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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/debugfs.h>
17#include <linux/completion.h>
18#include <linux/interrupt.h>
19
20#include <sound/core.h>
21#include <sound/control.h>
22#include <sound/info.h>
23
24/* monitor files for graceful shutdown (hotplug) */
25struct snd_monitor_file {
26 struct file *file;
27 const struct file_operations *disconnected_f_op;
28 struct list_head shutdown_list; /* still need to shutdown */
29 struct list_head list; /* link of monitor files */
30};
31
32static DEFINE_SPINLOCK(shutdown_lock);
33static LIST_HEAD(shutdown_files);
34
35static const struct file_operations snd_shutdown_f_ops;
36
37/* locked for registering/using */
38static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39static struct snd_card *snd_cards[SNDRV_CARDS];
40
41static DEFINE_MUTEX(snd_card_mutex);
42
43static char *slots[SNDRV_CARDS];
44module_param_array(slots, charp, NULL, 0444);
45MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
46
47/* return non-zero if the given index is reserved for the given
48 * module via slots option
49 */
50static int module_slot_match(struct module *module, int idx)
51{
52 int match = 1;
53#ifdef MODULE
54 const char *s1, *s2;
55
56 if (!module || !*module->name || !slots[idx])
57 return 0;
58
59 s1 = module->name;
60 s2 = slots[idx];
61 if (*s2 == '!') {
62 match = 0; /* negative match */
63 s2++;
64 }
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
67 */
68 for (;;) {
69 char c1 = *s1++;
70 char c2 = *s2++;
71 if (c1 == '-')
72 c1 = '_';
73 if (c2 == '-')
74 c2 = '_';
75 if (c1 != c2)
76 return !match;
77 if (!c1)
78 break;
79 }
80#endif /* MODULE */
81 return match;
82}
83
84#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87#endif
88
89static int check_empty_slot(struct module *module, int slot)
90{
91 return !slots[slot] || !*slots[slot];
92}
93
94/* return an empty slot number (>= 0) found in the given bitmask @mask.
95 * @mask == -1 == 0xffffffff means: take any free slot up to 32
96 * when no slot is available, return the original @mask as is.
97 */
98static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100{
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112}
113
114/* the default release callback set in snd_device_initialize() below;
115 * this is just NOP for now, as almost all jobs are already done in
116 * dev_free callback of snd_device chain instead.
117 */
118static void default_release(struct device *dev)
119{
120}
121
122/**
123 * snd_device_initialize - Initialize struct device for sound devices
124 * @dev: device to initialize
125 * @card: card to assign, optional
126 */
127void snd_device_initialize(struct device *dev, struct snd_card *card)
128{
129 device_initialize(dev);
130 if (card)
131 dev->parent = &card->card_dev;
132 dev->class = sound_class;
133 dev->release = default_release;
134}
135EXPORT_SYMBOL_GPL(snd_device_initialize);
136
137static int snd_card_do_free(struct snd_card *card);
138static const struct attribute_group card_dev_attr_group;
139
140static void release_card_device(struct device *dev)
141{
142 snd_card_do_free(dev_to_snd_card(dev));
143}
144
145/**
146 * snd_card_new - create and initialize a soundcard structure
147 * @parent: the parent device object
148 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
149 * @xid: card identification (ASCII string)
150 * @module: top level module for locking
151 * @extra_size: allocate this extra size after the main soundcard structure
152 * @card_ret: the pointer to store the created card instance
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#ifdef CONFIG_SND_DEBUG
167 char name[8];
168#endif
169
170 if (snd_BUG_ON(!card_ret))
171 return -EINVAL;
172 *card_ret = NULL;
173
174 if (extra_size < 0)
175 extra_size = 0;
176 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
177 if (!card)
178 return -ENOMEM;
179 if (extra_size > 0)
180 card->private_data = (char *)card + sizeof(struct snd_card);
181 if (xid)
182 strscpy(card->id, xid, sizeof(card->id));
183 err = 0;
184 mutex_lock(&snd_card_mutex);
185 if (idx < 0) /* first check the matching module-name slot */
186 idx = get_slot_from_bitmask(idx, module_slot_match, module);
187 if (idx < 0) /* if not matched, assign an empty slot */
188 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
189 if (idx < 0)
190 err = -ENODEV;
191 else if (idx < snd_ecards_limit) {
192 if (test_bit(idx, snd_cards_lock))
193 err = -EBUSY; /* invalid */
194 } else if (idx >= SNDRV_CARDS)
195 err = -ENODEV;
196 if (err < 0) {
197 mutex_unlock(&snd_card_mutex);
198 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
199 idx, snd_ecards_limit - 1, err);
200 kfree(card);
201 return err;
202 }
203 set_bit(idx, snd_cards_lock); /* lock it */
204 if (idx >= snd_ecards_limit)
