Root/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) */
35struct 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
42static DEFINE_SPINLOCK(shutdown_lock);
43static LIST_HEAD(shutdown_files);
44
45static const struct file_operations snd_shutdown_f_ops;
46
47static unsigned int snd_cards_lock; /* locked for registering/using */
48struct snd_card *snd_cards[SNDRV_CARDS];
49EXPORT_SYMBOL(snd_cards);
50
51static DEFINE_MUTEX(snd_card_mutex);
52
53static char *slots[SNDRV_CARDS];
54module_param_array(slots, charp, NULL, 0444);
55MODULE_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 */
60static 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)
95int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
96EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
97#endif
98
99#ifdef CONFIG_PROC_FS
100static 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
106static 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 */
147int 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}
241EXPORT_SYMBOL(snd_card_create);
242
243/* return non-zero if a card is already locked */
244int 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
254static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
255{
256    return -ENODEV;
257}
258
259static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
260                   size_t count, loff_t *offset)
261{
262    return -ENODEV;
263}
264
265static 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
271static 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
294static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
295{
296    return POLLERR | POLLNVAL;
297}
298
299static long snd_disconnect_ioctl(struct file *file,
300                 unsigned int cmd, unsigned long arg)
301{
302    return -ENODEV;
303}
304
305static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
306{
307    return -ENODEV;
308}
309
310static int snd_disconnect_fasync(int fd, struct file *file, int on)
311{
312    return -ENODEV;
313}
314
315static 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 */
342int snd_card_disconnect(struct snd_card *card)
343{
344    struct snd_monitor_file *mfile;
345    int err;
346
347    if (!card)
348        return -EINVAL;
349
350    spin_lock(&card->files_lock);
351    if (card->shutdown) {
352        spin_unlock(&card->files_lock);
353        return 0;
354    }
355    card->shutdown = 1;
356    spin_unlock(&card->files_lock);
357
358    /* phase 1: disable fops (user space) operations for ALSA API */
359    mutex_lock(&snd_card_mutex);
360    snd_cards[card->number] = NULL;
361    snd_cards_lock &= ~(1 << card->number);
362    mutex_unlock(&snd_card_mutex);
363    
364    /* phase 2: replace file->f_op with special dummy operations */
365    
366    spin_lock(&card->files_lock);
367    list_for_each_entry(mfile, &card->files_list, list) {
368        /* it's critical part, use endless loop */
369        /* we have no room to fail */
370        mfile->disconnected_f_op = mfile->file->f_op;
371
372        spin_lock(&shutdown_lock);
373        list_add(&mfile->shutdown_list, &shutdown_files);
374        spin_unlock(&shutdown_lock);
375
376        mfile->file->f_op = &snd_shutdown_f_ops;
377        fops_get(mfile->file->f_op);
378    }
379    spin_unlock(&card->files_lock);
380
381    /* phase 3: notify all connected devices about disconnection */
382    /* at this point, they cannot respond to any calls except release() */
383
384#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
385    if (snd_mixer_oss_notify_callback)
386        snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
387#endif
388
389    /* notify all devices that we are disconnected */
390    err = snd_device_disconnect_all(card);
391    if (err < 0)
392        snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
393
394    snd_info_card_disconnect(card);
395    if (card->card_dev) {
396        device_unregister(card->card_dev);
397        card->card_dev = NULL;
398    }
399#ifdef CONFIG_PM
400    wake_up(&card->power_sleep);
401#endif
402    return 0;
403}
404
405EXPORT_SYMBOL(snd_card_disconnect);
406
407/**
408 * snd_card_free - frees given soundcard structure
409 * @card: soundcard structure
410 *
411 * This function releases the soundcard structure and the all assigned
412 * devices automatically. That is, you don't have to release the devices
413 * by yourself.
414 *
415 * Returns zero. Frees all associated devices and frees the control
416 * interface associated to given soundcard.
