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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/*
2 * Initialization routines
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/sched.h>
24#include <linux/module.h>
25#include <linux/device.h>
26#include <linux/file.h>
27#include <linux/slab.h>
28#include <linux/time.h>
29#include <linux/ctype.h>
30#include <linux/pm.h>
31#include <linux/completion.h>
32
33#include <sound/core.h>
34#include <sound/control.h>
35#include <sound/info.h>
36
37/* monitor files for graceful shutdown (hotplug) */
38struct snd_monitor_file {
39 struct file *file;
40 const struct file_operations *disconnected_f_op;
41 struct list_head shutdown_list; /* still need to shutdown */
42 struct list_head list; /* link of monitor files */
43};
44
45static DEFINE_SPINLOCK(shutdown_lock);
46static LIST_HEAD(shutdown_files);
47
48static const struct file_operations snd_shutdown_f_ops;
49
50/* locked for registering/using */
51static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
52struct snd_card *snd_cards[SNDRV_CARDS];
53EXPORT_SYMBOL(snd_cards);
54
55static DEFINE_MUTEX(snd_card_mutex);
56
57static char *slots[SNDRV_CARDS];
58module_param_array(slots, charp, NULL, 0444);
59MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
60
61/* return non-zero if the given index is reserved for the given
62 * module via slots option
63 */
64static int module_slot_match(struct module *module, int idx)
65{
66 int match = 1;
67#ifdef MODULE
68 const char *s1, *s2;
69
70 if (!module || !*module->name || !slots[idx])
71 return 0;
72
73 s1 = module->name;
74 s2 = slots[idx];
75 if (*s2 == '!') {
76 match = 0; /* negative match */
77 s2++;
78 }
79 /* compare module name strings
80 * hyphens are handled as equivalent with underscore
81 */
82 for (;;) {
83 char c1 = *s1++;
84 char c2 = *s2++;
85 if (c1 == '-')
86 c1 = '_';
87 if (c2 == '-')
88 c2 = '_';
89 if (c1 != c2)
90 return !match;
91 if (!c1)
92 break;
93 }
94#endif /* MODULE */
95 return match;
96}
97
98#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
99int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
100EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
101#endif
102
103#ifdef CONFIG_PROC_FS
104static void snd_card_id_read(struct snd_info_entry *entry,
105 struct snd_info_buffer *buffer)
106{
107 snd_iprintf(buffer, "%s\n", entry->card->id);
108}
109
110static inline int init_info_for_card(struct snd_card *card)
111{
112 int err;
113 struct snd_info_entry *entry;
114
115 if ((err = snd_info_card_register(card)) < 0) {
116 dev_dbg(card->dev, "unable to create card info\n");
117 return err;
118 }
119 if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
120 dev_dbg(card->dev, "unable to create card entry\n");
121 return err;
122 }
123 entry->c.text.read = snd_card_id_read;
124 if (snd_info_register(entry) < 0) {
125 snd_info_free_entry(entry);
126 entry = NULL;
127 }
128 card->proc_id = entry;
129 return 0;
130}
131#else /* !CONFIG_PROC_FS */
132#define init_info_for_card(card)
133#endif
134
135static int check_empty_slot(struct module *module, int slot)
136{
137 return !slots[slot] || !*slots[slot];
138}
139
140/* return an empty slot number (>= 0) found in the given bitmask @mask.
141 * @mask == -1 == 0xffffffff means: take any free slot up to 32
142 * when no slot is available, return the original @mask as is.
143 */
144static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
145 struct module *module)
146{
147 int slot;
148
149 for (slot = 0; slot < SNDRV_CARDS; slot++) {
150 if (slot < 32 && !(mask & (1U << slot)))
151 continue;
152 if (!test_bit(slot, snd_cards_lock)) {
153 if (check(module, slot))
154 return slot; /* found */
155 }
156 }
157 return mask; /* unchanged */
158}
159
160static int snd_card_do_free(struct snd_card *card);
161static const struct attribute_group *card_dev_attr_groups[];
162
163static void release_card_device(struct device *dev)
164{
165 snd_card_do_free(dev_to_snd_card(dev));
166}
167
168/**
169 * snd_card_new - create and initialize a soundcard structure
170 * @parent: the parent device object
171 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
172 * @xid: card identification (ASCII string)
173 * @module: top level module for locking
174 * @extra_size: allocate this extra size after the main soundcard structure
175 * @card_ret: the pointer to store the created card instance
176 *
177 * Creates and initializes a soundcard structure.
