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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/completion.h>
17
18#include <sound/core.h>
19#include <sound/control.h>
20#include <sound/info.h>
21
22/* monitor files for graceful shutdown (hotplug) */
23struct snd_monitor_file {
24 struct file *file;
25 const struct file_operations *disconnected_f_op;
26 struct list_head shutdown_list; /* still need to shutdown */
27 struct list_head list; /* link of monitor files */
28};
29
30static DEFINE_SPINLOCK(shutdown_lock);
31static LIST_HEAD(shutdown_files);
32
33static const struct file_operations snd_shutdown_f_ops;
34
35/* locked for registering/using */
36static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
37static struct snd_card *snd_cards[SNDRV_CARDS];
38
39static DEFINE_MUTEX(snd_card_mutex);
40
41static char *slots[SNDRV_CARDS];
42module_param_array(slots, charp, NULL, 0444);
43MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
44
45/* return non-zero if the given index is reserved for the given
46 * module via slots option
47 */
48static int module_slot_match(struct module *module, int idx)
49{
50 int match = 1;
51#ifdef MODULE
52 const char *s1, *s2;
53
54 if (!module || !*module->name || !slots[idx])
55 return 0;
56
57 s1 = module->name;
58 s2 = slots[idx];
59 if (*s2 == '!') {
60 match = 0; /* negative match */
61 s2++;
62 }
63 /* compare module name strings
64 * hyphens are handled as equivalent with underscore
65 */
66 for (;;) {
67 char c1 = *s1++;
68 char c2 = *s2++;
69 if (c1 == '-')
70 c1 = '_';
71 if (c2 == '-')
72 c2 = '_';
73 if (c1 != c2)
74 return !match;
75 if (!c1)
76 break;
77 }
78#endif /* MODULE */
79 return match;
80}
81
82#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
83int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
84EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
85#endif
86
87static int check_empty_slot(struct module *module, int slot)
88{
89 return !slots[slot] || !*slots[slot];
90}
91
92/* return an empty slot number (>= 0) found in the given bitmask @mask.
93 * @mask == -1 == 0xffffffff means: take any free slot up to 32
94 * when no slot is available, return the original @mask as is.
95 */
96static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
97 struct module *module)
98{
99 int slot;
100
101 for (slot = 0; slot < SNDRV_CARDS; slot++) {
102 if (slot < 32 && !(mask & (1U << slot)))
103 continue;
104 if (!test_bit(slot, snd_cards_lock)) {
105 if (check(module, slot))
106 return slot; /* found */
107 }
108 }
109 return mask; /* unchanged */
110}
111
112/* the default release callback set in snd_device_initialize() below;
113 * this is just NOP for now, as almost all jobs are already done in
114 * dev_free callback of snd_device chain instead.
115 */
116static void default_release(struct device *dev)
117{
118}
119
120/**
121 * snd_device_initialize - Initialize struct device for sound devices
122 * @dev: device to initialize
123 * @card: card to assign, optional
124 */
125void snd_device_initialize(struct device *dev, struct snd_card *card)
126{
127 device_initialize(dev);
128 if (card)
129 dev->parent = &card->card_dev;
130 dev->class = sound_class;
131 dev->release = default_release;
132}
133EXPORT_SYMBOL_GPL(snd_device_initialize);
134
135static int snd_card_do_free(struct snd_card *card);
136static const struct attribute_group card_dev_attr_group;
137
138static void release_card_device(struct device *dev)
139{
140 snd_card_do_free(dev_to_snd_card(dev));
141}
142
143/**
144 * snd_card_new - create and initialize a soundcard structure
145 * @parent: the parent device object
146 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
147 * @xid: card identification (ASCII string)
148 * @module: top level module for locking
149 * @extra_size: allocate this extra size after the main soundcard structure
150 * @card_ret: the pointer to store the created card instance
151 *
152 * Creates and initializes a soundcard structure.
153 *
154 * The function allocates snd_card instance via kzalloc with the given
155 * space for the driver to use freely. The allocated struct is stored
156 * in the given card_ret pointer.
157 *
158 * Return: Zero if successful or a negative error code.
159 */
160int snd_card_new(struct device *parent, int idx, const char *xid,
161 struct module *module, int extra_size,
162 struct snd_card **card_ret)
163{
164 struct snd_card *card;
165 int err;
166
167 if (snd_BUG_ON(!card_ret))
168 return -EINVAL;
169 *card_ret = NULL;
170
171 if (extra_size < 0)
172 extra_size = 0;
173 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
174 if (!card)
175 return -ENOMEM;
176 if (extra_size > 0)
177 card->private_data = (char *)card + sizeof(struct snd_card);
178 if (xid)
179 strlcpy(card->id, xid, sizeof(card->id));
180 err = 0;
181 mutex_lock(&snd_card_mutex);
182 if (idx < 0) /* first check the matching module-name slot */
183 idx = get_slot_from_bitmask(idx, module_slot_match, module);
184 if (idx < 0) /* if not matched, assign an empty slot */
185 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
186 if (idx < 0)
187 err = -ENODEV;
188 else if (idx < snd_ecards_limit) {
189 if (test_bit(idx, snd_cards_lock))
190 err = -EBUSY; /* invalid */
191 } else if (idx >= SNDRV_CARDS)
192 err = -ENODEV;
193 if (err < 0) {
194 mutex_unlock(&snd_card_mutex);
195 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
196 idx, snd_ecards_limit - 1, err);
197 kfree(card);
198 return err;
199 }
200 set_bit(idx, snd_cards_lock); /* 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->dev = parent;
205 card->number = idx;
206 card->module = module;
207 INIT_LIST_HEAD(&card->devices);
208 init_rwsem(&card->controls_rwsem);
209 rwlock_init(&card->ctl_files_rwlock);
210 INIT_LIST_HEAD(&card->controls);
211 INIT_LIST_HEAD(&card->ctl_files);
212 spin_lock_init(&card->files_lock);
213 INIT_LIST_HEAD(&card->files_list);
214#ifdef CONFIG_PM
215 init_waitqueue_head(&card->power_sleep);
216#endif
217 init_waitqueue_head(&card->remove_sleep);
218
219 device_initialize(&card->card_dev);
220 card->card_dev.parent = parent;
221 card->card_dev.class = sound_class;
222 card->card_dev.release = release_card_device;
223 card->card_dev.groups = card->dev_groups;
224 card->dev_groups[0] = &card_dev_attr_group;
225 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
226 if (err < 0)
227 goto __error;
228
229 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
230 dev_driver_string(card->dev), dev_name(&card->card_dev));
231
232 /* the control interface cannot be accessed from the user space until */
233 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
234 err = snd_ctl_create(card);
235 if (err < 0) {
236 dev_err(parent, "unable to register control minors\n");
237 goto __error;
238 }
239 err = snd_info_card_create(card);
240 if (err < 0) {
241 dev_err(parent, "unable to create card info\n");
242 goto __error_ctl;
243 }
244 *card_ret = card;
245 return 0;
246
247 __error_ctl:
248 snd_device_free_all(card);
249 __error:
250 put_device(&card->card_dev);
251 return err;
252}
253EXPORT_SYMBOL(snd_card_new);
254
255/**
256 * snd_card_ref - Get the card object from the index
257 * @idx: the card index
258 *
259 * Returns a card object corresponding to the given index or NULL if not found.
260 * Release the object via snd_card_unref().