205 snd_ecards_limit = idx + 1; /* increase the limit */
206 mutex_unlock(&snd_card_mutex);
207 card->dev = parent;
208 card->number = idx;
209#ifdef MODULE
210 WARN_ON(!module);
211 card->module = module;
212#endif
213 INIT_LIST_HEAD(&card->devices);
214 init_rwsem(&card->controls_rwsem);
215 rwlock_init(&card->ctl_files_rwlock);
216 INIT_LIST_HEAD(&card->controls);
217 INIT_LIST_HEAD(&card->ctl_files);
218 spin_lock_init(&card->files_lock);
219 INIT_LIST_HEAD(&card->files_list);
220 mutex_init(&card->memory_mutex);
221#ifdef CONFIG_PM
222 init_waitqueue_head(&card->power_sleep);
223 init_waitqueue_head(&card->power_ref_sleep);
224 atomic_set(&card->power_ref, 0);
225#endif
226 init_waitqueue_head(&card->remove_sleep);
227 card->sync_irq = -1;
228
229 device_initialize(&card->card_dev);
230 card->card_dev.parent = parent;
231 card->card_dev.class = sound_class;
232 card->card_dev.release = release_card_device;
233 card->card_dev.groups = card->dev_groups;
234 card->dev_groups[0] = &card_dev_attr_group;
235 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
236 if (err < 0)
237 goto __error;
238
239 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
240 dev_driver_string(card->dev), dev_name(&card->card_dev));
241
242 /* the control interface cannot be accessed from the user space until */
243 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
244 err = snd_ctl_create(card);
245 if (err < 0) {
246 dev_err(parent, "unable to register control minors\n");
247 goto __error;
248 }
249 err = snd_info_card_create(card);
250 if (err < 0) {
251 dev_err(parent, "unable to create card info\n");
252 goto __error_ctl;
253 }
254
255#ifdef CONFIG_SND_DEBUG
256 sprintf(name, "card%d", idx);
257 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
258#endif
259
260 *card_ret = card;
261 return 0;
262
263 __error_ctl:
264 snd_device_free_all(card);
265 __error:
266 put_device(&card->card_dev);
267 return err;
268}
269EXPORT_SYMBOL(snd_card_new);
270
271/**
272 * snd_card_ref - Get the card object from the index
273 * @idx: the card index
274 *
275 * Returns a card object corresponding to the given index or NULL if not found.
276 * Release the object via snd_card_unref().
277 */
278struct snd_card *snd_card_ref(int idx)
279{
280 struct snd_card *card;
281
282 mutex_lock(&snd_card_mutex);
283 card = snd_cards[idx];
284 if (card)
285 get_device(&card->card_dev);
286 mutex_unlock(&snd_card_mutex);
287 return card;
288}
289EXPORT_SYMBOL_GPL(snd_card_ref);
290
291/* return non-zero if a card is already locked */
292int snd_card_locked(int card)
293{
294 int locked;
295
296 mutex_lock(&snd_card_mutex);
297 locked = test_bit(card, snd_cards_lock);
298 mutex_unlock(&snd_card_mutex);
299 return locked;
300}
301
302static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
303{
304 return -ENODEV;
305}
306
307static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
308 size_t count, loff_t *offset)
309{
310 return -ENODEV;
311}
312
313static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
314 size_t count, loff_t *offset)
315{
316 return -ENODEV;
317}
318
319static int snd_disconnect_release(struct inode *inode, struct file *file)
320{
321 struct snd_monitor_file *df = NULL, *_df;
322
323 spin_lock(&shutdown_lock);
324 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
325 if (_df->file == file) {
326 df = _df;
327 list_del_init(&df->shutdown_list);
328 break;
329 }
330 }
331 spin_unlock(&shutdown_lock);
332
333 if (likely(df)) {
334 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
335 df->disconnected_f_op->fasync(-1, file, 0);
336 return df->disconnected_f_op->release(inode, file);
337 }
338
339 panic("%s(%p, %p) failed!", __func__, inode, file);
340}
341
342static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
343{
344 return EPOLLERR | EPOLLNVAL;
345}
346
347static long snd_disconnect_ioctl(struct file *file,
348 unsigned int cmd, unsigned long arg)
349{
350 return -ENODEV;
351}
352
353static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
354{
355 return -ENODEV;
356}
357
358static int snd_disconnect_fasync(int fd, struct file *file, int on)
359{
360 return -ENODEV;
361}
362
363static const struct file_operations snd_shutdown_f_ops =
364{
365 .owner = THIS_MODULE,
366 .llseek = snd_disconnect_llseek,
367 .read = snd_disconnect_read,
368 .write = snd_disconnect_write,
369 .release = snd_disconnect_release,
370 .poll = snd_disconnect_poll,
371 .unlocked_ioctl = snd_disconnect_ioctl,
372#ifdef CONFIG_COMPAT
373 .compat_ioctl = snd_disconnect_ioctl,
374#endif
375 .mmap = snd_disconnect_mmap,
376 .fasync = snd_disconnect_fasync
377};
378
379/**
380 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
381 * @card: soundcard structure
382 *
383 * Disconnects all APIs from the file-operations (user space).
