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) */
25 struct 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
32 static DEFINE_SPINLOCK(shutdown_lock);
33 static LIST_HEAD(shutdown_files);
34
35 static const struct file_operations snd_shutdown_f_ops;
36
37 /* locked for registering/using */
38 static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39 static struct snd_card *snd_cards[SNDRV_CARDS];
40
41 static DEFINE_MUTEX(snd_card_mutex);
42
43 static char *slots[SNDRV_CARDS];
44 module_param_array(slots, charp, NULL, 0444);
45 MODULE_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 */
module_slot_match(struct module * module,int idx)50 static 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)
85 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87 #endif
88
check_empty_slot(struct module * module,int slot)89 static 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 */
get_slot_from_bitmask(int mask,int (* check)(struct module *,int),struct module * module)98 static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100 {
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112 }
113
114 /* the default release callback set in snd_device_initialize() below;
115 * this is just NOP for now, as almost all jobs are already done in
116 * dev_free callback of snd_device chain instead.
117 */
default_release(struct device * dev)118 static void default_release(struct device *dev)
119 {
120 }
121
122 /**
123 * snd_device_initialize - Initialize struct device for sound devices
124 * @dev: device to initialize
125 * @card: card to assign, optional
126 */
snd_device_initialize(struct device * dev,struct snd_card * card)127 void snd_device_initialize(struct device *dev, struct snd_card *card)
128 {
129 device_initialize(dev);
130 if (card)
131 dev->parent = &card->card_dev;
132 dev->class = sound_class;
133 dev->release = default_release;
134 }
135 EXPORT_SYMBOL_GPL(snd_device_initialize);
136
137 static int snd_card_init(struct snd_card *card, struct device *parent,
138 int idx, const char *xid, struct module *module,
139 size_t extra_size);
140 static int snd_card_do_free(struct snd_card *card);
141 static const struct attribute_group card_dev_attr_group;
142
release_card_device(struct device * dev)143 static void release_card_device(struct device *dev)
144 {
145 snd_card_do_free(dev_to_snd_card(dev));
146 }
147
148 /**
149 * snd_card_new - create and initialize a soundcard structure
150 * @parent: the parent device object
151 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
152 * @xid: card identification (ASCII string)
153 * @module: top level module for locking
154 * @extra_size: allocate this extra size after the main soundcard structure
155 * @card_ret: the pointer to store the created card instance
156 *
157 * The function allocates snd_card instance via kzalloc with the given
158 * space for the driver to use freely. The allocated struct is stored
159 * in the given card_ret pointer.
160 *
161 * Return: Zero if successful or a negative error code.
162 */
snd_card_new(struct device * parent,int idx,const char * xid,struct module * module,int extra_size,struct snd_card ** card_ret)163 int snd_card_new(struct device *parent, int idx, const char *xid,
164 struct module *module, int extra_size,
165 struct snd_card **card_ret)
166 {
167 struct snd_card *card;
168 int err;
169
170 if (snd_BUG_ON(!card_ret))
171 return -EINVAL;
172 *card_ret = NULL;
173
174 if (extra_size < 0)
175 extra_size = 0;
176 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
177 if (!card)
178 return -ENOMEM;
179
180 err = snd_card_init(card, parent, idx, xid, module, extra_size);
181 if (err < 0) {
182 kfree(card);
183 return err;
184 }
185
186 *card_ret = card;
187 return 0;
188 }
189 EXPORT_SYMBOL(snd_card_new);
190
__snd_card_release(struct device * dev,void * data)191 static void __snd_card_release(struct device *dev, void *data)
192 {
193 snd_card_free(data);
194 }
195
196 /**
197 * snd_devm_card_new - managed snd_card object creation
198 * @parent: the parent device object
199 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
200 * @xid: card identification (ASCII string)
201 * @module: top level module for locking
202 * @extra_size: allocate this extra size after the main soundcard structure
203 * @card_ret: the pointer to store the created card instance
204 *
205 * This function works like snd_card_new() but manages the allocated resource
206 * via devres, i.e. you don't need to free explicitly.
207 *
208 * When a snd_card object is created with this function and registered via
209 * snd_card_register(), the very first devres action to call snd_card_free()
210 * is added automatically. In that way, the resource disconnection is assured
211 * at first, then released in the expected order.
212 *
213 * If an error happens at the probe before snd_card_register() is called and
214 * there have been other devres resources, you'd need to free the card manually
215 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
216 * devres call orders. You can use snd_card_free_on_error() helper for
217 * handling it more easily.