261 */
262struct snd_card *snd_card_ref(int idx)
263{
264 struct snd_card *card;
265
266 mutex_lock(&snd_card_mutex);
267 card = snd_cards[idx];
268 if (card)
269 get_device(&card->card_dev);
270 mutex_unlock(&snd_card_mutex);
271 return card;
272}
273EXPORT_SYMBOL_GPL(snd_card_ref);
274
275/* return non-zero if a card is already locked */
276int snd_card_locked(int card)
277{
278 int locked;
279
280 mutex_lock(&snd_card_mutex);
281 locked = test_bit(card, snd_cards_lock);
282 mutex_unlock(&snd_card_mutex);
283 return locked;
284}
285
286static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
287{
288 return -ENODEV;
289}
290
291static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
292 size_t count, loff_t *offset)
293{
294 return -ENODEV;
295}
296
297static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
298 size_t count, loff_t *offset)
299{
300 return -ENODEV;
301}
302
303static int snd_disconnect_release(struct inode *inode, struct file *file)
304{
305 struct snd_monitor_file *df = NULL, *_df;
306
307 spin_lock(&shutdown_lock);
308 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
309 if (_df->file == file) {
310 df = _df;
311 list_del_init(&df->shutdown_list);
312 break;
313 }
314 }
315 spin_unlock(&shutdown_lock);
316
317 if (likely(df)) {
318 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
319 df->disconnected_f_op->fasync(-1, file, 0);
320 return df->disconnected_f_op->release(inode, file);
321 }
322
323 panic("%s(%p, %p) failed!", __func__, inode, file);
324}
325
326static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
327{
328 return EPOLLERR | EPOLLNVAL;
329}
330
331static long snd_disconnect_ioctl(struct file *file,
332 unsigned int cmd, unsigned long arg)
333{
334 return -ENODEV;
335}
336
337static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
338{
339 return -ENODEV;
340}
341
342static int snd_disconnect_fasync(int fd, struct file *file, int on)
343{
344 return -ENODEV;
345}
346
347static const struct file_operations snd_shutdown_f_ops =
348{
349 .owner = THIS_MODULE,
350 .llseek = snd_disconnect_llseek,
351 .read = snd_disconnect_read,
352 .write = snd_disconnect_write,
353 .release = snd_disconnect_release,
354 .poll = snd_disconnect_poll,
355 .unlocked_ioctl = snd_disconnect_ioctl,
356#ifdef CONFIG_COMPAT
357 .compat_ioctl = snd_disconnect_ioctl,
358#endif
359 .mmap = snd_disconnect_mmap,
360 .fasync = snd_disconnect_fasync
361};
362
363/**
364 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
365 * @card: soundcard structure
366 *
367 * Disconnects all APIs from the file-operations (user space).
368 *
369 * Return: Zero, otherwise a negative error code.
370 *
371 * Note: The current implementation replaces all active file->f_op with special
372 * dummy file operations (they do nothing except release).
373 */
374int snd_card_disconnect(struct snd_card *card)
375{
376 struct snd_monitor_file *mfile;
377
378 if (!card)
379 return -EINVAL;
380
381 spin_lock(&card->files_lock);
382 if (card->shutdown) {
383 spin_unlock(&card->files_lock);
384 return 0;
385 }
386 card->shutdown = 1;
387 spin_unlock(&card->files_lock);
388
389 /* replace file->f_op with special dummy operations */
390 spin_lock(&card->files_lock);
391 list_for_each_entry(mfile, &card->files_list, list) {
392 /* it's critical part, use endless loop */
393 /* we have no room to fail */
394 mfile->disconnected_f_op = mfile->file->f_op;
395
396 spin_lock(&shutdown_lock);
397 list_add(&mfile->shutdown_list, &shutdown_files);
398 spin_unlock(&shutdown_lock);
399
400 mfile->file->f_op = &snd_shutdown_f_ops;
401 fops_get(mfile->file->f_op);
402 }
403 spin_unlock(&card->files_lock);
404
405 /* notify all connected devices about disconnection */
406 /* at this point, they cannot respond to any calls except release() */
407
408#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
409 if (snd_mixer_oss_notify_callback)
410 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
411#endif
412
413 /* notify all devices that we are disconnected */
414 snd_device_disconnect_all(card);
415
416 snd_info_card_disconnect(card);
417 if (card->registered) {
418 device_del(&card->card_dev);
419 card->registered = false;
420 }
421
422 /* disable fops (user space) operations for ALSA API */
423 mutex_lock(&snd_card_mutex);
424 snd_cards[card->number] = NULL;
425 clear_bit(card->number, snd_cards_lock);
426 mutex_unlock(&snd_card_mutex);
427
428#ifdef CONFIG_PM
429 wake_up(&card->power_sleep);
430#endif
431 return 0;
432}
433EXPORT_SYMBOL(snd_card_disconnect);
434
435/**
436 * snd_card_disconnect_sync - disconnect card and wait until files get closed
437 * @card: card object to disconnect
438 *
439 * This calls snd_card_disconnect() for disconnecting all belonging components
440 * and waits until all pending files get closed.
441 * It assures that all accesses from user-space finished so that the driver
442 * can release its resources gracefully.
443 */
444void snd_card_disconnect_sync(struct snd_card *card)
445{
446 int err;
447
448 err = snd_card_disconnect(card);
449 if (err < 0) {
450 dev_err(card->dev,
451 "snd_card_disconnect error (%d), skipping sync\n",
452 err);
453 return;
454 }
455
456 spin_lock_irq(&card->files_lock);
457 wait_event_lock_irq(card->remove_sleep,
458 list_empty(&card->files_list),
459 card->files_lock);
460 spin_unlock_irq(&card->files_lock);
461}
462EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
463
464static int snd_card_do_free(struct snd_card *card)
465{
466#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
467 if (snd_mixer_oss_notify_callback)
468 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
469#endif
470 snd_device_free_all(card);
471 if (card->private_free)
472 card->private_free(card);
473 if (snd_info_card_free(card) < 0) {
474 dev_warn(card->dev, "unable to free card info\n");
475 /* Not fatal error */
476 }
477 if (card->release_completion)
478 complete(card->release_completion);
479 kfree(card);
480 return 0;
481}
482
483/**
484 * snd_card_free_when_closed - Disconnect the card, free it later eventually
485 * @card: soundcard structure
486 *
487 * Unlike snd_card_free(), this function doesn't try to release the card
488 * resource immediately, but tries to disconnect at first. When the card
489 * is still in use, the function returns before freeing the resources.
490 * The card resources will be freed when the refcount gets to zero.
491 */
492int snd_card_free_when_closed(struct snd_card *card)
493{
494 int ret = snd_card_disconnect(card);
495 if (ret)
496 return ret;
497 put_device(&card->card_dev);
498 return 0;
499}
500EXPORT_SYMBOL(snd_card_free_when_closed);
501
502/**
503 * snd_card_free - frees given soundcard structure
504 * @card: soundcard structure
505 *
506 * This function releases the soundcard structure and the all assigned
507 * devices automatically. That is, you don't have to release the devices
508 * by yourself.
509 *
510 * This function waits until the all resources are properly released.
511 *
512 * Return: Zero. Frees all associated devices and frees the control
513 * interface associated to given soundcard.