384 *
385 * Return: Zero, otherwise a negative error code.
386 *
387 * Note: The current implementation replaces all active file->f_op with special
388 * dummy file operations (they do nothing except release).
389 */
390int snd_card_disconnect(struct snd_card *card)
391{
392 struct snd_monitor_file *mfile;
393
394 if (!card)
395 return -EINVAL;
396
397 spin_lock(&card->files_lock);
398 if (card->shutdown) {
399 spin_unlock(&card->files_lock);
400 return 0;
401 }
402 card->shutdown = 1;
403
404 /* replace file->f_op with special dummy operations */
405 list_for_each_entry(mfile, &card->files_list, list) {
406 /* it's critical part, use endless loop */
407 /* we have no room to fail */
408 mfile->disconnected_f_op = mfile->file->f_op;
409
410 spin_lock(&shutdown_lock);
411 list_add(&mfile->shutdown_list, &shutdown_files);
412 spin_unlock(&shutdown_lock);
413
414 mfile->file->f_op = &snd_shutdown_f_ops;
415 fops_get(mfile->file->f_op);
416 }
417 spin_unlock(&card->files_lock);
418
419 /* notify all connected devices about disconnection */
420 /* at this point, they cannot respond to any calls except release() */
421
422#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
423 if (snd_mixer_oss_notify_callback)
424 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
425#endif
426
427 /* notify all devices that we are disconnected */
428 snd_device_disconnect_all(card);
429
430 if (card->sync_irq > 0)
431 synchronize_irq(card->sync_irq);
432
433 snd_info_card_disconnect(card);
434 if (card->registered) {
435 device_del(&card->card_dev);
436 card->registered = false;
437 }
438
439 /* disable fops (user space) operations for ALSA API */
440 mutex_lock(&snd_card_mutex);
441 snd_cards[card->number] = NULL;
442 clear_bit(card->number, snd_cards_lock);
443 mutex_unlock(&snd_card_mutex);
444
445#ifdef CONFIG_PM
446 wake_up(&card->power_sleep);
447 snd_power_sync_ref(card);
448#endif
449 return 0;
450}
451EXPORT_SYMBOL(snd_card_disconnect);
452
453/**
454 * snd_card_disconnect_sync - disconnect card and wait until files get closed
455 * @card: card object to disconnect
456 *
457 * This calls snd_card_disconnect() for disconnecting all belonging components
458 * and waits until all pending files get closed.
459 * It assures that all accesses from user-space finished so that the driver
460 * can release its resources gracefully.
