Merge branch 'linux-3.4.57' into rel-17
[linux-2.6.git] / sound / core / init.c
1 /*
2  *  Initialization routines
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/init.h>
23 #include <linux/sched.h>
24 #include <linux/module.h>
25 #include <linux/device.h>
26 #include <linux/file.h>
27 #include <linux/slab.h>
28 #include <linux/time.h>
29 #include <linux/ctype.h>
30 #include <linux/pm.h>
31
32 #include <sound/core.h>
33 #include <sound/control.h>
34 #include <sound/info.h>
35
36 /* monitor files for graceful shutdown (hotplug) */
37 struct snd_monitor_file {
38         struct file *file;
39         const struct file_operations *disconnected_f_op;
40         struct list_head shutdown_list; /* still need to shutdown */
41         struct list_head list;  /* link of monitor files */
42 };
43
44 static DEFINE_SPINLOCK(shutdown_lock);
45 static LIST_HEAD(shutdown_files);
46
47 static const struct file_operations snd_shutdown_f_ops;
48
49 static unsigned int snd_cards_lock;     /* locked for registering/using */
50 struct snd_card *snd_cards[SNDRV_CARDS];
51 EXPORT_SYMBOL(snd_cards);
52
53 static DEFINE_MUTEX(snd_card_mutex);
54
55 static char *slots[SNDRV_CARDS];
56 module_param_array(slots, charp, NULL, 0444);
57 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
58
59 /* return non-zero if the given index is reserved for the given
60  * module via slots option
61  */
62 static int module_slot_match(struct module *module, int idx)
63 {
64         int match = 1;
65 #ifdef MODULE
66         const char *s1, *s2;
67
68         if (!module || !module->name || !slots[idx])
69                 return 0;
70
71         s1 = module->name;
72         s2 = slots[idx];
73         if (*s2 == '!') {
74                 match = 0; /* negative match */
75                 s2++;
76         }
77         /* compare module name strings
78          * hyphens are handled as equivalent with underscore
79          */
80         for (;;) {
81                 char c1 = *s1++;
82                 char c2 = *s2++;
83                 if (c1 == '-')
84                         c1 = '_';
85                 if (c2 == '-')
86                         c2 = '_';
87                 if (c1 != c2)
88                         return !match;
89                 if (!c1)
90                         break;
91         }
92 #endif /* MODULE */
93         return match;
94 }
95
96 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
97 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
98 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
99 #endif
100
101 #ifdef CONFIG_PROC_FS
102 static void snd_card_id_read(struct snd_info_entry *entry,
103                              struct snd_info_buffer *buffer)
104 {
105         snd_iprintf(buffer, "%s\n", entry->card->id);
106 }
107
108 static inline int init_info_for_card(struct snd_card *card)
109 {
110         int err;
111         struct snd_info_entry *entry;
112
113         if ((err = snd_info_card_register(card)) < 0) {
114                 snd_printd("unable to create card info\n");
115                 return err;
116         }
117         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
118                 snd_printd("unable to create card entry\n");
119                 return err;
120         }
121         entry->c.text.read = snd_card_id_read;
122         if (snd_info_register(entry) < 0) {
123                 snd_info_free_entry(entry);
124                 entry = NULL;
125         }
126         card->proc_id = entry;
127         return 0;
128 }
129 #else /* !CONFIG_PROC_FS */
130 #define init_info_for_card(card)
131 #endif
132
133 /**
134  *  snd_card_create - create and initialize a soundcard structure
135  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
136  *  @xid: card identification (ASCII string)
137  *  @module: top level module for locking
138  *  @extra_size: allocate this extra size after the main soundcard structure
139  *  @card_ret: the pointer to store the created card instance
140  *
141  *  Creates and initializes a soundcard structure.
142  *
143  *  The function allocates snd_card instance via kzalloc with the given
144  *  space for the driver to use freely.  The allocated struct is stored
145  *  in the given card_ret pointer.
146  *
147  *  Returns zero if successful or a negative error code.
