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