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