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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_SND_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 int init_info_for_card(struct snd_card *card)
111{
112 struct snd_info_entry *entry;
113
114 entry = snd_info_create_card_entry(card, "id", card->proc_root);
115 if (!entry) {
116 dev_dbg(card->dev, "unable to create card entry\n");
117 return -ENOMEM;
118 }
119 entry->c.text.read = snd_card_id_read;
120 card->proc_id = entry;
121
122 return snd_info_card_register(card);
123}
124#else /* !CONFIG_SND_PROC_FS */
125#define init_info_for_card(card)
126#endif
127
128static int check_empty_slot(struct module *module, int slot)
129{
130 return !slots[slot] || !*slots[slot];
131}
132
133/* return an empty slot number (>= 0) found in the given bitmask @mask.
134 * @mask == -1 == 0xffffffff means: take any free slot up to 32
135 * when no slot is available, return the original @mask as is.
136 */
137static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
138 struct module *module)
139{
140 int slot;
141
142 for (slot = 0; slot < SNDRV_CARDS; slot++) {
143 if (slot < 32 && !(mask & (1U << slot)))
144 continue;
145 if (!test_bit(slot, snd_cards_lock)) {
146 if (check(module, slot))
147 return slot; /* found */
148 }
149 }
150 return mask; /* unchanged */
151}
152
153/* the default release callback set in snd_device_initialize() below;
154 * this is just NOP for now, as almost all jobs are already done in
155 * dev_free callback of snd_device chain instead.
156 */
157static void default_release(struct device *dev)
158{
159}
160
161/**
162 * snd_device_initialize - Initialize struct device for sound devices
163 * @dev: device to initialize
164 * @card: card to assign, optional
165 */
166void snd_device_initialize(struct device *dev, struct snd_card *card)
167{
168 device_initialize(dev);
169 if (card)
170 dev->parent = &card->card_dev;
171 dev->class = sound_class;
172 dev->release = default_release;
173}
174EXPORT_SYMBOL_GPL(snd_device_initialize);
175
176static int snd_card_do_free(struct snd_card *card);
177static const struct attribute_group card_dev_attr_group;
178
179static void release_card_device(struct device *dev)
180{
181 snd_card_do_free(dev_to_snd_card(dev));
182}
183
184/**
185 * snd_card_new - create and initialize a soundcard structure
186 * @parent: the parent device object
187 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
188 * @xid: card identification (ASCII string)
189 * @module: top level module for locking
190 * @extra_size: allocate this extra size after the main soundcard structure
191 * @card_ret: the pointer to store the created card instance
192 *
193 * Creates and initializes a soundcard structure.
194 *
195 * The function allocates snd_card instance via kzalloc with the given
196 * space for the driver to use freely. The allocated struct is stored
197 * in the given card_ret pointer.
198 *
199 * Return: Zero if successful or a negative error code.
200 */
201int snd_card_new(struct device *parent, int idx, const char *xid,
202 struct module *module, int extra_size,
203 struct snd_card **card_ret)
204{
205 struct snd_card *card;
206 int err;
207
208 if (snd_BUG_ON(!card_ret))
209 return -EINVAL;
210 *card_ret = NULL;
211
212 if (extra_size < 0)
213 extra_size = 0;
214 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
215 if (!card)
216 return -ENOMEM;
217 if (extra_size > 0)
218 card->private_data = (char *)card + sizeof(struct snd_card);
219 if (xid)
220 strlcpy(card->id, xid, sizeof(card->id));
221 err = 0;
222 mutex_lock(&snd_card_mutex);
223 if (idx < 0) /* first check the matching module-name slot */
224 idx = get_slot_from_bitmask(idx, module_slot_match, module);
225 if (idx < 0) /* if not matched, assign an empty slot */
226 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
227 if (idx < 0)
228 err = -ENODEV;
229 else if (idx < snd_ecards_limit) {
230 if (test_bit(idx, snd_cards_lock))
231 err = -EBUSY; /* invalid */
232 } else if (idx >= SNDRV_CARDS)
233 err = -ENODEV;
234 if (err < 0) {
235 mutex_unlock(&snd_card_mutex);
236 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
237 idx, snd_ecards_limit - 1, err);
238 kfree(card);
239 return err;
240 }
241 set_bit(idx, snd_cards_lock); /* lock it */
242 if (idx >= snd_ecards_limit)
243 snd_ecards_limit = idx + 1; /* increase the limit */
244 mutex_unlock(&snd_card_mutex);
245 card->dev = parent;
246 card->number = idx;
247 card->module = module;
248 INIT_LIST_HEAD(&card->devices);
249 init_rwsem(&card->controls_rwsem);
250 rwlock_init(&card->ctl_files_rwlock);
251 mutex_init(&card->user_ctl_lock);
252 INIT_LIST_HEAD(&card->controls);
253 INIT_LIST_HEAD(&card->ctl_files);
254 spin_lock_init(&card->files_lock);
255 INIT_LIST_HEAD(&card->files_list);
256#ifdef CONFIG_PM
257 mutex_init(&card->power_lock);
258 init_waitqueue_head(&card->power_sleep);
259#endif
260
261 device_initialize(&card->card_dev);
262 card->card_dev.parent = parent;
263 card->card_dev.class = sound_class;
264 card->card_dev.release = release_card_device;
265 card->card_dev.groups = card->dev_groups;
266 card->dev_groups[0] = &card_dev_attr_group;
267 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
268 if (err < 0)
269 goto __error;
270
271 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
272 dev_driver_string(card->dev), dev_name(&card->card_dev));
273
274 /* the control interface cannot be accessed from the user space until */
275 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
276 err = snd_ctl_create(card);
277 if (err < 0) {
278 dev_err(parent, "unable to register control minors\n");
279 goto __error;
280 }
281 err = snd_info_card_create(card);
282 if (err < 0) {
283 dev_err(parent, "unable to create card info\n");
284 goto __error_ctl;
285 }
286 *card_ret = card;
287 return 0;
288
289 __error_ctl:
290 snd_device_free_all(card);
291 __error:
292 put_device(&card->card_dev);
293 return err;
294}
295EXPORT_SYMBOL(snd_card_new);
296
297/* return non-zero if a card is already locked */
298int snd_card_locked(int card)
299{
300 int locked;
301
302 mutex_lock(&snd_card_mutex);
303 locked = test_bit(card, snd_cards_lock);
304 mutex_unlock(&snd_card_mutex);
305 return locked;
306}
307
308static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
309{
310 return -ENODEV;
311}
312
313static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
314 size_t count, loff_t *offset)
315{
316 return -ENODEV;
317}
318
319static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
320 size_t count, loff_t *offset)
321{
322 return -ENODEV;
323}
324
325static int snd_disconnect_release(struct inode *inode, struct file *file)
326{
327 struct snd_monitor_file *df = NULL, *_df;
328
329 spin_lock(&shutdown_lock);
330 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
331 if (_df->file == file) {
332 df = _df;
333 list_del_init(&df->shutdown_list);
334 break;
335 }
336 }
337 spin_unlock(&shutdown_lock);
338
339 if (likely(df)) {
340 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
341 df->disconnected_f_op->fasync(-1, file, 0);
342 return df->disconnected_f_op->release(inode, file);
343 }
344
345 panic("%s(%p, %p) failed!", __func__, inode, file);
346}
347
348static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
349{
350 return POLLERR | POLLNVAL;
351}
352
353static long snd_disconnect_ioctl(struct file *file,
354 unsigned int cmd, unsigned long arg)
355{
356 return -ENODEV;
357}
358
359static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
360{
361 return -ENODEV;
362}
363
364static int snd_disconnect_fasync(int fd, struct file *file, int on)
365{
366 return -ENODEV;
367}
368
369static const struct file_operations snd_shutdown_f_ops =
370{
371 .owner = THIS_MODULE,
372 .llseek = snd_disconnect_llseek,
373 .read = snd_disconnect_read,
374 .write = snd_disconnect_write,
375 .release = snd_disconnect_release,
376 .poll = snd_disconnect_poll,
377 .unlocked_ioctl = snd_disconnect_ioctl,
378#ifdef CONFIG_COMPAT
379 .compat_ioctl = snd_disconnect_ioctl,
380#endif
381 .mmap = snd_disconnect_mmap,
382 .fasync = snd_disconnect_fasync
383};
384
385/**
386 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
387 * @card: soundcard structure
388 *
389 * Disconnects all APIs from the file-operations (user space).