178 *
179 * The function allocates snd_card instance via kzalloc with the given
180 * space for the driver to use freely. The allocated struct is stored
181 * in the given card_ret pointer.
182 *
183 * Return: Zero if successful or a negative error code.
184 */
185int snd_card_new(struct device *parent, int idx, const char *xid,
186 struct module *module, int extra_size,
187 struct snd_card **card_ret)
188{
189 struct snd_card *card;
190 int err;
191
192 if (snd_BUG_ON(!card_ret))
193 return -EINVAL;
194 *card_ret = NULL;
195
196 if (extra_size < 0)
197 extra_size = 0;
198 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
199 if (!card)
200 return -ENOMEM;
201 if (extra_size > 0)
202 card->private_data = (char *)card + sizeof(struct snd_card);
203 if (xid)
204 strlcpy(card->id, xid, sizeof(card->id));
205 err = 0;
206 mutex_lock(&snd_card_mutex);
207 if (idx < 0) /* first check the matching module-name slot */
208 idx = get_slot_from_bitmask(idx, module_slot_match, module);
209 if (idx < 0) /* if not matched, assign an empty slot */
210 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
211 if (idx < 0)
212 err = -ENODEV;
213 else if (idx < snd_ecards_limit) {
214 if (test_bit(idx, snd_cards_lock))
215 err = -EBUSY; /* invalid */
216 } else if (idx >= SNDRV_CARDS)
217 err = -ENODEV;
218 if (err < 0) {
219 mutex_unlock(&snd_card_mutex);
220 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
221 idx, snd_ecards_limit - 1, err);
222 kfree(card);
223 return err;
224 }
225 set_bit(idx, snd_cards_lock); /* lock it */
226 if (idx >= snd_ecards_limit)
227 snd_ecards_limit = idx + 1; /* increase the limit */
228 mutex_unlock(&snd_card_mutex);
229 card->dev = parent;
230 card->number = idx;
231 card->module = module;
232 INIT_LIST_HEAD(&card->devices);
233 init_rwsem(&card->controls_rwsem);
234 rwlock_init(&card->ctl_files_rwlock);
235 INIT_LIST_HEAD(&card->controls);
236 INIT_LIST_HEAD(&card->ctl_files);
237 spin_lock_init(&card->files_lock);
238 INIT_LIST_HEAD(&card->files_list);
239#ifdef CONFIG_PM
240 mutex_init(&card->power_lock);
241 init_waitqueue_head(&card->power_sleep);
242#endif
243
244 device_initialize(&card->card_dev);
245 card->card_dev.parent = parent;
246 card->card_dev.class = sound_class;
247 card->card_dev.release = release_card_device;
248 card->card_dev.groups = card_dev_attr_groups;
249 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
250 if (err < 0)
251 goto __error;
252
253 /* the control interface cannot be accessed from the user space until */
254 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
255 err = snd_ctl_create(card);
256 if (err < 0) {
257 dev_err(parent, "unable to register control minors\n");
258 goto __error;
259 }
260 err = snd_info_card_create(card);
261 if (err < 0) {
262 dev_err(parent, "unable to create card info\n");
263 goto __error_ctl;
264 }
265 *card_ret = card;
266 return 0;
267
268 __error_ctl:
269 snd_device_free_all(card);
270 __error:
271 put_device(&card->card_dev);
272 return err;
273}
274EXPORT_SYMBOL(snd_card_new);
275
276/* return non-zero if a card is already locked */
277int snd_card_locked(int card)
278{
279 int locked;
280
281 mutex_lock(&snd_card_mutex);
282 locked = test_bit(card, snd_cards_lock);
283 mutex_unlock(&snd_card_mutex);
284 return locked;
285}
286
287static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
288{
289 return -ENODEV;
290}
291
292static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
293 size_t count, loff_t *offset)
294{
295 return -ENODEV;
296}
297
298static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
299 size_t count, loff_t *offset)
300{
301 return -ENODEV;
302}
303
304static int snd_disconnect_release(struct inode *inode, struct file *file)
305{
306 struct snd_monitor_file *df = NULL, *_df;
307
308 spin_lock(&shutdown_lock);
309 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
