si4713-i2c: avoid potential buffer overflow on si4713
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / sound / core / init.c
bloba0080aa45ae968dfbcd9607fa39f7b587acc7c33
1 /*
2 * Initialization routines
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
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>
30 #include <sound/core.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
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 */
42 static DEFINE_SPINLOCK(shutdown_lock);
43 static LIST_HEAD(shutdown_files);
45 static const struct file_operations snd_shutdown_f_ops;
47 static unsigned int snd_cards_lock; /* locked for registering/using */
48 struct snd_card *snd_cards[SNDRV_CARDS];
49 EXPORT_SYMBOL(snd_cards);
51 static DEFINE_MUTEX(snd_card_mutex);
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.");
57 /* return non-zero if the given index is reserved for the given
58 * module via slots option
60 static int module_slot_match(struct module *module, int idx)
62 int match = 1;
63 #ifdef MODULE
64 const char *s1, *s2;
66 if (!module || !module->name || !slots[idx])
67 return 0;
69 s1 = module->name;
70 s2 = slots[idx];
71 if (*s2 == '!') {
72 match = 0; /* negative match */
73 s2++;
75 /* compare module name strings
76 * hyphens are handled as equivalent with underscore
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;
90 #endif /* MODULE */
91 return match;
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
99 #ifdef CONFIG_PROC_FS
100 static void snd_card_id_read(struct snd_info_entry *entry,
101 struct snd_info_buffer *buffer)
103 snd_iprintf(buffer, "%s\n", entry->card->id);
106 static inline int init_info_for_card(struct snd_card *card)
108 int err;
109 struct snd_info_entry *entry;
111 if ((err = snd_info_card_register(card)) < 0) {
112 snd_printd("unable to create card info\n");
113 return err;
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;
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;
124 card->proc_id = entry;
125 return 0;
127 #else /* !CONFIG_PROC_FS */
128 #define init_info_for_card(card)
129 #endif
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
139 * Creates and initializes a soundcard structure.
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.
145 * Returns zero if successful or a negative error code.
147 int snd_card_create(int idx, const char *xid,
148 struct module *module, int extra_size,
149 struct snd_card **card_ret)
151 struct snd_card *card;
152 int err, idx2;
154 if (snd_BUG_ON(!card_ret))
155 return -EINVAL;
156 *card_ret = NULL;
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;
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;
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;
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;
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;
230 if (extra_size > 0)
231 card->private_data = (char *)card + sizeof(struct snd_card);
232 *card_ret = card;
233 return 0;
235 __error_ctl:
236 snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
237 __error:
238 kfree(card);
239 return err;
241 EXPORT_SYMBOL(snd_card_create);
243 /* return non-zero if a card is already locked */
244 int snd_card_locked(int card)
246 int locked;
248 mutex_lock(&snd_card_mutex);
249 locked = snd_cards_lock & (1 << card);
250 mutex_unlock(&snd_card_mutex);
251 return locked;
254 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
256 return -ENODEV;
259 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
260 size_t count, loff_t *offset)
262 return -ENODEV;
265 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
266 size_t count, loff_t *offset)
268 return -ENODEV;
271 static int snd_disconnect_release(struct inode *inode, struct file *file)
273 struct snd_monitor_file *df = NULL, *_df;
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;
283 spin_unlock(&shutdown_lock);
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);
291 panic("%s(%p, %p) failed!", __func__, inode, file);
294 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
296 return POLLERR | POLLNVAL;
299 static long snd_disconnect_ioctl(struct file *file,
300 unsigned int cmd, unsigned long arg)
302 return -ENODEV;
305 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
307 return -ENODEV;
310 static int snd_disconnect_fasync(int fd, struct file *file, int on)
312 return -ENODEV;
315 static const struct file_operations snd_shutdown_f_ops =
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
332 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
333 * @card: soundcard structure
335 * Disconnects all APIs from the file-operations (user space).
337 * Returns zero, otherwise a negative error code.