390 *
391 * Return: Zero, otherwise a negative error code.
392 *
393 * Note: The current implementation replaces all active file->f_op with special
394 * dummy file operations (they do nothing except release).
395 */
396int snd_card_disconnect(struct snd_card *card)
397{
398 struct snd_monitor_file *mfile;
399
400 if (!card)
401 return -EINVAL;
402
403 spin_lock(&card->files_lock);
404 if (card->shutdown) {
405 spin_unlock(&card->files_lock);
406 return 0;
407 }
408 card->shutdown = 1;
409 spin_unlock(&card->files_lock);
410
411 /* phase 1: disable fops (user space) operations for ALSA API */
412 mutex_lock(&snd_card_mutex);
413 snd_cards[card->number] = NULL;
414 clear_bit(card->number, snd_cards_lock);
415 mutex_unlock(&snd_card_mutex);
416
417 /* phase 2: replace file->f_op with special dummy operations */
418
419 spin_lock(&card->files_lock);
420 list_for_each_entry(mfile, &card->files_list, list) {
421 /* it's critical part, use endless loop */
422 /* we have no room to fail */
423 mfile->disconnected_f_op = mfile->file->f_op;
424
425 spin_lock(&shutdown_lock);
426 list_add(&mfile->shutdown_list, &shutdown_files);
427 spin_unlock(&shutdown_lock);
428
429 mfile->file->f_op = &snd_shutdown_f_ops;
430 fops_get(mfile->file->f_op);
431 }
432 spin_unlock(&card->files_lock);
433
434 /* phase 3: notify all connected devices about disconnection */
435 /* at this point, they cannot respond to any calls except release() */
436
437#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
438 if (snd_mixer_oss_notify_callback)
439 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
440#endif
441
442 /* notify all devices that we are disconnected */
443 snd_device_disconnect_all(card);
444
445 snd_info_card_disconnect(card);
446 if (card->registered) {
447 device_del(&card->card_dev);
448 card->registered = false;
449 }
450#ifdef CONFIG_PM
451 wake_up(&card->power_sleep);
452#endif
453 return 0;
454}
455
456EXPORT_SYMBOL(snd_card_disconnect);
457
458static int snd_card_do_free(struct snd_card *card)
459{
460#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
461 if (snd_mixer_oss_notify_callback)
462 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
463#endif
464 snd_device_free_all(card);
465 if (card->private_free)
466 card->private_free(card);
467 snd_info_free_entry(card->proc_id);
468 if (snd_info_card_free(card) < 0) {
469 dev_warn(card->dev, "unable to free card info\n");
470 /* Not fatal error */
471 }
472 if (card->release_completion)
473 complete(card->release_completion);
474 kfree(card);
475 return 0;
476}
477
478/**
479 * snd_card_free_when_closed - Disconnect the card, free it later eventually
480 * @card: soundcard structure
481 *
482 * Unlike snd_card_free(), this function doesn't try to release the card
483 * resource immediately, but tries to disconnect at first. When the card
484 * is still in use, the function returns before freeing the resources.
485 * The card resources will be freed when the refcount gets to zero.
486 */
487int snd_card_free_when_closed(struct snd_card *card)
488{
489 int ret = snd_card_disconnect(card);
490 if (ret)
491 return ret;
492 put_device(&card->card_dev);
493 return 0;
494}
495EXPORT_SYMBOL(snd_card_free_when_closed);
496
497/**
498 * snd_card_free - frees given soundcard structure
499 * @card: soundcard structure
500 *
501 * This function releases the soundcard structure and the all assigned
502 * devices automatically. That is, you don't have to release the devices
503 * by yourself.
504 *
505 * This function waits until the all resources are properly released.
506 *
507 * Return: Zero. Frees all associated devices and frees the control
508 * interface associated to given soundcard.
509 */
510int snd_card_free(struct snd_card *card)
511{
512 struct completion released;
513 int ret;
514
515 init_completion(&released);
516 card->release_completion = &released;
517 ret = snd_card_free_when_closed(card);
518 if (ret)
519 return ret;
520 /* wait, until all devices are ready for the free operation */
521 wait_for_completion(&released);
522 return 0;
523}
524EXPORT_SYMBOL(snd_card_free);
525
526/* retrieve the last word of shortname or longname */
527static const char *retrieve_id_from_card_name(const char *name)
528{
529 const char *spos = name;
530
531 while (*name) {
532 if (isspace(*name) && isalnum(name[1]))
533 spos = name + 1;
534 name++;
535 }
536 return spos;
537}
538
539/* return true if the given id string doesn't conflict any other card ids */
540static bool card_id_ok(struct snd_card *card, const char *id)
541{
542 int i;
543 if (!snd_info_check_reserved_words(id))
544 return false;
545 for (i = 0; i < snd_ecards_limit; i++) {
546 if (snd_cards[i] && snd_cards[i] != card &&
547 !strcmp(snd_cards[i]->id, id))
548 return false;
549 }
550 return true;
551}
552
553/* copy to card->id only with valid letters from nid */
554static void copy_valid_id_string(struct snd_card *card, const char *src,
555 const char *nid)
556{
557 char *id = card->id;
558
559 while (*nid && !isalnum(*nid))
560 nid++;
561 if (isdigit(*nid))
562 *id++ = isalpha(*src) ? *src : 'D';
563 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
564 if (isalnum(*nid))
565 *id++ = *nid;
566 nid++;
567 }
568 *id = 0;
569}
570
571/* Set card->id from the given string
572 * If the string conflicts with other ids, add a suffix to make it unique.
573 */
574static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
575 const char *nid)
576{
577 int len, loops;
578 bool is_default = false;
579 char *id;
580
581 copy_valid_id_string(card, src, nid);
582 id = card->id;
583
584 again:
585 /* use "Default" for obviously invalid strings
586 * ("card" conflicts with proc directories)
587 */
588 if (!*id || !strncmp(id, "card", 4)) {
589 strcpy(id, "Default");
590 is_default = true;
591 }
592
593 len = strlen(id);
594 for (loops = 0; loops < SNDRV_CARDS; loops++) {
595 char *spos;
596 char sfxstr[5]; /* "_012" */
597 int sfxlen;
598
599 if (card_id_ok(card, id))
600 return; /* OK */
601
602 /* Add _XYZ suffix */
603 sprintf(sfxstr, "_%X", loops + 1);
604 sfxlen = strlen(sfxstr);
605 if (len + sfxlen >= sizeof(card->id))
606 spos = id + sizeof(card->id) - sfxlen - 1;
607 else
608 spos = id + len;
609 strcpy(spos, sfxstr);
610 }
611 /* fallback to the default id */
612 if (!is_default) {
613 *id = 0;
614 goto again;
615 }
616 /* last resort... */
617 dev_err(card->dev, "unable to set card id (%s)\n", id);
618 if (card->proc_root->name)
619 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
620}
621
622/**
623 * snd_card_set_id - set card identification name
624 * @card: soundcard structure
625 * @nid: new identification string
626 *
627 * This function sets the card identification and checks for name
628 * collisions.