514 */
515int snd_card_free(struct snd_card *card)
516{
517 struct completion released;
518 int ret;
519
520 init_completion(&released);
521 card->release_completion = &released;
522 ret = snd_card_free_when_closed(card);
523 if (ret)
524 return ret;
525 /* wait, until all devices are ready for the free operation */
526 wait_for_completion(&released);
527 return 0;
528}
529EXPORT_SYMBOL(snd_card_free);
530
531/* retrieve the last word of shortname or longname */
532static const char *retrieve_id_from_card_name(const char *name)
533{
534 const char *spos = name;
535
536 while (*name) {
537 if (isspace(*name) && isalnum(name[1]))
538 spos = name + 1;
539 name++;
540 }
541 return spos;
542}
543
544/* return true if the given id string doesn't conflict any other card ids */
545static bool card_id_ok(struct snd_card *card, const char *id)
546{
547 int i;
548 if (!snd_info_check_reserved_words(id))
549 return false;
550 for (i = 0; i < snd_ecards_limit; i++) {
551 if (snd_cards[i] && snd_cards[i] != card &&
552 !strcmp(snd_cards[i]->id, id))
553 return false;
554 }
555 return true;
556}
557
558/* copy to card->id only with valid letters from nid */
559static void copy_valid_id_string(struct snd_card *card, const char *src,
560 const char *nid)
561{
562 char *id = card->id;
563
564 while (*nid && !isalnum(*nid))
565 nid++;
566 if (isdigit(*nid))
567 *id++ = isalpha(*src) ? *src : 'D';
568 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
569 if (isalnum(*nid))
570 *id++ = *nid;
571 nid++;
572 }
573 *id = 0;
574}
575
576/* Set card->id from the given string
577 * If the string conflicts with other ids, add a suffix to make it unique.
578 */
579static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
580 const char *nid)
581{
582 int len, loops;
583 bool is_default = false;
584 char *id;
585
586 copy_valid_id_string(card, src, nid);
587 id = card->id;
588
589 again:
590 /* use "Default" for obviously invalid strings
591 * ("card" conflicts with proc directories)
592 */
593 if (!*id || !strncmp(id, "card", 4)) {
594 strcpy(id, "Default");
595 is_default = true;
596 }
597
598 len = strlen(id);
599 for (loops = 0; loops < SNDRV_CARDS; loops++) {
600 char *spos;
601 char sfxstr[5]; /* "_012" */
602 int sfxlen;
603
604 if (card_id_ok(card, id))
605 return; /* OK */
606
607 /* Add _XYZ suffix */
608 sprintf(sfxstr, "_%X", loops + 1);
609 sfxlen = strlen(sfxstr);
610 if (len + sfxlen >= sizeof(card->id))
611 spos = id + sizeof(card->id) - sfxlen - 1;
612 else
613 spos = id + len;
614 strcpy(spos, sfxstr);
615 }
616 /* fallback to the default id */
617 if (!is_default) {
618 *id = 0;
619 goto again;
620 }
621 /* last resort... */
622 dev_err(card->dev, "unable to set card id (%s)\n", id);
623 if (card->proc_root->name)
624 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
625}
626
627/**
628 * snd_card_set_id - set card identification name
629 * @card: soundcard structure
630 * @nid: new identification string
631 *
632 * This function sets the card identification and checks for name
633 * collisions.
634 */
635void snd_card_set_id(struct snd_card *card, const char *nid)
636{
637 /* check if user specified own card->id */
638 if (card->id[0] != '\0')
639 return;
640 mutex_lock(&snd_card_mutex);
641 snd_card_set_id_no_lock(card, nid, nid);
642 mutex_unlock(&snd_card_mutex);
643}
644EXPORT_SYMBOL(snd_card_set_id);
645
646static ssize_t
647card_id_show_attr(struct device *dev,
648 struct device_attribute *attr, char *buf)
649{
650 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
651 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
652}
653
654static ssize_t
655card_id_store_attr(struct device *dev, struct device_attribute *attr,
656 const char *buf, size_t count)
657{
658 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
659 char buf1[sizeof(card->id)];
660 size_t copy = count > sizeof(card->id) - 1 ?
661 sizeof(card->id) - 1 : count;
662 size_t idx;
663 int c;
664
665 for (idx = 0; idx < copy; idx++) {
666 c = buf[idx];
667 if (!isalnum(c) && c != '_' && c != '-')
668 return -EINVAL;
669 }
670 memcpy(buf1, buf, copy);
671 buf1[copy] = '\0';
672 mutex_lock(&snd_card_mutex);
673 if (!card_id_ok(NULL, buf1)) {
674 mutex_unlock(&snd_card_mutex);
675 return -EEXIST;
676 }
677 strcpy(card->id, buf1);
678 snd_info_card_id_change(card);
679 mutex_unlock(&snd_card_mutex);
680
681 return count;
682}
683
684static DEVICE_ATTR(id, 0644, card_id_show_attr, card_id_store_attr);
685
686static ssize_t
687card_number_show_attr(struct device *dev,
688 struct device_attribute *attr, char *buf)
689{
690 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
691 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
692}
693
694static DEVICE_ATTR(number, 0444, card_number_show_attr, NULL);
695
696static struct attribute *card_dev_attrs[] = {
697 &dev_attr_id.attr,
698 &dev_attr_number.attr,
699 NULL
700};
701
702static const struct attribute_group card_dev_attr_group = {
703 .attrs = card_dev_attrs,
704};
705
706/**
707 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
708 * @card: card instance
709 * @group: attribute group to append
710 */
711int snd_card_add_dev_attr(struct snd_card *card,
712 const struct attribute_group *group)
713{
714 int i;
715
716 /* loop for (arraysize-1) here to keep NULL at the last entry */
717 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
718 if (!card->dev_groups[i]) {
719 card->dev_groups[i] = group;
720 return 0;
721 }
722 }
723
724 dev_err(card->dev, "Too many groups assigned\n");
725 return -ENOSPC;
726}
727EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
728
729/**
730 * snd_card_register - register the soundcard
731 * @card: soundcard structure
732 *
733 * This function registers all the devices assigned to the soundcard.
734 * Until calling this, the ALSA control interface is blocked from the
735 * external accesses. Thus, you should call this function at the end
736 * of the initialization of the card.
737 *
738 * Return: Zero otherwise a negative error code if the registration failed.
