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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Information interface for ALSA driver
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/time.h>
9#include <linux/mm.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12#include <linux/module.h>
13#include <sound/core.h>
14#include <sound/minors.h>
15#include <sound/info.h>
16#include <linux/utsname.h>
17#include <linux/proc_fs.h>
18#include <linux/mutex.h>
19#include <stdarg.h>
20
21int snd_info_check_reserved_words(const char *str)
22{
23 static char *reserved[] =
24 {
25 "version",
26 "meminfo",
27 "memdebug",
28 "detect",
29 "devices",
30 "oss",
31 "cards",
32 "timers",
33 "synth",
34 "pcm",
35 "seq",
36 NULL
37 };
38 char **xstr = reserved;
39
40 while (*xstr) {
41 if (!strcmp(*xstr, str))
42 return 0;
43 xstr++;
44 }
45 if (!strncmp(str, "card", 4))
46 return 0;
47 return 1;
48}
49
50static DEFINE_MUTEX(info_mutex);
51
52struct snd_info_private_data {
53 struct snd_info_buffer *rbuffer;
54 struct snd_info_buffer *wbuffer;
55 struct snd_info_entry *entry;
56 void *file_private_data;
57};
58
59static int snd_info_version_init(void);
60static void snd_info_disconnect(struct snd_info_entry *entry);
61
62/*
63
64 */
65
66static struct snd_info_entry *snd_proc_root;
67struct snd_info_entry *snd_seq_root;
68EXPORT_SYMBOL(snd_seq_root);
69
70#ifdef CONFIG_SND_OSSEMUL
71struct snd_info_entry *snd_oss_root;
72#endif
73
74static int alloc_info_private(struct snd_info_entry *entry,
75 struct snd_info_private_data **ret)
76{
77 struct snd_info_private_data *data;
78
79 if (!entry || !entry->p)
80 return -ENODEV;
81 if (!try_module_get(entry->module))
82 return -EFAULT;
83 data = kzalloc(sizeof(*data), GFP_KERNEL);
84 if (!data) {
85 module_put(entry->module);
86 return -ENOMEM;
87 }
88 data->entry = entry;
89 *ret = data;
90 return 0;
91}
92
93static bool valid_pos(loff_t pos, size_t count)
94{
95 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
96 return false;
97 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
98 return false;
99 return true;
100}
101
102/*
103 * file ops for binary proc files
104 */
105static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
106{
107 struct snd_info_private_data *data;
108 struct snd_info_entry *entry;
109 loff_t ret = -EINVAL, size;
110
111 data = file->private_data;
112 entry = data->entry;
113 mutex_lock(&entry->access);
114 if (entry->c.ops->llseek) {
115 offset = entry->c.ops->llseek(entry,
116 data->file_private_data,
117 file, offset, orig);
118 goto out;
119 }
120
121 size = entry->size;
122 switch (orig) {
123 case SEEK_SET:
124 break;
125 case SEEK_CUR:
126 offset += file->f_pos;
127 break;
128 case SEEK_END:
129 if (!size)
130 goto out;
131 offset += size;
132 break;
133 default:
134 goto out;
135 }
136 if (offset < 0)
137 goto out;
138 if (size && offset > size)
139 offset = size;
140 file->f_pos = offset;
141 ret = offset;
142 out:
143 mutex_unlock(&entry->access);
144 return ret;
145}
146
147static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
148 size_t count, loff_t * offset)
149{
150 struct snd_info_private_data *data = file->private_data;
151 struct snd_info_entry *entry = data->entry;
152 size_t size;
153 loff_t pos;
154
155 pos = *offset;
156 if (!valid_pos(pos, count))
157 return -EIO;
158 if (pos >= entry->size)
159 return 0;
160 size = entry->size - pos;
161 size = min(count, size);
162 size = entry->c.ops->read(entry, data->file_private_data,
163 file, buffer, size, pos);
164 if ((ssize_t) size > 0)
165 *offset = pos + size;
166 return size;
167}
168
169static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
170 size_t count, loff_t * offset)
171{
172 struct snd_info_private_data *data = file->private_data;
173 struct snd_info_entry *entry = data->entry;
174 ssize_t size = 0;
175 loff_t pos;
176
177 pos = *offset;
178 if (!valid_pos(pos, count))
179 return -EIO;
180 if (count > 0) {
181 size_t maxsize = entry->size - pos;
182 count = min(count, maxsize);
183 size = entry->c.ops->write(entry, data->file_private_data,
184 file, buffer, count, pos);
185 }
186 if (size > 0)
187 *offset = pos + size;
188 return size;
189}
190
191static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
192{
193 struct snd_info_private_data *data = file->private_data;
194 struct snd_info_entry *entry = data->entry;
195 __poll_t mask = 0;
196
197 if (entry->c.ops->poll)
198 return entry->c.ops->poll(entry,
199 data->file_private_data,
200 file, wait);
201 if (entry->c.ops->read)
202 mask |= EPOLLIN | EPOLLRDNORM;
203 if (entry->c.ops->write)
204 mask |= EPOLLOUT | EPOLLWRNORM;
205 return mask;
206}
207
208static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
209 unsigned long arg)
210{
211 struct snd_info_private_data *data = file->private_data;
212 struct snd_info_entry *entry = data->entry;
213
214 if (!entry->c.ops->ioctl)
215 return -ENOTTY;
216 return entry->c.ops->ioctl(entry, data->file_private_data,
217 file, cmd, arg);
218}
219
220static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
221{
222 struct inode *inode = file_inode(file);
223 struct snd_info_private_data *data;
224 struct snd_info_entry *entry;
225
226 data = file->private_data;
227 if (data == NULL)
228 return 0;
229 entry = data->entry;
230 if (!entry->c.ops->mmap)
231 return -ENXIO;
232 return entry->c.ops->mmap(entry, data->file_private_data,
233 inode, file, vma);
234}
235
236static int snd_info_entry_open(struct inode *inode, struct file *file)
237{
238 struct snd_info_entry *entry = PDE_DATA(inode);
239 struct snd_info_private_data *data;
240 int mode, err;
241
242 mutex_lock(&info_mutex);
243 err = alloc_info_private(entry, &data);
244 if (err < 0)
245 goto unlock;
246
247 mode = file->f_flags & O_ACCMODE;
248 if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