310 if (_df->file == file) {
311 df = _df;
312 list_del_init(&df->shutdown_list);
313 break;
314 }
315 }
316 spin_unlock(&shutdown_lock);
317
318 if (likely(df)) {
319 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
320 df->disconnected_f_op->fasync(-1, file, 0);
321 return df->disconnected_f_op->release(inode, file);
322 }
323
324 panic("%s(%p, %p) failed!", __func__, inode, file);
325}
326
327static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
328{
329 return POLLERR | POLLNVAL;
330}
331
332static long snd_disconnect_ioctl(struct file *file,
333 unsigned int cmd, unsigned long arg)
334{
335 return -ENODEV;
336}
337
338static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
339{
340 return -ENODEV;
341}
342
343static int snd_disconnect_fasync(int fd, struct file *file, int on)
344{
345 return -ENODEV;
346}
347
348static const struct file_operations snd_shutdown_f_ops =
349{
350 .owner = THIS_MODULE,
351 .llseek = snd_disconnect_llseek,
352 .read = snd_disconnect_read,
353 .write = snd_disconnect_write,
354 .release = snd_disconnect_release,
355 .poll = snd_disconnect_poll,
356 .unlocked_ioctl = snd_disconnect_ioctl,
357#ifdef CONFIG_COMPAT
358 .compat_ioctl = snd_disconnect_ioctl,
359#endif
360 .mmap = snd_disconnect_mmap,
361 .fasync = snd_disconnect_fasync
362};
363
364/**
365 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
366 * @card: soundcard structure
367 *
368 * Disconnects all APIs from the file-operations (user space).
369 *
370 * Return: Zero, otherwise a negative error code.
371 *
372 * Note: The current implementation replaces all active file->f_op with special
373 * dummy file operations (they do nothing except release).
374 */
375int snd_card_disconnect(struct snd_card *card)
376{
377 struct snd_monitor_file *mfile;
378 int err;
379
380 if (!card)
381 return -EINVAL;
382
383 spin_lock(&card->files_lock);
384 if (card->shutdown) {
385 spin_unlock(&card->files_lock);
386 return 0;
387 }
388 card->shutdown = 1;
389 spin_unlock(&card->files_lock);
390
391 /* phase 1: disable fops (user space) operations for ALSA API */
392 mutex_lock(&snd_card_mutex);
393 snd_cards[card->number] = NULL;
394 clear_bit(card->number, snd_cards_lock);
395 mutex_unlock(&snd_card_mutex);
396
397 /* phase 2: replace file->f_op with special dummy operations */
398
399 spin_lock(&card->files_lock);
400 list_for_each_entry(mfile, &card->files_list, list) {
401 /* it's critical part, use endless loop */
402 /* we have no room to fail */
403 mfile->disconnected_f_op = mfile->file->f_op;
404
405 spin_lock(&shutdown_lock);
406 list_add(&mfile->shutdown_list, &shutdown_files);
407 spin_unlock(&shutdown_lock);
408
409 mfile->file->f_op = &snd_shutdown_f_ops;
410 fops_get(mfile->file->f_op);
411 }
412 spin_unlock(&card->files_lock);
413
414 /* phase 3: notify all connected devices about disconnection */
415 /* at this point, they cannot respond to any calls except release() */
416
417#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
418 if (snd_mixer_oss_notify_callback)
419 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
420#endif
421
422 /* notify all devices that we are disconnected */
423 err = snd_device_disconnect_all(card);
424 if (err < 0)
425 dev_err(card->dev, "not all devices for card %i can be disconnected\n", card->number);
426
427 snd_info_card_disconnect(card);
428 if (card->registered) {
429 device_del(&card->card_dev);
430 card->registered = false;
431 }
432#ifdef CONFIG_PM
433 wake_up(&card->power_sleep);
434#endif
435 return 0;
436}
437
438EXPORT_SYMBOL(snd_card_disconnect);
439
440/**
441 * snd_card_free - frees given soundcard structure
442 * @card: soundcard structure
443 *
444 * This function releases the soundcard structure and the all assigned
445 * devices automatically. That is, you don't have to release the devices
446 * by yourself.