218 */
snd_devm_card_new(struct device * parent,int idx,const char * xid,struct module * module,size_t extra_size,struct snd_card ** card_ret)219 int snd_devm_card_new(struct device *parent, int idx, const char *xid,
220 struct module *module, size_t extra_size,
221 struct snd_card **card_ret)
222 {
223 struct snd_card *card;
224 int err;
225
226 *card_ret = NULL;
227 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
228 GFP_KERNEL);
229 if (!card)
230 return -ENOMEM;
231 card->managed = true;
232 err = snd_card_init(card, parent, idx, xid, module, extra_size);
233 if (err < 0) {
234 devres_free(card);
235 return err;
236 }
237
238 devres_add(parent, card);
239 *card_ret = card;
240 return 0;
241 }
242 EXPORT_SYMBOL_GPL(snd_devm_card_new);
243
244 /**
245 * snd_card_free_on_error - a small helper for handling devm probe errors
246 * @dev: the managed device object
247 * @ret: the return code from the probe callback
248 *
249 * This function handles the explicit snd_card_free() call at the error from
250 * the probe callback. It's just a small helper for simplifying the error
251 * handling with the managed devices.
252 */
snd_card_free_on_error(struct device * dev,int ret)253 int snd_card_free_on_error(struct device *dev, int ret)
254 {
255 struct snd_card *card;
256
257 if (!ret)
258 return 0;
259 card = devres_find(dev, __snd_card_release, NULL, NULL);
260 if (card)
261 snd_card_free(card);
262 return ret;
263 }
264 EXPORT_SYMBOL_GPL(snd_card_free_on_error);
265
snd_card_init(struct snd_card * card,struct device * parent,int idx,const char * xid,struct module * module,size_t extra_size)266 static int snd_card_init(struct snd_card *card, struct device *parent,
267 int idx, const char *xid, struct module *module,
268 size_t extra_size)
269 {
270 int err;
271 #ifdef CONFIG_SND_DEBUG
272 char name[8];
273 #endif
274
275 if (extra_size > 0)
276 card->private_data = (char *)card + sizeof(struct snd_card);
277 if (xid)
278 strscpy(card->id, xid, sizeof(card->id));
279 err = 0;
280 mutex_lock(&snd_card_mutex);
281 if (idx < 0) /* first check the matching module-name slot */
282 idx = get_slot_from_bitmask(idx, module_slot_match, module);
283 if (idx < 0) /* if not matched, assign an empty slot */
284 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
285 if (idx < 0)
286 err = -ENODEV;
287 else if (idx < snd_ecards_limit) {
288 if (test_bit(idx, snd_cards_lock))
289 err = -EBUSY; /* invalid */
290 } else if (idx >= SNDRV_CARDS)
291 err = -ENODEV;
292 if (err < 0) {
293 mutex_unlock(&snd_card_mutex);
294 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
295 idx, snd_ecards_limit - 1, err);
296 return err;
297 }
298 set_bit(idx, snd_cards_lock); /* lock it */
299 if (idx >= snd_ecards_limit)
300 snd_ecards_limit = idx + 1; /* increase the limit */
301 mutex_unlock(&snd_card_mutex);
302 card->dev = parent;
303 card->number = idx;
304 #ifdef MODULE
305 WARN_ON(!module);
306 card->module = module;
307 #endif
308 INIT_LIST_HEAD(&card->devices);
309 init_rwsem(&card->controls_rwsem);
310 rwlock_init(&card->ctl_files_rwlock);
311 INIT_LIST_HEAD(&card->controls);
312 INIT_LIST_HEAD(&card->ctl_files);
313 spin_lock_init(&card->files_lock);
314 INIT_LIST_HEAD(&card->files_list);
315 mutex_init(&card->memory_mutex);
316 #ifdef CONFIG_PM
317 init_waitqueue_head(&card->power_sleep);
318 init_waitqueue_head(&card->power_ref_sleep);
319 atomic_set(&card->power_ref, 0);
320 #endif
321 init_waitqueue_head(&card->remove_sleep);
322 card->sync_irq = -1;
323
324 device_initialize(&card->card_dev);
325 card->card_dev.parent = parent;
326 card->card_dev.class = sound_class;
327 card->card_dev.release = release_card_device;
328 card->card_dev.groups = card->dev_groups;
329 card->dev_groups[0] = &card_dev_attr_group;
330 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
331 if (err < 0)
332 goto __error;
333
334 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
335 dev_driver_string(card->dev), dev_name(&card->card_dev));
336
337 /* the control interface cannot be accessed from the user space until */
338 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
339 err = snd_ctl_create(card);
340 if (err < 0) {
341 dev_err(parent, "unable to register control minors\n");
342 goto __error;
343 }
344 err = snd_info_card_create(card);
345 if (err < 0) {
346 dev_err(parent, "unable to create card info\n");
347 goto __error_ctl;
348 }
349
350 #ifdef CONFIG_SND_DEBUG
351 sprintf(name, "card%d", idx);
352 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
353 #endif
354 return 0;
355
356 __error_ctl:
357 snd_device_free_all(card);
358 __error:
359 put_device(&card->card_dev);
360 return err;
361 }
362
363 /**
364 * snd_card_ref - Get the card object from the index
365 * @idx: the card index
366 *
367 * Returns a card object corresponding to the given index or NULL if not found.