249 ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
250 err = -ENODEV;
251 goto error;
252 }
253
254 if (entry->c.ops->open) {
255 err = entry->c.ops->open(entry, mode, &data->file_private_data);
256 if (err < 0)
257 goto error;
258 }
259
260 file->private_data = data;
261 mutex_unlock(&info_mutex);
262 return 0;
263
264 error:
265 kfree(data);
266 module_put(entry->module);
267 unlock:
268 mutex_unlock(&info_mutex);
269 return err;
270}
271
272static int snd_info_entry_release(struct inode *inode, struct file *file)
273{
274 struct snd_info_private_data *data = file->private_data;
275 struct snd_info_entry *entry = data->entry;
276
277 if (entry->c.ops->release)
278 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
279 data->file_private_data);
280 module_put(entry->module);
281 kfree(data);
282 return 0;
283}
284
285static const struct file_operations snd_info_entry_operations =
286{
287 .owner = THIS_MODULE,
288 .llseek = snd_info_entry_llseek,
289 .read = snd_info_entry_read,
290 .write = snd_info_entry_write,
291 .poll = snd_info_entry_poll,
292 .unlocked_ioctl = snd_info_entry_ioctl,
293 .mmap = snd_info_entry_mmap,
294 .open = snd_info_entry_open,
295 .release = snd_info_entry_release,
296};
297
298/*
299 * file ops for text proc files
300 */
301static ssize_t snd_info_text_entry_write(struct file *file,
302 const char __user *buffer,
303 size_t count, loff_t *offset)
304{
305 struct seq_file *m = file->private_data;
306 struct snd_info_private_data *data = m->private;
307 struct snd_info_entry *entry = data->entry;
308 struct snd_info_buffer *buf;
309 loff_t pos;
310 size_t next;
311 int err = 0;
312
313 if (!entry->c.text.write)
314 return -EIO;
315 pos = *offset;
316 if (!valid_pos(pos, count))
317 return -EIO;
318 next = pos + count;
319 /* don't handle too large text inputs */
320 if (next > 16 * 1024)
321 return -EIO;
322 mutex_lock(&entry->access);
323 buf = data->wbuffer;
324 if (!buf) {
325 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
326 if (!buf) {
327 err = -ENOMEM;
328 goto error;
329 }
330 }
331 if (next > buf->len) {
332 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
333 if (!nbuf) {
334 err = -ENOMEM;
335 goto error;
336 }
337 kvfree(buf->buffer);
338 buf->buffer = nbuf;
339 buf->len = PAGE_ALIGN(next);
340 }
341 if (copy_from_user(buf->buffer + pos, buffer, count)) {
342 err = -EFAULT;
343 goto error;
344 }
345 buf->size = next;
346 error:
347 mutex_unlock(&entry->access);
348 if (err < 0)
349 return err;
350 *offset = next;
351 return count;
352}
353
354static int snd_info_seq_show(struct seq_file *seq, void *p)
355{
356 struct snd_info_private_data *data = seq->private;
357 struct snd_info_entry *entry = data->entry;
358
359 if (!entry->c.text.read) {
360 return -EIO;
361 } else {
362 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
363 entry->c.text.read(entry, data->rbuffer);
364 }
365 return 0;
366}
367
368static int snd_info_text_entry_open(struct inode *inode, struct file *file)
369{
370 struct snd_info_entry *entry = PDE_DATA(inode);
371 struct snd_info_private_data *data;
372 int err;
373
374 mutex_lock(&info_mutex);
375 err = alloc_info_private(entry, &data);
376 if (err < 0)
377 goto unlock;
378
379 data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
380 if (!data->rbuffer) {
381 err = -ENOMEM;
382 goto error;
383 }
384 if (entry->size)
385 err = single_open_size(file, snd_info_seq_show, data,
386 entry->size);
387 else
388 err = single_open(file, snd_info_seq_show, data);
389 if (err < 0)
390 goto error;
391 mutex_unlock(&info_mutex);
392 return 0;
393
394 error:
395 kfree(data->rbuffer);
396 kfree(data);
397 module_put(entry->module);
398 unlock:
399 mutex_unlock(&info_mutex);
400 return err;
401}
402
403static int snd_info_text_entry_release(struct inode *inode, struct file *file)
404{
405 struct seq_file *m = file->private_data;
406 struct snd_info_private_data *data = m->private;
407 struct snd_info_entry *entry = data->entry;
408
409 if (data->wbuffer && entry->c.text.write)
410 entry->c.text.write(entry, data->wbuffer);
411
412 single_release(inode, file);
413 kfree(data->rbuffer);
414 if (data->wbuffer) {
415 kvfree(data->wbuffer->buffer);
416 kfree(data->wbuffer);
417 }
418
419 module_put(entry->module);
420 kfree(data);
421 return 0;
422}
423
424static const struct file_operations snd_info_text_entry_ops =
425{
426 .owner = THIS_MODULE,
427 .open = snd_info_text_entry_open,
428 .release = snd_info_text_entry_release,
429 .write = snd_info_text_entry_write,
430 .llseek = seq_lseek,
431 .read = seq_read,
432};
433
434static struct snd_info_entry *create_subdir(struct module *mod,
435 const char *name)
436{
437 struct snd_info_entry *entry;
438
439 entry = snd_info_create_module_entry(mod, name, NULL);
440 if (!entry)
441 return NULL;
442 entry->mode = S_IFDIR | 0555;
443 if (snd_info_register(entry) < 0) {
444 snd_info_free_entry(entry);
445 return NULL;
446 }
447 return entry;
448}
449
450static struct snd_info_entry *
451snd_info_create_entry(const char *name, struct snd_info_entry *parent,
452 struct module *module);
453
454int __init snd_info_init(void)
455{
456 snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
457 if (!snd_proc_root)
458 return -ENOMEM;
459 snd_proc_root->mode = S_IFDIR | 0555;
460 snd_proc_root->p = proc_mkdir("asound", NULL);
461 if (!snd_proc_root->p)
462 goto error;
463#ifdef CONFIG_SND_OSSEMUL
464 snd_oss_root = create_subdir(THIS_MODULE, "oss");
465 if (!snd_oss_root)
466 goto error;
467#endif
468#if IS_ENABLED(CONFIG_SND_SEQUENCER)
469 snd_seq_root = create_subdir(THIS_MODULE, "seq");
470 if (!snd_seq_root)
471 goto error;
472#endif
473 if (snd_info_version_init() < 0 ||
474 snd_minor_info_init() < 0 ||
475 snd_minor_info_oss_init() < 0 ||
476 snd_card_info_init() < 0 ||
477 snd_info_minor_register() < 0)