447 *
448 * Return: Zero. Frees all associated devices and frees the control
449 * interface associated to given soundcard.
450 */
451static int snd_card_do_free(struct snd_card *card)
452{
453#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
454 if (snd_mixer_oss_notify_callback)
455 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
456#endif
457 snd_device_free_all(card);
458 if (card->private_free)
459 card->private_free(card);
460 snd_info_free_entry(card->proc_id);
461 if (snd_info_card_free(card) < 0) {
462 dev_warn(card->dev, "unable to free card info\n");
463 /* Not fatal error */
464 }
465 if (card->release_completion)
466 complete(card->release_completion);
467 kfree(card);
468 return 0;
469}
470
471int snd_card_free_when_closed(struct snd_card *card)
472{
473 int ret = snd_card_disconnect(card);
474 if (ret)
475 return ret;
476 put_device(&card->card_dev);
477 return 0;
478}
479EXPORT_SYMBOL(snd_card_free_when_closed);
480
481int snd_card_free(struct snd_card *card)
482{
483 struct completion released;
484 int ret;
485
486 init_completion(&released);
487 card->release_completion = &released;
488 ret = snd_card_free_when_closed(card);
489 if (ret)
490 return ret;
491 /* wait, until all devices are ready for the free operation */
492 wait_for_completion(&released);
493 return 0;
494}
495EXPORT_SYMBOL(snd_card_free);
496
497/* retrieve the last word of shortname or longname */
498static const char *retrieve_id_from_card_name(const char *name)
499{
500 const char *spos = name;
501
502 while (*name) {
503 if (isspace(*name) && isalnum(name[1]))
504 spos = name + 1;
505 name++;
506 }
507 return spos;
508}
509
510/* return true if the given id string doesn't conflict any other card ids */
511static bool card_id_ok(struct snd_card *card, const char *id)
512{
513 int i;
514 if (!snd_info_check_reserved_words(id))
515 return false;
516 for (i = 0; i < snd_ecards_limit; i++) {
517 if (snd_cards[i] && snd_cards[i] != card &&
518 !strcmp(snd_cards[i]->id, id))
519 return false;
520 }
521 return true;
522}
523
524/* copy to card->id only with valid letters from nid */
525static void copy_valid_id_string(struct snd_card *card, const char *src,
526 const char *nid)
527{
528 char *id = card->id;
529
530 while (*nid && !isalnum(*nid))
531 nid++;
532 if (isdigit(*nid))
533 *id++ = isalpha(*src) ? *src : 'D';
534 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
535 if (isalnum(*nid))
536 *id++ = *nid;
537 nid++;
538 }
539 *id = 0;
540}
541
542/* Set card->id from the given string
543 * If the string conflicts with other ids, add a suffix to make it unique.
544 */
545static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
546 const char *nid)
547{
548 int len, loops;
549 bool is_default = false;
550 char *id;
551
552 copy_valid_id_string(card, src, nid);
553 id = card->id;
554
555 again:
556 /* use "Default" for obviously invalid strings
557 * ("card" conflicts with proc directories)
558 */
559 if (!*id || !strncmp(id, "card", 4)) {
560 strcpy(id, "Default");
561 is_default = true;
562 }
563
564 len = strlen(id);
565 for (loops = 0; loops < SNDRV_CARDS; loops++) {
566 char *spos;
567 char sfxstr[5]; /* "_012" */
568 int sfxlen;
569
570 if (card_id_ok(card, id))
571 return; /* OK */
572
573 /* Add _XYZ suffix */
574 sprintf(sfxstr, "_%X", loops + 1);
575 sfxlen = strlen(sfxstr);
576 if (len + sfxlen >= sizeof(card->id))
577 spos = id + sizeof(card->id) - sfxlen - 1;
578 else
579 spos = id + len;
580 strcpy(spos, sfxstr);
581 }
582 /* fallback to the default id */
583 if (!is_default) {
584 *id = 0;
585 goto again;
586 }
587 /* last resort... */
588 dev_err(card->dev, "unable to set card id (%s)\n", id);
589 if (card->proc_root->name)
590 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
591}
592
593/**
594 * snd_card_set_id - set card identification name
595 * @card: soundcard structure
596 * @nid: new identification string
597 *
598 * This function sets the card identification and checks for name
599 * collisions.
