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 | |
20 | int 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 | |
49 | static DEFINE_MUTEX(info_mutex); |
50 | |
51 | struct 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 | |
58 | static int snd_info_version_init(void); |
59 | static void snd_info_disconnect(struct snd_info_entry *entry); |
60 | |
61 | /* |
62 | |
63 | */ |
64 | |
65 | static struct snd_info_entry *snd_proc_root; |
66 | struct snd_info_entry *snd_seq_root; |
67 | EXPORT_SYMBOL(snd_seq_root); |
68 | |
69 | #ifdef CONFIG_SND_OSSEMUL |
70 | struct snd_info_entry *snd_oss_root; |
71 | #endif |
72 | |
73 | static 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(module: entry->module)) |
81 | return -EFAULT; |
82 | data = kzalloc(size: sizeof(*data), GFP_KERNEL); |
83 | if (!data) { |
84 | module_put(module: entry->module); |
85 | return -ENOMEM; |
86 | } |
87 | data->entry = entry; |
88 | *ret = data; |
89 | return 0; |
90 | } |
91 | |
92 | static 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 | */ |
104 | static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig) |
105 | { |
106 | struct snd_info_private_data *data; |
107 | struct snd_info_entry *entry; |
108 | loff_t ret = -EINVAL, size; |
109 | |
110 | data = file->private_data; |
111 | entry = data->entry; |
112 | mutex_lock(&entry->access); |
113 | if (entry->c.ops->llseek) { |
114 | ret = entry->c.ops->llseek(entry, |
115 | data->file_private_data, |
116 | file, offset, orig); |
117 | goto out; |
118 | } |
119 | |
120 | size = entry->size; |
121 | switch (orig) { |
122 | case SEEK_SET: |
123 | break; |
124 | case SEEK_CUR: |
125 | offset += file->f_pos; |
126 | break; |
127 | case SEEK_END: |
128 | if (!size) |
129 | goto out; |
130 | offset += size; |
131 | break; |
132 | default: |
133 | goto out; |
134 | } |
135 | if (offset < 0) |
136 | goto out; |
137 | if (size && offset > size) |
138 | offset = size; |
139 | file->f_pos = offset; |
140 | ret = offset; |
141 | out: |
142 | mutex_unlock(lock: &entry->access); |
143 | return ret; |
144 | } |
145 | |
146 | static ssize_t snd_info_entry_read(struct file *file, char __user *buffer, |
147 | size_t count, loff_t * offset) |
148 | { |
149 | struct snd_info_private_data *data = file->private_data; |
150 | struct snd_info_entry *entry = data->entry; |
151 | size_t size; |
152 | loff_t pos; |
153 | |
154 | pos = *offset; |
155 | if (!valid_pos(pos, count)) |
156 | return -EIO; |
157 | if (pos >= entry->size) |
158 | return 0; |
159 | size = entry->size - pos; |
160 | size = min(count, size); |
161 | size = entry->c.ops->read(entry, data->file_private_data, |
162 | file, buffer, size, pos); |
163 | if ((ssize_t) size > 0) |
164 | *offset = pos + size; |
165 | return size; |
166 | } |
167 | |
168 | static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer, |
169 | size_t count, loff_t * offset) |
170 | { |
171 | struct snd_info_private_data *data = file->private_data; |
172 | struct snd_info_entry *entry = data->entry; |
173 | ssize_t size = 0; |
174 | loff_t pos; |
175 | |
176 | pos = *offset; |
177 | if (!valid_pos(pos, count)) |
178 | return -EIO; |
179 | if (count > 0) { |
180 | size_t maxsize = entry->size - pos; |
181 | count = min(count, maxsize); |
182 | size = entry->c.ops->write(entry, data->file_private_data, |
183 | file, buffer, count, pos); |
184 | } |
185 | if (size > 0) |
186 | *offset = pos + size; |
187 | return size; |
188 | } |
189 | |
190 | static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait) |
191 | { |
192 | struct snd_info_private_data *data = file->private_data; |
193 | struct snd_info_entry *entry = data->entry; |
194 | __poll_t mask = 0; |
195 | |
196 | if (entry->c.ops->poll) |