148  */
149 int snd_card_create(int idx, const char *xid,
150                     struct module *module, int extra_size,
151                     struct snd_card **card_ret)
152 {
153         struct snd_card *card;
154         int err, idx2;
155
156         if (snd_BUG_ON(!card_ret))
157                 return -EINVAL;
158         *card_ret = NULL;
159
160         if (extra_size < 0)
161                 extra_size = 0;
162         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
163         if (!card)
164                 return -ENOMEM;
165         if (xid)
166                 strlcpy(card->id, xid, sizeof(card->id));
167         err = 0;
168         mutex_lock(&snd_card_mutex);
169         if (idx < 0) {
170                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
171                         /* idx == -1 == 0xffff means: take any free slot */
172                         if (~snd_cards_lock & idx & 1<<idx2) {
173                                 if (module_slot_match(module, idx2)) {
174                                         idx = idx2;
175                                         break;
176                                 }
177                         }
178         }
179         if (idx < 0) {
180                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
181                         /* idx == -1 == 0xffff means: take any free slot */
182                         if (~snd_cards_lock & idx & 1<<idx2) {
183                                 if (!slots[idx2] || !*slots[idx2]) {
184                                         idx = idx2;
185                                         break;
186                                 }
187                         }
188         }
189         if (idx < 0)
190                 err = -ENODEV;
191         else if (idx < snd_ecards_limit) {
192                 if (snd_cards_lock & (1 << idx))
193                         err = -EBUSY;   /* invalid */
194         } else if (idx >= SNDRV_CARDS)
195                 err = -ENODEV;
196         if (err < 0) {
197                 mutex_unlock(&snd_card_mutex);
198                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
199                          idx, snd_ecards_limit - 1, err);
200                 goto __error;
201         }
202         snd_cards_lock |= 1 << idx;             /* lock it */
203         if (idx >= snd_ecards_limit)
204                 snd_ecards_limit = idx + 1; /* increase the limit */
205         mutex_unlock(&snd_card_mutex);
206         card->number = idx;
207         card->module = module;
208         INIT_LIST_HEAD(&card->devices);
209         init_rwsem(&card->controls_rwsem);
210         rwlock_init(&card->ctl_files_rwlock);
211         INIT_LIST_HEAD(&card->controls);
212         INIT_LIST_HEAD(&card->ctl_files);
213         spin_lock_init(&card->files_lock);
214         INIT_LIST_HEAD(&card->files_list);
215         init_waitqueue_head(&card->shutdown_sleep);
216         atomic_set(&card->refcount, 0);
217 #ifdef CONFIG_PM
218         mutex_init(&card->power_lock);
219         init_waitqueue_head(&card->power_sleep);
220 #endif
221         /* the control interface cannot be accessed from the user space until */
222         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
223         err = snd_ctl_create(card);
224         if (err < 0) {
225                 snd_printk(KERN_ERR "unable to register control minors\n");
226                 goto __error;
227         }
228         err = snd_info_card_create(card);
229         if (err < 0) {
230                 snd_printk(KERN_ERR "unable to create card info\n");
231                 goto __error_ctl;
232         }
233         if (extra_size > 0)
234                 card->private_data = (char *)card + sizeof(struct snd_card);
235         *card_ret = card;
236         return 0;
237
238       __error_ctl:
239         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
240       __error:
241         kfree(card);
242         return err;
243 }
244 EXPORT_SYMBOL(snd_card_create);
245
246 /* return non-zero if a card is already locked */
247 int snd_card_locked(int card)
248 {
249         int locked;
250
251         mutex_lock(&snd_card_mutex);
252         locked = snd_cards_lock & (1 << card);
253         mutex_unlock(&snd_card_mutex);
254         return locked;
255 }
256
257 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
258 {
259         return -ENODEV;
260 }
261
262 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
263                                    size_t count, loff_t *offset)
264 {
265         return -ENODEV;
266 }
267
268 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
269                                     size_t count, loff_t *offset)
270 {
271         return -ENODEV;
272 }
273
274 static int snd_disconnect_release(struct inode *inode, struct file *file)
275 {
276         struct snd_monitor_file *df = NULL, *_df;
277
278         spin_lock(&shutdown_lock);
