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