417 */
418static int snd_card_do_free(struct snd_card *card)
419{
420#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
421    if (snd_mixer_oss_notify_callback)
422        snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
423#endif
424    if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
425        snd_printk(KERN_ERR "unable to free all devices (pre)\n");
426        /* Fatal, but this situation should never occur */
427    }
428    if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
429        snd_printk(KERN_ERR "unable to free all devices (normal)\n");
430        /* Fatal, but this situation should never occur */
431    }
432    if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
433        snd_printk(KERN_ERR "unable to free all devices (post)\n");
434        /* Fatal, but this situation should never occur */
435    }
436    if (card->private_free)
437        card->private_free(card);
438    snd_info_free_entry(card->proc_id);
439    if (snd_info_card_free(card) < 0) {
440        snd_printk(KERN_WARNING "unable to free card info\n");
441        /* Not fatal error */
442    }
443    kfree(card);
444    return 0;
445}
446
447int snd_card_free_when_closed(struct snd_card *card)
448{
449    int free_now = 0;
450    int ret = snd_card_disconnect(card);
451    if (ret)
452        return ret;
453
454    spin_lock(&card->files_lock);
455    if (list_empty(&card->files_list))
456        free_now = 1;
457    else
458        card->free_on_last_close = 1;
459    spin_unlock(&card->files_lock);
460
461    if (free_now)
462        snd_card_do_free(card);
463    return 0;
464}
465
466EXPORT_SYMBOL(snd_card_free_when_closed);
467
468int snd_card_free(struct snd_card *card)
469{
470    int ret = snd_card_disconnect(card);
471    if (ret)
472        return ret;
473
474    /* wait, until all devices are ready for the free operation */
475    wait_event(card->shutdown_sleep, list_empty(&card->files_list));
476    snd_card_do_free(card);
477    return 0;
478}
479
480EXPORT_SYMBOL(snd_card_free);
481
482static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
483{
484    int i, len, idx_flag = 0, loops = SNDRV_CARDS;
485    const char *spos, *src;
486    char *id;
487    
488    if (nid == NULL) {
489        id = card->shortname;
490        spos = src = id;
491        while (*id != '\0') {
492            if (*id == ' ')
493                spos = id + 1;
494            id++;
495        }
496    } else {
497        spos = src = nid;
498    }
499    id = card->id;
500    while (*spos != '\0' && !isalnum(*spos))
501        spos++;
502    if (isdigit(*spos))
503        *id++ = isalpha(src[0]) ? src[0] : 'D';
504    while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
505        if (isalnum(*spos))
506            *id++ = *spos;
507        spos++;
508    }
509    *id = '\0';
510
511    id = card->id;
512    
513    if (*id == '\0')
514        strcpy(id, "Default");
515
516    while (1) {
517              if (loops-- == 0) {
518            snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
519                  strcpy(card->id, card->proc_root->name);
520                  return;
521              }
522              if (!snd_info_check_reserved_words(id))
523                  goto __change;
524        for (i = 0; i < snd_ecards_limit; i++) {
525            if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
526                goto __change;
527        }
528        break;
529
530          __change:
531        len = strlen(id);
532        if (idx_flag) {
533            if (id[len-1] != '9')
534                id[len-1]++;
535            else
536                id[len-1] = 'A';
537        } else if ((size_t)len <= sizeof(card->id) - 3) {
538            strcat(id, "_1");
539            idx_flag++;
540        } else {
541            spos = id + len - 2;
542            if ((size_t)len <= sizeof(card->id) - 2)
543                spos++;
544            *(char *)spos++ = '_';
545            *(char *)spos++ = '1';
546            *(char *)spos++ = '\0';
547            idx_flag++;
548        }
549    }
550}
551
552/**
553 * snd_card_set_id - set card identification name
554 * @card: soundcard structure
555 * @nid: new identification string
556 *
557 * This function sets the card identification and checks for name
558 * collisions.
559 */
560void snd_card_set_id(struct snd_card *card, const char *nid)
561{
562    /* check if user specified own card->id */
563    if (card->id[0] != '\0')
564        return;
565    mutex_lock(&snd_card_mutex);
566    snd_card_set_id_no_lock(card, nid);
567    mutex_unlock(&snd_card_mutex);
568}
569EXPORT_SYMBOL(snd_card_set_id);
570
571static ssize_t
572card_id_show_attr(struct device *dev,
573          struct device_attribute *attr, char *buf)
574{
575    struct snd_card *card = dev_get_drvdata(dev);
576    return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
577}
578
579static ssize_t
580card_id_store_attr(struct device *dev, struct device_attribute *attr,
581           const char *buf, size_t count)
582{
583    struct snd_card *card = dev_get_drvdata(dev);
584    char buf1[sizeof(card->id)];
585    size_t copy = count > sizeof(card->id) - 1 ?
586                    sizeof(card->id) - 1 : count;
587    size_t idx;
588    int c;
589
590    for (idx = 0; idx < copy; idx++) {
591        c = buf[idx];
592        if (!isalnum(c) && c != '_' && c != '-')
593            return -EINVAL;
594    }
595    memcpy(buf1, buf, copy);
596    buf1[copy] = '\0';
597    mutex_lock(&snd_card_mutex);
598    if (!snd_info_check_reserved_words(buf1)) {
599         __exist:
600        mutex_unlock(&snd_card_mutex);
601        return -EEXIST;
602    }
603    for (idx = 0; idx < snd_ecards_limit; idx++) {
604        if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
605            if (card == snd_cards[idx])
606                goto __ok;
607            else
608                goto __exist;
609        }
610    }
611    strcpy(card->id, buf1);
612    snd_info_card_id_change(card);
613__ok:
614    mutex_unlock(&snd_card_mutex);
615
616    return count;
617}
618
619static struct device_attribute card_id_attrs =
620    __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
621
622static ssize_t
623card_number_show_attr(struct device *dev,
624             struct device_attribute *attr, char *buf)
625{
626    struct snd_card *card = dev_get_drvdata(dev);
627    return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
628}
629
630static struct device_attribute card_number_attrs =
631    __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
632
633/**
634 * snd_card_register - register the soundcard
635 * @card: soundcard structure
636 *
637 * This function registers all the devices assigned to the soundcard.
