Root/sound/core/control.c

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#define MAX_CONTROL_COUNT 1028
35
36struct snd_kctl_ioctl {
37    struct list_head list; /* list of all ioctls */
38    snd_kctl_ioctl_func_t fioctl;
39};
40
41static DECLARE_RWSEM(snd_ioctl_rwsem);
42static LIST_HEAD(snd_control_ioctls);
43#ifdef CONFIG_COMPAT
44static LIST_HEAD(snd_control_compat_ioctls);
45#endif
46
47static 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    err = nonseekable_open(inode, file);
55    if (err < 0)
56        return err;
57
58    card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
59    if (!card) {
60        err = -ENODEV;
61        goto __error1;
62    }
63    err = snd_card_file_add(card, file);
64    if (err < 0) {
65        err = -ENODEV;
66        goto __error1;
67    }
68    if (!try_module_get(card->module)) {
69        err = -EFAULT;
70        goto __error2;
71    }
72    ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
73    if (ctl == NULL) {
74        err = -ENOMEM;
75        goto __error;
76    }
77    INIT_LIST_HEAD(&ctl->events);
78    init_waitqueue_head(&ctl->change_sleep);
79    spin_lock_init(&ctl->read_lock);
80    ctl->card = card;
81    ctl->prefer_pcm_subdevice = -1;
82    ctl->prefer_rawmidi_subdevice = -1;
83    ctl->pid = get_pid(task_pid(current));
84    file->private_data = ctl;
85    write_lock_irqsave(&card->ctl_files_rwlock, flags);
86    list_add_tail(&ctl->list, &card->ctl_files);
87    write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
88    return 0;
89
90      __error:
91    module_put(card->module);
92      __error2:
93    snd_card_file_remove(card, file);
94      __error1:
95          return err;
96}
97
98static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
99{
100    unsigned long flags;
101    struct snd_kctl_event *cread;
102    
103    spin_lock_irqsave(&ctl->read_lock, flags);
104    while (!list_empty(&ctl->events)) {
105        cread = snd_kctl_event(ctl->events.next);
106        list_del(&cread->list);
107        kfree(cread);
108    }
109    spin_unlock_irqrestore(&ctl->read_lock, flags);
110}
111
112static int snd_ctl_release(struct inode *inode, struct file *file)
113{
114    unsigned long flags;
115    struct snd_card *card;
116    struct snd_ctl_file *ctl;
117    struct snd_kcontrol *control;
118    unsigned int idx;
119
120    ctl = file->private_data;
121    file->private_data = NULL;
122    card = ctl->card;
123    write_lock_irqsave(&card->ctl_files_rwlock, flags);
124    list_del(&ctl->list);
125    write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
126    down_write(&card->controls_rwsem);
127    list_for_each_entry(control, &card->controls, list)
128        for (idx = 0; idx < control->count; idx++)
129            if (control->vd[idx].owner == ctl)
130                control->vd[idx].owner = NULL;
131    up_write(&card->controls_rwsem);
132    snd_ctl_empty_read_queue(ctl);
133    put_pid(ctl->pid);
134    kfree(ctl);
135    module_put(card->module);
136    snd_card_file_remove(card, file);
137    return 0;
138}
139
140void snd_ctl_notify(struct snd_card *card, unsigned int mask,
141            struct snd_ctl_elem_id *id)
142{
143    unsigned long flags;
144    struct snd_ctl_file *ctl;
145    struct snd_kctl_event *ev;
146    
147    if (snd_BUG_ON(!card || !id))
148        return;
149    read_lock(&card->ctl_files_rwlock);
150#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
151    card->mixer_oss_change_count++;
152#endif
153    list_for_each_entry(ctl, &card->ctl_files, list) {
154        if (!ctl->subscribed)
155            continue;
156        spin_lock_irqsave(&ctl->read_lock, flags);
157        list_for_each_entry(ev, &ctl->events, list) {
158            if (ev->id.numid == id->numid) {
159                ev->mask |= mask;
160                goto _found;
161            }
162        }
163        ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
164        if (ev) {
165            ev->id = *id;
166            ev->mask = mask;
167            list_add_tail(&ev->list, &ctl->events);
168        } else {
169            snd_printk(KERN_ERR "No memory available to allocate event\n");
170        }
171    _found:
172        wake_up(&ctl->change_sleep);
173        spin_unlock_irqrestore(&ctl->read_lock, flags);
174        kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
175    }
176    read_unlock(&card->ctl_files_rwlock);
177}
178
179EXPORT_SYMBOL(snd_ctl_notify);
180
181/**
182 * snd_ctl_new - create a control instance from the template
183 * @control: the control template
184 * @access: the default control access
185 *
186 * Allocates a new struct snd_kcontrol instance and copies the given template
187 * to the new instance. It does not copy volatile data (access).
188 *
189 * Returns the pointer of the new instance, or NULL on failure.
190 */
191static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
192                    unsigned int access)
193{
194    struct snd_kcontrol *kctl;
195    unsigned int idx;
196    
197    if (snd_BUG_ON(!control || !control->count))
198        return NULL;
199
200    if (control->count > MAX_CONTROL_COUNT)
201        return NULL;
202
203    kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
204    if (kctl == NULL) {
205        snd_printk(KERN_ERR "Cannot allocate control instance\n");
206        return NULL;
207    }
208    *kctl = *control;
209    for (idx = 0; idx < kctl->count; idx++)
210        kctl->vd[idx].access = access;
211    return kctl;
212}
213
214/**
215 * snd_ctl_new1 - create a control instance from the template
216 * @ncontrol: the initialization record
217 * @private_data: the private data to set
218 *
219 * Allocates a new struct snd_kcontrol instance and initialize from the given
220 * template. When the access field of ncontrol is 0, it's assumed as
221 * READWRITE access. When the count field is 0, it's assumes as one.
222 *
223 * Returns the pointer of the newly generated instance, or NULL on failure.