629 */
630void snd_card_set_id(struct snd_card *card, const char *nid)
631{
632 /* check if user specified own card->id */
633 if (card->id[0] != '\0')
634 return;
635 mutex_lock(&snd_card_mutex);
636 snd_card_set_id_no_lock(card, nid, nid);
637 mutex_unlock(&snd_card_mutex);
638}
639EXPORT_SYMBOL(snd_card_set_id);
640
641static ssize_t
642card_id_show_attr(struct device *dev,
643 struct device_attribute *attr, char *buf)
644{
645 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
646 return snprintf(buf, PAGE_SIZE, "%s\n", card->id);
647}
648
649static ssize_t
650card_id_store_attr(struct device *dev, struct device_attribute *attr,
651 const char *buf, size_t count)
652{
653 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
654 char buf1[sizeof(card->id)];
655 size_t copy = count > sizeof(card->id) - 1 ?
656 sizeof(card->id) - 1 : count;
657 size_t idx;
658 int c;
659
660 for (idx = 0; idx < copy; idx++) {
661 c = buf[idx];
662 if (!isalnum(c) && c != '_' && c != '-')
663 return -EINVAL;
664 }
665 memcpy(buf1, buf, copy);
666 buf1[copy] = '\0';
667 mutex_lock(&snd_card_mutex);
668 if (!card_id_ok(NULL, buf1)) {
669 mutex_unlock(&snd_card_mutex);
670 return -EEXIST;
671 }
672 strcpy(card->id, buf1);
673 snd_info_card_id_change(card);
674 mutex_unlock(&snd_card_mutex);
675
676 return count;
677}
678
679static DEVICE_ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
680
681static ssize_t
682card_number_show_attr(struct device *dev,
683 struct device_attribute *attr, char *buf)
684{
685 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
686 return snprintf(buf, PAGE_SIZE, "%i\n", card->number);
687}
688
689static DEVICE_ATTR(number, S_IRUGO, card_number_show_attr, NULL);
690
691static struct attribute *card_dev_attrs[] = {
692 &dev_attr_id.attr,
693 &dev_attr_number.attr,
694 NULL
695};
696
697static const struct attribute_group card_dev_attr_group = {
698 .attrs = card_dev_attrs,
699};
700
701/**
702 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
703 * @card: card instance
704 * @group: attribute group to append
705 */
706int snd_card_add_dev_attr(struct snd_card *card,
707 const struct attribute_group *group)
708{
709 int i;
710
711 /* loop for (arraysize-1) here to keep NULL at the last entry */
712 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
713 if (!card->dev_groups[i]) {
714 card->dev_groups[i] = group;
715 return 0;
716 }
717 }
718
719 dev_err(card->dev, "Too many groups assigned\n");
720 return -ENOSPC;
721};
722EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
723
724/**
725 * snd_card_register - register the soundcard
726 * @card: soundcard structure
727 *
728 * This function registers all the devices assigned to the soundcard.
729 * Until calling this, the ALSA control interface is blocked from the
730 * external accesses. Thus, you should call this function at the end
731 * of the initialization of the card.
732 *
733 * Return: Zero otherwise a negative error code if the registration failed.
734 */
735int snd_card_register(struct snd_card *card)
736{
737 int err;
738
739 if (snd_BUG_ON(!card))
740 return -EINVAL;
741
742 if (!card->registered) {
743 err = device_add(&card->card_dev);
744 if (err < 0)
745 return err;
746 card->registered = true;
747 }
748
749 if ((err = snd_device_register_all(card)) < 0)
750 return err;
751 mutex_lock(&snd_card_mutex);
752 if (snd_cards[card->number]) {
753 /* already registered */
754 mutex_unlock(&snd_card_mutex);
755 return snd_info_card_register(card); /* register pending info */
756 }
757 if (*card->id) {
758 /* make a unique id name from the given string */
759 char tmpid[sizeof(card->id)];
760 memcpy(tmpid, card->id, sizeof(card->id));
761 snd_card_set_id_no_lock(card, tmpid, tmpid);
762 } else {
763 /* create an id from either shortname or longname */
764 const char *src;
765 src = *card->shortname ? card->shortname : card->longname;
766 snd_card_set_id_no_lock(card, src,
767 retrieve_id_from_card_name(src));
768 }
769 snd_cards[card->number] = card;
770 mutex_unlock(&snd_card_mutex);
771 init_info_for_card(card);
772#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
773 if (snd_mixer_oss_notify_callback)
774 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
775#endif
776 return 0;
777}
778
779EXPORT_SYMBOL(snd_card_register);
780
781#ifdef CONFIG_SND_PROC_FS
782static void snd_card_info_read(struct snd_info_entry *entry,
783 struct snd_info_buffer *buffer)
784{
785 int idx, count;
786 struct snd_card *card;
787
788 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
789 mutex_lock(&snd_card_mutex);
790 if ((card = snd_cards[idx]) != NULL) {
791 count++;
792 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
793 idx,
794 card->id,
795 card->driver,
796 card->shortname);
797 snd_iprintf(buffer, " %s\n",
798 card->longname);
799 }
800 mutex_unlock(&snd_card_mutex);
801 }
802 if (!count)
803 snd_iprintf(buffer, "--- no soundcards ---\n");
804}
805
806#ifdef CONFIG_SND_OSSEMUL
807void snd_card_info_read_oss(struct snd_info_buffer *buffer)
808{
809 int idx, count;
810 struct snd_card *card;
811
812 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
813 mutex_lock(&snd_card_mutex);
814 if ((card = snd_cards[idx]) != NULL) {
815 count++;
816 snd_iprintf(buffer, "%s\n", card->longname);
817 }
818 mutex_unlock(&snd_card_mutex);
819 }
820 if (!count) {
821 snd_iprintf(buffer, "--- no soundcards ---\n");
822 }
823}
824
825#endif
826
827#ifdef MODULE
828static void snd_card_module_info_read(struct snd_info_entry *entry,
829 struct snd_info_buffer *buffer)
830{
831 int idx;
832 struct snd_card *card;
833
834 for (idx = 0; idx < SNDRV_CARDS; idx++) {
835 mutex_lock(&snd_card_mutex);
836 if ((card = snd_cards[idx]) != NULL)
837 snd_iprintf(buffer, "%2i %s\n",
838 idx, card->module->name);
839 mutex_unlock(&snd_card_mutex);
840 }
841}
842#endif
843
844int __init snd_card_info_init(void)
845{
846 struct snd_info_entry *entry;
847
848 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
849 if (! entry)
850 return -ENOMEM;
851 entry->c.text.read = snd_card_info_read;
852 if (snd_info_register(entry) < 0)
853 return -ENOMEM; /* freed in error path */
854
855#ifdef MODULE
856 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
857 if (!entry)
858 return -ENOMEM;
859 entry->c.text.read = snd_card_module_info_read;
860 if (snd_info_register(entry) < 0)
861 return -ENOMEM; /* freed in error path */
862#endif
863
864 return 0;
865}
866#endif /* CONFIG_SND_PROC_FS */
867
868/**
869 * snd_component_add - add a component string
870 * @card: soundcard structure
871 * @component: the component id string
872 *
873 * This function adds the component id string to the supported list.