478 goto error;
479 return 0;
480
481 error:
482 snd_info_free_entry(snd_proc_root);
483 return -ENOMEM;
484}
485
486int __exit snd_info_done(void)
487{
488 snd_info_free_entry(snd_proc_root);
489 return 0;
490}
491
492static void snd_card_id_read(struct snd_info_entry *entry,
493 struct snd_info_buffer *buffer)
494{
495 struct snd_card *card = entry->private_data;
496
497 snd_iprintf(buffer, "%s\n", card->id);
498}
499
500/*
501 * create a card proc file
502 * called from init.c
503 */
504int snd_info_card_create(struct snd_card *card)
505{
506 char str[8];
507 struct snd_info_entry *entry;
508
509 if (snd_BUG_ON(!card))
510 return -ENXIO;
511
512 sprintf(str, "card%i", card->number);
513 entry = create_subdir(card->module, str);
514 if (!entry)
515 return -ENOMEM;
516 card->proc_root = entry;
517
518 return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
519}
520
521/*
522 * register the card proc file
523 * called from init.c
524 * can be called multiple times for reinitialization
525 */
526int snd_info_card_register(struct snd_card *card)
527{
528 struct proc_dir_entry *p;
529 int err;
530
531 if (snd_BUG_ON(!card))
532 return -ENXIO;
533
534 err = snd_info_register(card->proc_root);
535 if (err < 0)
536 return err;
537
538 if (!strcmp(card->id, card->proc_root->name))
539 return 0;
540
541 if (card->proc_root_link)
542 return 0;
543 p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
544 if (!p)
545 return -ENOMEM;
546 card->proc_root_link = p;
547 return 0;
548}
549
550/*
551 * called on card->id change
552 */
553void snd_info_card_id_change(struct snd_card *card)
554{
555 mutex_lock(&info_mutex);
556 if (card->proc_root_link) {
557 proc_remove(card->proc_root_link);
558 card->proc_root_link = NULL;
559 }
560 if (strcmp(card->id, card->proc_root->name))
561 card->proc_root_link = proc_symlink(card->id,
562 snd_proc_root->p,
563 card->proc_root->name);
564 mutex_unlock(&info_mutex);
565}
566
567/*
568 * de-register the card proc file
569 * called from init.c
570 */
571void snd_info_card_disconnect(struct snd_card *card)
572{
573 if (!card)
574 return;
575 mutex_lock(&info_mutex);
576 proc_remove(card->proc_root_link);
577 card->proc_root_link = NULL;
578 if (card->proc_root)
579 snd_info_disconnect(card->proc_root);
580 mutex_unlock(&info_mutex);
581}
582
583/*
584 * release the card proc file resources
585 * called from init.c
586 */
587int snd_info_card_free(struct snd_card *card)
588{
589 if (!card)
590 return 0;
591 snd_info_free_entry(card->proc_root);
592 card->proc_root = NULL;
593 return 0;
594}
595
596
597/**
598 * snd_info_get_line - read one line from the procfs buffer
599 * @buffer: the procfs buffer
600 * @line: the buffer to store
601 * @len: the max. buffer size
602 *
603 * Reads one line from the buffer and stores the string.
604 *
605 * Return: Zero if successful, or 1 if error or EOF.
606 */
607int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
608{
609 int c = -1;
610
611 if (snd_BUG_ON(!buffer || !buffer->buffer))
612 return 1;
613 if (len <= 0 || buffer->stop || buffer->error)
614 return 1;
615 while (!buffer->stop) {
616 c = buffer->buffer[buffer->curr++];
617 if (buffer->curr >= buffer->size)
618 buffer->stop = 1;
619 if (c == '\n')
620 break;
621 if (len > 1) {
622 len--;
623 *line++ = c;
624 }
625 }
626 *line = '\0';
627 return 0;
628}
629EXPORT_SYMBOL(snd_info_get_line);
630
631/**
632 * snd_info_get_str - parse a string token
633 * @dest: the buffer to store the string token
634 * @src: the original string
635 * @len: the max. length of token - 1
636 *
637 * Parses the original string and copy a token to the given
638 * string buffer.
639 *
640 * Return: The updated pointer of the original string so that
641 * it can be used for the next call.
642 */
643const char *snd_info_get_str(char *dest, const char *src, int len)
644{
645 int c;
646
647 while (*src == ' ' || *src == '\t')
648 src++;
649 if (*src == '"' || *src == '\'') {
650 c = *src++;
651 while (--len > 0 && *src && *src != c) {
652 *dest++ = *src++;
653 }
654 if (*src == c)
655 src++;
656 } else {
657 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
658 *dest++ = *src++;
659 }
660 }
661 *dest = 0;
662 while (*src == ' ' || *src == '\t')
663 src++;
664 return src;
665}
666EXPORT_SYMBOL(snd_info_get_str);
667
668/*
669 * snd_info_create_entry - create an info entry
670 * @name: the proc file name
671 * @parent: the parent directory
672 *
673 * Creates an info entry with the given file name and initializes as
674 * the default state.
675 *
676 * Usually called from other functions such as
677 * snd_info_create_card_entry().
678 *
679 * Return: The pointer of the new instance, or %NULL on failure.
680 */
681static struct snd_info_entry *
682snd_info_create_entry(const char *name, struct snd_info_entry *parent,
683 struct module *module)
684{
685 struct snd_info_entry *entry;
686 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
687 if (entry == NULL)
688 return NULL;
689 entry->name = kstrdup(name, GFP_KERNEL);
690 if (entry->name == NULL) {
691 kfree(entry);
692 return NULL;
693 }
694 entry->mode = S_IFREG | 0444;
695 entry->content = SNDRV_INFO_CONTENT_TEXT;
696 mutex_init(&entry->access);
697 INIT_LIST_HEAD(&entry->children);
698 INIT_LIST_HEAD(&entry->list);
699 entry->parent = parent;
700 entry->module = module;
701 if (parent) {
702 mutex_lock(&parent->access);
703 list_add_tail(&entry->list, &parent->children);
704 mutex_unlock(&parent->access);
705 }
706 return entry;
707}
708
709/**
710 * snd_info_create_module_entry - create an info entry for the given module
711 * @module: the module pointer
712 * @name: the file name
713 * @parent: the parent directory
714 *
715 * Creates a new info entry and assigns it to the given module.
716 *
717 * Return: The pointer of the new instance, or %NULL on failure.
