PTR_ERR(control);
739 
740 	snd_power_lock(card);
741 	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
742 	if (result >= 0)
743 		result = snd_ctl_elem_read(card, control);
744 	snd_power_unlock(card);
745 	if (result >= 0)
746 		if (copy_to_user(_control, control, sizeof(*control)))
747 			result = -EFAULT;
748 	kfree(control);
749 	return result;
750 }
751 
752 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
753 			      struct snd_ctl_elem_value *control)
754 {
755 	struct snd_kcontrol *kctl;
756 	struct snd_kcontrol_volatile *vd;
757 	unsigned int index_offset;
758 	int result;
759 
760 	down_read(&card->controls_rwsem);
761 	kctl = snd_ctl_find_id(card, &control->id);
762 	if (kctl == NULL) {
763 		result = -ENOENT;
764 	} else {
765 		index_offset = snd_ctl_get_ioff(kctl, &control->id);
766 		vd = &kctl->vd[index_offset];
767 		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
768 		    kctl->put == NULL ||
769 		    (file && vd->owner && vd->owner != file)) {
770 			result = -EPERM;
771 		} else {
772 			snd_ctl_build_ioff(&control->id, kctl, index_offset);
773 			result = kctl->put(kctl, control);
774 		}
775 		if (result > 0) {
776 			up_read(&card->controls_rwsem);
777 			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
778 				       &control->id);
779 			return 0;
780 		}
781 	}
782 	up_read(&card->controls_rwsem);
783 	return result;
784 }
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 = memdup_user(_control, sizeof(*control));
794 	if (IS_ERR(control))
795 		return PTR_ERR(control);
796 
797 	card = file->card;
798 	snd_power_lock(card);
799 	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
800 	if (result >= 0)
801 		result = snd_ctl_elem_write(card, file, control);
802 	snd_power_unlock(card);
803 	if (result >= 0)
804 		if (copy_to_user(_control, control, sizeof(*control)))
805 			result = -EFAULT;
806 	kfree(control);
807 	return result;
808 }
809 
810 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
811 			     struct snd_ctl_elem_id __user *_id)
812 {
813 	struct snd_card *card = file->card;
814 	struct snd_ctl_elem_id id;
815 	struct snd_kcontrol *kctl;
816 	struct snd_kcontrol_volatile *vd;
817 	int result;
818 
819 	if (copy_from_user(&id, _id, sizeof(id)))
820 		return -EFAULT;
821 	down_write(&card->controls_rwsem);
822 	kctl = snd_ctl_find_id(card, &id);
823 	if (kctl == NULL) {
824 		result = -ENOENT;
825 	} else {
826 		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
827 		if (vd->owner != NULL)
828 			result = -EBUSY;
829 		else {
830 			vd->owner = file;
831 			result = 0;
832 		}
833 	}
834 	up_write(&card->controls_rwsem);
835 	return result;
836 }
837 
838 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
839 			       struct snd_ctl_elem_id __user *_id)
840 {
841 	struct snd_card *card = file->card;
842 	struct snd_ctl_elem_id id;
843 	struct snd_kcontrol *kctl;
844 	struct snd_kcontrol_volatile *vd;
845 	int result;
846 
847 	if (copy_from_user(&id, _id, sizeof(id)))
848 		return -EFAULT;
849 	down_write(&card->controls_rwsem);
850 	kctl = snd_ctl_find_id(card, &id);
851 	if (kctl == NULL) {
852 		result = -ENOENT;
853 	} else {
854 		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
855 		if (vd->owner == NULL)
856 			result = -EINVAL;
857 		else if (vd->owner != file)
858 			result = -EPERM;
859 		else {
860 			vd->owner = NULL;
861 			result = 0;
862 		}
863 	}
864 	up_write(&card->controls_rwsem);
865 	return result;
866 }
867 
868 struct user_element {
869 	struct snd_ctl_elem_info info;