874 * The component can be referred from the alsa-lib.
875 *
876 * Return: Zero otherwise a negative error code.
877 */
878
879int snd_component_add(struct snd_card *card, const char *component)
880{
881 char *ptr;
882 int len = strlen(component);
883
884 ptr = strstr(card->components, component);
885 if (ptr != NULL) {
886 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
887 return 1;
888 }
889 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
890 snd_BUG();
891 return -ENOMEM;
892 }
893 if (card->components[0] != '\0')
894 strcat(card->components, " ");
895 strcat(card->components, component);
896 return 0;
897}
898
899EXPORT_SYMBOL(snd_component_add);
900
901/**
902 * snd_card_file_add - add the file to the file list of the card
903 * @card: soundcard structure
904 * @file: file pointer
905 *
906 * This function adds the file to the file linked-list of the card.
907 * This linked-list is used to keep tracking the connection state,
908 * and to avoid the release of busy resources by hotplug.
909 *
910 * Return: zero or a negative error code.
911 */
912int snd_card_file_add(struct snd_card *card, struct file *file)
913{
914 struct snd_monitor_file *mfile;
915
916 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
917 if (mfile == NULL)
918 return -ENOMEM;
919 mfile->file = file;
920 mfile->disconnected_f_op = NULL;
921 INIT_LIST_HEAD(&mfile->shutdown_list);
922 spin_lock(&card->files_lock);
923 if (card->shutdown) {
924 spin_unlock(&card->files_lock);
925 kfree(mfile);
926 return -ENODEV;
927 }
928 list_add(&mfile->list, &card->files_list);
929 get_device(&card->card_dev);
930 spin_unlock(&card->files_lock);
931 return 0;
932}
933
934EXPORT_SYMBOL(snd_card_file_add);
935
936/**
937 * snd_card_file_remove - remove the file from the file list
938 * @card: soundcard structure
939 * @file: file pointer
940 *
941 * This function removes the file formerly added to the card via
942 * snd_card_file_add() function.
943 * If all files are removed and snd_card_free_when_closed() was
944 * called beforehand, it processes the pending release of
945 * resources.
946 *
947 * Return: Zero or a negative error code.
948 */
949int snd_card_file_remove(struct snd_card *card, struct file *file)
950{
951 struct snd_monitor_file *mfile, *found = NULL;
952
953 spin_lock(&card->files_lock);
954 list_for_each_entry(mfile, &card->files_list, list) {
955 if (mfile->file == file) {
956 list_del(&mfile->list);
957 spin_lock(&shutdown_lock);
958 list_del(&mfile->shutdown_list);
959 spin_unlock(&shutdown_lock);
960 if (mfile->disconnected_f_op)
961 fops_put(mfile->disconnected_f_op);
962 found = mfile;
963 break;
964 }
965 }
966 spin_unlock(&card->files_lock);
967 if (!found) {
968 dev_err(card->dev, "card file remove problem (%p)\n", file);
969 return -ENOENT;
970 }
971 kfree(found);
972 put_device(&card->card_dev);
973 return 0;
974}
975
976EXPORT_SYMBOL(snd_card_file_remove);
977
978#ifdef CONFIG_PM
979/**
980 * snd_power_wait - wait until the power-state is changed.
981 * @card: soundcard structure
982 * @power_state: expected power state
983 *
984 * Waits until the power-state is changed.
985 *
986 * Return: Zero if successful, or a negative error code.
987 *
988 * Note: the power lock must be active before call.
989 */
990int snd_power_wait(struct snd_card *card, unsigned int power_state)
991{
992 wait_queue_t wait;
993 int result = 0;
994
995 /* fastpath */
996 if (snd_power_get_state(card) == power_state)
997 return 0;
998 init_waitqueue_entry(&wait, current);
999 add_wait_queue(&card->power_sleep, &wait);
1000 while (1) {
1001 if (card->shutdown) {
1002 result = -ENODEV;
1003 break;
1004 }
1005 if (snd_power_get_state(card) == power_state)
1006 break;
1007 set_current_state(TASK_UNINTERRUPTIBLE);
1008 snd_power_unlock(card);
1009 schedule_timeout(30 * HZ);
1010 snd_power_lock(card);
1011 }
1012 remove_wait_queue(&card->power_sleep, &wait);
1013 return result;
1014}
1015
1016EXPORT_SYMBOL(snd_power_wait);
1017#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_alloc() */
115static void default_release_alloc(struct device *dev)
116{
117 kfree(dev);
118}
119
120/**
121 * snd_device_alloc - Allocate and initialize struct device for sound devices
122 * @dev_p: pointer to store the allocated device
123 * @card: card to assign, optional
124 *
125 * For releasing the allocated device, call put_device().
126 */
127int snd_device_alloc(struct device **dev_p, struct snd_card *card)
128{
129 struct device *dev;
130
131 *dev_p = NULL;
132 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
133 if (!dev)
134 return -ENOMEM;
135 device_initialize(dev);
136 if (card)
137 dev->parent = &card->card_dev;
138 dev->class = &sound_class;
139 dev->release = default_release_alloc;
140 *dev_p = dev;
141 return 0;
142}
143EXPORT_SYMBOL_GPL(snd_device_alloc);
144
145static int snd_card_init(struct snd_card *card, struct device *parent,
146 int idx, const char *xid, struct module *module,
147 size_t extra_size);
148static int snd_card_do_free(struct snd_card *card);
149static const struct attribute_group card_dev_attr_group;
150
151static void release_card_device(struct device *dev)
152{
153 snd_card_do_free(dev_to_snd_card(dev));
154}
155
156/**
157 * snd_card_new - create and initialize a soundcard structure
158 * @parent: the parent device object
159 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
160 * @xid: card identification (ASCII string)
161 * @module: top level module for locking
162 * @extra_size: allocate this extra size after the main soundcard structure
163 * @card_ret: the pointer to store the created card instance
164 *
165 * The function allocates snd_card instance via kzalloc with the given
166 * space for the driver to use freely. The allocated struct is stored
167 * in the given card_ret pointer.
168 *
169 * Return: Zero if successful or a negative error code.
170 */
171int snd_card_new(struct device *parent, int idx, const char *xid,
172 struct module *module, int extra_size,
173 struct snd_card **card_ret)
174{
175 struct snd_card *card;
176 int err;
177
178 if (snd_BUG_ON(!card_ret))
179 return -EINVAL;
180 *card_ret = NULL;
181
182 if (extra_size < 0)
183 extra_size = 0;
184 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
185 if (!card)
186 return -ENOMEM;
187
188 err = snd_card_init(card, parent, idx, xid, module, extra_size);
189 if (err < 0)
190 return err; /* card is freed by error handler */
191
192 *card_ret = card;
193 return 0;
194}
195EXPORT_SYMBOL(snd_card_new);
196
197static void __snd_card_release(struct device *dev, void *data)
198{
199 snd_card_free(data);
200}
201
202/**
203 * snd_devm_card_new - managed snd_card object creation
204 * @parent: the parent device object
205 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
206 * @xid: card identification (ASCII string)
207 * @module: top level module for locking
208 * @extra_size: allocate this extra size after the main soundcard structure
209 * @card_ret: the pointer to store the created card instance
210 *
211 * This function works like snd_card_new() but manages the allocated resource
212 * via devres, i.e. you don't need to free explicitly.