739 */
740int snd_card_register(struct snd_card *card)
741{
742 int err;
743
744 if (snd_BUG_ON(!card))
745 return -EINVAL;
746
747 if (!card->registered) {
748 err = device_add(&card->card_dev);
749 if (err < 0)
750 return err;
751 card->registered = true;
752 }
753
754 if ((err = snd_device_register_all(card)) < 0)
755 return err;
756 mutex_lock(&snd_card_mutex);
757 if (snd_cards[card->number]) {
758 /* already registered */
759 mutex_unlock(&snd_card_mutex);
760 return snd_info_card_register(card); /* register pending info */
761 }
762 if (*card->id) {
763 /* make a unique id name from the given string */
764 char tmpid[sizeof(card->id)];
765 memcpy(tmpid, card->id, sizeof(card->id));
766 snd_card_set_id_no_lock(card, tmpid, tmpid);
767 } else {
768 /* create an id from either shortname or longname */
769 const char *src;
770 src = *card->shortname ? card->shortname : card->longname;
771 snd_card_set_id_no_lock(card, src,
772 retrieve_id_from_card_name(src));
773 }
774 snd_cards[card->number] = card;
775 mutex_unlock(&snd_card_mutex);
776 err = snd_info_card_register(card);
777 if (err < 0)
778 return err;
779
780#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
781 if (snd_mixer_oss_notify_callback)
782 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
783#endif
784 return 0;
785}
786EXPORT_SYMBOL(snd_card_register);
787
788#ifdef CONFIG_SND_PROC_FS
789static void snd_card_info_read(struct snd_info_entry *entry,
790 struct snd_info_buffer *buffer)
791{
792 int idx, count;
793 struct snd_card *card;
794
795 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
796 mutex_lock(&snd_card_mutex);
797 if ((card = snd_cards[idx]) != NULL) {
798 count++;
799 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
800 idx,
801 card->id,
802 card->driver,
803 card->shortname);
804 snd_iprintf(buffer, " %s\n",
805 card->longname);
806 }
807 mutex_unlock(&snd_card_mutex);
808 }
809 if (!count)
810 snd_iprintf(buffer, "--- no soundcards ---\n");
811}
812
813#ifdef CONFIG_SND_OSSEMUL
814void snd_card_info_read_oss(struct snd_info_buffer *buffer)
815{
816 int idx, count;
817 struct snd_card *card;
818
819 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
820 mutex_lock(&snd_card_mutex);
821 if ((card = snd_cards[idx]) != NULL) {
822 count++;
823 snd_iprintf(buffer, "%s\n", card->longname);
824 }
825 mutex_unlock(&snd_card_mutex);
826 }
827 if (!count) {
828 snd_iprintf(buffer, "--- no soundcards ---\n");
829 }
830}
831
832#endif
833
834#ifdef MODULE
835static void snd_card_module_info_read(struct snd_info_entry *entry,
836 struct snd_info_buffer *buffer)
837{
838 int idx;
839 struct snd_card *card;
840
841 for (idx = 0; idx < SNDRV_CARDS; idx++) {
842 mutex_lock(&snd_card_mutex);
843 if ((card = snd_cards[idx]) != NULL)
844 snd_iprintf(buffer, "%2i %s\n",
845 idx, card->module->name);
846 mutex_unlock(&snd_card_mutex);
847 }
848}
849#endif
850
851int __init snd_card_info_init(void)
852{
853 struct snd_info_entry *entry;
854
855 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
856 if (! entry)
857 return -ENOMEM;
858 entry->c.text.read = snd_card_info_read;
859 if (snd_info_register(entry) < 0)
860 return -ENOMEM; /* freed in error path */
861
862#ifdef MODULE
863 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
864 if (!entry)
865 return -ENOMEM;
866 entry->c.text.read = snd_card_module_info_read;
867 if (snd_info_register(entry) < 0)
868 return -ENOMEM; /* freed in error path */
869#endif
870
871 return 0;
872}
873#endif /* CONFIG_SND_PROC_FS */
874
875/**
876 * snd_component_add - add a component string
877 * @card: soundcard structure
878 * @component: the component id string
879 *
880 * This function adds the component id string to the supported list.
881 * The component can be referred from the alsa-lib.
882 *
883 * Return: Zero otherwise a negative error code.
884 */
885
886int snd_component_add(struct snd_card *card, const char *component)
887{
888 char *ptr;
889 int len = strlen(component);
890
891 ptr = strstr(card->components, component);
892 if (ptr != NULL) {
893 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
894 return 1;
895 }
896 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
897 snd_BUG();
898 return -ENOMEM;
899 }
900 if (card->components[0] != '\0')
901 strcat(card->components, " ");
902 strcat(card->components, component);
903 return 0;
904}
905EXPORT_SYMBOL(snd_component_add);
906
907/**
908 * snd_card_file_add - add the file to the file list of the card
909 * @card: soundcard structure
910 * @file: file pointer
911 *
912 * This function adds the file to the file linked-list of the card.
913 * This linked-list is used to keep tracking the connection state,
914 * and to avoid the release of busy resources by hotplug.
915 *
916 * Return: zero or a negative error code.
917 */
918int snd_card_file_add(struct snd_card *card, struct file *file)
919{
920 struct snd_monitor_file *mfile;
921
922 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
923 if (mfile == NULL)
924 return -ENOMEM;
925 mfile->file = file;
926 mfile->disconnected_f_op = NULL;
927 INIT_LIST_HEAD(&mfile->shutdown_list);
928 spin_lock(&card->files_lock);
929 if (card->shutdown) {
930 spin_unlock(&card->files_lock);
931 kfree(mfile);
932 return -ENODEV;
933 }
934 list_add(&mfile->list, &card->files_list);
935 get_device(&card->card_dev);
936 spin_unlock(&card->files_lock);
937 return 0;
938}
939EXPORT_SYMBOL(snd_card_file_add);
940
941/**
942 * snd_card_file_remove - remove the file from the file list
943 * @card: soundcard structure
944 * @file: file pointer
945 *
946 * This function removes the file formerly added to the card via
947 * snd_card_file_add() function.
948 * If all files are removed and snd_card_free_when_closed() was
949 * called beforehand, it processes the pending release of
950 * resources.
951 *
952 * Return: Zero or a negative error code.
953 */
954int snd_card_file_remove(struct snd_card *card, struct file *file)
955{
956 struct snd_monitor_file *mfile, *found = NULL;
957
958 spin_lock(&card->files_lock);
959 list_for_each_entry(mfile, &card->files_list, list) {
960 if (mfile->file == file) {
961 list_del(&mfile->list);
962 spin_lock(&shutdown_lock);
963 list_del(&mfile->shutdown_list);
964 spin_unlock(&shutdown_lock);
965 if (mfile->disconnected_f_op)
966 fops_put(mfile->disconnected_f_op);
967 found = mfile;
968 break;
969 }
970 }
971 if (list_empty(&card->files_list))
972 wake_up_all(&card->remove_sleep);
973 spin_unlock(&card->files_lock);
974 if (!found) {
975 dev_err(card->dev, "card file remove problem (%p)\n", file);
976 return -ENOENT;
977 }
978 kfree(found);
979 put_device(&card->card_dev);
980 return 0;
981}
982EXPORT_SYMBOL(snd_card_file_remove);
983
984#ifdef CONFIG_PM
985/**
986 * snd_power_wait - wait until the power-state is changed.
987 * @card: soundcard structure
988 * @power_state: expected power state
989 *
990 * Waits until the power-state is changed.
991 *
992 * Return: Zero if successful, or a negative error code.