870 	void *elem_data;		/* element data */
871 	unsigned long elem_data_size;	/* size of element data in bytes */
872 	void *tlv_data;			/* TLV data */
873 	unsigned long tlv_data_size;	/* TLV data size */
874 	void *priv_data;		/* private data (like strings for enumerated type) */
875 	unsigned long priv_data_size;	/* size of private data in bytes */
876 };
877 
878 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
879 				  struct snd_ctl_elem_info *uinfo)
880 {
881 	struct user_element *ue = kcontrol->private_data;
882 
883 	*uinfo = ue->info;
884 	return 0;
885 }
886 
887 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
888 				 struct snd_ctl_elem_value *ucontrol)
889 {
890 	struct user_element *ue = kcontrol->private_data;
891 
892 	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
893 	return 0;
894 }
895 
896 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
897 				 struct snd_ctl_elem_value *ucontrol)
898 {
899 	int change;
900 	struct user_element *ue = kcontrol->private_data;
901 
902 	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
903 	if (change)
904 		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
905 	return change;
906 }
907 
908 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
909 				 int op_flag,
910 				 unsigned int size,
911 				 unsigned int __user *tlv)
912 {
913 	struct user_element *ue = kcontrol->private_data;
914 	int change = 0;
915 	void *new_data;
916 
917 	if (op_flag > 0) {
918 		if (size > 1024 * 128)	/* sane value */
919 			return -EINVAL;
920 
921 		new_data = memdup_user(tlv, size);
922 		if (IS_ERR(new_data))
923 			return PTR_ERR(new_data);
924 		change = ue->tlv_data_size != size;
925 		if (!change)
926 			change = memcmp(ue->tlv_data, new_data, size);
927 		kfree(ue->tlv_data);
928 		ue->tlv_data = new_data;
929 		ue->tlv_data_size = size;
930 	} else {
931 		if (! ue->tlv_data_size || ! ue->tlv_data)
932 			return -ENXIO;
933 		if (size < ue->tlv_data_size)
934 			return -ENOSPC;
935 		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
936 			return -EFAULT;
937 	}
938 	return change;
939 }
940 
941 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
942 {
943 	struct user_element *ue = kcontrol->private_data;
944 	if (ue->tlv_data)
945 		kfree(ue->tlv_data);
946 	kfree(ue);
947 }
948 
949 static int snd_ctl_elem_add(struct snd_ctl_file *file,
950 			    struct snd_ctl_elem_info *info, int replace)
951 {
952 	struct snd_card *card = file->card;
953 	struct snd_kcontrol kctl, *_kctl;
954 	unsigned int access;
955 	long private_size;
956 	struct user_element *ue;
957 	int idx, err;
958 
959 	if (card->user_ctl_count >= MAX_USER_CONTROLS)
960 		return -ENOMEM;
961 	if (info->count < 1)
962 		return -EINVAL;
963 	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
964 		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
965 				 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
966 				 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
967 	info->id.numid = 0;
968 	memset(&kctl, 0, sizeof(kctl));
969 	down_write(&card->controls_rwsem);
970 	_kctl = snd_ctl_find_id(card, &info->id);
971 	err = 0;
972 	if (_kctl) {
973 		if (replace)
974 			err = snd_ctl_remove(card, _kctl);
975 		else
976 			err = -EBUSY;
977 	} else {
978 		if (replace)
979 			err = -ENOENT;
980 	}
981 	up_write(&card->controls_rwsem);
982 	if (err < 0)
983 		return err;
984 	memcpy(&kctl.id, &info->id, sizeof(info->id));
985 	kctl.count = info->owner ? info->owner : 1;
986 	access |= SNDRV_CTL_ELEM_ACCESS_USER;