224 */
225struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
226                  void *private_data)
227{
228    struct snd_kcontrol kctl;
229    unsigned int access;
230    
231    if (snd_BUG_ON(!ncontrol || !ncontrol->info))
232        return NULL;
233    memset(&kctl, 0, sizeof(kctl));
234    kctl.id.iface = ncontrol->iface;
235    kctl.id.device = ncontrol->device;
236    kctl.id.subdevice = ncontrol->subdevice;
237    if (ncontrol->name) {
238        strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
239        if (strcmp(ncontrol->name, kctl.id.name) != 0)
240            snd_printk(KERN_WARNING
241                   "Control name '%s' truncated to '%s'\n",
242                   ncontrol->name, kctl.id.name);
243    }
244    kctl.id.index = ncontrol->index;
245    kctl.count = ncontrol->count ? ncontrol->count : 1;
246    access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
247         (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
248                      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
249                      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
250                      SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
251                      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
252    kctl.info = ncontrol->info;
253    kctl.get = ncontrol->get;
254    kctl.put = ncontrol->put;
255    kctl.tlv.p = ncontrol->tlv.p;
256    kctl.private_value = ncontrol->private_value;
257    kctl.private_data = private_data;
258    return snd_ctl_new(&kctl, access);
259}
260
261EXPORT_SYMBOL(snd_ctl_new1);
262
263/**
264 * snd_ctl_free_one - release the control instance
265 * @kcontrol: the control instance
266 *
267 * Releases the control instance created via snd_ctl_new()
268 * or snd_ctl_new1().
269 * Don't call this after the control was added to the card.
270 */
271void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
272{
273    if (kcontrol) {
274        if (kcontrol->private_free)
275            kcontrol->private_free(kcontrol);
276        kfree(kcontrol);
277    }
278}
279
280EXPORT_SYMBOL(snd_ctl_free_one);
281
282static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
283                      unsigned int count)
284{
285    struct snd_kcontrol *kctl;
286
287    list_for_each_entry(kctl, &card->controls, list) {
288        if (kctl->id.numid < card->last_numid + 1 + count &&
289            kctl->id.numid + kctl->count > card->last_numid + 1) {
290                card->last_numid = kctl->id.numid + kctl->count - 1;
291            return true;
292        }
293    }
294    return false;
295}
296
297static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
298{
299    unsigned int iter = 100000;
300
301    while (snd_ctl_remove_numid_conflict(card, count)) {
302        if (--iter == 0) {
303            /* this situation is very unlikely */
304            snd_printk(KERN_ERR "unable to allocate new control numid\n");
305            return -ENOMEM;
306        }
307    }
308    return 0;
309}
310
311/**
312 * snd_ctl_add - add the control instance to the card
313 * @card: the card instance
314 * @kcontrol: the control instance to add
315 *
316 * Adds the control instance created via snd_ctl_new() or
317 * snd_ctl_new1() to the given card. Assigns also an unique
318 * numid used for fast search.
319 *
320 * Returns zero if successful, or a negative error code on failure.
321 *
322 * It frees automatically the control which cannot be added.
323 */
324int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
325{
326    struct snd_ctl_elem_id id;
327    unsigned int idx;
328    int err = -EINVAL;
329
330    if (! kcontrol)
331        return err;
332    if (snd_BUG_ON(!card || !kcontrol->info))
333        goto error;
334    id = kcontrol->id;
335    down_write(&card->controls_rwsem);
336    if (snd_ctl_find_id(card, &id)) {
337        up_write(&card->controls_rwsem);
338        snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
339                    id.iface,
340                    id.device,
341                    id.subdevice,
342                    id.name,
343                    id.index);
344        err = -EBUSY;
345        goto error;
346    }
347    if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
348        up_write(&card->controls_rwsem);
349        err = -ENOMEM;
350        goto error;
351    }
352    list_add_tail(&kcontrol->list, &card->controls);
353    card->controls_count += kcontrol->count;
354    kcontrol->id.numid = card->last_numid + 1;
355    card->last_numid += kcontrol->count;
356    up_write(&card->controls_rwsem);
357    for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
358        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
359    return 0;
360
361 error:
362    snd_ctl_free_one(kcontrol);
363    return err;
364}
365
366EXPORT_SYMBOL(snd_ctl_add);
367
368/**
369 * snd_ctl_replace - replace the control instance of the card
370 * @card: the card instance
371 * @kcontrol: the control instance to replace
372 * @add_on_replace: add the control if not already added
373 *
374 * Replaces the given control. If the given control does not exist
375 * and the add_on_replace flag is set, the control is added. If the
376 * control exists, it is destroyed first.
377 *
378 * Returns zero if successful, or a negative error code on failure.
379 *
380 * It frees automatically the control which cannot be added or replaced.
381 */
382int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
383            bool add_on_replace)
384{
385    struct snd_ctl_elem_id id;
386    unsigned int idx;
387    struct snd_kcontrol *old;
388    int ret;
389
390    if (!kcontrol)
391        return -EINVAL;
392    if (snd_BUG_ON(!card || !kcontrol->info)) {
393        ret = -EINVAL;
394        goto error;
395    }
396    id = kcontrol->id;
397    down_write(&card->controls_rwsem);
398    old = snd_ctl_find_id(card, &id);
399    if (!old) {
400        if (add_on_replace)
401            goto add;
402        up_write(&card->controls_rwsem);
403        ret = -EINVAL;
404        goto error;
405    }
406    ret = snd_ctl_remove(card, old);
407    if (ret < 0) {
408        up_write(&card->controls_rwsem);
409        goto error;
410    }
411add:
412    if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
413        up_write(&card->controls_rwsem);
414        ret = -ENOMEM;
415        goto error;
416    }
417    list_add_tail(&kcontrol->list, &card->controls);
418    card->controls_count += kcontrol->count;
419    kcontrol->id.numid = card->last_numid + 1;
420    card->last_numid += kcontrol->count;
421    up_write(&card->controls_rwsem);
422    for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
423        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
424    return 0;
425
426error:
427    snd_ctl_free_one(kcontrol);
428    return ret;
429}
430EXPORT_SYMBOL(snd_ctl_replace);
431
432/**
433 * snd_ctl_remove - remove the control from the card and release it
434 * @card: the card instance
435 * @kcontrol: the control instance to remove
436 *
437 * Removes the control from the card and then releases the instance.
438 * You don't need to call snd_ctl_free_one(). You must be in
439 * the write lock - down_write(&card->controls_rwsem).