718 */
719struct snd_info_entry *snd_info_create_module_entry(struct module * module,
720 const char *name,
721 struct snd_info_entry *parent)
722{
723 if (!parent)
724 parent = snd_proc_root;
725 return snd_info_create_entry(name, parent, module);
726}
727EXPORT_SYMBOL(snd_info_create_module_entry);
728
729/**
730 * snd_info_create_card_entry - create an info entry for the given card
731 * @card: the card instance
732 * @name: the file name
733 * @parent: the parent directory
734 *
735 * Creates a new info entry and assigns it to the given card.
736 *
737 * Return: The pointer of the new instance, or %NULL on failure.
738 */
739struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
740 const char *name,
741 struct snd_info_entry * parent)
742{
743 if (!parent)
744 parent = card->proc_root;
745 return snd_info_create_entry(name, parent, card->module);
746}
747EXPORT_SYMBOL(snd_info_create_card_entry);
748
749static void snd_info_disconnect(struct snd_info_entry *entry)
750{
751 struct snd_info_entry *p;
752
753 if (!entry->p)
754 return;
755 list_for_each_entry(p, &entry->children, list)
756 snd_info_disconnect(p);
757 proc_remove(entry->p);
758 entry->p = NULL;
759}
760
761/**
762 * snd_info_free_entry - release the info entry
763 * @entry: the info entry
764 *
765 * Releases the info entry.
766 */
767void snd_info_free_entry(struct snd_info_entry * entry)
768{
769 struct snd_info_entry *p, *n;
770
771 if (!entry)
772 return;
773 if (entry->p) {
774 mutex_lock(&info_mutex);
775 snd_info_disconnect(entry);
776 mutex_unlock(&info_mutex);
777 }
778
779 /* free all children at first */
780 list_for_each_entry_safe(p, n, &entry->children, list)
781 snd_info_free_entry(p);
782
783 p = entry->parent;
784 if (p) {
785 mutex_lock(&p->access);
786 list_del(&entry->list);
787 mutex_unlock(&p->access);
788 }
789 kfree(entry->name);
790 if (entry->private_free)
791 entry->private_free(entry);
792 kfree(entry);
793}
794EXPORT_SYMBOL(snd_info_free_entry);
795
796static int __snd_info_register(struct snd_info_entry *entry)
797{
798 struct proc_dir_entry *root, *p = NULL;
799
800 if (snd_BUG_ON(!entry))
801 return -ENXIO;
802 root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
803 mutex_lock(&info_mutex);
804 if (entry->p || !root)
805 goto unlock;
806 if (S_ISDIR(entry->mode)) {
807 p = proc_mkdir_mode(entry->name, entry->mode, root);
808 if (!p) {
809 mutex_unlock(&info_mutex);
810 return -ENOMEM;
811 }
812 } else {
813 const struct file_operations *ops;
814 if (entry->content == SNDRV_INFO_CONTENT_DATA)
815 ops = &snd_info_entry_operations;
816 else
817 ops = &snd_info_text_entry_ops;
818 p = proc_create_data(entry->name, entry->mode, root,
819 ops, entry);
820 if (!p) {
821 mutex_unlock(&info_mutex);
822 return -ENOMEM;
823 }
824 proc_set_size(p, entry->size);
825 }
826 entry->p = p;
827 unlock:
828 mutex_unlock(&info_mutex);
829 return 0;
830}
831
832/**
833 * snd_info_register - register the info entry
834 * @entry: the info entry
835 *
836 * Registers the proc info entry.
837 * The all children entries are registered recursively.
838 *
839 * Return: Zero if successful, or a negative error code on failure.
840 */
841int snd_info_register(struct snd_info_entry *entry)
842{
843 struct snd_info_entry *p;
844 int err;
845
846 if (!entry->p) {
847 err = __snd_info_register(entry);
848 if (err < 0)
849 return err;
850 }
851
852 list_for_each_entry(p, &entry->children, list) {
853 err = snd_info_register(p);
854 if (err < 0)
855 return err;
856 }
857
858 return 0;
859}
860EXPORT_SYMBOL(snd_info_register);
861
862/**
863 * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
864 * @card: the card instance
865 * @name: the file name
866 * @private_data: the arbitrary private data
867 * @read: the read callback
868 * @write: the write callback, NULL for read-only
869 *
870 * This proc file entry will be registered via snd_card_register() call, and
871 * it will be removed automatically at the card removal, too.
872 */
873int snd_card_rw_proc_new(struct snd_card *card, const char *name,
874 void *private_data,
875 void (*read)(struct snd_info_entry *,
876 struct snd_info_buffer *),
877 void (*write)(struct snd_info_entry *entry,
878 struct snd_info_buffer *buffer))
879{
880 struct snd_info_entry *entry;
881
882 entry = snd_info_create_card_entry(card, name, card->proc_root);
883 if (!entry)
884 return -ENOMEM;
885 snd_info_set_text_ops(entry, private_data, read);
886 if (write) {
887 entry->mode |= 0200;
888 entry->c.text.write = write;
889 }
890 return 0;
891}
892EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
893
894/*
895
896 */
897
898static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
899{
900 snd_iprintf(buffer,
901 "Advanced Linux Sound Architecture Driver Version k%s.\n",
902 init_utsname()->release);
903}
904
905static int __init snd_info_version_init(void)
906{
907 struct snd_info_entry *entry;
908
909 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
910 if (entry == NULL)
911 return -ENOMEM;
912 entry->c.text.read = snd_info_version_read;
913 return snd_info_register(entry); /* freed in error path */
914}
1/*
2 * Information interface for ALSA driver
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/time.h>
24#include <linux/mm.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/module.h>
28#include <sound/core.h>
29#include <sound/minors.h>
30#include <sound/info.h>
31#include <linux/utsname.h>
32#include <linux/proc_fs.h>
33#include <linux/mutex.h>
34#include <stdarg.h>
35
36/*
37 *
38 */
39
40#ifdef CONFIG_PROC_FS
41
42int snd_info_check_reserved_words(const char *str)
43{
44 static char *reserved[] =
45 {
46 "version",
47 "meminfo",
48 "memdebug",
49 "detect",
50 "devices",
51 "oss",
52 "cards",
53 "timers",
54 "synth",
55 "pcm",
56 "seq",
57 NULL
58 };
59 char **xstr = reserved;
60
61 while (*xstr) {
62 if (!strcmp(*xstr, str))
63 return 0;
64 xstr++;
65 }
66 if (!strncmp(str, "card", 4))
67 return 0;
68 return 1;
69}
70
71static DEFINE_MUTEX(info_mutex);
72
73struct snd_info_private_data {
74 struct snd_info_buffer *rbuffer;
75 struct snd_info_buffer *wbuffer;
76 struct snd_info_entry *entry;
77 void *file_private_data;
78};
79
80static int snd_info_version_init(void);
81static int snd_info_version_done(void);
82static void snd_info_disconnect(struct snd_info_entry *entry);
83
84
85/* resize the proc r/w buffer */
86static int resize_info_buffer(struct snd_info_buffer *buffer,
87 unsigned int nsize)
88{
89 char *nbuf;
90
91 nsize = PAGE_ALIGN(nsize);
92 nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL | __GFP_ZERO);
93 if (! nbuf)
94 return -ENOMEM;
95
96 buffer->buffer = nbuf;
97 buffer->len = nsize;
98 return 0;
99}
100
101/**
102 * snd_iprintf - printf on the procfs buffer
103 * @buffer: the procfs buffer
104 * @fmt: the printf format
105 *
106 * Outputs the string on the procfs buffer just like printf().