368 * Release the object via snd_card_unref().
369 */
snd_card_ref(int idx)370 struct snd_card *snd_card_ref(int idx)
371 {
372 struct snd_card *card;
373
374 mutex_lock(&snd_card_mutex);
375 card = snd_cards[idx];
376 if (card)
377 get_device(&card->card_dev);
378 mutex_unlock(&snd_card_mutex);
379 return card;
380 }
381 EXPORT_SYMBOL_GPL(snd_card_ref);
382
383 /* return non-zero if a card is already locked */
snd_card_locked(int card)384 int snd_card_locked(int card)
385 {
386 int locked;
387
388 mutex_lock(&snd_card_mutex);
389 locked = test_bit(card, snd_cards_lock);
390 mutex_unlock(&snd_card_mutex);
391 return locked;
392 }
393
snd_disconnect_llseek(struct file * file,loff_t offset,int orig)394 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
395 {
396 return -ENODEV;
397 }
398
snd_disconnect_read(struct file * file,char __user * buf,size_t count,loff_t * offset)399 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
400 size_t count, loff_t *offset)
401 {
402 return -ENODEV;
403 }
404
snd_disconnect_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)405 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
406 size_t count, loff_t *offset)
407 {
408 return -ENODEV;
409 }
410
snd_disconnect_release(struct inode * inode,struct file * file)411 static int snd_disconnect_release(struct inode *inode, struct file *file)
412 {
413 struct snd_monitor_file *df = NULL, *_df;
414
415 spin_lock(&shutdown_lock);
416 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
417 if (_df->file == file) {
418 df = _df;
419 list_del_init(&df->shutdown_list);
420 break;
421 }
422 }
423 spin_unlock(&shutdown_lock);
424
425 if (likely(df)) {
426 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
427 df->disconnected_f_op->fasync(-1, file, 0);
428 return df->disconnected_f_op->release(inode, file);
429 }
430
431 panic("%s(%p, %p) failed!", __func__, inode, file);
432 }
433
snd_disconnect_poll(struct file * file,poll_table * wait)434 static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
435 {
436 return EPOLLERR | EPOLLNVAL;
437 }
438
snd_disconnect_ioctl(struct file * file,unsigned int cmd,unsigned long arg)439 static long snd_disconnect_ioctl(struct file *file,
440 unsigned int cmd, unsigned long arg)
441 {
442 return -ENODEV;
443 }
444
snd_disconnect_mmap(struct file * file,struct vm_area_struct * vma)445 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
446 {
447 return -ENODEV;
448 }
449
snd_disconnect_fasync(int fd,struct file * file,int on)450 static int snd_disconnect_fasync(int fd, struct file *file, int on)
451 {
452 return -ENODEV;
453 }
454
455 static const struct file_operations snd_shutdown_f_ops =
456 {
457 .owner = THIS_MODULE,
458 .llseek = snd_disconnect_llseek,
459 .read = snd_disconnect_read,
460 .write = snd_disconnect_write,
461 .release = snd_disconnect_release,
462 .poll = snd_disconnect_poll,
463 .unlocked_ioctl = snd_disconnect_ioctl,
464 #ifdef CONFIG_COMPAT
465 .compat_ioctl = snd_disconnect_ioctl,
466 #endif
467 .mmap = snd_disconnect_mmap,
468 .fasync = snd_disconnect_fasync
469 };
470
471 /**
472 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
473 * @card: soundcard structure
474 *
475 * Disconnects all APIs from the file-operations (user space).
476 *
477 * Return: Zero, otherwise a negative error code.
478 *
479 * Note: The current implementation replaces all active file->f_op with special
480 * dummy file operations (they do nothing except release).