638 * Until calling this, the ALSA control interface is blocked from the
639 * external accesses. Thus, you should call this function at the end
640 * of the initialization of the card.
641 *
642 * Returns zero otherwise a negative error code if the registration failed.
643 */
644int snd_card_register(struct snd_card *card)
645{
646    int err;
647
648    if (snd_BUG_ON(!card))
649        return -EINVAL;
650
651    if (!card->card_dev) {
652        card->card_dev = device_create(sound_class, card->dev,
653                           MKDEV(0, 0), card,
654                           "card%i", card->number);
655        if (IS_ERR(card->card_dev))
656            card->card_dev = NULL;
657    }
658
659    if ((err = snd_device_register_all(card)) < 0)
660        return err;
661    mutex_lock(&snd_card_mutex);
662    if (snd_cards[card->number]) {
663        /* already registered */
664        mutex_unlock(&snd_card_mutex);
665        return 0;
666    }
667    snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);
668    snd_cards[card->number] = card;
669    mutex_unlock(&snd_card_mutex);
670    init_info_for_card(card);
671#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
672    if (snd_mixer_oss_notify_callback)
673        snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
674#endif
675    if (card->card_dev) {
676        err = device_create_file(card->card_dev, &card_id_attrs);
677        if (err < 0)
678            return err;
679        err = device_create_file(card->card_dev, &card_number_attrs);
680        if (err < 0)
681            return err;
682    }
683
684    return 0;
685}
686
687EXPORT_SYMBOL(snd_card_register);
688
689#ifdef CONFIG_PROC_FS
690static struct snd_info_entry *snd_card_info_entry;
691
692static void snd_card_info_read(struct snd_info_entry *entry,
693                   struct snd_info_buffer *buffer)
694{
695    int idx, count;
696    struct snd_card *card;
697
698    for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
699        mutex_lock(&snd_card_mutex);
700        if ((card = snd_cards[idx]) != NULL) {
701            count++;
702            snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
703                    idx,
704                    card->id,
705                    card->driver,
706                    card->shortname);
707            snd_iprintf(buffer, " %s\n",
708                    card->longname);
709        }
710        mutex_unlock(&snd_card_mutex);
711    }
712    if (!count)
713        snd_iprintf(buffer, "--- no soundcards ---\n");
714}
715
716#ifdef CONFIG_SND_OSSEMUL
717
718void snd_card_info_read_oss(struct snd_info_buffer *buffer)
719{
720    int idx, count;
721    struct snd_card *card;
722
723    for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
724        mutex_lock(&snd_card_mutex);
725        if ((card = snd_cards[idx]) != NULL) {
726            count++;
727            snd_iprintf(buffer, "%s\n", card->longname);
728        }
729        mutex_unlock(&snd_card_mutex);
730    }
731    if (!count) {
732        snd_iprintf(buffer, "--- no soundcards ---\n");
733    }
734}
735
736#endif
737
738#ifdef MODULE
739static struct snd_info_entry *snd_card_module_info_entry;
740static void snd_card_module_info_read(struct snd_info_entry *entry,
741                      struct snd_info_buffer *buffer)
742{
743    int idx;
744    struct snd_card *card;
745
746    for (idx = 0; idx < SNDRV_CARDS; idx++) {
747        mutex_lock(&snd_card_mutex);
748        if ((card = snd_cards[idx]) != NULL)
749            snd_iprintf(buffer, "%2i %s\n",
750                    idx, card->module->name);
751        mutex_unlock(&snd_card_mutex);
752    }
753}
754#endif
755
756int __init snd_card_info_init(void)
757{
758    struct snd_info_entry *entry;
759
760    entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
761    if (! entry)
762        return -ENOMEM;
763    entry->c.text.read = snd_card_info_read;
764    if (snd_info_register(entry) < 0) {
765        snd_info_free_entry(entry);
766        return -ENOMEM;
767    }
768    snd_card_info_entry = entry;
769
770#ifdef MODULE
771    entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
772    if (entry) {
773        entry->c.text.read = snd_card_module_info_read;
774        if (snd_info_register(entry) < 0)
775            snd_info_free_entry(entry);
776        else
777            snd_card_module_info_entry = entry;
778    }
779#endif
780
781    return 0;
782}
783
784int __exit snd_card_info_done(void)
785{
786    snd_info_free_entry(snd_card_info_entry);
787#ifdef MODULE
788    snd_info_free_entry(snd_card_module_info_entry);
789#endif
790    return 0;
791}
792
793#endif /* CONFIG_PROC_FS */
794
795/**
796 * snd_component_add - add a component string
797 * @card: soundcard structure
798 * @component: the component id string
799 *
800 * This function adds the component id string to the supported list.
