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