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