279         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
280                 if (_df->file == file) {
281                         df = _df;
282                         list_del_init(&df->shutdown_list);
283                         break;
284                 }
285         }
286         spin_unlock(&shutdown_lock);
287
288         if (likely(df)) {
289                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
290                         df->disconnected_f_op->fasync(-1, file, 0);
291                 return df->disconnected_f_op->release(inode, file);
292         }
293
294         panic("%s(%p, %p) failed!", __func__, inode, file);
295 }
296
297 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
298 {
299         return POLLERR | POLLNVAL;
300 }
301
302 static long snd_disconnect_ioctl(struct file *file,
303                                  unsigned int cmd, unsigned long arg)
304 {
305         return -ENODEV;
306 }
307
308 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
309 {
310         return -ENODEV;
311 }
312
313 static int snd_disconnect_fasync(int fd, struct file *file, int on)
314 {
315         return -ENODEV;
316 }
317
318 static const struct file_operations snd_shutdown_f_ops =
319 {
320         .owner =        THIS_MODULE,
321         .llseek =       snd_disconnect_llseek,
322         .read =         snd_disconnect_read,
323         .write =        snd_disconnect_write,
324         .release =      snd_disconnect_release,
325         .poll =         snd_disconnect_poll,
326         .unlocked_ioctl = snd_disconnect_ioctl,
327 #ifdef CONFIG_COMPAT
328         .compat_ioctl = snd_disconnect_ioctl,
329 #endif
330         .mmap =         snd_disconnect_mmap,
331         .fasync =       snd_disconnect_fasync
332 };
333
334 /**
335  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
336  *  @card: soundcard structure
337  *
338  *  Disconnects all APIs from the file-operations (user space).
339  *
340  *  Returns zero, otherwise a negative error code.
341  *
342  *  Note: The current implementation replaces all active file->f_op with special
343  *        dummy file operations (they do nothing except release).
344  */
345 int snd_card_disconnect(struct snd_card *card)
346 {
347         struct snd_monitor_file *mfile;
348         int err;
349
350         if (!card)
351                 return -EINVAL;
352
353         spin_lock(&card->files_lock);
354         if (card->shutdown) {
355                 spin_unlock(&card->files_lock);
356                 return 0;
357         }
358         card->shutdown = 1;
359         spin_unlock(&card->files_lock);
360
361         /* phase 1: disable fops (user space) operations for ALSA API */
362         mutex_lock(&snd_card_mutex);
363         snd_cards[card->number] = NULL;
364         snd_cards_lock &= ~(1 << card->number);
365         mutex_unlock(&snd_card_mutex);
366         
367         /* phase 2: replace file->f_op with special dummy operations */
368         
369         spin_lock(&card->files_lock);
370         list_for_each_entry(mfile, &card->files_list, list) {
371                 /* it's critical part, use endless loop */
372                 /* we have no room to fail */
373                 mfile->disconnected_f_op = mfile->file->f_op;
374
375                 spin_lock(&shutdown_lock);
376                 list_add(&mfile->shutdown_list, &shutdown_files);
377                 spin_unlock(&shutdown_lock);
378
379                 mfile->file->f_op = &snd_shutdown_f_ops;
380                 fops_get(mfile->file->f_op);
381         }
382         spin_unlock(&card->files_lock); 
383
384         /* phase 3: notify all connected devices about disconnection */
385         /* at this point, they cannot respond to any calls except release() */
386
387 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
388         if (snd_mixer_oss_notify_callback)
389                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
390 #endif
391
392         /* notify all devices that we are disconnected */
393         err = snd_device_disconnect_all(card);
394         if (err < 0)
395                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
396
397         snd_info_card_disconnect(card);
398         if (card->card_dev) {
399                 device_unregister(card->card_dev);
400                 card->card_dev = NULL;
401         }
402 #ifdef CONFIG_PM
403         wake_up(&card->power_sleep);
404 #endif
405         return 0;       
406 }
407
408 EXPORT_SYMBOL(snd_card_disconnect);
409
410 /**
411  *  snd_card_free - frees given soundcard structure
412  *  @card: soundcard structure
413  *
414  *  This function releases the soundcard structure and the all assigned
415  *  devices automatically.  That is, you don't have to release the devices
416  *  by yourself.
417  *
418  *  Returns zero. Frees all associated devices and frees the control
419  *  interface associated to given soundcard.