481 */
snd_card_disconnect(struct snd_card * card)482 int snd_card_disconnect(struct snd_card *card)
483 {
484 struct snd_monitor_file *mfile;
485
486 if (!card)
487 return -EINVAL;
488
489 spin_lock(&card->files_lock);
490 if (card->shutdown) {
491 spin_unlock(&card->files_lock);
492 return 0;
493 }
494 card->shutdown = 1;
495
496 /* replace file->f_op with special dummy operations */
497 list_for_each_entry(mfile, &card->files_list, list) {
498 /* it's critical part, use endless loop */
499 /* we have no room to fail */
500 mfile->disconnected_f_op = mfile->file->f_op;
501
502 spin_lock(&shutdown_lock);
503 list_add(&mfile->shutdown_list, &shutdown_files);
504 spin_unlock(&shutdown_lock);
505
506 mfile->file->f_op = &snd_shutdown_f_ops;
507 fops_get(mfile->file->f_op);
508 }
509 spin_unlock(&card->files_lock);
510
511 /* notify all connected devices about disconnection */
512 /* at this point, they cannot respond to any calls except release() */
513
514 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
515 if (snd_mixer_oss_notify_callback)
516 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
517 #endif
518
519 /* notify all devices that we are disconnected */
520 snd_device_disconnect_all(card);
521
522 if (card->sync_irq > 0)
523 synchronize_irq(card->sync_irq);
524
525 snd_info_card_disconnect(card);
526 if (card->registered) {
527 device_del(&card->card_dev);
528 card->registered = false;
529 }
530
531 /* disable fops (user space) operations for ALSA API */
532 mutex_lock(&snd_card_mutex);
533 snd_cards[card->number] = NULL;
534 clear_bit(card->number, snd_cards_lock);
535 mutex_unlock(&snd_card_mutex);
536
537 #ifdef CONFIG_PM
538 wake_up(&card->power_sleep);
539 snd_power_sync_ref(card);
540 #endif
541 return 0;
542 }
543 EXPORT_SYMBOL(snd_card_disconnect);
544
545 /**
546 * snd_card_disconnect_sync - disconnect card and wait until files get closed
547 * @card: card object to disconnect
548 *
549 * This calls snd_card_disconnect() for disconnecting all belonging components
550 * and waits until all pending files get closed.
551 * It assures that all accesses from user-space finished so that the driver
552 * can release its resources gracefully.
553 */
snd_card_disconnect_sync(struct snd_card * card)554 void snd_card_disconnect_sync(struct snd_card *card)
555 {
556 int err;
557
558 err = snd_card_disconnect(card);
559 if (err < 0) {
560 dev_err(card->dev,
561 "snd_card_disconnect error (%d), skipping sync\n",
562 err);
563 return;
564 }
565
566 spin_lock_irq(&card->files_lock);
567 wait_event_lock_irq(card->remove_sleep,
568 list_empty(&card->files_list),
569 card->files_lock);
570 spin_unlock_irq(&card->files_lock);
571 }
572 EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
573
snd_card_do_free(struct snd_card * card)574 static int snd_card_do_free(struct snd_card *card)
575 {
576 card->releasing = true;
577 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
578 if (snd_mixer_oss_notify_callback)
579 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
580 #endif
581 snd_device_free_all(card);
582 if (card->private_free)
583 card->private_free(card);
584 if (snd_info_card_free(card) < 0) {
585 dev_warn(card->dev, "unable to free card info\n");
586 /* Not fatal error */
587 }
588 #ifdef CONFIG_SND_DEBUG
589 debugfs_remove(card->debugfs_root);
590 card->debugfs_root = NULL;
591 #endif
592 if (card->release_completion)
593 complete(card->release_completion);
594 if (!card->managed)
595 kfree(card);
596 return 0;
597 }
598
599 /**
600 * snd_card_free_when_closed - Disconnect the card, free it later eventually
601 * @card: soundcard structure
602 *
603 * Unlike snd_card_free(), this function doesn't try to release the card
604 * resource immediately, but tries to disconnect at first. When the card
605 * is still in use, the function returns before freeing the resources.
606 * The card resources will be freed when the refcount gets to zero.