440 *
441 * Returns 0 if successful, or a negative error code on failure.
442 */
443int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
444{
445    struct snd_ctl_elem_id id;
446    unsigned int idx;
447
448    if (snd_BUG_ON(!card || !kcontrol))
449        return -EINVAL;
450    list_del(&kcontrol->list);
451    card->controls_count -= kcontrol->count;
452    id = kcontrol->id;
453    for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
454        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
455    snd_ctl_free_one(kcontrol);
456    return 0;
457}
458
459EXPORT_SYMBOL(snd_ctl_remove);
460
461/**
462 * snd_ctl_remove_id - remove the control of the given id and release it
463 * @card: the card instance
464 * @id: the control id to remove
465 *
466 * Finds the control instance with the given id, removes it from the
467 * card list and releases it.
468 *
469 * Returns 0 if successful, or a negative error code on failure.
470 */
471int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
472{
473    struct snd_kcontrol *kctl;
474    int ret;
475
476    down_write(&card->controls_rwsem);
477    kctl = snd_ctl_find_id(card, id);
478    if (kctl == NULL) {
479        up_write(&card->controls_rwsem);
480        return -ENOENT;
481    }
482    ret = snd_ctl_remove(card, kctl);
483    up_write(&card->controls_rwsem);
484    return ret;
485}
486
487EXPORT_SYMBOL(snd_ctl_remove_id);
488
489/**
490 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
491 * @file: active control handle
492 * @id: the control id to remove
493 *
494 * Finds the control instance with the given id, removes it from the
495 * card list and releases it.
496 *
497 * Returns 0 if successful, or a negative error code on failure.
498 */
499static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
500                   struct snd_ctl_elem_id *id)
501{
502    struct snd_card *card = file->card;
503    struct snd_kcontrol *kctl;
504    int idx, ret;
505
506    down_write(&card->controls_rwsem);
507    kctl = snd_ctl_find_id(card, id);
508    if (kctl == NULL) {
509        ret = -ENOENT;
510        goto error;
511    }
512    if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
513        ret = -EINVAL;
514        goto error;
515    }
516    for (idx = 0; idx < kctl->count; idx++)
517        if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
518            ret = -EBUSY;
519            goto error;
520        }
521    ret = snd_ctl_remove(card, kctl);
522    if (ret < 0)
523        goto error;
524    card->user_ctl_count--;
525error:
526    up_write(&card->controls_rwsem);
527    return ret;
528}
529
530/**
531 * snd_ctl_activate_id - activate/inactivate the control of the given id
532 * @card: the card instance
533 * @id: the control id to activate/inactivate
534 * @active: non-zero to activate
535 *
536 * Finds the control instance with the given id, and activate or
537 * inactivate the control together with notification, if changed.
538 *
539 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
540 */
541int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
542            int active)
543{
544    struct snd_kcontrol *kctl;
545    struct snd_kcontrol_volatile *vd;
546    unsigned int index_offset;
547    int ret;
548
549    down_write(&card->controls_rwsem);
550    kctl = snd_ctl_find_id(card, id);
551    if (kctl == NULL) {
552        ret = -ENOENT;
553        goto unlock;
554    }
555    index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
556    vd = &kctl->vd[index_offset];
557    ret = 0;
558    if (active) {
559        if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
560            goto unlock;
561        vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
562    } else {
563        if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
564            goto unlock;
565        vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
566    }
567    ret = 1;
568 unlock:
569    up_write(&card->controls_rwsem);
570    if (ret > 0)
571        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
572    return ret;
573}
574EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
575
576/**
577 * snd_ctl_rename_id - replace the id of a control on the card
578 * @card: the card instance
579 * @src_id: the old id
580 * @dst_id: the new id
581 *
582 * Finds the control with the old id from the card, and replaces the
583 * id with the new one.
584 *
585 * Returns zero if successful, or a negative error code on failure.
586 */
587int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
588              struct snd_ctl_elem_id *dst_id)
589{
590    struct snd_kcontrol *kctl;
591
592    down_write(&card->controls_rwsem);
593    kctl = snd_ctl_find_id(card, src_id);
594    if (kctl == NULL) {
595        up_write(&card->controls_rwsem);
596        return -ENOENT;
597    }
598    kctl->id = *dst_id;
599    kctl->id.numid = card->last_numid + 1;
600    card->last_numid += kctl->count;
601    up_write(&card->controls_rwsem);
602    return 0;
603}
604
605EXPORT_SYMBOL(snd_ctl_rename_id);
606
607/**
608 * snd_ctl_find_numid - find the control instance with the given number-id
609 * @card: the card instance
610 * @numid: the number-id to search
611 *
612 * Finds the control instance with the given number-id from the card.
613 *
614 * Returns the pointer of the instance if found, or NULL if not.
615 *
616 * The caller must down card->controls_rwsem before calling this function
617 * (if the race condition can happen).
618 */
619struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
620{
621    struct snd_kcontrol *kctl;
622
623    if (snd_BUG_ON(!card || !numid))
624        return NULL;
625    list_for_each_entry(kctl, &card->controls, list) {
626        if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
627            return kctl;
628    }
629    return NULL;
630}
631
632EXPORT_SYMBOL(snd_ctl_find_numid);
633
634/**
635 * snd_ctl_find_id - find the control instance with the given id
636 * @card: the card instance
637 * @id: the id to search
638 *
639 * Finds the control instance with the given id from the card.
640 *
641 * Returns the pointer of the instance if found, or NULL if not.
642 *
643 * The caller must down card->controls_rwsem before calling this function
644 * (if the race condition can happen).