420  */
421 static int snd_card_do_free(struct snd_card *card)
422 {
423 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
424         if (snd_mixer_oss_notify_callback)
425                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
426 #endif
427         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
428                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
429                 /* Fatal, but this situation should never occur */
430         }
431         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
432                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
433                 /* Fatal, but this situation should never occur */
434         }
435         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
436                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
437                 /* Fatal, but this situation should never occur */
438         }
439         if (card->private_free)
440                 card->private_free(card);
441         snd_info_free_entry(card->proc_id);
442         if (snd_info_card_free(card) < 0) {
443                 snd_printk(KERN_WARNING "unable to free card info\n");
444                 /* Not fatal error */
445         }
446         kfree(card);
447         return 0;
448 }
449
450 /**
451  * snd_card_unref - release the reference counter
452  * @card: the card instance
453  *
454  * Decrements the reference counter.  When it reaches to zero, wake up
455  * the sleeper and call the destructor if needed.
456  */
457 void snd_card_unref(struct snd_card *card)
458 {
459         if (atomic_dec_and_test(&card->refcount)) {
460                 wake_up(&card->shutdown_sleep);
461                 if (card->free_on_last_close)
462                         snd_card_do_free(card);
463         }
464 }
465 EXPORT_SYMBOL(snd_card_unref);
466
467 int snd_card_free_when_closed(struct snd_card *card)
468 {
469         int ret;
470
471         atomic_inc(&card->refcount);
472         ret = snd_card_disconnect(card);
473         if (ret) {
474                 atomic_dec(&card->refcount);
475                 return ret;
476         }
477
478         card->free_on_last_close = 1;
479         if (atomic_dec_and_test(&card->refcount))
480                 snd_card_do_free(card);
481         return 0;
482 }
483
484 EXPORT_SYMBOL(snd_card_free_when_closed);
485
486 int snd_card_free(struct snd_card *card)
487 {
488         int ret = snd_card_disconnect(card);
489         if (ret)
490                 return ret;
491
492         /* wait, until all devices are ready for the free operation */
493         wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
494         snd_card_do_free(card);
495         return 0;
496 }
497
498 EXPORT_SYMBOL(snd_card_free);
499
500 /* retrieve the last word of shortname or longname */
501 static const char *retrieve_id_from_card_name(const char *name)
502 {
503         const char *spos = name;
504
505         while (*name) {
506                 if (isspace(*name) && isalnum(name[1]))
507                         spos = name + 1;
508                 name++;
509         }
510         return spos;
511 }
512
513 /* return true if the given id string doesn't conflict any other card ids */
514 static bool card_id_ok(struct snd_card *card, const char *id)
515 {
516         int i;
517         if (!snd_info_check_reserved_words(id))
518                 return false;
519         for (i = 0; i < snd_ecards_limit; i++) {
520                 if (snd_cards[i] && snd_cards[i] != card &&
521                     !strcmp(snd_cards[i]->id, id))
522                         return false;
523         }
524         return true;
525 }
526
527 /* copy to card->id only with valid letters from nid */
528 static void copy_valid_id_string(struct snd_card *card, const char *src,
529                                  const char *nid)
530 {
531         char *id = card->id;
532
533         while (*nid && !isalnum(*nid))
534                 nid++;
535         if (isdigit(*nid))
536                 *id++ = isalpha(*src) ? *src : 'D';
537         while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
538                 if (isalnum(*nid))
539                         *id++ = *nid;
540                 nid++;
541         }
542         *id = 0;
543 }
544
545 /* Set card->id from the given string
546  * If the string conflicts with other ids, add a suffix to make it unique.
547  */
548 static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
549                                     const char *nid)
550 {
551         int len, loops;
552         bool with_suffix;
553         bool is_default = false;
554         char *id;
555         
556         copy_valid_id_string(card, src, nid);
557         id = card->id;
558
559  again:
560         /* use "Default" for obviously invalid strings
561          * ("card" conflicts with proc directories)
562          */
563         if (!*id || !strncmp(id, "card", 4)) {
564                 strcpy(id, "Default");
565                 is_default = true;
566         }
567
568         with_suffix = false;
569         for (loops = 0; loops < SNDRV_CARDS; loops++) {
570                 if (card_id_ok(card, id))
571                         return; /* OK */
572
573                 len = strlen(id);
574                 if (!with_suffix) {
575                         /* add the "_X" suffix */
576                         char *spos = id + len;
577                         if (len >  sizeof(card->id) - 3)
578                                 spos = id + sizeof(card->id) - 3;
579                         strcpy(spos, "_1");
580                         with_suffix = true;
581                 } else {
582                         /* modify the existing suffix */
583                         if (id[len - 1] != '9')
584                                 id[len - 1]++;
585                         else
586                                 id[len - 1] = 'A';
587                 }
588         }
589         /* fallback to the default id */
590         if (!is_default) {
591                 *id = 0;
592                 goto again;
593         }
594         /* last resort... */
595         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
596         if (card->proc_root->name)
597                 strcpy(card->id, card->proc_root->name);
598 }
599
600 /**
601  *  snd_card_set_id - set card identification name
602  *  @card: soundcard structure
603  *  @nid: new identification string
604  *
605  *  This function sets the card identification and checks for name
606  *  collisions.