993 */
994int snd_power_wait(struct snd_card *card, unsigned int power_state)
995{
996 wait_queue_entry_t wait;
997 int result = 0;
998
999 /* fastpath */
1000 if (snd_power_get_state(card) == power_state)
1001 return 0;
1002 init_waitqueue_entry(&wait, current);
1003 add_wait_queue(&card->power_sleep, &wait);
1004 while (1) {
1005 if (card->shutdown) {
1006 result = -ENODEV;
1007 break;
1008 }
1009 if (snd_power_get_state(card) == power_state)
1010 break;
1011 set_current_state(TASK_UNINTERRUPTIBLE);
1012 schedule_timeout(30 * HZ);
1013 }
1014 remove_wait_queue(&card->power_sleep, &wait);
1015 return result;
1016}
1017EXPORT_SYMBOL(snd_power_wait);
1018#endif /* CONFIG_PM */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/completion.h>
17
18#include <sound/core.h>
19#include <sound/control.h>
20#include <sound/info.h>
21
22/* monitor files for graceful shutdown (hotplug) */
23struct snd_monitor_file {
24 struct file *file;
25 const struct file_operations *disconnected_f_op;
26 struct list_head shutdown_list; /* still need to shutdown */
27 struct list_head list; /* link of monitor files */
28};
29
30static DEFINE_SPINLOCK(shutdown_lock);
31static LIST_HEAD(shutdown_files);
32
33static const struct file_operations snd_shutdown_f_ops;
34
35/* locked for registering/using */
36static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
37static struct snd_card *snd_cards[SNDRV_CARDS];
38
39static DEFINE_MUTEX(snd_card_mutex);
40
41static char *slots[SNDRV_CARDS];
42module_param_array(slots, charp, NULL, 0444);
43MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
44
45/* return non-zero if the given index is reserved for the given
46 * module via slots option
47 */
48static int module_slot_match(struct module *module, int idx)
49{
50 int match = 1;
51#ifdef MODULE
52 const char *s1, *s2;
53
54 if (!module || !*module->name || !slots[idx])
55 return 0;
56
57 s1 = module->name;
58 s2 = slots[idx];
59 if (*s2 == '!') {
60 match = 0; /* negative match */
61 s2++;
62 }
63 /* compare module name strings
64 * hyphens are handled as equivalent with underscore
65 */
66 for (;;) {
67 char c1 = *s1++;
68 char c2 = *s2++;
69 if (c1 == '-')
70 c1 = '_';
71 if (c2 == '-')
72 c2 = '_';
73 if (c1 != c2)
74 return !match;
75 if (!c1)
76 break;
77 }
78#endif /* MODULE */
79 return match;
80}
81
82#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
83int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
84EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
85#endif
86
87static int check_empty_slot(struct module *module, int slot)
88{
89 return !slots[slot] || !*slots[slot];
90}
91
92/* return an empty slot number (>= 0) found in the given bitmask @mask.
93 * @mask == -1 == 0xffffffff means: take any free slot up to 32
94 * when no slot is available, return the original @mask as is.
95 */
96static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
97 struct module *module)
98{
99 int slot;
100
101 for (slot = 0; slot < SNDRV_CARDS; slot++) {
102 if (slot < 32 && !(mask & (1U << slot)))
103 continue;
104 if (!test_bit(slot, snd_cards_lock)) {
105 if (check(module, slot))
106 return slot; /* found */
107 }
108 }
109 return mask; /* unchanged */
110}
111
112/* the default release callback set in snd_device_initialize() below;
113 * this is just NOP for now, as almost all jobs are already done in
114 * dev_free callback of snd_device chain instead.
115 */
116static void default_release(struct device *dev)
117{
118}
119
120/**
121 * snd_device_initialize - Initialize struct device for sound devices
122 * @dev: device to initialize
123 * @card: card to assign, optional
124 */
125void snd_device_initialize(struct device *dev, struct snd_card *card)
126{
127 device_initialize(dev);
128 if (card)
129 dev->parent = &card->card_dev;
130 dev->class = sound_class;
131 dev->release = default_release;
132}
133EXPORT_SYMBOL_GPL(snd_device_initialize);
134
135static int snd_card_do_free(struct snd_card *card);
136static const struct attribute_group card_dev_attr_group;
137
138static void release_card_device(struct device *dev)
139{
140 snd_card_do_free(dev_to_snd_card(dev));
141}
142
143/**
144 * snd_card_new - create and initialize a soundcard structure
145 * @parent: the parent device object
146 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
147 * @xid: card identification (ASCII string)
148 * @module: top level module for locking
149 * @extra_size: allocate this extra size after the main soundcard structure
150 * @card_ret: the pointer to store the created card instance
151 *
152 * Creates and initializes a soundcard structure.
153 *
154 * The function allocates snd_card instance via kzalloc with the given
155 * space for the driver to use freely. The allocated struct is stored
156 * in the given card_ret pointer.
157 *
158 * Return: Zero if successful or a negative error code.
159 */
160int snd_card_new(struct device *parent, int idx, const char *xid,
161 struct module *module, int extra_size,
162 struct snd_card **card_ret)
163{
164 struct snd_card *card;
165 int err;
166
167 if (snd_BUG_ON(!card_ret))
168 return -EINVAL;
169 *card_ret = NULL;
170
171 if (extra_size < 0)
172 extra_size = 0;
173 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
174 if (!card)
175 return -ENOMEM;
176 if (extra_size > 0)
177 card->private_data = (char *)card + sizeof(struct snd_card);
178 if (xid)
179 strlcpy(card->id, xid, sizeof(card->id));
180 err = 0;
181 mutex_lock(&snd_card_mutex);
182 if (idx < 0) /* first check the matching module-name slot */
183 idx = get_slot_from_bitmask(idx, module_slot_match, module);
184 if (idx < 0) /* if not matched, assign an empty slot */
185 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
186 if (idx < 0)
187 err = -ENODEV;
188 else if (idx < snd_ecards_limit) {
189 if (test_bit(idx, snd_cards_lock))
190 err = -EBUSY; /* invalid */
191 } else if (idx >= SNDRV_CARDS)
192 err = -ENODEV;
193 if (err < 0) {
194 mutex_unlock(&snd_card_mutex);
195 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
196 idx, snd_ecards_limit - 1, err);
197 kfree(card);
198 return err;
199 }
200 set_bit(idx, snd_cards_lock); /* 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->dev = parent;
205 card->number = idx;
206#ifdef MODULE
207 WARN_ON(!module);
208 card->module = module;
209#endif
210 INIT_LIST_HEAD(&card->devices);
211 init_rwsem(&card->controls_rwsem);
212 rwlock_init(&card->ctl_files_rwlock);
213 INIT_LIST_HEAD(&card->controls);
214 INIT_LIST_HEAD(&card->ctl_files);
215 spin_lock_init(&card->files_lock);
216 INIT_LIST_HEAD(&card->files_list);
217 mutex_init(&card->memory_mutex);
218#ifdef CONFIG_PM
219 init_waitqueue_head(&card->power_sleep);
220#endif
221 init_waitqueue_head(&card->remove_sleep);
222 card->sync_irq = -1;
223
224 device_initialize(&card->card_dev);
225 card->card_dev.parent = parent;
226 card->card_dev.class = sound_class;
227 card->card_dev.release = release_card_device;
228 card->card_dev.groups = card->dev_groups;
229 card->dev_groups[0] = &card_dev_attr_group;
230 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
231 if (err < 0)
232 goto __error;
233
234 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
235 dev_driver_string(card->dev), dev_name(&card->card_dev));
236
237 /* the control interface cannot be accessed from the user space until */
238 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
239 err = snd_ctl_create(card);
240 if (err < 0) {
241 dev_err(parent, "unable to register control minors\n");
242 goto __error;
243 }
244 err = snd_info_card_create(card);
245 if (err < 0) {
246 dev_err(parent, "unable to create card info\n");
247 goto __error_ctl;
248 }
249 *card_ret = card;
250 return 0;
251
252 __error_ctl:
253 snd_device_free_all(card);
254 __error:
255 put_device(&card->card_dev);
256 return err;
257}
258EXPORT_SYMBOL(snd_card_new);
259
260/**
261 * snd_card_ref - Get the card object from the index
262 * @idx: the card index
263 *
264 * Returns a card object corresponding to the given index or NULL if not found.