461 */
462void snd_card_disconnect_sync(struct snd_card *card)
463{
464 int err;
465
466 err = snd_card_disconnect(card);
467 if (err < 0) {
468 dev_err(card->dev,
469 "snd_card_disconnect error (%d), skipping sync\n",
470 err);
471 return;
472 }
473
474 spin_lock_irq(&card->files_lock);
475 wait_event_lock_irq(card->remove_sleep,
476 list_empty(&card->files_list),
477 card->files_lock);
478 spin_unlock_irq(&card->files_lock);
479}
480EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
481
482static int snd_card_do_free(struct snd_card *card)
483{
484#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
485 if (snd_mixer_oss_notify_callback)
486 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
487#endif
488 snd_device_free_all(card);
489 if (card->private_free)
490 card->private_free(card);
491 if (snd_info_card_free(card) < 0) {
492 dev_warn(card->dev, "unable to free card info\n");
493 /* Not fatal error */
494 }
495#ifdef CONFIG_SND_DEBUG
496 debugfs_remove(card->debugfs_root);
497 card->debugfs_root = NULL;
498#endif
499 if (card->release_completion)
500 complete(card->release_completion);
501 kfree(card);
502 return 0;
503}
504
505/**
506 * snd_card_free_when_closed - Disconnect the card, free it later eventually
507 * @card: soundcard structure
508 *
509 * Unlike snd_card_free(), this function doesn't try to release the card
510 * resource immediately, but tries to disconnect at first. When the card
511 * is still in use, the function returns before freeing the resources.
512 * The card resources will be freed when the refcount gets to zero.
513 */
514int snd_card_free_when_closed(struct snd_card *card)
515{
516 int ret = snd_card_disconnect(card);
517 if (ret)
518 return ret;
519 put_device(&card->card_dev);
520 return 0;
521}
522EXPORT_SYMBOL(snd_card_free_when_closed);
523
524/**
525 * snd_card_free - frees given soundcard structure
526 * @card: soundcard structure
527 *
528 * This function releases the soundcard structure and the all assigned
529 * devices automatically. That is, you don't have to release the devices
530 * by yourself.
531 *
532 * This function waits until the all resources are properly released.
533 *
534 * Return: Zero. Frees all associated devices and frees the control
535 * interface associated to given soundcard.
536 */
537int snd_card_free(struct snd_card *card)
538{
539 DECLARE_COMPLETION_ONSTACK(released);
540 int ret;
541
542 card->release_completion = &released;
543 ret = snd_card_free_when_closed(card);
544 if (ret)
545 return ret;
546 /* wait, until all devices are ready for the free operation */
547 wait_for_completion(&released);
548
549 return 0;
550}
551EXPORT_SYMBOL(snd_card_free);
552
553/* retrieve the last word of shortname or longname */
554static const char *retrieve_id_from_card_name(const char *name)
555{
556 const char *spos = name;
557
558 while (*name) {
559 if (isspace(*name) && isalnum(name[1]))
560 spos = name + 1;
561 name++;
562 }
563 return spos;
564}
565
566/* return true if the given id string doesn't conflict any other card ids */
567static bool card_id_ok(struct snd_card *card, const char *id)
568{
569 int i;
570 if (!snd_info_check_reserved_words(id))
571 return false;
572 for (i = 0; i < snd_ecards_limit; i++) {
573 if (snd_cards[i] && snd_cards[i] != card &&
574 !strcmp(snd_cards[i]->id, id))
575 return false;
576 }
577 return true;
578}
579
580/* copy to card->id only with valid letters from nid */
581static void copy_valid_id_string(struct snd_card *card, const char *src,
582 const char *nid)
583{
584 char *id = card->id;
585
586 while (*nid && !isalnum(*nid))
587 nid++;
588 if (isdigit(*nid))
589 *id++ = isalpha(*src) ? *src : 'D';
590 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
591 if (isalnum(*nid))
592 *id++ = *nid;
593 nid++;
594 }
595 *id = 0;
596}
597
598/* Set card->id from the given string
599 * If the string conflicts with other ids, add a suffix to make it unique.
600 */
601static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
602 const char *nid)
603{
604 int len, loops;
605 bool is_default = false;
606 char *id;
607
608 copy_valid_id_string(card, src, nid);
609 id = card->id;
610
611 again:
612 /* use "Default" for obviously invalid strings
613 * ("card" conflicts with proc directories)
614 */
615 if (!*id || !strncmp(id, "card", 4)) {
616 strcpy(id, "Default");
617 is_default = true;
618 }
619
620 len = strlen(id);
621 for (loops = 0; loops < SNDRV_CARDS; loops++) {
622 char *spos;
623 char sfxstr[5]; /* "_012" */
624 int sfxlen;
625
626 if (card_id_ok(card, id))
627 return; /* OK */
628
629 /* Add _XYZ suffix */
630 sprintf(sfxstr, "_%X", loops + 1);
631 sfxlen = strlen(sfxstr);
632 if (len + sfxlen >= sizeof(card->id))
633 spos = id + sizeof(card->id) - sfxlen - 1;
634 else
635 spos = id + len;
636 strcpy(spos, sfxstr);
637 }
638 /* fallback to the default id */
639 if (!is_default) {
640 *id = 0;
641 goto again;
642 }
643 /* last resort... */
644 dev_err(card->dev, "unable to set card id (%s)\n", id);
645 if (card->proc_root->name)
646 strscpy(card->id, card->proc_root->name, sizeof(card->id));
647}
648
649/**
650 * snd_card_set_id - set card identification name
651 * @card: soundcard structure
652 * @nid: new identification string
653 *
654 * This function sets the card identification and checks for name
655 * collisions.