607  */
608 void snd_card_set_id(struct snd_card *card, const char *nid)
609 {
610         /* check if user specified own card->id */
611         if (card->id[0] != '\0')
612                 return;
613         mutex_lock(&snd_card_mutex);
614         snd_card_set_id_no_lock(card, nid, nid);
615         mutex_unlock(&snd_card_mutex);
616 }
617 EXPORT_SYMBOL(snd_card_set_id);
618
619 static ssize_t
620 card_id_show_attr(struct device *dev,
621                   struct device_attribute *attr, char *buf)
622 {
623         struct snd_card *card = dev_get_drvdata(dev);
624         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
625 }
626
627 static ssize_t
628 card_id_store_attr(struct device *dev, struct device_attribute *attr,
629                    const char *buf, size_t count)
630 {
631         struct snd_card *card = dev_get_drvdata(dev);
632         char buf1[sizeof(card->id)];
633         size_t copy = count > sizeof(card->id) - 1 ?
634                                         sizeof(card->id) - 1 : count;
635         size_t idx;
636         int c;
637
638         for (idx = 0; idx < copy; idx++) {
639                 c = buf[idx];
640                 if (!isalnum(c) && c != '_' && c != '-')
641                         return -EINVAL;
642         }
643         memcpy(buf1, buf, copy);
644         buf1[copy] = '\0';
645         mutex_lock(&snd_card_mutex);
646         if (!card_id_ok(NULL, buf1)) {
647                 mutex_unlock(&snd_card_mutex);
648                 return -EEXIST;
649         }
650         strcpy(card->id, buf1);
651         snd_info_card_id_change(card);
652         mutex_unlock(&snd_card_mutex);
653
654         return count;
655 }
656
657 static struct device_attribute card_id_attrs =
658         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
659
660 static ssize_t
661 card_number_show_attr(struct device *dev,
662                      struct device_attribute *attr, char *buf)
663 {
664         struct snd_card *card = dev_get_drvdata(dev);
665         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
666 }
667
668 static struct device_attribute card_number_attrs =
669         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
670
671 /**
672  *  snd_card_register - register the soundcard
673  *  @card: soundcard structure
674  *
675  *  This function registers all the devices assigned to the soundcard.
676  *  Until calling this, the ALSA control interface is blocked from the
677  *  external accesses.  Thus, you should call this function at the end
678  *  of the initialization of the card.
679  *
680  *  Returns zero otherwise a negative error code if the registration failed.