265 * Release the object via snd_card_unref().
266 */
267struct snd_card *snd_card_ref(int idx)
268{
269 struct snd_card *card;
270
271 mutex_lock(&snd_card_mutex);
272 card = snd_cards[idx];
273 if (card)
274 get_device(&card->card_dev);
275 mutex_unlock(&snd_card_mutex);
276 return card;
277}
278EXPORT_SYMBOL_GPL(snd_card_ref);
279
280/* return non-zero if a card is already locked */
281int snd_card_locked(int card)
282{
283 int locked;
284
285 mutex_lock(&snd_card_mutex);
286 locked = test_bit(card, snd_cards_lock);
287 mutex_unlock(&snd_card_mutex);
288 return locked;
289}
290
291static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
292{
293 return -ENODEV;
294}
295
296static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
297 size_t count, loff_t *offset)
298{
299 return -ENODEV;
300}
301
302static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
303 size_t count, loff_t *offset)
304{
305 return -ENODEV;
306}
307
308static int snd_disconnect_release(struct inode *inode, struct file *file)
309{
310 struct snd_monitor_file *df = NULL, *_df;
311
312 spin_lock(&shutdown_lock);
313 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
314 if (_df->file == file) {
315 df = _df;
316 list_del_init(&df->shutdown_list);
317 break;
318 }
319 }
320 spin_unlock(&shutdown_lock);
321
322 if (likely(df)) {
323 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
324 df->disconnected_f_op->fasync(-1, file, 0);
325 return df->disconnected_f_op->release(inode, file);
326 }
327
328 panic("%s(%p, %p) failed!", __func__, inode, file);
329}
330
331static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
332{
333 return EPOLLERR | EPOLLNVAL;
334}
335
336static long snd_disconnect_ioctl(struct file *file,
337 unsigned int cmd, unsigned long arg)
338{
339 return -ENODEV;
340}
341
342static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
343{
344 return -ENODEV;
345}
346
347static int snd_disconnect_fasync(int fd, struct file *file, int on)
348{
349 return -ENODEV;
350}
351
352static const struct file_operations snd_shutdown_f_ops =
353{
354 .owner = THIS_MODULE,
355 .llseek = snd_disconnect_llseek,
356 .read = snd_disconnect_read,
357 .write = snd_disconnect_write,
358 .release = snd_disconnect_release,
359 .poll = snd_disconnect_poll,
360 .unlocked_ioctl = snd_disconnect_ioctl,
361#ifdef CONFIG_COMPAT
362 .compat_ioctl = snd_disconnect_ioctl,
363#endif
364 .mmap = snd_disconnect_mmap,
365 .fasync = snd_disconnect_fasync
366};
367
368/**
369 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
370 * @card: soundcard structure
371 *
372 * Disconnects all APIs from the file-operations (user space).
373 *
374 * Return: Zero, otherwise a negative error code.
375 *
376 * Note: The current implementation replaces all active file->f_op with special
377 * dummy file operations (they do nothing except release).
378 */
379int snd_card_disconnect(struct snd_card *card)
380{
381 struct snd_monitor_file *mfile;
382
383 if (!card)
384 return -EINVAL;
385
386 spin_lock(&card->files_lock);
387 if (card->shutdown) {
388 spin_unlock(&card->files_lock);
389 return 0;
390 }
391 card->shutdown = 1;
392 spin_unlock(&card->files_lock);
393
394 /* replace file->f_op with special dummy operations */
395 spin_lock(&card->files_lock);
396 list_for_each_entry(mfile, &card->files_list, list) {
397 /* it's critical part, use endless loop */
398 /* we have no room to fail */
399 mfile->disconnected_f_op = mfile->file->f_op;
400
401 spin_lock(&shutdown_lock);
402 list_add(&mfile->shutdown_list, &shutdown_files);
403 spin_unlock(&shutdown_lock);
404
405 mfile->file->f_op = &snd_shutdown_f_ops;
406 fops_get(mfile->file->f_op);
407 }
408 spin_unlock(&card->files_lock);
409
410 /* notify all connected devices about disconnection */
411 /* at this point, they cannot respond to any calls except release() */
412
413#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
414 if (snd_mixer_oss_notify_callback)
415 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
416#endif
417
418 /* notify all devices that we are disconnected */
419 snd_device_disconnect_all(card);
420
421 snd_info_card_disconnect(card);
422 if (card->registered) {
423 device_del(&card->card_dev);
424 card->registered = false;
425 }
426
427 /* disable fops (user space) operations for ALSA API */
428 mutex_lock(&snd_card_mutex);
429 snd_cards[card->number] = NULL;
430 clear_bit(card->number, snd_cards_lock);
431 mutex_unlock(&snd_card_mutex);
432
433#ifdef CONFIG_PM
434 wake_up(&card->power_sleep);
435#endif
436 return 0;
437}
438EXPORT_SYMBOL(snd_card_disconnect);
439
440/**
441 * snd_card_disconnect_sync - disconnect card and wait until files get closed
442 * @card: card object to disconnect
443 *
444 * This calls snd_card_disconnect() for disconnecting all belonging components
445 * and waits until all pending files get closed.
446 * It assures that all accesses from user-space finished so that the driver
447 * can release its resources gracefully.
448 */
449void snd_card_disconnect_sync(struct snd_card *card)
450{
451 int err;
452
453 err = snd_card_disconnect(card);
454 if (err < 0) {
455 dev_err(card->dev,
456 "snd_card_disconnect error (%d), skipping sync\n",
457 err);
458 return;
459 }
460
461 spin_lock_irq(&card->files_lock);
462 wait_event_lock_irq(card->remove_sleep,
463 list_empty(&card->files_list),
464 card->files_lock);
465 spin_unlock_irq(&card->files_lock);
466}
467EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
468
469static int snd_card_do_free(struct snd_card *card)
470{
471#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
472 if (snd_mixer_oss_notify_callback)
473 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
474#endif
475 snd_device_free_all(card);
476 if (card->private_free)
477 card->private_free(card);
478 if (snd_info_card_free(card) < 0) {
479 dev_warn(card->dev, "unable to free card info\n");
480 /* Not fatal error */
481 }
482 if (card->release_completion)
483 complete(card->release_completion);
484 kfree(card);
485 return 0;
486}
487
488/**
489 * snd_card_free_when_closed - Disconnect the card, free it later eventually
490 * @card: soundcard structure
491 *
492 * Unlike snd_card_free(), this function doesn't try to release the card
493 * resource immediately, but tries to disconnect at first. When the card
494 * is still in use, the function returns before freeing the resources.
495 * The card resources will be freed when the refcount gets to zero.
496 */
497int snd_card_free_when_closed(struct snd_card *card)
498{
499 int ret = snd_card_disconnect(card);
500 if (ret)
501 return ret;
502 put_device(&card->card_dev);
503 return 0;
504}
505EXPORT_SYMBOL(snd_card_free_when_closed);
506
507/**
508 * snd_card_free - frees given soundcard structure
509 * @card: soundcard structure
510 *
511 * This function releases the soundcard structure and the all assigned
512 * devices automatically. That is, you don't have to release the devices
513 * by yourself.
514 *
515 * This function waits until the all resources are properly released.
516 *
517 * Return: Zero. Frees all associated devices and frees the control
518 * interface associated to given soundcard.