600 */
601void snd_card_set_id(struct snd_card *card, const char *nid)
602{
603 /* check if user specified own card->id */
604 if (card->id[0] != '\0')
605 return;
606 mutex_lock(&snd_card_mutex);
607 snd_card_set_id_no_lock(card, nid, nid);
608 mutex_unlock(&snd_card_mutex);
609}
610EXPORT_SYMBOL(snd_card_set_id);
611
612static ssize_t
613card_id_show_attr(struct device *dev,
614 struct device_attribute *attr, char *buf)
615{
616 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
617 return snprintf(buf, PAGE_SIZE, "%s\n", card->id);
618}
619
620static ssize_t
621card_id_store_attr(struct device *dev, struct device_attribute *attr,
622 const char *buf, size_t count)
623{
624 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
625 char buf1[sizeof(card->id)];
626 size_t copy = count > sizeof(card->id) - 1 ?
627 sizeof(card->id) - 1 : count;
628 size_t idx;
629 int c;
630
631 for (idx = 0; idx < copy; idx++) {
632 c = buf[idx];
633 if (!isalnum(c) && c != '_' && c != '-')
634 return -EINVAL;
635 }
636 memcpy(buf1, buf, copy);
637 buf1[copy] = '\0';
638 mutex_lock(&snd_card_mutex);
639 if (!card_id_ok(NULL, buf1)) {
640 mutex_unlock(&snd_card_mutex);
641 return -EEXIST;
642 }
643 strcpy(card->id, buf1);
644 snd_info_card_id_change(card);
645 mutex_unlock(&snd_card_mutex);
646
647 return count;
648}
649
650static DEVICE_ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
651
652static ssize_t
653card_number_show_attr(struct device *dev,
654 struct device_attribute *attr, char *buf)
655{
656 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
657 return snprintf(buf, PAGE_SIZE, "%i\n", card->number);
658}
659
660static DEVICE_ATTR(number, S_IRUGO, card_number_show_attr, NULL);
661
662static struct attribute *card_dev_attrs[] = {
663 &dev_attr_id.attr,
664 &dev_attr_number.attr,
665 NULL
666};
667
668static struct attribute_group card_dev_attr_group = {
669 .attrs = card_dev_attrs,
670};
671
672static const struct attribute_group *card_dev_attr_groups[] = {
673 &card_dev_attr_group,
674 NULL
675};
676
677/**
678 * snd_card_register - register the soundcard
679 * @card: soundcard structure
680 *
681 * This function registers all the devices assigned to the soundcard.
682 * Until calling this, the ALSA control interface is blocked from the
683 * external accesses. Thus, you should call this function at the end
684 * of the initialization of the card.
685 *
686 * Return: Zero otherwise a negative error code if the registration failed.