645 */
646struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
647                     struct snd_ctl_elem_id *id)
648{
649    struct snd_kcontrol *kctl;
650
651    if (snd_BUG_ON(!card || !id))
652        return NULL;
653    if (id->numid != 0)
654        return snd_ctl_find_numid(card, id->numid);
655    list_for_each_entry(kctl, &card->controls, list) {
656        if (kctl->id.iface != id->iface)
657            continue;
658        if (kctl->id.device != id->device)
659            continue;
660        if (kctl->id.subdevice != id->subdevice)
661            continue;
662        if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
663            continue;
664        if (kctl->id.index > id->index)
665            continue;
666        if (kctl->id.index + kctl->count <= id->index)
667            continue;
668        return kctl;
669    }
670    return NULL;
671}
672
673EXPORT_SYMBOL(snd_ctl_find_id);
674
675static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
676                 unsigned int cmd, void __user *arg)
677{
678    struct snd_ctl_card_info *info;
679
680    info = kzalloc(sizeof(*info), GFP_KERNEL);
681    if (! info)
682        return -ENOMEM;
683    down_read(&snd_ioctl_rwsem);
684    info->card = card->number;
685    strlcpy(info->id, card->id, sizeof(info->id));
686    strlcpy(info->driver, card->driver, sizeof(info->driver));
687    strlcpy(info->name, card->shortname, sizeof(info->name));
688    strlcpy(info->longname, card->longname, sizeof(info->longname));
689    strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
690    strlcpy(info->components, card->components, sizeof(info->components));
691    up_read(&snd_ioctl_rwsem);
692    if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
693        kfree(info);
694        return -EFAULT;
695    }
696    kfree(info);
697    return 0;
698}
699
700static int snd_ctl_elem_list(struct snd_card *card,
701                 struct snd_ctl_elem_list __user *_list)
702{
703    struct list_head *plist;
704    struct snd_ctl_elem_list list;
705    struct snd_kcontrol *kctl;
706    struct snd_ctl_elem_id *dst, *id;
707    unsigned int offset, space, jidx;
708    
709    if (copy_from_user(&list, _list, sizeof(list)))
710        return -EFAULT;
711    offset = list.offset;
712    space = list.space;
713    /* try limit maximum space */
714    if (space > 16384)
715        return -ENOMEM;
716    if (space > 0) {
717        /* allocate temporary buffer for atomic operation */
718        dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
719        if (dst == NULL)
720            return -ENOMEM;
721        down_read(&card->controls_rwsem);
722        list.count = card->controls_count;
723        plist = card->controls.next;
724        while (plist != &card->controls) {
725            if (offset == 0)
726                break;
727            kctl = snd_kcontrol(plist);
728            if (offset < kctl->count)
729                break;
730            offset -= kctl->count;
731            plist = plist->next;
732        }
733        list.used = 0;
734        id = dst;
735        while (space > 0 && plist != &card->controls) {
736            kctl = snd_kcontrol(plist);
737            for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
738                snd_ctl_build_ioff(id, kctl, jidx);
739                id++;
740                space--;
741                list.used++;
742            }
743            plist = plist->next;
744            offset = 0;
745        }
746        up_read(&card->controls_rwsem);
747        if (list.used > 0 &&
748            copy_to_user(list.pids, dst,
749                 list.used * sizeof(struct snd_ctl_elem_id))) {
750            vfree(dst);
751            return -EFAULT;
752        }
753        vfree(dst);
754    } else {
755        down_read(&card->controls_rwsem);
756        list.count = card->controls_count;
757        up_read(&card->controls_rwsem);
758    }
759    if (copy_to_user(_list, &list, sizeof(list)))
760        return -EFAULT;
761    return 0;
762}
763
764static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
765                 struct snd_ctl_elem_info *info)
766{
767    struct snd_card *card = ctl->card;
768    struct snd_kcontrol *kctl;
769    struct snd_kcontrol_volatile *vd;
770    unsigned int index_offset;
771    int result;
772    
773    down_read(&card->controls_rwsem);
774    kctl = snd_ctl_find_id(card, &info->id);
775    if (kctl == NULL) {
776        up_read(&card->controls_rwsem);
777        return -ENOENT;
778    }
779#ifdef CONFIG_SND_DEBUG
780    info->access = 0;
781#endif
782    result = kctl->info(kctl, info);
783    if (result >= 0) {
784        snd_BUG_ON(info->access);
785        index_offset = snd_ctl_get_ioff(kctl, &info->id);
786        vd = &kctl->vd[index_offset];
787        snd_ctl_build_ioff(&info->id, kctl, index_offset);
788        info->access = vd->access;
789        if (vd->owner) {
790            info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
791            if (vd->owner == ctl)
792                info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
793            info->owner = pid_vnr(vd->owner->pid);
794        } else {
795            info->owner = -1;
796        }
797    }
798    up_read(&card->controls_rwsem);
799    return result;
800}
801
802static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
803                  struct snd_ctl_elem_info __user *_info)
804{
805    struct snd_ctl_elem_info info;
806    int result;
807
808    if (copy_from_user(&info, _info, sizeof(info)))
809        return -EFAULT;
810    snd_power_lock(ctl->card);
811    result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
812    if (result >= 0)
813        result = snd_ctl_elem_info(ctl, &info);
814    snd_power_unlock(ctl->card);
815    if (result >= 0)
816        if (copy_to_user(_info, &info, sizeof(info)))
817            return -EFAULT;
818    return result;
819}
820
821static int snd_ctl_elem_read(struct snd_card *card,
822                 struct snd_ctl_elem_value *control)
823{
824    struct snd_kcontrol *kctl;
825    struct snd_kcontrol_volatile *vd;
826    unsigned int index_offset;
827    int result;
828
829    down_read(&card->controls_rwsem);
830    kctl = snd_ctl_find_id(card, &control->id);
831    if (kctl == NULL) {
832        result = -ENOENT;
833    } else {
834        index_offset = snd_ctl_get_ioff(kctl, &control->id);
835        vd = &kctl->vd[index_offset];
836        if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
837            kctl->get != NULL) {
838            snd_ctl_build_ioff(&control->id, kctl, index_offset);
839            result = kctl->get(kctl, control);
840        } else
841            result = -EPERM;