607 */
snd_card_free_when_closed(struct snd_card * card)608 int snd_card_free_when_closed(struct snd_card *card)
609 {
610 int ret = snd_card_disconnect(card);
611 if (ret)
612 return ret;
613 put_device(&card->card_dev);
614 return 0;
615 }
616 EXPORT_SYMBOL(snd_card_free_when_closed);
617
618 /**
619 * snd_card_free - frees given soundcard structure
620 * @card: soundcard structure
621 *
622 * This function releases the soundcard structure and the all assigned
623 * devices automatically. That is, you don't have to release the devices
624 * by yourself.
625 *
626 * This function waits until the all resources are properly released.
627 *
628 * Return: Zero. Frees all associated devices and frees the control
629 * interface associated to given soundcard.
630 */
snd_card_free(struct snd_card * card)631 int snd_card_free(struct snd_card *card)
632 {
633 DECLARE_COMPLETION_ONSTACK(released);
634 int ret;
635
636 /* The call of snd_card_free() is allowed from various code paths;
637 * a manual call from the driver and the call via devres_free, and
638 * we need to avoid double-free. Moreover, the release via devres
639 * may call snd_card_free() twice due to its nature, we need to have
640 * the check here at the beginning.
641 */
642 if (card->releasing)
643 return 0;
644
645 card->release_completion = &released;
646 ret = snd_card_free_when_closed(card);
647 if (ret)
648 return ret;
649 /* wait, until all devices are ready for the free operation */
650 wait_for_completion(&released);
651
652 return 0;
653 }
654 EXPORT_SYMBOL(snd_card_free);
655
656 /* retrieve the last word of shortname or longname */
retrieve_id_from_card_name(const char * name)657 static const char *retrieve_id_from_card_name(const char *name)
658 {
659 const char *spos = name;
660
661 while (*name) {
662 if (isspace(*name) && isalnum(name[1]))
663 spos = name + 1;
664 name++;
665 }
666 return spos;
667 }
668
669 /* return true if the given id string doesn't conflict any other card ids */
card_id_ok(struct snd_card * card,const char * id)670 static bool card_id_ok(struct snd_card *card, const char *id)
671 {
672 int i;
673 if (!snd_info_check_reserved_words(id))
674 return false;
675 for (i = 0; i < snd_ecards_limit; i++) {
676 if (snd_cards[i] && snd_cards[i] != card &&
677 !strcmp(snd_cards[i]->id, id))
678 return false;
679 }
680 return true;
681 }
682
683 /* copy to card->id only with valid letters from nid */
copy_valid_id_string(struct snd_card * card,const char * src,const char * nid)684 static void copy_valid_id_string(struct snd_card *card, const char *src,
685 const char *nid)
686 {
687 char *id = card->id;
688
689 while (*nid && !isalnum(*nid))
690 nid++;
691 if (isdigit(*nid))
692 *id++ = isalpha(*src) ? *src : 'D';
693 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
694 if (isalnum(*nid))
695 *id++ = *nid;
696 nid++;
697 }
698 *id = 0;
699 }
700
701 /* Set card->id from the given string
702 * If the string conflicts with other ids, add a suffix to make it unique.
703 */
snd_card_set_id_no_lock(struct snd_card * card,const char * src,const char * nid)704 static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
705 const char *nid)
706 {
707 int len, loops;
708 bool is_default = false;
709 char *id;
710
711 copy_valid_id_string(card, src, nid);
712 id = card->id;
713
714 again:
715 /* use "Default" for obviously invalid strings
716 * ("card" conflicts with proc directories)
717 */
718 if (!*id || !strncmp(id, "card", 4)) {
719 strcpy(id, "Default");
720 is_default = true;
721 }
722
723 len = strlen(id);
724 for (loops = 0; loops < SNDRV_CARDS; loops++) {
725 char *spos;
726 char sfxstr[5]; /* "_012" */
727 int sfxlen;
728
729 if (card_id_ok(card, id))
730 return; /* OK */
731
732 /* Add _XYZ suffix */
733 sprintf(sfxstr, "_%X", loops + 1);
734 sfxlen = strlen(sfxstr);
735 if (len + sfxlen >= sizeof(card->id))
736 spos = id + sizeof(card->id) - sfxlen - 1;
737 else
738 spos = id + len;
739 strcpy(spos, sfxstr);
740 }
741 /* fallback to the default id */
742 if (!is_default) {
743 *id = 0;
744 goto again;
745 }
746 /* last resort... */
747 dev_err(card->dev, "unable to set card id (%s)\n", id);
748 if (card->proc_root->name)
749 strscpy(card->id, card->proc_root->name, sizeof(card->id));
750 }
751
752 /**
753 * snd_card_set_id - set card identification name
754 * @card: soundcard structure
755 * @nid: new identification string
756 *
757 * This function sets the card identification and checks for name
758 * collisions.