687 */
688int snd_card_register(struct snd_card *card)
689{
690 int err;
691
692 if (snd_BUG_ON(!card))
693 return -EINVAL;
694
695 if (!card->registered) {
696 err = device_add(&card->card_dev);
697 if (err < 0)
698 return err;
699 card->registered = true;
700 }
701
702 if ((err = snd_device_register_all(card)) < 0)
703 return err;
704 mutex_lock(&snd_card_mutex);
705 if (snd_cards[card->number]) {
706 /* already registered */
707 mutex_unlock(&snd_card_mutex);
708 return 0;
709 }
710 if (*card->id) {
711 /* make a unique id name from the given string */
712 char tmpid[sizeof(card->id)];
713 memcpy(tmpid, card->id, sizeof(card->id));
714 snd_card_set_id_no_lock(card, tmpid, tmpid);
715 } else {
716 /* create an id from either shortname or longname */
717 const char *src;
718 src = *card->shortname ? card->shortname : card->longname;
719 snd_card_set_id_no_lock(card, src,
720 retrieve_id_from_card_name(src));
721 }
722 snd_cards[card->number] = card;
723 mutex_unlock(&snd_card_mutex);
724 init_info_for_card(card);
725#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
726 if (snd_mixer_oss_notify_callback)
727 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
728#endif
729 return 0;
730}
731
732EXPORT_SYMBOL(snd_card_register);
733
734#ifdef CONFIG_PROC_FS
735static struct snd_info_entry *snd_card_info_entry;
736
737static void snd_card_info_read(struct snd_info_entry *entry,
738 struct snd_info_buffer *buffer)
739{
740 int idx, count;
741 struct snd_card *card;
742
743 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
744 mutex_lock(&snd_card_mutex);
745 if ((card = snd_cards[idx]) != NULL) {
746 count++;
747 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
748 idx,
749 card->id,
750 card->driver,
751 card->shortname);
752 snd_iprintf(buffer, " %s\n",
753 card->longname);
754 }
755 mutex_unlock(&snd_card_mutex);
756 }
757 if (!count)
758 snd_iprintf(buffer, "--- no soundcards ---\n");
759}
760
761#ifdef CONFIG_SND_OSSEMUL
762
763void snd_card_info_read_oss(struct snd_info_buffer *buffer)
764{
765 int idx, count;
766 struct snd_card *card;
767
768 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
769 mutex_lock(&snd_card_mutex);
770 if ((card = snd_cards[idx]) != NULL) {
771 count++;
772 snd_iprintf(buffer, "%s\n", card->longname);
773 }
774 mutex_unlock(&snd_card_mutex);
775 }
776 if (!count) {
777 snd_iprintf(buffer, "--- no soundcards ---\n");
778 }
779}
780
781#endif
782
783#ifdef MODULE
784static struct snd_info_entry *snd_card_module_info_entry;
785static void snd_card_module_info_read(struct snd_info_entry *entry,
786 struct snd_info_buffer *buffer)
787{
788 int idx;
789 struct snd_card *card;
790
791 for (idx = 0; idx < SNDRV_CARDS; idx++) {
792 mutex_lock(&snd_card_mutex);
793 if ((card = snd_cards[idx]) != NULL)
794 snd_iprintf(buffer, "%2i %s\n",
795 idx, card->module->name);
796 mutex_unlock(&snd_card_mutex);
797 }
798}
799#endif
800
801int __init snd_card_info_init(void)
802{
803 struct snd_info_entry *entry;
804
805 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
806 if (! entry)
807 return -ENOMEM;
808 entry->c.text.read = snd_card_info_read;
809 if (snd_info_register(entry) < 0) {
810 snd_info_free_entry(entry);
811 return -ENOMEM;
812 }
813 snd_card_info_entry = entry;
814
815#ifdef MODULE
816 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
817 if (entry) {
818 entry->c.text.read = snd_card_module_info_read;
819 if (snd_info_register(entry) < 0)
820 snd_info_free_entry(entry);
821 else
822 snd_card_module_info_entry = entry;
823 }
824#endif
825
826 return 0;
827}
828
829int __exit snd_card_info_done(void)
830{
831 snd_info_free_entry(snd_card_info_entry);
832#ifdef MODULE
833 snd_info_free_entry(snd_card_module_info_entry);
834#endif
835 return 0;
836}
837
838#endif /* CONFIG_PROC_FS */
839
840/**
841 * snd_component_add - add a component string
842 * @card: soundcard structure
843 * @component: the component id string
844 *
845 * This function adds the component id string to the supported list.
846 * The component can be referred from the alsa-lib.
847 *
848 * Return: Zero otherwise a negative error code.