842    }
843    up_read(&card->controls_rwsem);
844    return result;
845}
846
847static int snd_ctl_elem_read_user(struct snd_card *card,
848                  struct snd_ctl_elem_value __user *_control)
849{
850    struct snd_ctl_elem_value *control;
851    int result;
852
853    control = memdup_user(_control, sizeof(*control));
854    if (IS_ERR(control))
855        return PTR_ERR(control);
856
857    snd_power_lock(card);
858    result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
859    if (result >= 0)
860        result = snd_ctl_elem_read(card, control);
861    snd_power_unlock(card);
862    if (result >= 0)
863        if (copy_to_user(_control, control, sizeof(*control)))
864            result = -EFAULT;
865    kfree(control);
866    return result;
867}
868
869static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
870                  struct snd_ctl_elem_value *control)
871{
872    struct snd_kcontrol *kctl;
873    struct snd_kcontrol_volatile *vd;
874    unsigned int index_offset;
875    int result;
876
877    down_read(&card->controls_rwsem);
878    kctl = snd_ctl_find_id(card, &control->id);
879    if (kctl == NULL) {
880        result = -ENOENT;
881    } else {
882        index_offset = snd_ctl_get_ioff(kctl, &control->id);
883        vd = &kctl->vd[index_offset];
884        if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
885            kctl->put == NULL ||
886            (file && vd->owner && vd->owner != file)) {
887            result = -EPERM;
888        } else {
889            snd_ctl_build_ioff(&control->id, kctl, index_offset);
890            result = kctl->put(kctl, control);
891        }
892        if (result > 0) {
893            up_read(&card->controls_rwsem);
894            snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
895                       &control->id);
896            return 0;
897        }
898    }
899    up_read(&card->controls_rwsem);
900    return result;
901}
902
903static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
904                   struct snd_ctl_elem_value __user *_control)
905{
906    struct snd_ctl_elem_value *control;
907    struct snd_card *card;
908    int result;
909
910    control = memdup_user(_control, sizeof(*control));
911    if (IS_ERR(control))
912        return PTR_ERR(control);
913
914    card = file->card;
915    snd_power_lock(card);
916    result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
917    if (result >= 0)
918        result = snd_ctl_elem_write(card, file, control);
919    snd_power_unlock(card);
920    if (result >= 0)
921        if (copy_to_user(_control, control, sizeof(*control)))
922            result = -EFAULT;
923    kfree(control);
924    return result;
925}
926
927static int snd_ctl_elem_lock(struct snd_ctl_file *file,
928                 struct snd_ctl_elem_id __user *_id)
929{
930    struct snd_card *card = file->card;
931    struct snd_ctl_elem_id id;
932    struct snd_kcontrol *kctl;
933    struct snd_kcontrol_volatile *vd;
934    int result;
935    
936    if (copy_from_user(&id, _id, sizeof(id)))
937        return -EFAULT;
938    down_write(&card->controls_rwsem);
939    kctl = snd_ctl_find_id(card, &id);
940    if (kctl == NULL) {
941        result = -ENOENT;
942    } else {
943        vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
944        if (vd->owner != NULL)
945            result = -EBUSY;
946        else {
947            vd->owner = file;
948            result = 0;
949        }
950    }
951    up_write(&card->controls_rwsem);
952    return result;
953}
954
955static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
956                   struct snd_ctl_elem_id __user *_id)
957{
958    struct snd_card *card = file->card;
959    struct snd_ctl_elem_id id;
960    struct snd_kcontrol *kctl;
961    struct snd_kcontrol_volatile *vd;
962    int result;
963    
964    if (copy_from_user(&id, _id, sizeof(id)))
965        return -EFAULT;
966    down_write(&card->controls_rwsem);
967    kctl = snd_ctl_find_id(card, &id);
968    if (kctl == NULL) {
969        result = -ENOENT;
970    } else {
971        vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
972        if (vd->owner == NULL)
973            result = -EINVAL;
974        else if (vd->owner != file)
975            result = -EPERM;
976        else {
977            vd->owner = NULL;
978            result = 0;
979        }
980    }
981    up_write(&card->controls_rwsem);
982    return result;
983}
984
985struct user_element {
986    struct snd_ctl_elem_info info;
987    void *elem_data; /* element data */
988    unsigned long elem_data_size; /* size of element data in bytes */
989    void *tlv_data; /* TLV data */
990    unsigned long tlv_data_size; /* TLV data size */
991    void *priv_data; /* private data (like strings for enumerated type) */
992    unsigned long priv_data_size; /* size of private data in bytes */
993};
994
995static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
996                  struct snd_ctl_elem_info *uinfo)
997{
998    struct user_element *ue = kcontrol->private_data;
999
1000    *uinfo = ue->info;
1001    return 0;
1002}
1003
1004static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1005                 struct snd_ctl_elem_value *ucontrol)
1006{
1007    struct user_element *ue = kcontrol->private_data;
1008
1009    memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1010    return 0;
1011}
1012
1013static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1014                 struct snd_ctl_elem_value *ucontrol)
1015{
1016    int change;
1017    struct user_element *ue = kcontrol->private_data;
1018    
1019    change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1020    if (change)
1021        memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1022    return change;
1023}
1024
1025static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1026                 int op_flag,
1027                 unsigned int size,
1028                 unsigned int __user *tlv)
1029{
1030    struct user_element *ue = kcontrol->private_data;
1031    int change = 0;
1032    void *new_data;
1033
1034    if (op_flag > 0) {
1035        if (size > 1024 * 128) /* sane value */
1036            return -EINVAL;
1037
1038        new_data = memdup_user(tlv, size);
1039        if (IS_ERR(new_data))
1040            return PTR_ERR(new_data);
1041        change = ue->tlv_data_size != size;
1042        if (!change)
1043            change = memcmp(ue->tlv_data, new_data, size);
1044        kfree(ue->tlv_data);
1045        ue->tlv_data = new_data;
1046        ue->tlv_data_size = size;
1047    } else {
1048        if (! ue->tlv_data_size || ! ue->tlv_data)
1049            return -ENXIO;