213 *
214 * When a snd_card object is created with this function and registered via
215 * snd_card_register(), the very first devres action to call snd_card_free()
216 * is added automatically. In that way, the resource disconnection is assured
217 * at first, then released in the expected order.
218 *
219 * If an error happens at the probe before snd_card_register() is called and
220 * there have been other devres resources, you'd need to free the card manually
221 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
222 * devres call orders. You can use snd_card_free_on_error() helper for
223 * handling it more easily.
224 *
225 * Return: zero if successful, or a negative error code
226 */
227int snd_devm_card_new(struct device *parent, int idx, const char *xid,
228 struct module *module, size_t extra_size,
229 struct snd_card **card_ret)
230{
231 struct snd_card *card;
232 int err;
233
234 *card_ret = NULL;
235 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
236 GFP_KERNEL);
237 if (!card)
238 return -ENOMEM;
239 card->managed = true;
240 err = snd_card_init(card, parent, idx, xid, module, extra_size);
241 if (err < 0) {
242 devres_free(card); /* in managed mode, we need to free manually */
243 return err;
244 }
245
246 devres_add(parent, card);
247 *card_ret = card;
248 return 0;
249}
250EXPORT_SYMBOL_GPL(snd_devm_card_new);
251
252/**
253 * snd_card_free_on_error - a small helper for handling devm probe errors
254 * @dev: the managed device object
255 * @ret: the return code from the probe callback
256 *
257 * This function handles the explicit snd_card_free() call at the error from
258 * the probe callback. It's just a small helper for simplifying the error
259 * handling with the managed devices.
260 *
261 * Return: zero if successful, or a negative error code
262 */
263int snd_card_free_on_error(struct device *dev, int ret)
264{
265 struct snd_card *card;
266
267 if (!ret)
268 return 0;
269 card = devres_find(dev, __snd_card_release, NULL, NULL);
270 if (card)
271 snd_card_free(card);
272 return ret;
273}
274EXPORT_SYMBOL_GPL(snd_card_free_on_error);
275
276static int snd_card_init(struct snd_card *card, struct device *parent,
277 int idx, const char *xid, struct module *module,
278 size_t extra_size)
279{
280 int err;
281
282 if (extra_size > 0)
283 card->private_data = (char *)card + sizeof(struct snd_card);
284 if (xid)
285 strscpy(card->id, xid, sizeof(card->id));
286 err = 0;
287 mutex_lock(&snd_card_mutex);
288 if (idx < 0) /* first check the matching module-name slot */
289 idx = get_slot_from_bitmask(idx, module_slot_match, module);
290 if (idx < 0) /* if not matched, assign an empty slot */
291 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
292 if (idx < 0)
293 err = -ENODEV;
294 else if (idx < snd_ecards_limit) {
295 if (test_bit(idx, snd_cards_lock))
296 err = -EBUSY; /* invalid */
297 } else if (idx >= SNDRV_CARDS)
298 err = -ENODEV;
299 if (err < 0) {
300 mutex_unlock(&snd_card_mutex);
301 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
302 idx, snd_ecards_limit - 1, err);
303 if (!card->managed)
304 kfree(card); /* manually free here, as no destructor called */
305 return err;
306 }
307 set_bit(idx, snd_cards_lock); /* lock it */
308 if (idx >= snd_ecards_limit)
309 snd_ecards_limit = idx + 1; /* increase the limit */
310 mutex_unlock(&snd_card_mutex);
311 card->dev = parent;
312 card->number = idx;
313#ifdef MODULE
314 WARN_ON(!module);
315 card->module = module;
316#endif
317 INIT_LIST_HEAD(&card->devices);
318 init_rwsem(&card->controls_rwsem);
319 rwlock_init(&card->ctl_files_rwlock);
320 INIT_LIST_HEAD(&card->controls);
321 INIT_LIST_HEAD(&card->ctl_files);
322#ifdef CONFIG_SND_CTL_FAST_LOOKUP
323 xa_init(&card->ctl_numids);
324 xa_init(&card->ctl_hash);
325#endif
326 spin_lock_init(&card->files_lock);
327 INIT_LIST_HEAD(&card->files_list);
328 mutex_init(&card->memory_mutex);
329#ifdef CONFIG_PM
330 init_waitqueue_head(&card->power_sleep);
331 init_waitqueue_head(&card->power_ref_sleep);
332 atomic_set(&card->power_ref, 0);
333#endif
334 init_waitqueue_head(&card->remove_sleep);
335 card->sync_irq = -1;
336
337 device_initialize(&card->card_dev);
338 card->card_dev.parent = parent;
339 card->card_dev.class = &sound_class;
340 card->card_dev.release = release_card_device;
341 card->card_dev.groups = card->dev_groups;
342 card->dev_groups[0] = &card_dev_attr_group;
343 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
344 if (err < 0)
345 goto __error;
346
347 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
348 dev_driver_string(card->dev), dev_name(&card->card_dev));
349
350 /* the control interface cannot be accessed from the user space until */
351 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
352 err = snd_ctl_create(card);
353 if (err < 0) {
354 dev_err(parent, "unable to register control minors\n");
355 goto __error;
356 }
357 err = snd_info_card_create(card);
358 if (err < 0) {
359 dev_err(parent, "unable to create card info\n");
360 goto __error_ctl;
361 }
362
363#ifdef CONFIG_SND_DEBUG
364 card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
365 sound_debugfs_root);
366#endif
367 return 0;
368
369 __error_ctl:
370 snd_device_free_all(card);
371 __error:
372 put_device(&card->card_dev);
373 return err;
374}
375
376/**
377 * snd_card_ref - Get the card object from the index
378 * @idx: the card index
379 *
380 * Returns a card object corresponding to the given index or NULL if not found.
381 * Release the object via snd_card_unref().