987 	kctl.info = snd_ctl_elem_user_info;
988 	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
989 		kctl.get = snd_ctl_elem_user_get;
990 	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
991 		kctl.put = snd_ctl_elem_user_put;
992 	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
993 		kctl.tlv.c = snd_ctl_elem_user_tlv;
994 		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
995 	}
996 	switch (info->type) {
997 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
998 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
999 		private_size = sizeof(long);
1000 		if (info->count > 128)
1001 			return -EINVAL;
1002 		break;
1003 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1004 		private_size = sizeof(long long);
1005 		if (info->count > 64)
1006 			return -EINVAL;
1007 		break;
1008 	case SNDRV_CTL_ELEM_TYPE_BYTES:
1009 		private_size = sizeof(unsigned char);
1010 		if (info->count > 512)
1011 			return -EINVAL;
1012 		break;
1013 	case SNDRV_CTL_ELEM_TYPE_IEC958:
1014 		private_size = sizeof(struct snd_aes_iec958);
1015 		if (info->count != 1)
1016 			return -EINVAL;
1017 		break;
1018 	default:
1019 		return -EINVAL;
1020 	}
1021 	private_size *= info->count;
1022 	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1023 	if (ue == NULL)
1024 		return -ENOMEM;
1025 	ue->info = *info;
1026 	ue->info.access = 0;
1027 	ue->elem_data = (char *)ue + sizeof(*ue);
1028 	ue->elem_data_size = private_size;
1029 	kctl.private_free = snd_ctl_elem_user_free;
1030 	_kctl = snd_ctl_new(&kctl, access);
1031 	if (_kctl == NULL) {
1032 		kfree(ue);
1033 		return -ENOMEM;
1034 	}
1035 	_kctl->private_data = ue;
1036 	for (idx = 0; idx < _kctl->count; idx++)
1037 		_kctl->vd[idx].owner = file;
1038 	err = snd_ctl_add(card, _kctl);
1039 	if (err < 0)
1040 		return err;
1041 
1042 	down_write(&card->controls_rwsem);
1043 	card->user_ctl_count++;
1044 	up_write(&card->controls_rwsem);
1045 
1046 	return 0;
1047 }
1048 
1049 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1050 				 struct snd_ctl_elem_info __user *_info, int replace)
1051 {
1052 	struct snd_ctl_elem_info info;
1053 	if (copy_from_user(&info, _info, sizeof(info)))
1054 		return -EFAULT;
1055 	return snd_ctl_elem_add(file, &info, replace);
1056 }
1057 
1058 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1059 			       struct snd_ctl_elem_id __user *_id)
1060 {
1061 	struct snd_ctl_elem_id id;
1062 
1063 	if (copy_from_user(&id, _id, sizeof(id)))
1064 		return -EFAULT;
1065 	return snd_ctl_remove_user_ctl(file, &id);
1066 }
1067 
1068 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1069 {
1070 	int subscribe;
1071 	if (get_user(subscribe, ptr))
1072 		return -EFAULT;
1073 	if (subscribe < 0) {
1074 		subscribe = file->subscribed;
1075 		if (put_user(subscribe, ptr))
1076 			return -EFAULT;
1077 		return 0;
1078 	}
1079 	if (subscribe) {
1080 		file->subscribed = 1;
1081 		return 0;
1082 	} else if (file->subscribed) {
1083 		snd_ctl_empty_read_queue(file);
1084 		file->subscribed = 0;
1085 	}
1086 	return 0;
1087 }
1088 
1089 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1090                              struct snd_ctl_tlv __user *_tlv,
1091                              int op_flag)
1092 {
1093 	struct snd_card *card = file->card;
1094 	struct snd_ctl_tlv tlv;
1095 	struct snd_kcontrol *kctl;
1096 	struct snd_kcontrol_volatile *vd;
1097 	unsigned int len;
1098 	int err = 0;
1099 
1100 	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1101 		return -EFAULT;