1050        if (size < ue->tlv_data_size)
1051            return -ENOSPC;
1052        if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1053            return -EFAULT;
1054    }
1055    return change;
1056}
1057
1058static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1059{
1060    struct user_element *ue = kcontrol->private_data;
1061    if (ue->tlv_data)
1062        kfree(ue->tlv_data);
1063    kfree(ue);
1064}
1065
1066static int snd_ctl_elem_add(struct snd_ctl_file *file,
1067                struct snd_ctl_elem_info *info, int replace)
1068{
1069    struct snd_card *card = file->card;
1070    struct snd_kcontrol kctl, *_kctl;
1071    unsigned int access;
1072    long private_size;
1073    struct user_element *ue;
1074    int idx, err;
1075    
1076    if (card->user_ctl_count >= MAX_USER_CONTROLS)
1077        return -ENOMEM;
1078    if (info->count < 1)
1079        return -EINVAL;
1080    access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1081        (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1082                 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1083                 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1084    info->id.numid = 0;
1085    memset(&kctl, 0, sizeof(kctl));
1086    down_write(&card->controls_rwsem);
1087    _kctl = snd_ctl_find_id(card, &info->id);
1088    err = 0;
1089    if (_kctl) {
1090        if (replace)
1091            err = snd_ctl_remove(card, _kctl);
1092        else
1093            err = -EBUSY;
1094    } else {
1095        if (replace)
1096            err = -ENOENT;
1097    }
1098    up_write(&card->controls_rwsem);
1099    if (err < 0)
1100        return err;
1101    memcpy(&kctl.id, &info->id, sizeof(info->id));
1102    kctl.count = info->owner ? info->owner : 1;
1103    access |= SNDRV_CTL_ELEM_ACCESS_USER;
1104    kctl.info = snd_ctl_elem_user_info;
1105    if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1106        kctl.get = snd_ctl_elem_user_get;
1107    if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1108        kctl.put = snd_ctl_elem_user_put;
1109    if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1110        kctl.tlv.c = snd_ctl_elem_user_tlv;
1111        access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1112    }
1113    switch (info->type) {
1114    case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1115    case SNDRV_CTL_ELEM_TYPE_INTEGER:
1116        private_size = sizeof(long);
1117        if (info->count > 128)
1118            return -EINVAL;
1119        break;
1120    case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1121        private_size = sizeof(long long);
1122        if (info->count > 64)
1123            return -EINVAL;
1124        break;
1125    case SNDRV_CTL_ELEM_TYPE_BYTES:
1126        private_size = sizeof(unsigned char);
1127        if (info->count > 512)
1128            return -EINVAL;
1129        break;
1130    case SNDRV_CTL_ELEM_TYPE_IEC958:
1131        private_size = sizeof(struct snd_aes_iec958);
1132        if (info->count != 1)
1133            return -EINVAL;
1134        break;
1135    default:
1136        return -EINVAL;
1137    }
1138    private_size *= info->count;
1139    ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1140    if (ue == NULL)
1141        return -ENOMEM;
1142    ue->info = *info;
1143    ue->info.access = 0;
1144    ue->elem_data = (char *)ue + sizeof(*ue);
1145    ue->elem_data_size = private_size;
1146    kctl.private_free = snd_ctl_elem_user_free;
1147    _kctl = snd_ctl_new(&kctl, access);
1148    if (_kctl == NULL) {
1149        kfree(ue);
1150        return -ENOMEM;
1151    }
1152    _kctl->private_data = ue;
1153    for (idx = 0; idx < _kctl->count; idx++)
1154        _kctl->vd[idx].owner = file;
1155    err = snd_ctl_add(card, _kctl);
1156    if (err < 0)
1157        return err;
1158
1159    down_write(&card->controls_rwsem);
1160    card->user_ctl_count++;
1161    up_write(&card->controls_rwsem);
1162
1163    return 0;
1164}
1165
1166static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1167                 struct snd_ctl_elem_info __user *_info, int replace)
1168{
1169    struct snd_ctl_elem_info info;
1170    if (copy_from_user(&info, _info, sizeof(info)))
1171        return -EFAULT;
1172    return snd_ctl_elem_add(file, &info, replace);
1173}
1174
1175static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1176                   struct snd_ctl_elem_id __user *_id)
1177{
1178    struct snd_ctl_elem_id id;
1179
1180    if (copy_from_user(&id, _id, sizeof(id)))
1181        return -EFAULT;
1182    return snd_ctl_remove_user_ctl(file, &id);
1183}
1184
1185static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1186{
1187    int subscribe;
1188    if (get_user(subscribe, ptr))
1189        return -EFAULT;
1190    if (subscribe < 0) {
1191        subscribe = file->subscribed;
1192        if (put_user(subscribe, ptr))
1193            return -EFAULT;
1194        return 0;
1195    }
1196    if (subscribe) {
1197        file->subscribed = 1;
1198        return 0;
1199    } else if (file->subscribed) {
1200        snd_ctl_empty_read_queue(file);
1201        file->subscribed = 0;
1202    }
1203    return 0;
1204}
1205
1206static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1207                             struct snd_ctl_tlv __user *_tlv,
1208                             int op_flag)
1209{
1210    struct snd_card *card = file->card;
1211    struct snd_ctl_tlv tlv;
1212    struct snd_kcontrol *kctl;
1213    struct snd_kcontrol_volatile *vd;
1214    unsigned int len;
1215    int err = 0;
1216
1217    if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1218        return -EFAULT;
1219    if (tlv.length < sizeof(unsigned int) * 2)
1220        return -EINVAL;
1221    down_read(&card->controls_rwsem);
1222    kctl = snd_ctl_find_numid(card, tlv.numid);
1223    if (kctl == NULL) {
1224        err = -ENOENT;
1225        goto __kctl_end;
1226    }
1227    if (kctl->tlv.p == NULL) {
1228        err = -ENXIO;
1229        goto __kctl_end;
1230    }
1231    vd = &kctl->vd[tlv.numid - kctl->id.numid];
1232    if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1233        (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1234        (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1235            err = -ENXIO;
1236            goto __kctl_end;
1237    }
1238    if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1239        if (vd->owner != NULL && vd->owner != file) {
1240            err = -EPERM;
1241            goto __kctl_end;
1242        }
1243        err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1244        if (err > 0) {
1245            up_read(&card->controls_rwsem);