382 *
383 * Return: a card object or NULL
384 */
385struct snd_card *snd_card_ref(int idx)
386{
387 struct snd_card *card;
388
389 mutex_lock(&snd_card_mutex);
390 card = snd_cards[idx];
391 if (card)
392 get_device(&card->card_dev);
393 mutex_unlock(&snd_card_mutex);
394 return card;
395}
396EXPORT_SYMBOL_GPL(snd_card_ref);
397
398/* return non-zero if a card is already locked */
399int snd_card_locked(int card)
400{
401 int locked;
402
403 mutex_lock(&snd_card_mutex);
404 locked = test_bit(card, snd_cards_lock);
405 mutex_unlock(&snd_card_mutex);
406 return locked;
407}
408
409static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
410{
411 return -ENODEV;
412}
413
414static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
415 size_t count, loff_t *offset)
416{
417 return -ENODEV;
418}
419
420static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
421 size_t count, loff_t *offset)
422{
423 return -ENODEV;
424}
425
426static int snd_disconnect_release(struct inode *inode, struct file *file)
427{
428 struct snd_monitor_file *df = NULL, *_df;
429
430 spin_lock(&shutdown_lock);
431 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
432 if (_df->file == file) {
433 df = _df;
434 list_del_init(&df->shutdown_list);
435 break;
436 }
437 }
438 spin_unlock(&shutdown_lock);
439
440 if (likely(df)) {
441 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
442 df->disconnected_f_op->fasync(-1, file, 0);
443 return df->disconnected_f_op->release(inode, file);
444 }
445
446 panic("%s(%p, %p) failed!", __func__, inode, file);
447}
448
449static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
450{
451 return EPOLLERR | EPOLLNVAL;
452}
453
454static long snd_disconnect_ioctl(struct file *file,
455 unsigned int cmd, unsigned long arg)
456{
457 return -ENODEV;
458}
459
460static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
461{
462 return -ENODEV;
463}
464
465static int snd_disconnect_fasync(int fd, struct file *file, int on)
466{
467 return -ENODEV;
468}
469
470static const struct file_operations snd_shutdown_f_ops =
471{
472 .owner = THIS_MODULE,
473 .llseek = snd_disconnect_llseek,
474 .read = snd_disconnect_read,
475 .write = snd_disconnect_write,
476 .release = snd_disconnect_release,
477 .poll = snd_disconnect_poll,
478 .unlocked_ioctl = snd_disconnect_ioctl,
479#ifdef CONFIG_COMPAT
480 .compat_ioctl = snd_disconnect_ioctl,
481#endif
482 .mmap = snd_disconnect_mmap,
483 .fasync = snd_disconnect_fasync
484};
485
486/**
487 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
488 * @card: soundcard structure
489 *
490 * Disconnects all APIs from the file-operations (user space).
491 *
492 * Return: Zero, otherwise a negative error code.
493 *
494 * Note: The current implementation replaces all active file->f_op with special
495 * dummy file operations (they do nothing except release).
496 */
497void snd_card_disconnect(struct snd_card *card)
498{
499 struct snd_monitor_file *mfile;
500
501 if (!card)
502 return;
503
504 spin_lock(&card->files_lock);
505 if (card->shutdown) {
506 spin_unlock(&card->files_lock);
507 return;
508 }
509 card->shutdown = 1;
510
511 /* replace file->f_op with special dummy operations */
512 list_for_each_entry(mfile, &card->files_list, list) {
513 /* it's critical part, use endless loop */
514 /* we have no room to fail */
515 mfile->disconnected_f_op = mfile->file->f_op;
516
517 spin_lock(&shutdown_lock);
518 list_add(&mfile->shutdown_list, &shutdown_files);
519 spin_unlock(&shutdown_lock);
520
521 mfile->file->f_op = &snd_shutdown_f_ops;
522 fops_get(mfile->file->f_op);
523 }
524 spin_unlock(&card->files_lock);
525
526 /* notify all connected devices about disconnection */
527 /* at this point, they cannot respond to any calls except release() */
528
529#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
530 if (snd_mixer_oss_notify_callback)
531 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
532#endif
533
534 /* notify all devices that we are disconnected */
535 snd_device_disconnect_all(card);
536
537 if (card->sync_irq > 0)
538 synchronize_irq(card->sync_irq);
539
540 snd_info_card_disconnect(card);
541 if (card->registered) {
542 device_del(&card->card_dev);
543 card->registered = false;
544 }
545
546 /* disable fops (user space) operations for ALSA API */
547 mutex_lock(&snd_card_mutex);
548 snd_cards[card->number] = NULL;
549 clear_bit(card->number, snd_cards_lock);
550 mutex_unlock(&snd_card_mutex);
551
552#ifdef CONFIG_PM
553 wake_up(&card->power_sleep);
554 snd_power_sync_ref(card);
555#endif
556}
557EXPORT_SYMBOL(snd_card_disconnect);
558
559/**
560 * snd_card_disconnect_sync - disconnect card and wait until files get closed
561 * @card: card object to disconnect
562 *
563 * This calls snd_card_disconnect() for disconnecting all belonging components
564 * and waits until all pending files get closed.
565 * It assures that all accesses from user-space finished so that the driver
566 * can release its resources gracefully.
567 */
568void snd_card_disconnect_sync(struct snd_card *card)
569{
570 snd_card_disconnect(card);
571
572 spin_lock_irq(&card->files_lock);
573 wait_event_lock_irq(card->remove_sleep,
574 list_empty(&card->files_list),
575 card->files_lock);
576 spin_unlock_irq(&card->files_lock);
577}
578EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
579
580static int snd_card_do_free(struct snd_card *card)
581{
582 card->releasing = true;
583#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
584 if (snd_mixer_oss_notify_callback)
585 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
586#endif
587 snd_device_free_all(card);
588 if (card->private_free)
589 card->private_free(card);
590 if (snd_info_card_free(card) < 0) {
591 dev_warn(card->dev, "unable to free card info\n");
592 /* Not fatal error */
593 }
594#ifdef CONFIG_SND_DEBUG
595 debugfs_remove(card->debugfs_root);
596 card->debugfs_root = NULL;
597#endif
598 if (card->release_completion)
599 complete(card->release_completion);
600 if (!card->managed)
601 kfree(card);
602 return 0;
603}
604
605/**
606 * snd_card_free_when_closed - Disconnect the card, free it later eventually
607 * @card: soundcard structure
608 *
609 * Unlike snd_card_free(), this function doesn't try to release the card
610 * resource immediately, but tries to disconnect at first. When the card
611 * is still in use, the function returns before freeing the resources.
612 * The card resources will be freed when the refcount gets to zero.
613 *
614 * Return: zero if successful, or a negative error code
615 */
616void snd_card_free_when_closed(struct snd_card *card)
617{
618 if (!card)
619 return;
620
621 snd_card_disconnect(card);
622 put_device(&card->card_dev);
623 return;
624}
625EXPORT_SYMBOL(snd_card_free_when_closed);
626
627/**
628 * snd_card_free - frees given soundcard structure
629 * @card: soundcard structure
630 *
631 * This function releases the soundcard structure and the all assigned
632 * devices automatically. That is, you don't have to release the devices
633 * by yourself.
634 *
635 * This function waits until the all resources are properly released.
636 *
637 * Return: Zero. Frees all associated devices and frees the control
638 * interface associated to given soundcard.
639 */
640void snd_card_free(struct snd_card *card)
641{
642 DECLARE_COMPLETION_ONSTACK(released);
643
644 /* The call of snd_card_free() is allowed from various code paths;
645 * a manual call from the driver and the call via devres_free, and
646 * we need to avoid double-free. Moreover, the release via devres
647 * may call snd_card_free() twice due to its nature, we need to have
648 * the check here at the beginning.
649 */
650 if (card->releasing)
651 return;
652
653 card->release_completion = &released;
654 snd_card_free_when_closed(card);
655
656 /* wait, until all devices are ready for the free operation */
657 wait_for_completion(&released);
658}
659EXPORT_SYMBOL(snd_card_free);
660
661/* retrieve the last word of shortname or longname */
662static const char *retrieve_id_from_card_name(const char *name)
663{
664 const char *spos = name;
665
666 while (*name) {
667 if (isspace(*name) && isalnum(name[1]))
668 spos = name + 1;
669 name++;
670 }
671 return spos;
672}
673
674/* return true if the given id string doesn't conflict any other card ids */
675static bool card_id_ok(struct snd_card *card, const char *id)
676{
677 int i;
678 if (!snd_info_check_reserved_words(id))
679 return false;
680 for (i = 0; i < snd_ecards_limit; i++) {
681 if (snd_cards[i] && snd_cards[i] != card &&
682 !strcmp(snd_cards[i]->id, id))
683 return false;
684 }
685 return true;
686}
687
688/* copy to card->id only with valid letters from nid */
689static void copy_valid_id_string(struct snd_card *card, const char *src,
690 const char *nid)
691{
692 char *id = card->id;
693
694 while (*nid && !isalnum(*nid))
695 nid++;
696 if (isdigit(*nid))
697 *id++ = isalpha(*src) ? *src : 'D';
698 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
699 if (isalnum(*nid))
700 *id++ = *nid;
701 nid++;
702 }
703 *id = 0;
704}
705
706/* Set card->id from the given string
707 * If the string conflicts with other ids, add a suffix to make it unique.