1102 	if (tlv.length < sizeof(unsigned int) * 3)
1103 		return -EINVAL;
1104 	down_read(&card->controls_rwsem);
1105 	kctl = snd_ctl_find_numid(card, tlv.numid);
1106 	if (kctl == NULL) {
1107 		err = -ENOENT;
1108 		goto __kctl_end;
1109 	}
1110 	if (kctl->tlv.p == NULL) {
1111 		err = -ENXIO;
1112 		goto __kctl_end;
1113 	}
1114 	vd = &kctl->vd[tlv.numid - kctl->id.numid];
1115 	if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1116 	    (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1117 	    (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1118 	    	err = -ENXIO;
1119 	    	goto __kctl_end;
1120 	}
1121 	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1122 		if (vd->owner != NULL && vd->owner != file) {
1123 			err = -EPERM;
1124 			goto __kctl_end;
1125 		}
1126 		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1127 		if (err > 0) {
1128 			up_read(&card->controls_rwsem);
1129 			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1130 			return 0;
1131 		}
1132 	} else {
1133 		if (op_flag) {
1134 			err = -ENXIO;
1135 			goto __kctl_end;
1136 		}
1137 		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1138 		if (tlv.length < len) {
1139 			err = -ENOMEM;
1140 			goto __kctl_end;
1141 		}
1142 		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1143 			err = -EFAULT;
1144 	}
1145       __kctl_end:
1146 	up_read(&card->controls_rwsem);
1147 	return err;
1148 }
1149 
1150 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1151 {
1152 	struct snd_ctl_file *ctl;
1153 	struct snd_card *card;
1154 	struct snd_kctl_ioctl *p;
1155 	void __user *argp = (void __user *)arg;
1156 	int __user *ip = argp;
1157 	int err;
1158 
1159 	ctl = file->private_data;
1160 	card = ctl->card;
1161 	if (snd_BUG_ON(!card))
1162 		return -ENXIO;
1163 	switch (cmd) {
1164 	case SNDRV_CTL_IOCTL_PVERSION:
1165 		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1166 	case SNDRV_CTL_IOCTL_CARD_INFO:
1167 		return snd_ctl_card_info(card, ctl, cmd, argp);
1168 	case SNDRV_CTL_IOCTL_ELEM_LIST:
1169 		return snd_ctl_elem_list(card, argp);
1170 	case SNDRV_CTL_IOCTL_ELEM_INFO:
1171 		return snd_ctl_elem_info_user(ctl, argp);
1172 	case SNDRV_CTL_IOCTL_ELEM_READ:
1173 		return snd_ctl_elem_read_user(card, argp);
1174 	case SNDRV_CTL_IOCTL_ELEM_WRITE:
1175 		return snd_ctl_elem_write_user(ctl, argp);
1176 	case SNDRV_CTL_IOCTL_ELEM_LOCK:
1177 		return snd_ctl_elem_lock(ctl, argp);
1178 	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1179 		return snd_ctl_elem_unlock(ctl, argp);
1180 	case SNDRV_CTL_IOCTL_ELEM_ADD:
1181 		return snd_ctl_elem_add_user(ctl, argp, 0);
1182 	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1183 		return snd_ctl_elem_add_user(ctl, argp, 1);
1184 	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1185 		return snd_ctl_elem_remove(ctl, argp);
1186 	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1187 		return snd_ctl_subscribe_events(ctl, ip);
1188 	case SNDRV_CTL_IOCTL_TLV_READ:
1189 		return snd_ctl_tlv_ioctl(ctl, argp, 0);
1190 	case SNDRV_CTL_IOCTL_TLV_WRITE:
1191 		return snd_ctl_tlv_ioctl(ctl, argp, 1);
1192 	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1193 		return snd_ctl_tlv_ioctl(ctl, argp, -1);
1194 	case SNDRV_CTL_IOCTL_POWER:
1195 		return -ENOPROTOOPT;
1196 	case SNDRV_CTL_IOCTL_POWER_STATE:
1197 #ifdef CONFIG_PM
1198 		return put_user(card->power_state, ip) ? -EFAULT : 0;
1199 #else
1200 		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1201 #endif
1202 	}
1203 	down_read(&snd_ioctl_rwsem);
