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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// 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}