107 *
108 * Return: The size of output string, or a negative error code.
109 */
110int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
111{
112 va_list args;
113 int len, res;
114 int err = 0;
115
116 might_sleep();
117 if (buffer->stop || buffer->error)
118 return 0;
119 len = buffer->len - buffer->size;
120 va_start(args, fmt);
121 for (;;) {
122 va_list ap;
123 va_copy(ap, args);
124 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
125 va_end(ap);
126 if (res < len)
127 break;
128 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
129 if (err < 0)
130 break;
131 len = buffer->len - buffer->size;
132 }
133 va_end(args);
134
135 if (err < 0)
136 return err;
137 buffer->curr += res;
138 buffer->size += res;
139 return res;
140}
141
142EXPORT_SYMBOL(snd_iprintf);
143
144/*
145
146 */
147
148static struct proc_dir_entry *snd_proc_root;
149struct snd_info_entry *snd_seq_root;
150EXPORT_SYMBOL(snd_seq_root);
151
152#ifdef CONFIG_SND_OSSEMUL
153struct snd_info_entry *snd_oss_root;
154#endif
155
156static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
157{
158 struct snd_info_private_data *data;
159 struct snd_info_entry *entry;
160 loff_t ret = -EINVAL, size;
161
162 data = file->private_data;
163 entry = data->entry;
164 mutex_lock(&entry->access);
165 if (entry->content == SNDRV_INFO_CONTENT_DATA &&
166 entry->c.ops->llseek) {
167 offset = entry->c.ops->llseek(entry,
168 data->file_private_data,
169 file, offset, orig);
170 goto out;
171 }
172 if (entry->content == SNDRV_INFO_CONTENT_DATA)
173 size = entry->size;
174 else
175 size = 0;
176 switch (orig) {
177 case SEEK_SET:
178 break;
179 case SEEK_CUR:
180 offset += file->f_pos;
181 break;
182 case SEEK_END:
183 if (!size)
184 goto out;
185 offset += size;
186 break;
187 default:
188 goto out;
189 }
190 if (offset < 0)
191 goto out;
192 if (size && offset > size)
193 offset = size;
194 file->f_pos = offset;
195 ret = offset;
196 out:
197 mutex_unlock(&entry->access);
198 return ret;
199}
200
201static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
202 size_t count, loff_t * offset)
203{
204 struct snd_info_private_data *data;
205 struct snd_info_entry *entry;
206 struct snd_info_buffer *buf;
207 size_t size = 0;
208 loff_t pos;
209
210 data = file->private_data;
211 if (snd_BUG_ON(!data))
212 return -ENXIO;
213 pos = *offset;
214 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
215 return -EIO;
216 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
217 return -EIO;
218 entry = data->entry;
219 switch (entry->content) {
220 case SNDRV_INFO_CONTENT_TEXT:
221 buf = data->rbuffer;
222 if (buf == NULL)
223 return -EIO;
224 if (pos >= buf->size)
225 return 0;
226 size = buf->size - pos;
227 size = min(count, size);
228 if (copy_to_user(buffer, buf->buffer + pos, size))
229 return -EFAULT;
230 break;
231 case SNDRV_INFO_CONTENT_DATA:
232 if (pos >= entry->size)
233 return 0;
234 if (entry->c.ops->read) {
235 size = entry->size - pos;
236 size = min(count, size);
237 size = entry->c.ops->read(entry,
238 data->file_private_data,
239 file, buffer, size, pos);
240 }
241 break;
242 }
243 if ((ssize_t) size > 0)
244 *offset = pos + size;
245 return size;
246}
247
248static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
249 size_t count, loff_t * offset)
250{
251 struct snd_info_private_data *data;
252 struct snd_info_entry *entry;
253 struct snd_info_buffer *buf;
254 ssize_t size = 0;
255 loff_t pos;
256
257 data = file->private_data;
258 if (snd_BUG_ON(!data))
259 return -ENXIO;
260 entry = data->entry;
261 pos = *offset;
262 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
263 return -EIO;
264 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
265 return -EIO;
266 switch (entry->content) {
267 case SNDRV_INFO_CONTENT_TEXT:
268 buf = data->wbuffer;
269 if (buf == NULL)
270 return -EIO;
271 mutex_lock(&entry->access);
272 if (pos + count >= buf->len) {
273 if (resize_info_buffer(buf, pos + count)) {
274 mutex_unlock(&entry->access);
275 return -ENOMEM;
276 }
277 }
278 if (copy_from_user(buf->buffer + pos, buffer, count)) {
279 mutex_unlock(&entry->access);
280 return -EFAULT;
281 }
282 buf->size = pos + count;
283 mutex_unlock(&entry->access);
284 size = count;
285 break;
286 case SNDRV_INFO_CONTENT_DATA:
287 if (entry->c.ops->write && count > 0) {
288 size_t maxsize = entry->size - pos;
289 count = min(count, maxsize);
290 size = entry->c.ops->write(entry,
291 data->file_private_data,
292 file, buffer, count, pos);
293 }
294 break;
295 }
296 if ((ssize_t) size > 0)
297 *offset = pos + size;
298 return size;
299}
300
301static int snd_info_entry_open(struct inode *inode, struct file *file)
302{
303 struct snd_info_entry *entry;
304 struct snd_info_private_data *data;
305 struct snd_info_buffer *buffer;
306 int mode, err;
307
308 mutex_lock(&info_mutex);
309 entry = PDE_DATA(inode);
310 if (entry == NULL || ! entry->p) {
311 mutex_unlock(&info_mutex);
312 return -ENODEV;
313 }
314 if (!try_module_get(entry->module)) {
315 err = -EFAULT;
316 goto __error1;
317 }
318 mode = file->f_flags & O_ACCMODE;
319 if (mode == O_RDONLY || mode == O_RDWR) {
320 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
321 entry->c.ops->read == NULL)) {
322 err = -ENODEV;
323 goto __error;
324 }
325 }
326 if (mode == O_WRONLY || mode == O_RDWR) {
327 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
328 entry->c.ops->write == NULL)) {
329 err = -ENODEV;
330 goto __error;
331 }
332 }
333 data = kzalloc(sizeof(*data), GFP_KERNEL);
334 if (data == NULL) {
335 err = -ENOMEM;
336 goto __error;
337 }