849 */
850
851int snd_component_add(struct snd_card *card, const char *component)
852{
853 char *ptr;
854 int len = strlen(component);
855
856 ptr = strstr(card->components, component);
857 if (ptr != NULL) {
858 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
859 return 1;
860 }
861 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
862 snd_BUG();
863 return -ENOMEM;
864 }
865 if (card->components[0] != '\0')
866 strcat(card->components, " ");
867 strcat(card->components, component);
868 return 0;
869}
870
871EXPORT_SYMBOL(snd_component_add);
872
873/**
874 * snd_card_file_add - add the file to the file list of the card
875 * @card: soundcard structure
876 * @file: file pointer
877 *
878 * This function adds the file to the file linked-list of the card.
879 * This linked-list is used to keep tracking the connection state,
880 * and to avoid the release of busy resources by hotplug.
881 *
882 * Return: zero or a negative error code.
883 */
884int snd_card_file_add(struct snd_card *card, struct file *file)
885{
886 struct snd_monitor_file *mfile;
887
888 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
889 if (mfile == NULL)
890 return -ENOMEM;
891 mfile->file = file;
892 mfile->disconnected_f_op = NULL;
893 INIT_LIST_HEAD(&mfile->shutdown_list);
894 spin_lock(&card->files_lock);
895 if (card->shutdown) {
896 spin_unlock(&card->files_lock);
897 kfree(mfile);
898 return -ENODEV;
899 }
900 list_add(&mfile->list, &card->files_list);
901 get_device(&card->card_dev);
902 spin_unlock(&card->files_lock);
903 return 0;
904}
905
906EXPORT_SYMBOL(snd_card_file_add);
907
908/**
909 * snd_card_file_remove - remove the file from the file list
910 * @card: soundcard structure
911 * @file: file pointer
912 *
913 * This function removes the file formerly added to the card via
914 * snd_card_file_add() function.
915 * If all files are removed and snd_card_free_when_closed() was
916 * called beforehand, it processes the pending release of
917 * resources.
918 *
919 * Return: Zero or a negative error code.
920 */
921int snd_card_file_remove(struct snd_card *card, struct file *file)
922{
923 struct snd_monitor_file *mfile, *found = NULL;
924
925 spin_lock(&card->files_lock);
926 list_for_each_entry(mfile, &card->files_list, list) {
927 if (mfile->file == file) {
928 list_del(&mfile->list);
929 spin_lock(&shutdown_lock);
930 list_del(&mfile->shutdown_list);
931 spin_unlock(&shutdown_lock);
932 if (mfile->disconnected_f_op)
933 fops_put(mfile->disconnected_f_op);
934 found = mfile;
935 break;
936 }
937 }
938 spin_unlock(&card->files_lock);
939 if (!found) {
940 dev_err(card->dev, "card file remove problem (%p)\n", file);
941 return -ENOENT;
942 }
943 kfree(found);
944 put_device(&card->card_dev);
945 return 0;
946}
947
948EXPORT_SYMBOL(snd_card_file_remove);
949
950#ifdef CONFIG_PM
951/**
952 * snd_power_wait - wait until the power-state is changed.
953 * @card: soundcard structure
954 * @power_state: expected power state
955 *
956 * Waits until the power-state is changed.
957 *
958 * Return: Zero if successful, or a negative error code.
959 *
960 * Note: the power lock must be active before call.
961 */
962int snd_power_wait(struct snd_card *card, unsigned int power_state)
963{
964 wait_queue_t wait;
965 int result = 0;
966
967 /* fastpath */
968 if (snd_power_get_state(card) == power_state)
969 return 0;
970 init_waitqueue_entry(&wait, current);
971 add_wait_queue(&card->power_sleep, &wait);
972 while (1) {
973 if (card->shutdown) {
974 result = -ENODEV;
975 break;
976 }
977 if (snd_power_get_state(card) == power_state)
978 break;
979 set_current_state(TASK_UNINTERRUPTIBLE);
980 snd_power_unlock(card);
981 schedule_timeout(30 * HZ);
982 snd_power_lock(card);
983 }
984 remove_wait_queue(&card->power_sleep, &wait);
985 return result;
986}
987
988EXPORT_SYMBOL(snd_power_wait);
989#endif /* CONFIG_PM */