759 */
snd_card_set_id(struct snd_card * card,const char * nid)760 void snd_card_set_id(struct snd_card *card, const char *nid)
761 {
762 /* check if user specified own card->id */
763 if (card->id[0] != '\0')
764 return;
765 mutex_lock(&snd_card_mutex);
766 snd_card_set_id_no_lock(card, nid, nid);
767 mutex_unlock(&snd_card_mutex);
768 }
769 EXPORT_SYMBOL(snd_card_set_id);
770
id_show(struct device * dev,struct device_attribute * attr,char * buf)771 static ssize_t id_show(struct device *dev,
772 struct device_attribute *attr, char *buf)
773 {
774 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
775 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
776 }
777
id_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)778 static ssize_t id_store(struct device *dev, struct device_attribute *attr,
779 const char *buf, size_t count)
780 {
781 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
782 char buf1[sizeof(card->id)];
783 size_t copy = count > sizeof(card->id) - 1 ?
784 sizeof(card->id) - 1 : count;
785 size_t idx;
786 int c;
787
788 for (idx = 0; idx < copy; idx++) {
789 c = buf[idx];
790 if (!isalnum(c) && c != '_' && c != '-')
791 return -EINVAL;
792 }
793 memcpy(buf1, buf, copy);
794 buf1[copy] = '\0';
795 mutex_lock(&snd_card_mutex);
796 if (!card_id_ok(NULL, buf1)) {
797 mutex_unlock(&snd_card_mutex);
798 return -EEXIST;
799 }
800 strcpy(card->id, buf1);
801 snd_info_card_id_change(card);
802 mutex_unlock(&snd_card_mutex);
803
804 return count;
805 }
806
807 static DEVICE_ATTR_RW(id);
808
number_show(struct device * dev,struct device_attribute * attr,char * buf)809 static ssize_t number_show(struct device *dev,
810 struct device_attribute *attr, char *buf)
811 {
812 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
813 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
814 }
815
816 static DEVICE_ATTR_RO(number);
817
818 static struct attribute *card_dev_attrs[] = {
819 &dev_attr_id.attr,
820 &dev_attr_number.attr,
821 NULL
822 };
823
824 static const struct attribute_group card_dev_attr_group = {
825 .attrs = card_dev_attrs,
826 };
827
828 /**
829 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
830 * @card: card instance
831 * @group: attribute group to append
832 */
snd_card_add_dev_attr(struct snd_card * card,const struct attribute_group * group)833 int snd_card_add_dev_attr(struct snd_card *card,
834 const struct attribute_group *group)
835 {
836 int i;
837
838 /* loop for (arraysize-1) here to keep NULL at the last entry */
839 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
840 if (!card->dev_groups[i]) {
841 card->dev_groups[i] = group;
842 return 0;
843 }
844 }
845
846 dev_err(card->dev, "Too many groups assigned\n");
847 return -ENOSPC;
848 }
849 EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
850
trigger_card_free(void * data)851 static void trigger_card_free(void *data)
852 {
853 snd_card_free(data);
854 }
855
856 /**
857 * snd_card_register - register the soundcard
858 * @card: soundcard structure
859 *
860 * This function registers all the devices assigned to the soundcard.
861 * Until calling this, the ALSA control interface is blocked from the
862 * external accesses. Thus, you should call this function at the end
863 * of the initialization of the card.
864 *
865 * Return: Zero otherwise a negative error code if the registration failed.