1246            snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1247            return 0;
1248        }
1249    } else {
1250        if (op_flag) {
1251            err = -ENXIO;
1252            goto __kctl_end;
1253        }
1254        len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1255        if (tlv.length < len) {
1256            err = -ENOMEM;
1257            goto __kctl_end;
1258        }
1259        if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1260            err = -EFAULT;
1261    }
1262      __kctl_end:
1263    up_read(&card->controls_rwsem);
1264    return err;
1265}
1266
1267static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1268{
1269    struct snd_ctl_file *ctl;
1270    struct snd_card *card;
1271    struct snd_kctl_ioctl *p;
1272    void __user *argp = (void __user *)arg;
1273    int __user *ip = argp;
1274    int err;
1275
1276    ctl = file->private_data;
1277    card = ctl->card;
1278    if (snd_BUG_ON(!card))
1279        return -ENXIO;
1280    switch (cmd) {
1281    case SNDRV_CTL_IOCTL_PVERSION:
1282        return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1283    case SNDRV_CTL_IOCTL_CARD_INFO:
1284        return snd_ctl_card_info(card, ctl, cmd, argp);
1285    case SNDRV_CTL_IOCTL_ELEM_LIST:
1286        return snd_ctl_elem_list(card, argp);
1287    case SNDRV_CTL_IOCTL_ELEM_INFO:
1288        return snd_ctl_elem_info_user(ctl, argp);
1289    case SNDRV_CTL_IOCTL_ELEM_READ:
1290        return snd_ctl_elem_read_user(card, argp);
1291    case SNDRV_CTL_IOCTL_ELEM_WRITE:
1292        return snd_ctl_elem_write_user(ctl, argp);
1293    case SNDRV_CTL_IOCTL_ELEM_LOCK:
1294        return snd_ctl_elem_lock(ctl, argp);
1295    case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1296        return snd_ctl_elem_unlock(ctl, argp);
1297    case SNDRV_CTL_IOCTL_ELEM_ADD:
1298        return snd_ctl_elem_add_user(ctl, argp, 0);
1299    case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1300        return snd_ctl_elem_add_user(ctl, argp, 1);
1301    case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1302        return snd_ctl_elem_remove(ctl, argp);
1303    case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1304        return snd_ctl_subscribe_events(ctl, ip);
1305    case SNDRV_CTL_IOCTL_TLV_READ:
1306        return snd_ctl_tlv_ioctl(ctl, argp, 0);
1307    case SNDRV_CTL_IOCTL_TLV_WRITE:
1308        return snd_ctl_tlv_ioctl(ctl, argp, 1);
1309    case SNDRV_CTL_IOCTL_TLV_COMMAND:
1310        return snd_ctl_tlv_ioctl(ctl, argp, -1);
1311    case SNDRV_CTL_IOCTL_POWER:
1312        return -ENOPROTOOPT;
1313    case SNDRV_CTL_IOCTL_POWER_STATE:
1314#ifdef CONFIG_PM
1315        return put_user(card->power_state, ip) ? -EFAULT : 0;
1316#else
1317        return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1318#endif
1319    }
1320    down_read(&snd_ioctl_rwsem);
1321    list_for_each_entry(p, &snd_control_ioctls, list) {
1322        err = p->fioctl(card, ctl, cmd, arg);
1323        if (err != -ENOIOCTLCMD) {
1324            up_read(&snd_ioctl_rwsem);
1325            return err;
1326        }
1327    }
1328    up_read(&snd_ioctl_rwsem);
1329    snd_printdd("unknown ioctl = 0x%x\n", cmd);
1330    return -ENOTTY;
1331}
1332
1333static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1334                size_t count, loff_t * offset)
1335{
1336    struct snd_ctl_file *ctl;
1337    int err = 0;
1338    ssize_t result = 0;
1339
1340    ctl = file->private_data;
1341    if (snd_BUG_ON(!ctl || !ctl->card))
1342        return -ENXIO;
1343    if (!ctl->subscribed)
1344        return -EBADFD;
1345    if (count < sizeof(struct snd_ctl_event))
1346        return -EINVAL;
1347    spin_lock_irq(&ctl->read_lock);
1348    while (count >= sizeof(struct snd_ctl_event)) {
1349        struct snd_ctl_event ev;
1350        struct snd_kctl_event *kev;
1351        while (list_empty(&ctl->events)) {
1352            wait_queue_t wait;
1353            if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1354                err = -EAGAIN;
1355                goto __end_lock;
1356            }
1357            init_waitqueue_entry(&wait, current);
1358            add_wait_queue(&ctl->change_sleep, &wait);
1359            set_current_state(TASK_INTERRUPTIBLE);
1360            spin_unlock_irq(&ctl->read_lock);
1361            schedule();
1362            remove_wait_queue(&ctl->change_sleep, &wait);
1363            if (signal_pending(current))
1364                return -ERESTARTSYS;
1365            spin_lock_irq(&ctl->read_lock);
1366        }
1367        kev = snd_kctl_event(ctl->events.next);
1368        ev.type = SNDRV_CTL_EVENT_ELEM;
1369        ev.data.elem.mask = kev->mask;
1370        ev.data.elem.id = kev->id;
1371        list_del(&kev->list);
1372        spin_unlock_irq(&ctl->read_lock);
1373        kfree(kev);
1374        if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1375            err = -EFAULT;
1376            goto __end;
1377        }
1378        spin_lock_irq(&ctl->read_lock);
1379        buffer += sizeof(struct snd_ctl_event);
1380        count -= sizeof(struct snd_ctl_event);
1381        result += sizeof(struct snd_ctl_event);
1382    }
1383      __end_lock:
1384    spin_unlock_irq(&ctl->read_lock);
1385      __end:
1386          return result > 0 ? result : err;
1387}
1388
1389static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1390{
1391    unsigned int mask;
1392    struct snd_ctl_file *ctl;
1393
1394    ctl = file->private_data;
1395    if (!ctl->subscribed)
1396        return 0;
1397    poll_wait(file, &ctl->change_sleep, wait);
1398
1399    mask = 0;
1400    if (!list_empty(&ctl->events))
1401        mask |= POLLIN | POLLRDNORM;
1402
1403    return mask;
1404}
1405
1406/*
1407 * register the device-specific control-ioctls.
1408 * called from each device manager like pcm.c, hwdep.c, etc.
1409 */
1410static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1411{
1412    struct snd_kctl_ioctl *pn;
1413
1414    pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1415    if (pn == NULL)
1416        return -ENOMEM;
1417    pn->fioctl = fcn;
1418    down_write(&snd_ioctl_rwsem);
1419    list_add_tail(&pn->list, lists);
1420    up_write(&snd_ioctl_rwsem);
1421    return 0;
1422}
1423
1424int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1425{
1426    return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1427}
1428
1429EXPORT_SYMBOL(snd_ctl_register_ioctl);
1430
1431#ifdef CONFIG_COMPAT
1432int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1433{
1434    return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1435}
1436
1437EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1438#endif
1439
1440/*
1441 * de-register the device-specific control-ioctls.