338 data->entry = entry;
339 switch (entry->content) {
340 case SNDRV_INFO_CONTENT_TEXT:
341 if (mode == O_RDONLY || mode == O_RDWR) {
342 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
343 if (buffer == NULL)
344 goto __nomem;
345 data->rbuffer = buffer;
346 buffer->len = PAGE_SIZE;
347 buffer->buffer = kzalloc(buffer->len, GFP_KERNEL);
348 if (buffer->buffer == NULL)
349 goto __nomem;
350 }
351 if (mode == O_WRONLY || mode == O_RDWR) {
352 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
353 if (buffer == NULL)
354 goto __nomem;
355 data->wbuffer = buffer;
356 buffer->len = PAGE_SIZE;
357 buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
358 if (buffer->buffer == NULL)
359 goto __nomem;
360 }
361 break;
362 case SNDRV_INFO_CONTENT_DATA: /* data */
363 if (entry->c.ops->open) {
364 if ((err = entry->c.ops->open(entry, mode,
365 &data->file_private_data)) < 0) {
366 kfree(data);
367 goto __error;
368 }
369 }
370 break;
371 }
372 file->private_data = data;
373 mutex_unlock(&info_mutex);
374 if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
375 (mode == O_RDONLY || mode == O_RDWR)) {
376 if (entry->c.text.read) {
377 mutex_lock(&entry->access);
378 entry->c.text.read(entry, data->rbuffer);
379 mutex_unlock(&entry->access);
380 }
381 }
382 return 0;
383
384 __nomem:
385 if (data->rbuffer) {
386 kfree(data->rbuffer->buffer);
387 kfree(data->rbuffer);
388 }
389 if (data->wbuffer) {
390 kfree(data->wbuffer->buffer);
391 kfree(data->wbuffer);
392 }
393 kfree(data);
394 err = -ENOMEM;
395 __error:
396 module_put(entry->module);
397 __error1:
398 mutex_unlock(&info_mutex);
399 return err;
400}
401
402static int snd_info_entry_release(struct inode *inode, struct file *file)
403{
404 struct snd_info_entry *entry;
405 struct snd_info_private_data *data;
406 int mode;
407
408 mode = file->f_flags & O_ACCMODE;
409 data = file->private_data;
410 entry = data->entry;
411 switch (entry->content) {
412 case SNDRV_INFO_CONTENT_TEXT:
413 if (data->rbuffer) {
414 kfree(data->rbuffer->buffer);
415 kfree(data->rbuffer);
416 }
417 if (data->wbuffer) {
418 if (entry->c.text.write) {
419 entry->c.text.write(entry, data->wbuffer);
420 if (data->wbuffer->error) {
421 if (entry->card)
422 dev_warn(entry->card->dev, "info: data write error to %s (%i)\n",
423 entry->name,
424 data->wbuffer->error);
425 else
426 pr_warn("ALSA: info: data write error to %s (%i)\n",
427 entry->name,
428 data->wbuffer->error);
429 }
430 }
431 kfree(data->wbuffer->buffer);
432 kfree(data->wbuffer);
433 }
434 break;
435 case SNDRV_INFO_CONTENT_DATA:
436 if (entry->c.ops->release)
437 entry->c.ops->release(entry, mode,
438 data->file_private_data);
439 break;
440 }
441 module_put(entry->module);
442 kfree(data);
443 return 0;
444}
445
446static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
447{
448 struct snd_info_private_data *data;
449 struct snd_info_entry *entry;
450 unsigned int mask;
451
452 data = file->private_data;
453 if (data == NULL)
454 return 0;
455 entry = data->entry;
456 mask = 0;
457 switch (entry->content) {
458 case SNDRV_INFO_CONTENT_DATA:
459 if (entry->c.ops->poll)
460 return entry->c.ops->poll(entry,
461 data->file_private_data,
462 file, wait);
463 if (entry->c.ops->read)
464 mask |= POLLIN | POLLRDNORM;
465 if (entry->c.ops->write)
466 mask |= POLLOUT | POLLWRNORM;
467 break;
468 }
469 return mask;
470}
471
472static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
473 unsigned long arg)
474{
475 struct snd_info_private_data *data;
476 struct snd_info_entry *entry;
477
478 data = file->private_data;
479 if (data == NULL)
480 return 0;
481 entry = data->entry;
482 switch (entry->content) {
483 case SNDRV_INFO_CONTENT_DATA:
484 if (entry->c.ops->ioctl)
485 return entry->c.ops->ioctl(entry,
486 data->file_private_data,
487 file, cmd, arg);
488 break;
489 }
490 return -ENOTTY;
491}
492
493static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
494{
495 struct inode *inode = file_inode(file);
496 struct snd_info_private_data *data;
497 struct snd_info_entry *entry;
498
499 data = file->private_data;
500 if (data == NULL)
501 return 0;
502 entry = data->entry;
503 switch (entry->content) {
504 case SNDRV_INFO_CONTENT_DATA:
505 if (entry->c.ops->mmap)
506 return entry->c.ops->mmap(entry,
507 data->file_private_data,
508 inode, file, vma);
509 break;
510 }
511 return -ENXIO;
512}
513
514static const struct file_operations snd_info_entry_operations =
515{
516 .owner = THIS_MODULE,
517 .llseek = snd_info_entry_llseek,
518 .read = snd_info_entry_read,
519 .write = snd_info_entry_write,
520 .poll = snd_info_entry_poll,
521 .unlocked_ioctl = snd_info_entry_ioctl,
522 .mmap = snd_info_entry_mmap,
523 .open = snd_info_entry_open,
524 .release = snd_info_entry_release,
525};
526
527int __init snd_info_init(void)
528{
529 struct proc_dir_entry *p;
530
531 p = proc_mkdir("asound", NULL);
532 if (p == NULL)
533 return -ENOMEM;
534 snd_proc_root = p;
535#ifdef CONFIG_SND_OSSEMUL
536 {
537 struct snd_info_entry *entry;
538 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
539 return -ENOMEM;
540 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
541 if (snd_info_register(entry) < 0) {
542 snd_info_free_entry(entry);
543 return -ENOMEM;
544 }
545 snd_oss_root = entry;
546 }
547#endif
548#if IS_ENABLED(CONFIG_SND_SEQUENCER)
549 {
550 struct snd_info_entry *entry;
551 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
552 return -ENOMEM;
553 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
554 if (snd_info_register(entry) < 0) {
555 snd_info_free_entry(entry);
556 return -ENOMEM;