866 */
snd_card_register(struct snd_card * card)867 int snd_card_register(struct snd_card *card)
868 {
869 int err;
870
871 if (snd_BUG_ON(!card))
872 return -EINVAL;
873
874 if (!card->registered) {
875 err = device_add(&card->card_dev);
876 if (err < 0)
877 return err;
878 card->registered = true;
879 } else {
880 if (card->managed)
881 devm_remove_action(card->dev, trigger_card_free, card);
882 }
883
884 if (card->managed) {
885 err = devm_add_action(card->dev, trigger_card_free, card);
886 if (err < 0)
887 return err;
888 }
889
890 err = snd_device_register_all(card);
891 if (err < 0)
892 return err;
893 mutex_lock(&snd_card_mutex);
894 if (snd_cards[card->number]) {
895 /* already registered */
896 mutex_unlock(&snd_card_mutex);
897 return snd_info_card_register(card); /* register pending info */
898 }
899 if (*card->id) {
900 /* make a unique id name from the given string */
901 char tmpid[sizeof(card->id)];
902 memcpy(tmpid, card->id, sizeof(card->id));
903 snd_card_set_id_no_lock(card, tmpid, tmpid);
904 } else {
905 /* create an id from either shortname or longname */
906 const char *src;
907 src = *card->shortname ? card->shortname : card->longname;
908 snd_card_set_id_no_lock(card, src,
909 retrieve_id_from_card_name(src));
910 }
911 snd_cards[card->number] = card;
912 mutex_unlock(&snd_card_mutex);
913 err = snd_info_card_register(card);
914 if (err < 0)
915 return err;
916
917 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
918 if (snd_mixer_oss_notify_callback)
919 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
920 #endif
921 return 0;
922 }
923 EXPORT_SYMBOL(snd_card_register);
924
925 #ifdef CONFIG_SND_PROC_FS
snd_card_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)926 static void snd_card_info_read(struct snd_info_entry *entry,
927 struct snd_info_buffer *buffer)
928 {
929 int idx, count;
930 struct snd_card *card;
931
932 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
933 mutex_lock(&snd_card_mutex);
934 card = snd_cards[idx];
935 if (card) {
936 count++;
937 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
938 idx,
939 card->id,
940 card->driver,
941 card->shortname);
942 snd_iprintf(buffer, " %s\n",
943 card->longname);
944 }
945 mutex_unlock(&snd_card_mutex);
946 }
947 if (!count)
948 snd_iprintf(buffer, "--- no soundcards ---\n");
949 }
950
951 #ifdef CONFIG_SND_OSSEMUL
snd_card_info_read_oss(struct snd_info_buffer * buffer)952 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
953 {
954 int idx, count;
955 struct snd_card *card;
956
957 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
958 mutex_lock(&snd_card_mutex);
959 card = snd_cards[idx];
960 if (card) {
961 count++;
962 snd_iprintf(buffer, "%s\n", card->longname);
963 }
964 mutex_unlock(&snd_card_mutex);
965 }
966 if (!count) {
967 snd_iprintf(buffer, "--- no soundcards ---\n");
968 }
969 }
970
971 #endif
972
973 #ifdef MODULE
snd_card_module_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)974 static void snd_card_module_info_read(struct snd_info_entry *entry,
975 struct snd_info_buffer *buffer)
976 {
977 int idx;
978 struct snd_card *card;
979
980 for (idx = 0; idx < SNDRV_CARDS; idx++) {
981 mutex_lock(&snd_card_mutex);
982 card = snd_cards[idx];
983 if (card)
984 snd_iprintf(buffer, "%2i %s\n",
985 idx, card->module->name);
986 mutex_unlock(&snd_card_mutex);
987 }
988 }
989 #endif
990
snd_card_info_init(void)991 int __init snd_card_info_init(void)
992 {
993 struct snd_info_entry *entry;
994
995 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
996 if (! entry)
997 return -ENOMEM;
998 entry->c.text.read = snd_card_info_read;
999 if (snd_info_register(entry) < 0)
1000 return -ENOMEM; /* freed in error path */
1001
1002 #ifdef MODULE
1003 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1004 if (!entry)
1005 return -ENOMEM;
1006 entry->c.text.read = snd_card_module_info_read;
1007 if (snd_info_register(entry) < 0)
1008 return -ENOMEM; /* freed in error path */
1009 #endif
1010
1011 return 0;
1012 }
1013 #endif /* CONFIG_SND_PROC_FS */
1014
1015 /**
1016 * snd_component_add - add a component string
1017 * @card: soundcard structure
1018 * @component: the component id string
1019 *
1020 * This function adds the component id string to the supported list.
1021 * The component can be referred from the alsa-lib.
1022 *
1023 * Return: Zero otherwise a negative error code.
1024 */
1025
snd_component_add(struct snd_card * card,const char * component)1026 int snd_component_add(struct snd_card *card, const char *component)
1027 {
1028 char *ptr;
1029 int len = strlen(component);
1030
1031 ptr = strstr(card->components, component);
1032 if (ptr != NULL) {
1033 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1034 return 1;
1035 }
1036 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1037 snd_BUG();
1038 return -ENOMEM;
1039 }
1040 if (card->components[0] != '\0')
1041 strcat(card->components, " ");
1042 strcat(card->components, component);
1043 return 0;
1044 }
1045 EXPORT_SYMBOL(snd_component_add);
1046
1047 /**
1048 * snd_card_file_add - add the file to the file list of the card
1049 * @card: soundcard structure
1050 * @file: file pointer
1051 *
1052 * This function adds the file to the file linked-list of the card.