801 * The component can be referred from the alsa-lib.
802 *
803 * Returns zero otherwise a negative error code.
804 */
805  
806int snd_component_add(struct snd_card *card, const char *component)
807{
808    char *ptr;
809    int len = strlen(component);
810
811    ptr = strstr(card->components, component);
812    if (ptr != NULL) {
813        if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
814            return 1;
815    }
816    if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
817        snd_BUG();
818        return -ENOMEM;
819    }
820    if (card->components[0] != '\0')
821        strcat(card->components, " ");
822    strcat(card->components, component);
823    return 0;
824}
825
826EXPORT_SYMBOL(snd_component_add);
827
828/**
829 * snd_card_file_add - add the file to the file list of the card
830 * @card: soundcard structure
831 * @file: file pointer
832 *
833 * This function adds the file to the file linked-list of the card.
834 * This linked-list is used to keep tracking the connection state,
835 * and to avoid the release of busy resources by hotplug.
836 *
837 * Returns zero or a negative error code.
838 */
839int snd_card_file_add(struct snd_card *card, struct file *file)
840{
841    struct snd_monitor_file *mfile;
842
843    mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
844    if (mfile == NULL)
845        return -ENOMEM;
846    mfile->file = file;
847    mfile->disconnected_f_op = NULL;
848    INIT_LIST_HEAD(&mfile->shutdown_list);
849    spin_lock(&card->files_lock);
850    if (card->shutdown) {
851        spin_unlock(&card->files_lock);
852        kfree(mfile);
853        return -ENODEV;
854    }
855    list_add(&mfile->list, &card->files_list);
856    spin_unlock(&card->files_lock);
857    return 0;
858}
859
860EXPORT_SYMBOL(snd_card_file_add);
861
862/**
863 * snd_card_file_remove - remove the file from the file list
864 * @card: soundcard structure
865 * @file: file pointer
866 *
867 * This function removes the file formerly added to the card via
868 * snd_card_file_add() function.
869 * If all files are removed and snd_card_free_when_closed() was
870 * called beforehand, it processes the pending release of
871 * resources.
872 *
873 * Returns zero or a negative error code.
874 */
875int snd_card_file_remove(struct snd_card *card, struct file *file)
876{
877    struct snd_monitor_file *mfile, *found = NULL;
878    int last_close = 0;
879
880    spin_lock(&card->files_lock);
881    list_for_each_entry(mfile, &card->files_list, list) {
882        if (mfile->file == file) {
883            list_del(&mfile->list);
884            spin_lock(&shutdown_lock);
885            list_del(&mfile->shutdown_list);
886            spin_unlock(&shutdown_lock);
887            if (mfile->disconnected_f_op)
888                fops_put(mfile->disconnected_f_op);
889            found = mfile;
890            break;
891        }
892    }
893    if (list_empty(&card->files_list))
894        last_close = 1;
895    spin_unlock(&card->files_lock);
896    if (last_close) {
897        wake_up(&card->shutdown_sleep);
898        if (card->free_on_last_close)
899            snd_card_do_free(card);
900    }
901    if (!found) {
902        snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
903        return -ENOENT;
904    }
905    kfree(found);
906    return 0;
907}
908
909EXPORT_SYMBOL(snd_card_file_remove);
910
911#ifdef CONFIG_PM
912/**
913 * snd_power_wait - wait until the power-state is changed.
914 * @card: soundcard structure
915 * @power_state: expected power state
916 *
917 * Waits until the power-state is changed.
918 *
919 * Note: the power lock must be active before call.
920 */
921int snd_power_wait(struct snd_card *card, unsigned int power_state)
922{
923    wait_queue_t wait;
924    int result = 0;
925
926    /* fastpath */
927    if (snd_power_get_state(card) == power_state)
928        return 0;
929    init_waitqueue_entry(&wait, current);
930    add_wait_queue(&card->power_sleep, &wait);
931    while (1) {
932        if (card->shutdown) {
933            result = -ENODEV;
934            break;
935        }
936        if (snd_power_get_state(card) == power_state)
937            break;
938        set_current_state(TASK_UNINTERRUPTIBLE);
939        snd_power_unlock(card);
940        schedule_timeout(30 * HZ);
941        snd_power_lock(card);
942    }
943    remove_wait_queue(&card->power_sleep, &wait);
944    return result;
945}
946
947EXPORT_SYMBOL(snd_power_wait);
948#endif /* CONFIG_PM */
949

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