557 }
558 snd_seq_root = entry;
559 }
560#endif
561 snd_info_version_init();
562 snd_minor_info_init();
563 snd_minor_info_oss_init();
564 snd_card_info_init();
565 return 0;
566}
567
568int __exit snd_info_done(void)
569{
570 snd_card_info_done();
571 snd_minor_info_oss_done();
572 snd_minor_info_done();
573 snd_info_version_done();
574 if (snd_proc_root) {
575#if IS_ENABLED(CONFIG_SND_SEQUENCER)
576 snd_info_free_entry(snd_seq_root);
577#endif
578#ifdef CONFIG_SND_OSSEMUL
579 snd_info_free_entry(snd_oss_root);
580#endif
581 proc_remove(snd_proc_root);
582 }
583 return 0;
584}
585
586/*
587
588 */
589
590
591/*
592 * create a card proc file
593 * called from init.c
594 */
595int snd_info_card_create(struct snd_card *card)
596{
597 char str[8];
598 struct snd_info_entry *entry;
599
600 if (snd_BUG_ON(!card))
601 return -ENXIO;
602
603 sprintf(str, "card%i", card->number);
604 if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
605 return -ENOMEM;
606 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
607 if (snd_info_register(entry) < 0) {
608 snd_info_free_entry(entry);
609 return -ENOMEM;
610 }
611 card->proc_root = entry;
612 return 0;
613}
614
615/*
616 * register the card proc file
617 * called from init.c
618 */
619int snd_info_card_register(struct snd_card *card)
620{
621 struct proc_dir_entry *p;
622
623 if (snd_BUG_ON(!card))
624 return -ENXIO;
625
626 if (!strcmp(card->id, card->proc_root->name))
627 return 0;
628
629 p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
630 if (p == NULL)
631 return -ENOMEM;
632 card->proc_root_link = p;
633 return 0;
634}
635
636/*
637 * called on card->id change
638 */
639void snd_info_card_id_change(struct snd_card *card)
640{
641 mutex_lock(&info_mutex);
642 if (card->proc_root_link) {
643 proc_remove(card->proc_root_link);
644 card->proc_root_link = NULL;
645 }
646 if (strcmp(card->id, card->proc_root->name))
647 card->proc_root_link = proc_symlink(card->id,
648 snd_proc_root,
649 card->proc_root->name);
650 mutex_unlock(&info_mutex);
651}
652
653/*
654 * de-register the card proc file
655 * called from init.c
656 */
657void snd_info_card_disconnect(struct snd_card *card)
658{
659 if (!card)
660 return;
661 mutex_lock(&info_mutex);
662 proc_remove(card->proc_root_link);
663 card->proc_root_link = NULL;
664 if (card->proc_root)
665 snd_info_disconnect(card->proc_root);
666 mutex_unlock(&info_mutex);
667}
668
669/*
670 * release the card proc file resources
671 * called from init.c
672 */
673int snd_info_card_free(struct snd_card *card)
674{
675 if (!card)
676 return 0;
677 snd_info_free_entry(card->proc_root);
678 card->proc_root = NULL;
679 return 0;
680}
681
682
683/**
684 * snd_info_get_line - read one line from the procfs buffer
685 * @buffer: the procfs buffer
686 * @line: the buffer to store
687 * @len: the max. buffer size - 1
688 *
689 * Reads one line from the buffer and stores the string.
690 *
691 * Return: Zero if successful, or 1 if error or EOF.
692 */
693int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
694{
695 int c = -1;
696
697 if (snd_BUG_ON(!buffer || !buffer->buffer))
698 return 1;
699 if (len <= 0 || buffer->stop || buffer->error)
700 return 1;
701 while (!buffer->stop) {
702 c = buffer->buffer[buffer->curr++];
703 if (buffer->curr >= buffer->size)
704 buffer->stop = 1;
705 if (c == '\n')
706 break;
707 if (len) {
708 len--;
709 *line++ = c;
710 }
711 }
712 *line = '\0';
713 return 0;
714}
715
716EXPORT_SYMBOL(snd_info_get_line);
717
718/**
719 * snd_info_get_str - parse a string token
720 * @dest: the buffer to store the string token
721 * @src: the original string
722 * @len: the max. length of token - 1
723 *
724 * Parses the original string and copy a token to the given
725 * string buffer.
726 *
727 * Return: The updated pointer of the original string so that
728 * it can be used for the next call.
729 */
730const char *snd_info_get_str(char *dest, const char *src, int len)
731{
732 int c;
733
734 while (*src == ' ' || *src == '\t')
735 src++;
736 if (*src == '"' || *src == '\'') {
737 c = *src++;
738 while (--len > 0 && *src && *src != c) {
739 *dest++ = *src++;
740 }
741 if (*src == c)
742 src++;
743 } else {
744 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
745 *dest++ = *src++;
746 }
747 }
748 *dest = 0;
749 while (*src == ' ' || *src == '\t')
750 src++;
751 return src;
752}
753
754EXPORT_SYMBOL(snd_info_get_str);
755
756/**
757 * snd_info_create_entry - create an info entry
758 * @name: the proc file name
759 *
760 * Creates an info entry with the given file name and initializes as
761 * the default state.
762 *
763 * Usually called from other functions such as
764 * snd_info_create_card_entry().
765 *
766 * Return: The pointer of the new instance, or %NULL on failure.
767 */
768static struct snd_info_entry *snd_info_create_entry(const char *name)
769{
770 struct snd_info_entry *entry;
771 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
772 if (entry == NULL)
773 return NULL;
774 entry->name = kstrdup(name, GFP_KERNEL);
775 if (entry->name == NULL) {
776 kfree(entry);
777 return NULL;
778 }
779 entry->mode = S_IFREG | S_IRUGO;
780 entry->content = SNDRV_INFO_CONTENT_TEXT;
781 mutex_init(&entry->access);
782 INIT_LIST_HEAD(&entry->children);
783 INIT_LIST_HEAD(&entry->list);
784 return entry;
785}
786
787/**
788 * snd_info_create_module_entry - create an info entry for the given module
789 * @module: the module pointer
790 * @name: the file name
791 * @parent: the parent directory
792 *
793 * Creates a new info entry and assigns it to the given module.