681  */
682 int snd_card_register(struct snd_card *card)
683 {
684         int err;
685
686         if (snd_BUG_ON(!card))
687                 return -EINVAL;
688
689         if (!card->card_dev) {
690                 card->card_dev = device_create(sound_class, card->dev,
691                                                MKDEV(0, 0), card,
692                                                "card%i", card->number);
693                 if (IS_ERR(card->card_dev))
694                         card->card_dev = NULL;
695         }
696
697         if ((err = snd_device_register_all(card)) < 0)
698                 return err;
699         mutex_lock(&snd_card_mutex);
700         if (snd_cards[card->number]) {
701                 /* already registered */
702                 mutex_unlock(&snd_card_mutex);
703                 return 0;
704         }
705         if (*card->id) {
706                 /* make a unique id name from the given string */
707                 char tmpid[sizeof(card->id)];
708                 memcpy(tmpid, card->id, sizeof(card->id));
709                 snd_card_set_id_no_lock(card, tmpid, tmpid);
710         } else {
711                 /* create an id from either shortname or longname */
712                 const char *src;
713                 src = *card->shortname ? card->shortname : card->longname;
714                 snd_card_set_id_no_lock(card, src,
715                                         retrieve_id_from_card_name(src));
716         }
717         snd_cards[card->number] = card;
718         mutex_unlock(&snd_card_mutex);
719         init_info_for_card(card);
720 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
721         if (snd_mixer_oss_notify_callback)
722                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
723 #endif
724         if (card->card_dev) {
725                 err = device_create_file(card->card_dev, &card_id_attrs);
726                 if (err < 0)
727                         return err;
728                 err = device_create_file(card->card_dev, &card_number_attrs);
729                 if (err < 0)
730                         return err;
731         }
732
733         return 0;
734 }
735
736 EXPORT_SYMBOL(snd_card_register);
737
738 #ifdef CONFIG_PROC_FS
739 static struct snd_info_entry *snd_card_info_entry;
740
741 static void snd_card_info_read(struct snd_info_entry *entry,
742                                struct snd_info_buffer *buffer)
743 {
744         int idx, count;
745         struct snd_card *card;
746
747         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
748                 mutex_lock(&snd_card_mutex);
749                 if ((card = snd_cards[idx]) != NULL) {
750                         count++;
751                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
752                                         idx,
753                                         card->id,
754                                         card->driver,
755                                         card->shortname);
756                         snd_iprintf(buffer, "                      %s\n",
757                                         card->longname);
758                 }
759                 mutex_unlock(&snd_card_mutex);
760         }
761         if (!count)
762                 snd_iprintf(buffer, "--- no soundcards ---\n");
763 }
764
765 #ifdef CONFIG_SND_OSSEMUL
766
767 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
768 {
769         int idx, count;
770         struct snd_card *card;
771
772         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
773                 mutex_lock(&snd_card_mutex);
774                 if ((card = snd_cards[idx]) != NULL) {
775                         count++;
776                         snd_iprintf(buffer, "%s\n", card->longname);
777                 }
778                 mutex_unlock(&snd_card_mutex);
779         }
780         if (!count) {
781                 snd_iprintf(buffer, "--- no soundcards ---\n");
782         }
783 }
784
785 #endif
786
787 #ifdef MODULE
788 static struct snd_info_entry *snd_card_module_info_entry;
789 static void snd_card_module_info_read(struct snd_info_entry *entry,
790                                       struct snd_info_buffer *buffer)
791 {
792         int idx;
793         struct snd_card *card;
794
795         for (idx = 0; idx < SNDRV_CARDS; idx++) {
796                 mutex_lock(&snd_card_mutex);
797                 if ((card = snd_cards[idx]) != NULL)
798                         snd_iprintf(buffer, "%2i %s\n",
799                                     idx, card->module->name);
800                 mutex_unlock(&snd_card_mutex);
801         }
802 }
803 #endif
804
805 int __init snd_card_info_init(void)
806 {
807         struct snd_info_entry *entry;
808
809         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
810         if (! entry)
811                 return -ENOMEM;
812         entry->c.text.read = snd_card_info_read;
813         if (snd_info_register(entry) < 0) {
814                 snd_info_free_entry(entry);
815                 return -ENOMEM;
816         }
817         snd_card_info_entry = entry;
818
819 #ifdef MODULE
820         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
821         if (entry) {
822                 entry->c.text.read = snd_card_module_info_read;
823                 if (snd_info_register(entry) < 0)
824                         snd_info_free_entry(entry);
825                 else
826                         snd_card_module_info_entry = entry;
827         }
828 #endif
829
830         return 0;
831 }
832
833 int __exit snd_card_info_done(void)
834 {
835         snd_info_free_entry(snd_card_info_entry);
836 #ifdef MODULE
837         snd_info_free_entry(snd_card_module_info_entry);
838 #endif
839         return 0;
840 }
841
842 #endif /* CONFIG_PROC_FS */
843
844 /**
845  *  snd_component_add - add a component string
846  *  @card: soundcard structure
847  *  @component: the component id string
848  *
849  *  This function adds the component id string to the supported list.
850  *  The component can be referred from the alsa-lib.
851  *
852  *  Returns zero otherwise a negative error code.