1053 * This linked-list is used to keep tracking the connection state,
1054 * and to avoid the release of busy resources by hotplug.
1055 *
1056 * Return: zero or a negative error code.
1057 */
snd_card_file_add(struct snd_card * card,struct file * file)1058 int snd_card_file_add(struct snd_card *card, struct file *file)
1059 {
1060 struct snd_monitor_file *mfile;
1061
1062 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1063 if (mfile == NULL)
1064 return -ENOMEM;
1065 mfile->file = file;
1066 mfile->disconnected_f_op = NULL;
1067 INIT_LIST_HEAD(&mfile->shutdown_list);
1068 spin_lock(&card->files_lock);
1069 if (card->shutdown) {
1070 spin_unlock(&card->files_lock);
1071 kfree(mfile);
1072 return -ENODEV;
1073 }
1074 list_add(&mfile->list, &card->files_list);
1075 get_device(&card->card_dev);
1076 spin_unlock(&card->files_lock);
1077 return 0;
1078 }
1079 EXPORT_SYMBOL(snd_card_file_add);
1080
1081 /**
1082 * snd_card_file_remove - remove the file from the file list
1083 * @card: soundcard structure
1084 * @file: file pointer
1085 *
1086 * This function removes the file formerly added to the card via
1087 * snd_card_file_add() function.
1088 * If all files are removed and snd_card_free_when_closed() was
1089 * called beforehand, it processes the pending release of
1090 * resources.
1091 *
1092 * Return: Zero or a negative error code.
1093 */
snd_card_file_remove(struct snd_card * card,struct file * file)1094 int snd_card_file_remove(struct snd_card *card, struct file *file)
1095 {
1096 struct snd_monitor_file *mfile, *found = NULL;
1097
1098 spin_lock(&card->files_lock);
1099 list_for_each_entry(mfile, &card->files_list, list) {
1100 if (mfile->file == file) {
1101 list_del(&mfile->list);
1102 spin_lock(&shutdown_lock);
1103 list_del(&mfile->shutdown_list);
1104 spin_unlock(&shutdown_lock);
1105 if (mfile->disconnected_f_op)
1106 fops_put(mfile->disconnected_f_op);
1107 found = mfile;
1108 break;
1109 }
1110 }
1111 if (list_empty(&card->files_list))
1112 wake_up_all(&card->remove_sleep);
1113 spin_unlock(&card->files_lock);
1114 if (!found) {
1115 dev_err(card->dev, "card file remove problem (%p)\n", file);
1116 return -ENOENT;
1117 }
1118 kfree(found);
1119 put_device(&card->card_dev);
1120 return 0;
1121 }
1122 EXPORT_SYMBOL(snd_card_file_remove);
1123
1124 #ifdef CONFIG_PM
1125 /**
1126 * snd_power_ref_and_wait - wait until the card gets powered up
1127 * @card: soundcard structure
1128 *
1129 * Take the power_ref reference count of the given card, and
1130 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1131 * The refcount is down again while sleeping until power-up, hence this
1132 * function can be used for syncing the floating control ops accesses,
1133 * typically around calling control ops.
1134 *
1135 * The caller needs to pull down the refcount via snd_power_unref() later
1136 * no matter whether the error is returned from this function or not.
1137 *
1138 * Return: Zero if successful, or a negative error code.
1139 */
snd_power_ref_and_wait(struct snd_card * card)1140 int snd_power_ref_and_wait(struct snd_card *card)
1141 {
1142 snd_power_ref(card);
1143 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1144 return 0;
1145 wait_event_cmd(card->power_sleep,
1146 card->shutdown ||
1147 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1148 snd_power_unref(card), snd_power_ref(card));
1149 return card->shutdown ? -ENODEV : 0;
1150 }
1151 EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1152
1153 /**
1154 * snd_power_wait - wait until the card gets powered up (old form)
1155 * @card: soundcard structure
1156 *
1157 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1158 *
1159 * Return: Zero if successful, or a negative error code.
1160 */
snd_power_wait(struct snd_card * card)1161 int snd_power_wait(struct snd_card *card)
1162 {
1163 int ret;
1164
1165 ret = snd_power_ref_and_wait(card);
1166 snd_power_unref(card);
1167 return ret;
1168 }
1169 EXPORT_SYMBOL(snd_power_wait);
1170 #endif /* CONFIG_PM */
1171