794 *
795 * Return: The pointer of the new instance, or %NULL on failure.
796 */
797struct snd_info_entry *snd_info_create_module_entry(struct module * module,
798 const char *name,
799 struct snd_info_entry *parent)
800{
801 struct snd_info_entry *entry = snd_info_create_entry(name);
802 if (entry) {
803 entry->module = module;
804 entry->parent = parent;
805 }
806 return entry;
807}
808
809EXPORT_SYMBOL(snd_info_create_module_entry);
810
811/**
812 * snd_info_create_card_entry - create an info entry for the given card
813 * @card: the card instance
814 * @name: the file name
815 * @parent: the parent directory
816 *
817 * Creates a new info entry and assigns it to the given card.
818 *
819 * Return: The pointer of the new instance, or %NULL on failure.
820 */
821struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
822 const char *name,
823 struct snd_info_entry * parent)
824{
825 struct snd_info_entry *entry = snd_info_create_entry(name);
826 if (entry) {
827 entry->module = card->module;
828 entry->card = card;
829 entry->parent = parent;
830 }
831 return entry;
832}
833
834EXPORT_SYMBOL(snd_info_create_card_entry);
835
836static void snd_info_disconnect(struct snd_info_entry *entry)
837{
838 struct list_head *p, *n;
839 struct proc_dir_entry *root;
840
841 list_for_each_safe(p, n, &entry->children) {
842 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
843 }
844
845 if (! entry->p)
846 return;
847 list_del_init(&entry->list);
848 root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
849 snd_BUG_ON(!root);
850 proc_remove(entry->p);
851 entry->p = NULL;
852}
853
854static int snd_info_dev_free_entry(struct snd_device *device)
855{
856 struct snd_info_entry *entry = device->device_data;
857 snd_info_free_entry(entry);
858 return 0;
859}
860
861static int snd_info_dev_register_entry(struct snd_device *device)
862{
863 struct snd_info_entry *entry = device->device_data;
864 return snd_info_register(entry);
865}
866
867/**
868 * snd_card_proc_new - create an info entry for the given card
869 * @card: the card instance
870 * @name: the file name
871 * @entryp: the pointer to store the new info entry
872 *
873 * Creates a new info entry and assigns it to the given card.
874 * Unlike snd_info_create_card_entry(), this function registers the
875 * info entry as an ALSA device component, so that it can be
876 * unregistered/released without explicit call.
877 * Also, you don't have to register this entry via snd_info_register(),
878 * since this will be registered by snd_card_register() automatically.
879 *
880 * The parent is assumed as card->proc_root.
881 *
882 * For releasing this entry, use snd_device_free() instead of
883 * snd_info_free_entry().
884 *
885 * Return: Zero if successful, or a negative error code on failure.
886 */
887int snd_card_proc_new(struct snd_card *card, const char *name,
888 struct snd_info_entry **entryp)
889{
890 static struct snd_device_ops ops = {
891 .dev_free = snd_info_dev_free_entry,
892 .dev_register = snd_info_dev_register_entry,
893 /* disconnect is done via snd_info_card_disconnect() */
894 };
895 struct snd_info_entry *entry;
896 int err;
897
898 entry = snd_info_create_card_entry(card, name, card->proc_root);
899 if (! entry)
900 return -ENOMEM;
901 if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
902 snd_info_free_entry(entry);
903 return err;
904 }
905 if (entryp)
906 *entryp = entry;
907 return 0;
908}
909
910EXPORT_SYMBOL(snd_card_proc_new);
911
912/**
913 * snd_info_free_entry - release the info entry
914 * @entry: the info entry
915 *
916 * Releases the info entry. Don't call this after registered.
917 */
918void snd_info_free_entry(struct snd_info_entry * entry)
919{
920 if (entry == NULL)
921 return;
922 if (entry->p) {
923 mutex_lock(&info_mutex);
924 snd_info_disconnect(entry);
925 mutex_unlock(&info_mutex);
926 }
927 kfree(entry->name);
928 if (entry->private_free)
929 entry->private_free(entry);
930 kfree(entry);
931}
932
933EXPORT_SYMBOL(snd_info_free_entry);
934
935/**
936 * snd_info_register - register the info entry
937 * @entry: the info entry
938 *
939 * Registers the proc info entry.
940 *
941 * Return: Zero if successful, or a negative error code on failure.
942 */
943int snd_info_register(struct snd_info_entry * entry)
944{
945 struct proc_dir_entry *root, *p = NULL;
946
947 if (snd_BUG_ON(!entry))
948 return -ENXIO;
949 root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
950 mutex_lock(&info_mutex);
951 if (S_ISDIR(entry->mode)) {
952 p = proc_mkdir_mode(entry->name, entry->mode, root);
953 if (!p) {
954 mutex_unlock(&info_mutex);
955 return -ENOMEM;
956 }
957 } else {
958 p = proc_create_data(entry->name, entry->mode, root,
959 &snd_info_entry_operations, entry);
960 if (!p) {
961 mutex_unlock(&info_mutex);
962 return -ENOMEM;
963 }
964 proc_set_size(p, entry->size);
965 }
966 entry->p = p;
967 if (entry->parent)
968 list_add_tail(&entry->list, &entry->parent->children);
969 mutex_unlock(&info_mutex);
970 return 0;
971}
972
973EXPORT_SYMBOL(snd_info_register);
974
975/*
976
977 */
978
979static struct snd_info_entry *snd_info_version_entry;
980
981static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
982{
983 snd_iprintf(buffer,
984 "Advanced Linux Sound Architecture Driver Version k%s.\n",
985 init_utsname()->release);
986}
987
988static int __init snd_info_version_init(void)
989{
990 struct snd_info_entry *entry;
991
992 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
993 if (entry == NULL)
994 return -ENOMEM;
995 entry->c.text.read = snd_info_version_read;
996 if (snd_info_register(entry) < 0) {
997 snd_info_free_entry(entry);
998 return -ENOMEM;
999 }
1000 snd_info_version_entry = entry;
1001 return 0;
1002}
1003
1004static int __exit snd_info_version_done(void)
1005{
1006 snd_info_free_entry(snd_info_version_entry);
1007 return 0;
1008}
1009
1010#endif /* CONFIG_PROC_FS */