519 */
520int snd_card_free(struct snd_card *card)
521{
522 struct completion released;
523 int ret;
524
525 init_completion(&released);
526 card->release_completion = &released;
527 ret = snd_card_free_when_closed(card);
528 if (ret)
529 return ret;
530 /* wait, until all devices are ready for the free operation */
531 wait_for_completion(&released);
532 return 0;
533}
534EXPORT_SYMBOL(snd_card_free);
535
536/* retrieve the last word of shortname or longname */
537static const char *retrieve_id_from_card_name(const char *name)
538{
539 const char *spos = name;
540
541 while (*name) {
542 if (isspace(*name) && isalnum(name[1]))
543 spos = name + 1;
544 name++;
545 }
546 return spos;
547}
548
549/* return true if the given id string doesn't conflict any other card ids */
550static bool card_id_ok(struct snd_card *card, const char *id)
551{
552 int i;
553 if (!snd_info_check_reserved_words(id))
554 return false;
555 for (i = 0; i < snd_ecards_limit; i++) {
556 if (snd_cards[i] && snd_cards[i] != card &&
557 !strcmp(snd_cards[i]->id, id))
558 return false;
559 }
560 return true;
561}
562
563/* copy to card->id only with valid letters from nid */
564static void copy_valid_id_string(struct snd_card *card, const char *src,
565 const char *nid)
566{
567 char *id = card->id;
568
569 while (*nid && !isalnum(*nid))
570 nid++;
571 if (isdigit(*nid))
572 *id++ = isalpha(*src) ? *src : 'D';
573 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
574 if (isalnum(*nid))
575 *id++ = *nid;
576 nid++;
577 }
578 *id = 0;
579}
580
581/* Set card->id from the given string
582 * If the string conflicts with other ids, add a suffix to make it unique.
583 */
584static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
585 const char *nid)
586{
587 int len, loops;
588 bool is_default = false;
589 char *id;
590
591 copy_valid_id_string(card, src, nid);
592 id = card->id;
593
594 again:
595 /* use "Default" for obviously invalid strings
596 * ("card" conflicts with proc directories)
597 */
598 if (!*id || !strncmp(id, "card", 4)) {
599 strcpy(id, "Default");
600 is_default = true;
601 }
602
603 len = strlen(id);
604 for (loops = 0; loops < SNDRV_CARDS; loops++) {
605 char *spos;
606 char sfxstr[5]; /* "_012" */
607 int sfxlen;
608
609 if (card_id_ok(card, id))
610 return; /* OK */
611
612 /* Add _XYZ suffix */
613 sprintf(sfxstr, "_%X", loops + 1);
614 sfxlen = strlen(sfxstr);
615 if (len + sfxlen >= sizeof(card->id))
616 spos = id + sizeof(card->id) - sfxlen - 1;
617 else
618 spos = id + len;
619 strcpy(spos, sfxstr);
620 }
621 /* fallback to the default id */
622 if (!is_default) {
623 *id = 0;
624 goto again;
625 }
626 /* last resort... */
627 dev_err(card->dev, "unable to set card id (%s)\n", id);
628 if (card->proc_root->name)
629 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
630}
631
632/**
633 * snd_card_set_id - set card identification name
634 * @card: soundcard structure
635 * @nid: new identification string
636 *
637 * This function sets the card identification and checks for name
638 * collisions.
639 */
640void snd_card_set_id(struct snd_card *card, const char *nid)
641{
642 /* check if user specified own card->id */
643 if (card->id[0] != '\0')
644 return;
645 mutex_lock(&snd_card_mutex);
646 snd_card_set_id_no_lock(card, nid, nid);
647 mutex_unlock(&snd_card_mutex);
648}
649EXPORT_SYMBOL(snd_card_set_id);
650
651static ssize_t
652card_id_show_attr(struct device *dev,
653 struct device_attribute *attr, char *buf)
654{
655 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
656 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
657}
658
659static ssize_t
660card_id_store_attr(struct device *dev, struct device_attribute *attr,
661 const char *buf, size_t count)
662{
663 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
664 char buf1[sizeof(card->id)];
665 size_t copy = count > sizeof(card->id) - 1 ?
666 sizeof(card->id) - 1 : count;
667 size_t idx;
668 int c;
669
670 for (idx = 0; idx < copy; idx++) {
671 c = buf[idx];
672 if (!isalnum(c) && c != '_' && c != '-')
673 return -EINVAL;
674 }
675 memcpy(buf1, buf, copy);
676 buf1[copy] = '\0';
677 mutex_lock(&snd_card_mutex);
678 if (!card_id_ok(NULL, buf1)) {
679 mutex_unlock(&snd_card_mutex);
680 return -EEXIST;
681 }
682 strcpy(card->id, buf1);
683 snd_info_card_id_change(card);
684 mutex_unlock(&snd_card_mutex);
685
686 return count;
687}
688
689static DEVICE_ATTR(id, 0644, card_id_show_attr, card_id_store_attr);
690
691static ssize_t
692card_number_show_attr(struct device *dev,
693 struct device_attribute *attr, char *buf)
694{
695 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
696 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
697}
698
699static DEVICE_ATTR(number, 0444, card_number_show_attr, NULL);
700
701static struct attribute *card_dev_attrs[] = {
702 &dev_attr_id.attr,
703 &dev_attr_number.attr,
704 NULL
705};
706
707static const struct attribute_group card_dev_attr_group = {
708 .attrs = card_dev_attrs,
709};
710
711/**
712 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
713 * @card: card instance
714 * @group: attribute group to append
715 */
716int snd_card_add_dev_attr(struct snd_card *card,
717 const struct attribute_group *group)
718{
719 int i;
720
721 /* loop for (arraysize-1) here to keep NULL at the last entry */
722 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
723 if (!card->dev_groups[i]) {
724 card->dev_groups[i] = group;
725 return 0;
726 }
727 }
728
729 dev_err(card->dev, "Too many groups assigned\n");
730 return -ENOSPC;
731}
732EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
733
734/**
735 * snd_card_register - register the soundcard
736 * @card: soundcard structure
737 *
738 * This function registers all the devices assigned to the soundcard.
739 * Until calling this, the ALSA control interface is blocked from the
740 * external accesses. Thus, you should call this function at the end
741 * of the initialization of the card.
742 *
743 * Return: Zero otherwise a negative error code if the registration failed.