1442 */
1443static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1444                     struct list_head *lists)
1445{
1446    struct snd_kctl_ioctl *p;
1447
1448    if (snd_BUG_ON(!fcn))
1449        return -EINVAL;
1450    down_write(&snd_ioctl_rwsem);
1451    list_for_each_entry(p, lists, list) {
1452        if (p->fioctl == fcn) {
1453            list_del(&p->list);
1454            up_write(&snd_ioctl_rwsem);
1455            kfree(p);
1456            return 0;
1457        }
1458    }
1459    up_write(&snd_ioctl_rwsem);
1460    snd_BUG();
1461    return -EINVAL;
1462}
1463
1464int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1465{
1466    return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1467}
1468
1469EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1470
1471#ifdef CONFIG_COMPAT
1472int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1473{
1474    return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1475}
1476
1477EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1478#endif
1479
1480static int snd_ctl_fasync(int fd, struct file * file, int on)
1481{
1482    struct snd_ctl_file *ctl;
1483
1484    ctl = file->private_data;
1485    return fasync_helper(fd, file, on, &ctl->fasync);
1486}
1487
1488/*
1489 * ioctl32 compat
1490 */
1491#ifdef CONFIG_COMPAT
1492#include "control_compat.c"
1493#else
1494#define snd_ctl_ioctl_compat NULL
1495#endif
1496
1497/*
1498 * INIT PART
1499 */
1500
1501static const struct file_operations snd_ctl_f_ops =
1502{
1503    .owner = THIS_MODULE,
1504    .read = snd_ctl_read,
1505    .open = snd_ctl_open,
1506    .release = snd_ctl_release,
1507    .llseek = no_llseek,
1508    .poll = snd_ctl_poll,
1509    .unlocked_ioctl = snd_ctl_ioctl,
1510    .compat_ioctl = snd_ctl_ioctl_compat,
1511    .fasync = snd_ctl_fasync,
1512};
1513
1514/*
1515 * registration of the control device
1516 */
1517static int snd_ctl_dev_register(struct snd_device *device)
1518{
1519    struct snd_card *card = device->device_data;
1520    int err, cardnum;
1521    char name[16];
1522
1523    if (snd_BUG_ON(!card))
1524        return -ENXIO;
1525    cardnum = card->number;
1526    if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1527        return -ENXIO;
1528    sprintf(name, "controlC%i", cardnum);
1529    if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1530                       &snd_ctl_f_ops, card, name)) < 0)
1531        return err;
1532    return 0;
1533}
1534
1535/*
1536 * disconnection of the control device
1537 */
1538static int snd_ctl_dev_disconnect(struct snd_device *device)
1539{
1540    struct snd_card *card = device->device_data;
1541    struct snd_ctl_file *ctl;
1542    int err, cardnum;
1543
1544    if (snd_BUG_ON(!card))
1545        return -ENXIO;
1546    cardnum = card->number;
1547    if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1548        return -ENXIO;
1549
1550    read_lock(&card->ctl_files_rwlock);
1551    list_for_each_entry(ctl, &card->ctl_files, list) {
1552        wake_up(&ctl->change_sleep);
1553        kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1554    }
1555    read_unlock(&card->ctl_files_rwlock);
1556
1557    if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1558                     card, -1)) < 0)
1559        return err;
1560    return 0;
1561}
1562
1563/*
1564 * free all controls
1565 */
1566static int snd_ctl_dev_free(struct snd_device *device)
1567{
1568    struct snd_card *card = device->device_data;
1569    struct snd_kcontrol *control;
1570
1571    down_write(&card->controls_rwsem);
1572    while (!list_empty(&card->controls)) {
1573        control = snd_kcontrol(card->controls.next);
1574        snd_ctl_remove(card, control);
1575    }
1576    up_write(&card->controls_rwsem);
1577    return 0;
1578}
1579
1580/*
1581 * create control core:
1582 * called from init.c
1583 */
1584int snd_ctl_create(struct snd_card *card)
1585{
1586    static struct snd_device_ops ops = {
1587        .dev_free = snd_ctl_dev_free,
1588        .dev_register = snd_ctl_dev_register,
1589        .dev_disconnect = snd_ctl_dev_disconnect,
1590    };
1591
1592    if (snd_BUG_ON(!card))
1593        return -ENXIO;
1594    return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1595}
1596
1597/*
1598 * Frequently used control callbacks/helpers
1599 */
1600int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1601                  struct snd_ctl_elem_info *uinfo)
1602{
1603    uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1604    uinfo->count = 1;
1605    uinfo->value.integer.min = 0;
1606    uinfo->value.integer.max = 1;
1607    return 0;
1608}
1609
1610EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1611
1612int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1613                struct snd_ctl_elem_info *uinfo)
1614{
1615    uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1616    uinfo->count = 2;
1617    uinfo->value.integer.min = 0;
1618    uinfo->value.integer.max = 1;
1619    return 0;
1620}
1621
1622EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1623
1624/**
1625 * snd_ctl_enum_info - fills the info structure for an enumerated control
1626 * @info: the structure to be filled
1627 * @channels: the number of the control's channels; often one
1628 * @items: the number of control values; also the size of @names
1629 * @names: an array containing the names of all control values
1630 *
1631 * Sets all required fields in @info to their appropriate values.
1632 * If the control's accessibility is not the default (readable and writable),
1633 * the caller has to fill @info->access.
1634 */
1635int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1636              unsigned int items, const char *const names[])
1637{
1638    info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1639    info->count = channels;
1640    info->value.enumerated.items = items;
1641    if (info->value.enumerated.item >= items)
1642        info->value.enumerated.item = items - 1;
1643    strlcpy(info->value.enumerated.name,
1644        names[info->value.enumerated.item],
1645        sizeof(info->value.enumerated.name));
1646    return 0;
1647}
1648EXPORT_SYMBOL(snd_ctl_enum_info);
1649

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