656 */
657void snd_card_set_id(struct snd_card *card, const char *nid)
658{
659 /* check if user specified own card->id */
660 if (card->id[0] != '\0')
661 return;
662 mutex_lock(&snd_card_mutex);
663 snd_card_set_id_no_lock(card, nid, nid);
664 mutex_unlock(&snd_card_mutex);
665}
666EXPORT_SYMBOL(snd_card_set_id);
667
668static ssize_t id_show(struct device *dev,
669 struct device_attribute *attr, char *buf)
670{
671 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
672 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
673}
674
675static ssize_t id_store(struct device *dev, struct device_attribute *attr,
676 const char *buf, size_t count)
677{
678 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
679 char buf1[sizeof(card->id)];
680 size_t copy = count > sizeof(card->id) - 1 ?
681 sizeof(card->id) - 1 : count;
682 size_t idx;
683 int c;
684
685 for (idx = 0; idx < copy; idx++) {
686 c = buf[idx];
687 if (!isalnum(c) && c != '_' && c != '-')
688 return -EINVAL;
689 }
690 memcpy(buf1, buf, copy);
691 buf1[copy] = '\0';
692 mutex_lock(&snd_card_mutex);
693 if (!card_id_ok(NULL, buf1)) {
694 mutex_unlock(&snd_card_mutex);
695 return -EEXIST;
696 }
697 strcpy(card->id, buf1);
698 snd_info_card_id_change(card);
699 mutex_unlock(&snd_card_mutex);
700
701 return count;
702}
703
704static DEVICE_ATTR_RW(id);
705
706static ssize_t number_show(struct device *dev,
707 struct device_attribute *attr, char *buf)
708{
709 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
710 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
711}
712
713static DEVICE_ATTR_RO(number);
714
715static struct attribute *card_dev_attrs[] = {
716 &dev_attr_id.attr,
717 &dev_attr_number.attr,
718 NULL
719};
720
721static const struct attribute_group card_dev_attr_group = {
722 .attrs = card_dev_attrs,
723};
724
725/**
726 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
727 * @card: card instance
728 * @group: attribute group to append
729 */
730int snd_card_add_dev_attr(struct snd_card *card,
731 const struct attribute_group *group)
732{
733 int i;
734
735 /* loop for (arraysize-1) here to keep NULL at the last entry */
736 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
737 if (!card->dev_groups[i]) {
738 card->dev_groups[i] = group;
739 return 0;
740 }
741 }
742
743 dev_err(card->dev, "Too many groups assigned\n");
744 return -ENOSPC;
745}
746EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
747
748/**
749 * snd_card_register - register the soundcard
750 * @card: soundcard structure
751 *
752 * This function registers all the devices assigned to the soundcard.
753 * Until calling this, the ALSA control interface is blocked from the
754 * external accesses. Thus, you should call this function at the end
755 * of the initialization of the card.
756 *
757 * Return: Zero otherwise a negative error code if the registration failed.