1204 	list_for_each_entry(p, &snd_control_ioctls, list) {
1205 		err = p->fioctl(card, ctl, cmd, arg);
1206 		if (err != -ENOIOCTLCMD) {
1207 			up_read(&snd_ioctl_rwsem);
1208 			return err;
1209 		}
1210 	}
1211 	up_read(&snd_ioctl_rwsem);
1212 	snd_printdd("unknown ioctl = 0x%x\n", cmd);
1213 	return -ENOTTY;
1214 }
1215 
1216 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1217 			    size_t count, loff_t * offset)
1218 {
1219 	struct snd_ctl_file *ctl;
1220 	int err = 0;
1221 	ssize_t result = 0;
1222 
1223 	ctl = file->private_data;
1224 	if (snd_BUG_ON(!ctl || !ctl->card))
1225 		return -ENXIO;
1226 	if (!ctl->subscribed)
1227 		return -EBADFD;
1228 	if (count < sizeof(struct snd_ctl_event))
1229 		return -EINVAL;
1230 	spin_lock_irq(&ctl->read_lock);
1231 	while (count >= sizeof(struct snd_ctl_event)) {
1232 		struct snd_ctl_event ev;
1233 		struct snd_kctl_event *kev;
1234 		while (list_empty(&ctl->events)) {
1235 			wait_queue_t wait;
1236 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1237 				err = -EAGAIN;
1238 				goto __end_lock;
1239 			}
1240 			init_waitqueue_entry(&wait, current);
1241 			add_wait_queue(&ctl->change_sleep, &wait);
1242 			set_current_state(TASK_INTERRUPTIBLE);
1243 			spin_unlock_irq(&ctl->read_lock);
1244 			schedule();
1245 			remove_wait_queue(&ctl->change_sleep, &wait);
1246 			if (signal_pending(current))
1247 				return -ERESTARTSYS;
1248 			spin_lock_irq(&ctl->read_lock);
1249 		}
1250 		kev = snd_kctl_event(ctl->events.next);
1251 		ev.type = SNDRV_CTL_EVENT_ELEM;
1252 		ev.data.elem.mask = kev->mask;
1253 		ev.data.elem.id = kev->id;
1254 		list_del(&kev->list);
1255 		spin_unlock_irq(&ctl->read_lock);
1256 		kfree(kev);
1257 		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1258 			err = -EFAULT;
1259 			goto __end;
1260 		}
1261 		spin_lock_irq(&ctl->read_lock);
1262 		buffer += sizeof(struct snd_ctl_event);
1263 		count -= sizeof(struct snd_ctl_event);
1264 		result += sizeof(struct snd_ctl_event);
1265 	}
1266       __end_lock:
1267 	spin_unlock_irq(&ctl->read_lock);
1268       __end:
1269       	return result > 0 ? result : err;
1270 }
1271 
1272 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1273 {
1274 	unsigned int mask;
1275 	struct snd_ctl_file *ctl;
1276 
1277 	ctl = file->private_data;
1278 	if (!ctl->subscribed)
1279 		return 0;
1280 	poll_wait(file, &ctl->change_sleep, wait);
1281 
1282 	mask = 0;
1283 	if (!list_empty(&ctl->events))
1284 		mask |= POLLIN | POLLRDNORM;
1285 
1286 	return mask;
1287 }
1288 
1289 /*
1290  * register the device-specific control-ioctls.
1291  * called from each device manager like pcm.c, hwdep.c, etc.
1292  */
1293 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1294 {
1295 	struct snd_kctl_ioctl *pn;
1296 
1297 	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1298 	if (pn == NULL)
1299 		return -ENOMEM;
1300 	pn->fioctl = fcn;
1301 	down_write(&snd_ioctl_rwsem);
1302 	list_add_tail(&pn->list, lists);
1303 	up_write(&snd_ioctl_rwsem);
1304 	return 0;
1305 }
1306 
1307 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1308 {
1309 	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1310 }
1311 
1312 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1313 
1314 #ifdef CONFIG_COMPAT
1315 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1316 {
1317 	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1318 }
1319 
1320 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1321 #endif
1322 
1323 /*
1324  * de-register the device-specific control-ioctls.