708 */
709static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
710 const char *nid)
711{
712 int len, loops;
713 bool is_default = false;
714 char *id;
715
716 copy_valid_id_string(card, src, nid);
717 id = card->id;
718
719 again:
720 /* use "Default" for obviously invalid strings
721 * ("card" conflicts with proc directories)
722 */
723 if (!*id || !strncmp(id, "card", 4)) {
724 strcpy(id, "Default");
725 is_default = true;
726 }
727
728 len = strlen(id);
729 for (loops = 0; loops < SNDRV_CARDS; loops++) {
730 char *spos;
731 char sfxstr[5]; /* "_012" */
732 int sfxlen;
733
734 if (card_id_ok(card, id))
735 return; /* OK */
736
737 /* Add _XYZ suffix */
738 sprintf(sfxstr, "_%X", loops + 1);
739 sfxlen = strlen(sfxstr);
740 if (len + sfxlen >= sizeof(card->id))
741 spos = id + sizeof(card->id) - sfxlen - 1;
742 else
743 spos = id + len;
744 strcpy(spos, sfxstr);
745 }
746 /* fallback to the default id */
747 if (!is_default) {
748 *id = 0;
749 goto again;
750 }
751 /* last resort... */
752 dev_err(card->dev, "unable to set card id (%s)\n", id);
753 if (card->proc_root->name)
754 strscpy(card->id, card->proc_root->name, sizeof(card->id));
755}
756
757/**
758 * snd_card_set_id - set card identification name
759 * @card: soundcard structure
760 * @nid: new identification string
761 *
762 * This function sets the card identification and checks for name
763 * collisions.
764 */
765void snd_card_set_id(struct snd_card *card, const char *nid)
766{
767 /* check if user specified own card->id */
768 if (card->id[0] != '\0')
769 return;
770 mutex_lock(&snd_card_mutex);
771 snd_card_set_id_no_lock(card, nid, nid);
772 mutex_unlock(&snd_card_mutex);
773}
774EXPORT_SYMBOL(snd_card_set_id);
775
776static ssize_t id_show(struct device *dev,
777 struct device_attribute *attr, char *buf)
778{
779 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
780 return sysfs_emit(buf, "%s\n", card->id);
781}
782
783static ssize_t id_store(struct device *dev, struct device_attribute *attr,
784 const char *buf, size_t count)
785{
786 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
787 char buf1[sizeof(card->id)];
788 size_t copy = count > sizeof(card->id) - 1 ?
789 sizeof(card->id) - 1 : count;
790 size_t idx;
791 int c;
792
793 for (idx = 0; idx < copy; idx++) {
794 c = buf[idx];
795 if (!isalnum(c) && c != '_' && c != '-')
796 return -EINVAL;
797 }
798 memcpy(buf1, buf, copy);
799 buf1[copy] = '\0';
800 mutex_lock(&snd_card_mutex);
801 if (!card_id_ok(NULL, buf1)) {
802 mutex_unlock(&snd_card_mutex);
803 return -EEXIST;
804 }
805 strcpy(card->id, buf1);
806 snd_info_card_id_change(card);
807 mutex_unlock(&snd_card_mutex);
808
809 return count;
810}
811
812static DEVICE_ATTR_RW(id);
813
814static ssize_t number_show(struct device *dev,
815 struct device_attribute *attr, char *buf)
816{
817 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
818 return sysfs_emit(buf, "%i\n", card->number);
819}
820
821static DEVICE_ATTR_RO(number);
822
823static struct attribute *card_dev_attrs[] = {
824 &dev_attr_id.attr,
825 &dev_attr_number.attr,
826 NULL
827};
828
829static const struct attribute_group card_dev_attr_group = {
830 .attrs = card_dev_attrs,
831};
832
833/**
834 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
835 * @card: card instance
836 * @group: attribute group to append
837 *
838 * Return: zero if successful, or a negative error code
839 */
840int snd_card_add_dev_attr(struct snd_card *card,
841 const struct attribute_group *group)
842{
843 int i;
844
845 /* loop for (arraysize-1) here to keep NULL at the last entry */
846 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
847 if (!card->dev_groups[i]) {
848 card->dev_groups[i] = group;
849 return 0;
850 }
851 }
852
853 dev_err(card->dev, "Too many groups assigned\n");
854 return -ENOSPC;
855}
856EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
857
858static void trigger_card_free(void *data)
859{
860 snd_card_free(data);
861}
862
863/**
864 * snd_card_register - register the soundcard
865 * @card: soundcard structure
866 *
867 * This function registers all the devices assigned to the soundcard.
868 * Until calling this, the ALSA control interface is blocked from the
869 * external accesses. Thus, you should call this function at the end
870 * of the initialization of the card.
871 *
872 * Return: Zero otherwise a negative error code if the registration failed.