339 * Note: The current implementation replaces all active file->f_op with special
340 * dummy file operations (they do nothing except release).
342 int snd_card_disconnect(struct snd_card *card)
344 struct snd_monitor_file *mfile;
345 struct file *file;
346 int err;
348 if (!card)
349 return -EINVAL;
351 spin_lock(&card->files_lock);
352 if (card->shutdown) {
353 spin_unlock(&card->files_lock);
354 return 0;
356 card->shutdown = 1;
357 spin_unlock(&card->files_lock);
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);
365 /* phase 2: replace file->f_op with special dummy operations */
367 spin_lock(&card->files_lock);
368 list_for_each_entry(mfile, &card->files_list, list) {
369 file = mfile->file;
371 /* it's critical part, use endless loop */
372 /* we have no room to fail */
373 mfile->disconnected_f_op = mfile->file->f_op;
375 spin_lock(&shutdown_lock);
376 list_add(&mfile->shutdown_list, &shutdown_files);
377 spin_unlock(&shutdown_lock);
379 mfile->file->f_op = &snd_shutdown_f_ops;
380 fops_get(mfile->file->f_op);
382 spin_unlock(&card->files_lock);
384 /* phase 3: notify all connected devices about disconnection */
385 /* at this point, they cannot respond to any calls except release() */
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
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);
397 snd_info_card_disconnect(card);
398 if (card->card_dev) {
399 device_unregister(card->card_dev);
400 card->card_dev = NULL;
402 #ifdef CONFIG_PM
403 wake_up(&card->power_sleep);
404 #endif
405 return 0;
408 EXPORT_SYMBOL(snd_card_disconnect);
411 * snd_card_free - frees given soundcard structure
412 * @card: soundcard structure
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.
418 * Returns zero. Frees all associated devices and frees the control
419 * interface associated to given soundcard.
421 static int snd_card_do_free(struct snd_card *card)
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 */
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 */
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 */
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 */
446 kfree(card);
447 return 0;
450 int snd_card_free_when_closed(struct snd_card *card)
452 int free_now = 0;
453 int ret = snd_card_disconnect(card);
454 if (ret)
455 return ret;
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);
464 if (free_now)
465 snd_card_do_free(card);
466 return 0;
469 EXPORT_SYMBOL(snd_card_free_when_closed);
471 int snd_card_free(struct snd_card *card)
473 int ret = snd_card_disconnect(card);
474 if (ret)
475 return ret;
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;
483 EXPORT_SYMBOL(snd_card_free);
485 static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
487 int i, len, idx_flag = 0, loops = SNDRV_CARDS;
488 const char *spos, *src;
489 char *id;
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++;
499 } else {
500 spos = src = nid;
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++;
512 *id = '\0';
514 id = card->id;
516 if (*id == '\0')
517 strcpy(id, "default");
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;
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;
531 break;
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++;
556 * snd_card_set_id - set card identification name
557 * @card: soundcard structure
558 * @nid: new identification string
560 * This function sets the card identification and checks for name
561 * collisions.
563 void snd_card_set_id(struct snd_card *card, const char *nid)
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);
572 EXPORT_SYMBOL(snd_card_set_id);
574 static ssize_t
575 card_id_show_attr(struct device *dev,
576 struct device_attribute *attr, char *buf)
578 struct snd_card *card = dev_get_drvdata(dev);
579 return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
582 static ssize_t
583 card_id_store_attr(struct device *dev, struct device_attribute *attr,
584 const char *buf, size_t count)
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;
593 for (idx = 0; idx < copy; idx++) {
594 c = buf[idx];
595 if (!isalnum(c) && c != '_' && c != '-')
596 return -EINVAL;
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;
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;
614 strcpy(card->id, buf1);
615 snd_info_card_id_change(card);
616 __ok:
617 mutex_unlock(&snd_card_mutex);
619 return count;
622 static struct device_attribute card_id_attrs =
623 __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
625 static ssize_t
626 card_number_show_attr(struct device *dev,
627 struct device_attribute *attr, char *buf)
629 struct snd_card *card = dev_get_drvdata(dev);
630 return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
633 static struct device_attribute card_number_attrs =
634 __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
637 * snd_card_register - register the soundcard
638 * @card: soundcard structure
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.