1325  */
1326 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1327 				     struct list_head *lists)
1328 {
1329 	struct snd_kctl_ioctl *p;
1330 
1331 	if (snd_BUG_ON(!fcn))
1332 		return -EINVAL;
1333 	down_write(&snd_ioctl_rwsem);
1334 	list_for_each_entry(p, lists, list) {
1335 		if (p->fioctl == fcn) {
1336 			list_del(&p->list);
1337 			up_write(&snd_ioctl_rwsem);
1338 			kfree(p);
1339 			return 0;
1340 		}
1341 	}
1342 	up_write(&snd_ioctl_rwsem);
1343 	snd_BUG();
1344 	return -EINVAL;
1345 }
1346 
1347 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1348 {
1349 	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1350 }
1351 
1352 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1353 
1354 #ifdef CONFIG_COMPAT
1355 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1356 {
1357 	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1358 }
1359 
1360 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1361 #endif
1362 
1363 static int snd_ctl_fasync(int fd, struct file * file, int on)
1364 {
1365 	struct snd_ctl_file *ctl;
1366 
1367 	ctl = file->private_data;
1368 	return fasync_helper(fd, file, on, &ctl->fasync);
1369 }
1370 
1371 /*
1372  * ioctl32 compat
1373  */
1374 #ifdef CONFIG_COMPAT
1375 #include "control_compat.c"
1376 #else
1377 #define snd_ctl_ioctl_compat	NULL
1378 #endif
1379 
1380 /*
1381  *  INIT PART
1382  */
1383 
1384 static const struct file_operations snd_ctl_f_ops =
1385 {
1386 	.owner =	THIS_MODULE,
1387 	.read =		snd_ctl_read,
1388 	.open =		snd_ctl_open,
1389 	.release =	snd_ctl_release,
1390 	.poll =		snd_ctl_poll,
1391 	.unlocked_ioctl =	snd_ctl_ioctl,
1392 	.compat_ioctl =	snd_ctl_ioctl_compat,
1393 	.fasync =	snd_ctl_fasync,
1394 };
1395 
1396 /*
1397  * registration of the control device
1398  */
1399 static int snd_ctl_dev_register(struct snd_device *device)
1400 {
1401 	struct snd_card *card = device->device_data;
1402 	int err, cardnum;
1403 	char name[16];
1404 
1405 	if (snd_BUG_ON(!card))
1406 		return -ENXIO;
1407 	cardnum = card->number;
1408 	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1409 		return -ENXIO;
1410 	sprintf(name, "controlC%i", cardnum);
1411 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1412 				       &snd_ctl_f_ops, card, name)) < 0)
1413 		return err;
1414 	return 0;
1415 }
1416 
1417 /*
1418  * disconnection of the control device
1419  */
1420 static int snd_ctl_dev_disconnect(struct snd_device *device)
1421 {
1422 	struct snd_card *card = device->device_data;
1423 	struct snd_ctl_file *ctl;
1424 	int err, cardnum;
1425 
1426 	if (snd_BUG_ON(!card))
1427 		return -ENXIO;
1428 	cardnum = card->number;
1429 	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1430 		return -ENXIO;
1431 
1432 	read_lock(&card->ctl_files_rwlock);
1433 	list_for_each_entry(ctl, &card->ctl_files, list) {
1434 		wake_up(&ctl->change_sleep);
1435 		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1436 	}
1437 	read_unlock(&card->ctl_files_rwlock);
1438 
1439 	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1440 					 card, -1)) < 0)
1441 		return err;
1442 	return 0;
1443 }
1444 
1445 /*
1446  * free all controls
1447  */
1448 static int snd_ctl_dev_free(struct snd_device *device)
1449 {
1450 	struct snd_card *card = device->device_data;
1451 	struct snd_kcontrol *control;
1452 
1453 	down_write(&card->controls_rwsem);
1454 	while (!list_empty(&card->controls)) {
1455 		control = snd_kcontrol(card->controls.next);
1456 		snd_ctl_remove(card, control);
1457 	}
1458 	up_write(&card->controls_rwsem);
1459 	return 0;
1460 }
1461 
1462 /*
1463  * create control core:
1464  * called from init.c
1465  */
1466 int snd_ctl_create(struct snd_card *card)
1467 {
1468 	static struct snd_device_ops ops = {
1469 		.dev_free = snd_ctl_dev_free,
1470 		.dev_register =	snd_ctl_dev_register,
1471 		.dev_disconnect = snd_ctl_dev_disconnect,
1472 	};
1473 
1474 	if (snd_BUG_ON(!card))
1475 		return -ENXIO;
1476 	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1477 }
1478 
1479 /*
1480  * Frequently used control callbacks
1481  */
1482 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1483 			      struct snd_ctl_elem_info *uinfo)
1484 {
1485 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1486 	uinfo->count = 1;
1487 	uinfo->value.integer.min = 0;
1488 	uinfo->value.integer.max = 1;
1489 	return 0;
1490 }
1491 
1492 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1493 
1494 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1495 				struct snd_ctl_elem_info *uinfo)
1496 {
1497 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1498 	uinfo->count = 2;
1499 	uinfo->value.integer.min = 0;
1500 	uinfo->value.integer.max = 1;
1501 	return 0;
1502 }
1503 
1504 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1505