873 */
874int snd_card_register(struct snd_card *card)
875{
876 int err;
877
878 if (snd_BUG_ON(!card))
879 return -EINVAL;
880
881 if (!card->registered) {
882 err = device_add(&card->card_dev);
883 if (err < 0)
884 return err;
885 card->registered = true;
886 } else {
887 if (card->managed)
888 devm_remove_action(card->dev, trigger_card_free, card);
889 }
890
891 if (card->managed) {
892 err = devm_add_action(card->dev, trigger_card_free, card);
893 if (err < 0)
894 return err;
895 }
896
897 err = snd_device_register_all(card);
898 if (err < 0)
899 return err;
900 mutex_lock(&snd_card_mutex);
901 if (snd_cards[card->number]) {
902 /* already registered */
903 mutex_unlock(&snd_card_mutex);
904 return snd_info_card_register(card); /* register pending info */
905 }
906 if (*card->id) {
907 /* make a unique id name from the given string */
908 char tmpid[sizeof(card->id)];
909 memcpy(tmpid, card->id, sizeof(card->id));
910 snd_card_set_id_no_lock(card, tmpid, tmpid);
911 } else {
912 /* create an id from either shortname or longname */
913 const char *src;
914 src = *card->shortname ? card->shortname : card->longname;
915 snd_card_set_id_no_lock(card, src,
916 retrieve_id_from_card_name(src));
917 }
918 snd_cards[card->number] = card;
919 mutex_unlock(&snd_card_mutex);
920 err = snd_info_card_register(card);
921 if (err < 0)
922 return err;
923
924#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
925 if (snd_mixer_oss_notify_callback)
926 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
927#endif
928 return 0;
929}
930EXPORT_SYMBOL(snd_card_register);
931
932#ifdef CONFIG_SND_PROC_FS
933static void snd_card_info_read(struct snd_info_entry *entry,
934 struct snd_info_buffer *buffer)
935{
936 int idx, count;
937 struct snd_card *card;
938
939 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
940 mutex_lock(&snd_card_mutex);
941 card = snd_cards[idx];
942 if (card) {
943 count++;
944 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
945 idx,
946 card->id,
947 card->driver,
948 card->shortname);
949 snd_iprintf(buffer, " %s\n",
950 card->longname);
951 }
952 mutex_unlock(&snd_card_mutex);
953 }
954 if (!count)
955 snd_iprintf(buffer, "--- no soundcards ---\n");
956}
957
958#ifdef CONFIG_SND_OSSEMUL
959void snd_card_info_read_oss(struct snd_info_buffer *buffer)
960{
961 int idx, count;
962 struct snd_card *card;
963
964 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
965 mutex_lock(&snd_card_mutex);
966 card = snd_cards[idx];
967 if (card) {
968 count++;
969 snd_iprintf(buffer, "%s\n", card->longname);
970 }
971 mutex_unlock(&snd_card_mutex);
972 }
973 if (!count) {
974 snd_iprintf(buffer, "--- no soundcards ---\n");
975 }
976}
977
978#endif
979
980#ifdef MODULE
981static void snd_card_module_info_read(struct snd_info_entry *entry,
982 struct snd_info_buffer *buffer)
983{
984 int idx;
985 struct snd_card *card;
986
987 for (idx = 0; idx < SNDRV_CARDS; idx++) {
988 mutex_lock(&snd_card_mutex);
989 card = snd_cards[idx];
990 if (card)
991 snd_iprintf(buffer, "%2i %s\n",
992 idx, card->module->name);
993 mutex_unlock(&snd_card_mutex);
994 }
995}
996#endif
997
998int __init snd_card_info_init(void)
999{
1000 struct snd_info_entry *entry;
1001
1002 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
1003 if (! entry)
1004 return -ENOMEM;
1005 entry->c.text.read = snd_card_info_read;
1006 if (snd_info_register(entry) < 0)
1007 return -ENOMEM; /* freed in error path */
1008
1009#ifdef MODULE
1010 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1011 if (!entry)
1012 return -ENOMEM;
1013 entry->c.text.read = snd_card_module_info_read;
1014 if (snd_info_register(entry) < 0)
1015 return -ENOMEM; /* freed in error path */
1016#endif
1017
1018 return 0;
1019}
1020#endif /* CONFIG_SND_PROC_FS */
1021
1022/**
1023 * snd_component_add - add a component string
1024 * @card: soundcard structure
1025 * @component: the component id string
1026 *
1027 * This function adds the component id string to the supported list.
1028 * The component can be referred from the alsa-lib.
1029 *
1030 * Return: Zero otherwise a negative error code.
1031 */
1032
1033int snd_component_add(struct snd_card *card, const char *component)
1034{
1035 char *ptr;
1036 int len = strlen(component);
1037
1038 ptr = strstr(card->components, component);
1039 if (ptr != NULL) {
1040 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1041 return 1;
1042 }
1043 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1044 snd_BUG();
1045 return -ENOMEM;
1046 }
1047 if (card->components[0] != '\0')
1048 strcat(card->components, " ");
1049 strcat(card->components, component);
1050 return 0;
1051}
1052EXPORT_SYMBOL(snd_component_add);
1053
1054/**
1055 * snd_card_file_add - add the file to the file list of the card
1056 * @card: soundcard structure
1057 * @file: file pointer
1058 *
1059 * This function adds the file to the file linked-list of the card.
1060 * This linked-list is used to keep tracking the connection state,
1061 * and to avoid the release of busy resources by hotplug.
1062 *
1063 * Return: zero or a negative error code.
1064 */
1065int snd_card_file_add(struct snd_card *card, struct file *file)
1066{
1067 struct snd_monitor_file *mfile;
1068
1069 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1070 if (mfile == NULL)
1071 return -ENOMEM;
1072 mfile->file = file;
1073 mfile->disconnected_f_op = NULL;
1074 INIT_LIST_HEAD(&mfile->shutdown_list);
1075 spin_lock(&card->files_lock);
1076 if (card->shutdown) {
1077 spin_unlock(&card->files_lock);
1078 kfree(mfile);
1079 return -ENODEV;
1080 }
1081 list_add(&mfile->list, &card->files_list);
1082 get_device(&card->card_dev);
1083 spin_unlock(&card->files_lock);
1084 return 0;
1085}
1086EXPORT_SYMBOL(snd_card_file_add);
1087
1088/**
1089 * snd_card_file_remove - remove the file from the file list
1090 * @card: soundcard structure
1091 * @file: file pointer
1092 *
1093 * This function removes the file formerly added to the card via
1094 * snd_card_file_add() function.
1095 * If all files are removed and snd_card_free_when_closed() was
1096 * called beforehand, it processes the pending release of
1097 * resources.
1098 *
1099 * Return: Zero or a negative error code.
1100 */
1101int snd_card_file_remove(struct snd_card *card, struct file *file)
1102{
1103 struct snd_monitor_file *mfile, *found = NULL;
1104
1105 spin_lock(&card->files_lock);
1106 list_for_each_entry(mfile, &card->files_list, list) {
1107 if (mfile->file == file) {
1108 list_del(&mfile->list);
1109 spin_lock(&shutdown_lock);
1110 list_del(&mfile->shutdown_list);
1111 spin_unlock(&shutdown_lock);
1112 if (mfile->disconnected_f_op)
1113 fops_put(mfile->disconnected_f_op);
1114 found = mfile;
1115 break;
1116 }
1117 }
1118 if (list_empty(&card->files_list))
1119 wake_up_all(&card->remove_sleep);
1120 spin_unlock(&card->files_lock);
1121 if (!found) {
1122 dev_err(card->dev, "card file remove problem (%p)\n", file);
1123 return -ENOENT;
1124 }
1125 kfree(found);
1126 put_device(&card->card_dev);
1127 return 0;
1128}
1129EXPORT_SYMBOL(snd_card_file_remove);
1130
1131#ifdef CONFIG_PM
1132/**
1133 * snd_power_ref_and_wait - wait until the card gets powered up
1134 * @card: soundcard structure
1135 *
1136 * Take the power_ref reference count of the given card, and
1137 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1138 * The refcount is down again while sleeping until power-up, hence this
1139 * function can be used for syncing the floating control ops accesses,
1140 * typically around calling control ops.
1141 *
1142 * The caller needs to pull down the refcount via snd_power_unref() later
1143 * no matter whether the error is returned from this function or not.
1144 *
1145 * Return: Zero if successful, or a negative error code.
1146 */
1147int snd_power_ref_and_wait(struct snd_card *card)
1148{
1149 snd_power_ref(card);
1150 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1151 return 0;
1152 wait_event_cmd(card->power_sleep,
1153 card->shutdown ||
1154 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1155 snd_power_unref(card), snd_power_ref(card));
1156 return card->shutdown ? -ENODEV : 0;
1157}
1158EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1159
1160/**
1161 * snd_power_wait - wait until the card gets powered up (old form)
1162 * @card: soundcard structure
1163 *
1164 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1165 *
1166 * Return: Zero if successful, or a negative error code.
1167 */
1168int snd_power_wait(struct snd_card *card)
1169{
1170 int ret;
1171
1172 ret = snd_power_ref_and_wait(card);
1173 snd_power_unref(card);
1174 return ret;
1175}
1176EXPORT_SYMBOL(snd_power_wait);
1177#endif /* CONFIG_PM */