645 * Returns zero otherwise a negative error code if the registration failed.
647 int snd_card_register(struct snd_card *card)
649 int err;
651 if (snd_BUG_ON(!card))
652 return -EINVAL;
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;
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;
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;
687 return 0;
690 EXPORT_SYMBOL(snd_card_register);
692 #ifdef CONFIG_PROC_FS
693 static struct snd_info_entry *snd_card_info_entry;
695 static void snd_card_info_read(struct snd_info_entry *entry,
696 struct snd_info_buffer *buffer)
698 int idx, count;
699 struct snd_card *card;
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);
713 mutex_unlock(&snd_card_mutex);
715 if (!count)
716 snd_iprintf(buffer, "--- no soundcards ---\n");
719 #ifdef CONFIG_SND_OSSEMUL
721 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
723 int idx, count;
724 struct snd_card *card;
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);
732 mutex_unlock(&snd_card_mutex);
734 if (!count) {
735 snd_iprintf(buffer, "--- no soundcards ---\n");
739 #endif
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)
746 int idx;
747 struct snd_card *card;
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);
757 #endif
759 int __init snd_card_info_init(void)
761 struct snd_info_entry *entry;
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;
771 snd_card_info_entry = entry;
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;
782 #endif
784 return 0;
787 int __exit snd_card_info_done(void)
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;
796 #endif /* CONFIG_PROC_FS */
799 * snd_component_add - add a component string
800 * @card: soundcard structure
801 * @component: the component id string
803 * This function adds the component id string to the supported list.
804 * The component can be referred from the alsa-lib.
806 * Returns zero otherwise a negative error code.
809 int snd_component_add(struct snd_card *card, const char *component)
811 char *ptr;
812 int len = strlen(component);
814 ptr = strstr(card->components, component);
815 if (ptr != NULL) {
816 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
817 return 1;
819 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
820 snd_BUG();
821 return -ENOMEM;
823 if (card->components[0] != '\0')
824 strcat(card->components, " ");
825 strcat(card->components, component);
826 return 0;
829 EXPORT_SYMBOL(snd_component_add);
832 * snd_card_file_add - add the file to the file list of the card
833 * @card: soundcard structure
834 * @file: file pointer
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.
840 * Returns zero or a negative error code.
842 int snd_card_file_add(struct snd_card *card, struct file *file)
844 struct snd_monitor_file *mfile;
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;
858 list_add(&mfile->list, &card->files_list);
859 spin_unlock(&card->files_lock);
860 return 0;
863 EXPORT_SYMBOL(snd_card_file_add);
866 * snd_card_file_remove - remove the file from the file list
867 * @card: soundcard structure
868 * @file: file pointer
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.
876 * Returns zero or a negative error code.
878 int snd_card_file_remove(struct snd_card *card, struct file *file)
880 struct snd_monitor_file *mfile, *found = NULL;
881 int last_close = 0;
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;
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);
904 if (!found) {
905 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
906 return -ENOENT;
908 kfree(found);
909 return 0;
912 EXPORT_SYMBOL(snd_card_file_remove);
914 #ifdef CONFIG_PM
916 * snd_power_wait - wait until the power-state is changed.
917 * @card: soundcard structure
918 * @power_state: expected power state
920 * Waits until the power-state is changed.
922 * Note: the power lock must be active before call.
924 int snd_power_wait(struct snd_card *card, unsigned int power_state)
926 wait_queue_t wait;
927 int result = 0;
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;
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);
946 remove_wait_queue(&card->power_sleep, &wait);
947 return result;
950 EXPORT_SYMBOL(snd_power_wait);
951 #endif /* CONFIG_PM */