744 */
745int snd_card_register(struct snd_card *card)
746{
747 int err;
748
749 if (snd_BUG_ON(!card))
750 return -EINVAL;
751
752 if (!card->registered) {
753 err = device_add(&card->card_dev);
754 if (err < 0)
755 return err;
756 card->registered = true;
757 }
758
759 if ((err = snd_device_register_all(card)) < 0)
760 return err;
761 mutex_lock(&snd_card_mutex);
762 if (snd_cards[card->number]) {
763 /* already registered */
764 mutex_unlock(&snd_card_mutex);
765 return snd_info_card_register(card); /* register pending info */
766 }
767 if (*card->id) {
768 /* make a unique id name from the given string */
769 char tmpid[sizeof(card->id)];
770 memcpy(tmpid, card->id, sizeof(card->id));
771 snd_card_set_id_no_lock(card, tmpid, tmpid);
772 } else {
773 /* create an id from either shortname or longname */
774 const char *src;
775 src = *card->shortname ? card->shortname : card->longname;
776 snd_card_set_id_no_lock(card, src,
777 retrieve_id_from_card_name(src));
778 }
779 snd_cards[card->number] = card;
780 mutex_unlock(&snd_card_mutex);
781 err = snd_info_card_register(card);
782 if (err < 0)
783 return err;
784
785#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
786 if (snd_mixer_oss_notify_callback)
787 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
788#endif
789 return 0;
790}
791EXPORT_SYMBOL(snd_card_register);
792
793#ifdef CONFIG_SND_PROC_FS
794static void snd_card_info_read(struct snd_info_entry *entry,
795 struct snd_info_buffer *buffer)
796{
797 int idx, count;
798 struct snd_card *card;
799
800 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
801 mutex_lock(&snd_card_mutex);
802 if ((card = snd_cards[idx]) != NULL) {
803 count++;
804 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
805 idx,
806 card->id,
807 card->driver,
808 card->shortname);
809 snd_iprintf(buffer, " %s\n",
810 card->longname);
811 }
812 mutex_unlock(&snd_card_mutex);
813 }
814 if (!count)
815 snd_iprintf(buffer, "--- no soundcards ---\n");
816}
817
818#ifdef CONFIG_SND_OSSEMUL
819void snd_card_info_read_oss(struct snd_info_buffer *buffer)
820{
821 int idx, count;
822 struct snd_card *card;
823
824 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
825 mutex_lock(&snd_card_mutex);
826 if ((card = snd_cards[idx]) != NULL) {
827 count++;
828 snd_iprintf(buffer, "%s\n", card->longname);
829 }
830 mutex_unlock(&snd_card_mutex);
831 }
832 if (!count) {
833 snd_iprintf(buffer, "--- no soundcards ---\n");
834 }
835}
836
837#endif
838
839#ifdef MODULE
840static void snd_card_module_info_read(struct snd_info_entry *entry,
841 struct snd_info_buffer *buffer)
842{
843 int idx;
844 struct snd_card *card;
845
846 for (idx = 0; idx < SNDRV_CARDS; idx++) {
847 mutex_lock(&snd_card_mutex);
848 if ((card = snd_cards[idx]) != NULL)
849 snd_iprintf(buffer, "%2i %s\n",
850 idx, card->module->name);
851 mutex_unlock(&snd_card_mutex);
852 }
853}
854#endif
855
856int __init snd_card_info_init(void)
857{
858 struct snd_info_entry *entry;
859
860 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
861 if (! entry)
862 return -ENOMEM;
863 entry->c.text.read = snd_card_info_read;
864 if (snd_info_register(entry) < 0)
865 return -ENOMEM; /* freed in error path */
866
867#ifdef MODULE
868 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
869 if (!entry)
870 return -ENOMEM;
871 entry->c.text.read = snd_card_module_info_read;
872 if (snd_info_register(entry) < 0)
873 return -ENOMEM; /* freed in error path */
874#endif
875
876 return 0;
877}
878#endif /* CONFIG_SND_PROC_FS */
879
880/**
881 * snd_component_add - add a component string
882 * @card: soundcard structure
883 * @component: the component id string
884 *
885 * This function adds the component id string to the supported list.
886 * The component can be referred from the alsa-lib.
887 *
888 * Return: Zero otherwise a negative error code.
889 */
890
891int snd_component_add(struct snd_card *card, const char *component)
892{
893 char *ptr;
894 int len = strlen(component);
895
896 ptr = strstr(card->components, component);
897 if (ptr != NULL) {
898 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
899 return 1;
900 }
901 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
902 snd_BUG();
903 return -ENOMEM;
904 }
905 if (card->components[0] != '\0')
906 strcat(card->components, " ");
907 strcat(card->components, component);
908 return 0;
909}
910EXPORT_SYMBOL(snd_component_add);
911
912/**
913 * snd_card_file_add - add the file to the file list of the card
914 * @card: soundcard structure
915 * @file: file pointer
916 *
917 * This function adds the file to the file linked-list of the card.
918 * This linked-list is used to keep tracking the connection state,
919 * and to avoid the release of busy resources by hotplug.
920 *
921 * Return: zero or a negative error code.
922 */
923int snd_card_file_add(struct snd_card *card, struct file *file)
924{
925 struct snd_monitor_file *mfile;
926
927 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
928 if (mfile == NULL)
929 return -ENOMEM;
930 mfile->file = file;
931 mfile->disconnected_f_op = NULL;
932 INIT_LIST_HEAD(&mfile->shutdown_list);
933 spin_lock(&card->files_lock);
934 if (card->shutdown) {
935 spin_unlock(&card->files_lock);
936 kfree(mfile);
937 return -ENODEV;
938 }
939 list_add(&mfile->list, &card->files_list);
940 get_device(&card->card_dev);
941 spin_unlock(&card->files_lock);
942 return 0;
943}
944EXPORT_SYMBOL(snd_card_file_add);
945
946/**
947 * snd_card_file_remove - remove the file from the file list
948 * @card: soundcard structure
949 * @file: file pointer
950 *
951 * This function removes the file formerly added to the card via
952 * snd_card_file_add() function.
953 * If all files are removed and snd_card_free_when_closed() was
954 * called beforehand, it processes the pending release of
955 * resources.
956 *
957 * Return: Zero or a negative error code.
958 */
959int snd_card_file_remove(struct snd_card *card, struct file *file)
960{
961 struct snd_monitor_file *mfile, *found = NULL;
962
963 spin_lock(&card->files_lock);
964 list_for_each_entry(mfile, &card->files_list, list) {
965 if (mfile->file == file) {
966 list_del(&mfile->list);
967 spin_lock(&shutdown_lock);
968 list_del(&mfile->shutdown_list);
969 spin_unlock(&shutdown_lock);
970 if (mfile->disconnected_f_op)
971 fops_put(mfile->disconnected_f_op);
972 found = mfile;
973 break;
974 }
975 }
976 if (list_empty(&card->files_list))
977 wake_up_all(&card->remove_sleep);
978 spin_unlock(&card->files_lock);
979 if (!found) {
980 dev_err(card->dev, "card file remove problem (%p)\n", file);
981 return -ENOENT;
982 }
983 kfree(found);
984 put_device(&card->card_dev);
985 return 0;
986}
987EXPORT_SYMBOL(snd_card_file_remove);
988
989#ifdef CONFIG_PM
990/**
991 * snd_power_wait - wait until the power-state is changed.
992 * @card: soundcard structure
993 * @power_state: expected power state
994 *
995 * Waits until the power-state is changed.
996 *
997 * Return: Zero if successful, or a negative error code.
998 */
999int snd_power_wait(struct snd_card *card, unsigned int power_state)
1000{
1001 wait_queue_entry_t wait;
1002 int result = 0;
1003
1004 /* fastpath */
1005 if (snd_power_get_state(card) == power_state)
1006 return 0;
1007 init_waitqueue_entry(&wait, current);
1008 add_wait_queue(&card->power_sleep, &wait);
1009 while (1) {
1010 if (card->shutdown) {
1011 result = -ENODEV;
1012 break;
1013 }
1014 if (snd_power_get_state(card) == power_state)
1015 break;
1016 set_current_state(TASK_UNINTERRUPTIBLE);
1017 schedule_timeout(30 * HZ);
1018 }
1019 remove_wait_queue(&card->power_sleep, &wait);
1020 return result;
1021}
1022EXPORT_SYMBOL(snd_power_wait);
1023#endif /* CONFIG_PM */