758 */
759int snd_card_register(struct snd_card *card)
760{
761 int err;
762
763 if (snd_BUG_ON(!card))
764 return -EINVAL;
765
766 if (!card->registered) {
767 err = device_add(&card->card_dev);
768 if (err < 0)
769 return err;
770 card->registered = true;
771 }
772
773 err = snd_device_register_all(card);
774 if (err < 0)
775 return err;
776 mutex_lock(&snd_card_mutex);
777 if (snd_cards[card->number]) {
778 /* already registered */
779 mutex_unlock(&snd_card_mutex);
780 return snd_info_card_register(card); /* register pending info */
781 }
782 if (*card->id) {
783 /* make a unique id name from the given string */
784 char tmpid[sizeof(card->id)];
785 memcpy(tmpid, card->id, sizeof(card->id));
786 snd_card_set_id_no_lock(card, tmpid, tmpid);
787 } else {
788 /* create an id from either shortname or longname */
789 const char *src;
790 src = *card->shortname ? card->shortname : card->longname;
791 snd_card_set_id_no_lock(card, src,
792 retrieve_id_from_card_name(src));
793 }
794 snd_cards[card->number] = card;
795 mutex_unlock(&snd_card_mutex);
796 err = snd_info_card_register(card);
797 if (err < 0)
798 return err;
799
800#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
801 if (snd_mixer_oss_notify_callback)
802 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
803#endif
804 return 0;
805}
806EXPORT_SYMBOL(snd_card_register);
807
808#ifdef CONFIG_SND_PROC_FS
809static void snd_card_info_read(struct snd_info_entry *entry,
810 struct snd_info_buffer *buffer)
811{
812 int idx, count;
813 struct snd_card *card;
814
815 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
816 mutex_lock(&snd_card_mutex);
817 card = snd_cards[idx];
818 if (card) {
819 count++;
820 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
821 idx,
822 card->id,
823 card->driver,
824 card->shortname);
825 snd_iprintf(buffer, " %s\n",
826 card->longname);
827 }
828 mutex_unlock(&snd_card_mutex);
829 }
830 if (!count)
831 snd_iprintf(buffer, "--- no soundcards ---\n");
832}
833
834#ifdef CONFIG_SND_OSSEMUL
835void snd_card_info_read_oss(struct snd_info_buffer *buffer)
836{
837 int idx, count;
838 struct snd_card *card;
839
840 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
841 mutex_lock(&snd_card_mutex);
842 card = snd_cards[idx];
843 if (card) {
844 count++;
845 snd_iprintf(buffer, "%s\n", card->longname);
846 }
847 mutex_unlock(&snd_card_mutex);
848 }
849 if (!count) {
850 snd_iprintf(buffer, "--- no soundcards ---\n");
851 }
852}
853
854#endif
855
856#ifdef MODULE
857static void snd_card_module_info_read(struct snd_info_entry *entry,
858 struct snd_info_buffer *buffer)
859{
860 int idx;
861 struct snd_card *card;
862
863 for (idx = 0; idx < SNDRV_CARDS; idx++) {
864 mutex_lock(&snd_card_mutex);
865 card = snd_cards[idx];
866 if (card)
867 snd_iprintf(buffer, "%2i %s\n",
868 idx, card->module->name);
869 mutex_unlock(&snd_card_mutex);
870 }
871}
872#endif
873
874int __init snd_card_info_init(void)
875{
876 struct snd_info_entry *entry;
877
878 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
879 if (! entry)
880 return -ENOMEM;
881 entry->c.text.read = snd_card_info_read;
882 if (snd_info_register(entry) < 0)
883 return -ENOMEM; /* freed in error path */
884
885#ifdef MODULE
886 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
887 if (!entry)
888 return -ENOMEM;
889 entry->c.text.read = snd_card_module_info_read;
890 if (snd_info_register(entry) < 0)
891 return -ENOMEM; /* freed in error path */
892#endif
893
894 return 0;
895}
896#endif /* CONFIG_SND_PROC_FS */
897
898/**
899 * snd_component_add - add a component string
900 * @card: soundcard structure
901 * @component: the component id string
902 *
903 * This function adds the component id string to the supported list.
904 * The component can be referred from the alsa-lib.
905 *
906 * Return: Zero otherwise a negative error code.
907 */
908
909int snd_component_add(struct snd_card *card, const char *component)
910{
911 char *ptr;
912 int len = strlen(component);
913
914 ptr = strstr(card->components, component);
915 if (ptr != NULL) {
916 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
917 return 1;
918 }
919 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
920 snd_BUG();
921 return -ENOMEM;
922 }
923 if (card->components[0] != '\0')
924 strcat(card->components, " ");
925 strcat(card->components, component);
926 return 0;
927}
928EXPORT_SYMBOL(snd_component_add);
929
930/**
931 * snd_card_file_add - add the file to the file list of the card
932 * @card: soundcard structure
933 * @file: file pointer
934 *
935 * This function adds the file to the file linked-list of the card.