853  */
854   
855 int snd_component_add(struct snd_card *card, const char *component)
856 {
857         char *ptr;
858         int len = strlen(component);
859
860         ptr = strstr(card->components, component);
861         if (ptr != NULL) {
862                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
863                         return 1;
864         }
865         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
866                 snd_BUG();
867                 return -ENOMEM;
868         }
869         if (card->components[0] != '\0')
870                 strcat(card->components, " ");
871         strcat(card->components, component);
872         return 0;
873 }
874
875 EXPORT_SYMBOL(snd_component_add);
876
877 /**
878  *  snd_card_file_add - add the file to the file list of the card
879  *  @card: soundcard structure
880  *  @file: file pointer
881  *
882  *  This function adds the file to the file linked-list of the card.
883  *  This linked-list is used to keep tracking the connection state,
884  *  and to avoid the release of busy resources by hotplug.
885  *
886  *  Returns zero or a negative error code.
887  */
888 int snd_card_file_add(struct snd_card *card, struct file *file)
889 {
890         struct snd_monitor_file *mfile;
891
892         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
893         if (mfile == NULL)
894                 return -ENOMEM;
895         mfile->file = file;
896         mfile->disconnected_f_op = NULL;
897         INIT_LIST_HEAD(&mfile->shutdown_list);
898         spin_lock(&card->files_lock);
899         if (card->shutdown) {
900                 spin_unlock(&card->files_lock);
901                 kfree(mfile);
902                 return -ENODEV;
903         }
904         list_add(&mfile->list, &card->files_list);
905         atomic_inc(&card->refcount);
906         spin_unlock(&card->files_lock);
907         return 0;
908 }
909
910 EXPORT_SYMBOL(snd_card_file_add);
911
912 /**
913  *  snd_card_file_remove - remove the file from the file list
914  *  @card: soundcard structure
915  *  @file: file pointer
916  *
917  *  This function removes the file formerly added to the card via
918  *  snd_card_file_add() function.
919  *  If all files are removed and snd_card_free_when_closed() was
920  *  called beforehand, it processes the pending release of
921  *  resources.
922  *
923  *  Returns zero or a negative error code.
924  */
925 int snd_card_file_remove(struct snd_card *card, struct file *file)
926 {
927         struct snd_monitor_file *mfile, *found = NULL;
928
929         spin_lock(&card->files_lock);
930         list_for_each_entry(mfile, &card->files_list, list) {
931                 if (mfile->file == file) {
932                         list_del(&mfile->list);
933                         spin_lock(&shutdown_lock);
934                         list_del(&mfile->shutdown_list);
935                         spin_unlock(&shutdown_lock);
936                         if (mfile->disconnected_f_op)
937                                 fops_put(mfile->disconnected_f_op);
938                         found = mfile;
939                         break;
940                 }
941         }
942         spin_unlock(&card->files_lock);
943         if (!found) {
944                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
945                 return -ENOENT;
946         }
947         kfree(found);
948         snd_card_unref(card);
949         return 0;
950 }
951
952 EXPORT_SYMBOL(snd_card_file_remove);
953
954 #ifdef CONFIG_PM
955 /**
956  *  snd_power_wait - wait until the power-state is changed.
957  *  @card: soundcard structure
958  *  @power_state: expected power state
959  *
960  *  Waits until the power-state is changed.
961  *
962  *  Note: the power lock must be active before call.
963  */
964 int snd_power_wait(struct snd_card *card, unsigned int power_state)
965 {
966         wait_queue_t wait;
967         int result = 0;
968
969         /* fastpath */
970         if (snd_power_get_state(card) == power_state)
971                 return 0;
972         init_waitqueue_entry(&wait, current);
973         add_wait_queue(&card->power_sleep, &wait);
974         while (1) {
975                 if (card->shutdown) {
976                         result = -ENODEV;
977                         break;
978                 }
979                 if (snd_power_get_state(card) == power_state)
980                         break;
981                 set_current_state(TASK_UNINTERRUPTIBLE);
982                 snd_power_unlock(card);
983                 schedule_timeout(30 * HZ);
984                 snd_power_lock(card);
985         }
986         remove_wait_queue(&card->power_sleep, &wait);
987         return result;
988 }
989
990 EXPORT_SYMBOL(snd_power_wait);
991 #endif /* CONFIG_PM */