936 * This linked-list is used to keep tracking the connection state,
937 * and to avoid the release of busy resources by hotplug.
938 *
939 * Return: zero or a negative error code.
940 */
941int snd_card_file_add(struct snd_card *card, struct file *file)
942{
943 struct snd_monitor_file *mfile;
944
945 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
946 if (mfile == NULL)
947 return -ENOMEM;
948 mfile->file = file;
949 mfile->disconnected_f_op = NULL;
950 INIT_LIST_HEAD(&mfile->shutdown_list);
951 spin_lock(&card->files_lock);
952 if (card->shutdown) {
953 spin_unlock(&card->files_lock);
954 kfree(mfile);
955 return -ENODEV;
956 }
957 list_add(&mfile->list, &card->files_list);
958 get_device(&card->card_dev);
959 spin_unlock(&card->files_lock);
960 return 0;
961}
962EXPORT_SYMBOL(snd_card_file_add);
963
964/**
965 * snd_card_file_remove - remove the file from the file list
966 * @card: soundcard structure
967 * @file: file pointer
968 *
969 * This function removes the file formerly added to the card via
970 * snd_card_file_add() function.
971 * If all files are removed and snd_card_free_when_closed() was
972 * called beforehand, it processes the pending release of
973 * resources.
974 *
975 * Return: Zero or a negative error code.
976 */
977int snd_card_file_remove(struct snd_card *card, struct file *file)
978{
979 struct snd_monitor_file *mfile, *found = NULL;
980
981 spin_lock(&card->files_lock);
982 list_for_each_entry(mfile, &card->files_list, list) {
983 if (mfile->file == file) {
984 list_del(&mfile->list);
985 spin_lock(&shutdown_lock);
986 list_del(&mfile->shutdown_list);
987 spin_unlock(&shutdown_lock);
988 if (mfile->disconnected_f_op)
989 fops_put(mfile->disconnected_f_op);
990 found = mfile;
991 break;
992 }
993 }
994 if (list_empty(&card->files_list))
995 wake_up_all(&card->remove_sleep);
996 spin_unlock(&card->files_lock);
997 if (!found) {
998 dev_err(card->dev, "card file remove problem (%p)\n", file);
999 return -ENOENT;
1000 }
1001 kfree(found);
1002 put_device(&card->card_dev);
1003 return 0;
1004}
1005EXPORT_SYMBOL(snd_card_file_remove);
1006
1007#ifdef CONFIG_PM
1008/**
1009 * snd_power_ref_and_wait - wait until the card gets powered up
1010 * @card: soundcard structure
1011 *
1012 * Take the power_ref reference count of the given card, and
1013 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1014 * The refcount is down again while sleeping until power-up, hence this
1015 * function can be used for syncing the floating control ops accesses,
1016 * typically around calling control ops.
1017 *
1018 * The caller needs to pull down the refcount via snd_power_unref() later
1019 * no matter whether the error is returned from this function or not.
1020 *
1021 * Return: Zero if successful, or a negative error code.
1022 */
1023int snd_power_ref_and_wait(struct snd_card *card)
1024{
1025 wait_queue_entry_t wait;
1026 int result = 0;
1027
1028 snd_power_ref(card);
1029 /* fastpath */
1030 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1031 return 0;
1032 init_waitqueue_entry(&wait, current);
1033 add_wait_queue(&card->power_sleep, &wait);
1034 while (1) {
1035 if (card->shutdown) {
1036 result = -ENODEV;
1037 break;
1038 }
1039 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1040 break;
1041 snd_power_unref(card);
1042 set_current_state(TASK_UNINTERRUPTIBLE);
1043 schedule_timeout(30 * HZ);
1044 snd_power_ref(card);
1045 }
1046 remove_wait_queue(&card->power_sleep, &wait);
1047 return result;
1048}
1049EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1050
1051/**
1052 * snd_power_wait - wait until the card gets powered up (old form)
1053 * @card: soundcard structure
1054 *
1055 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1056 *
1057 * Return: Zero if successful, or a negative error code.
1058 */
1059int snd_power_wait(struct snd_card *card)
1060{
1061 int ret;
1062
1063 ret = snd_power_ref_and_wait(card);
1064 snd_power_unref(card);
1065 return ret;
1066}
1067EXPORT_SYMBOL(snd_power_wait);
1068#endif /* CONFIG_PM */