197 | return entry->c.ops->poll(entry, |
198 | data->file_private_data, |
199 | file, wait); |
200 | if (entry->c.ops->read) |
201 | mask |= EPOLLIN | EPOLLRDNORM; |
202 | if (entry->c.ops->write) |
203 | mask |= EPOLLOUT | EPOLLWRNORM; |
204 | return mask; |
205 | } |
206 | |
207 | static long snd_info_entry_ioctl(struct file *file, unsigned int cmd, |
208 | unsigned long arg) |
209 | { |
210 | struct snd_info_private_data *data = file->private_data; |
211 | struct snd_info_entry *entry = data->entry; |
212 | |
213 | if (!entry->c.ops->ioctl) |
214 | return -ENOTTY; |
215 | return entry->c.ops->ioctl(entry, data->file_private_data, |
216 | file, cmd, arg); |
217 | } |
218 | |
219 | static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma) |
220 | { |
221 | struct inode *inode = file_inode(f: file); |
222 | struct snd_info_private_data *data; |
223 | struct snd_info_entry *entry; |
224 | |
225 | data = file->private_data; |
226 | if (data == NULL) |
227 | return 0; |
228 | entry = data->entry; |
229 | if (!entry->c.ops->mmap) |
230 | return -ENXIO; |
231 | return entry->c.ops->mmap(entry, data->file_private_data, |
232 | inode, file, vma); |
233 | } |
234 | |
235 | static int snd_info_entry_open(struct inode *inode, struct file *file) |
236 | { |
237 | struct snd_info_entry *entry = pde_data(inode); |
238 | struct snd_info_private_data *data; |
239 | int mode, err; |
240 | |
241 | mutex_lock(&info_mutex); |
242 | err = alloc_info_private(entry, ret: &data); |
243 | if (err < 0) |
244 | goto unlock; |
245 | |
246 | mode = file->f_flags & O_ACCMODE; |
247 | if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) || |
248 | ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) { |
249 | err = -ENODEV; |
250 | goto error; |
251 | } |
252 | |
253 | if (entry->c.ops->open) { |
254 | err = entry->c.ops->open(entry, mode, &data->file_private_data); |
255 | if (err < 0) |
256 | goto error; |
257 | } |
258 | |
259 | file->private_data = data; |
260 | mutex_unlock(lock: &info_mutex); |
261 | return 0; |
262 | |
263 | error: |
264 | kfree(objp: data); |
265 | module_put(module: entry->module); |
266 | unlock: |
267 | mutex_unlock(lock: &info_mutex); |
268 | return err; |
269 | } |
270 | |
271 | static int snd_info_entry_release(struct inode *inode, struct file *file) |
272 | { |
273 | struct snd_info_private_data *data = file->private_data; |
274 | struct snd_info_entry *entry = data->entry; |
275 | |
276 | if (entry->c.ops->release) |
277 | entry->c.ops->release(entry, file->f_flags & O_ACCMODE, |
278 | data->file_private_data); |
279 | module_put(module: entry->module); |
280 | kfree(objp: data); |
281 | return 0; |
282 | } |
283 | |
284 | static const struct proc_ops snd_info_entry_operations = |
285 | { |
286 | .proc_lseek = snd_info_entry_llseek, |
287 | .proc_read = snd_info_entry_read, |
288 | .proc_write = snd_info_entry_write, |
289 | .proc_poll = snd_info_entry_poll, |
290 | .proc_ioctl = snd_info_entry_ioctl, |
291 | .proc_mmap = snd_info_entry_mmap, |
292 | .proc_open = snd_info_entry_open, |
293 | .proc_release = snd_info_entry_release, |
294 | }; |
295 | |
296 | /* |
297 | * file ops for text proc files |
298 | */ |
299 | static ssize_t snd_info_text_entry_write(struct file *file, |
300 | const char __user *buffer, |
301 | size_t count, loff_t *offset) |
302 | { |
303 | struct seq_file *m = file->private_data; |
304 | struct snd_info_private_data *data = m->private; |
305 | struct snd_info_entry *entry = data->entry; |
306 | struct snd_info_buffer *buf; |
307 | loff_t pos; |
308 | size_t next; |
309 | int err = 0; |
310 | |
311 | if (!entry->c.text.write) |
312 | return -EIO; |
313 | pos = *offset; |
314 | if (!valid_pos(pos, count)) |
315 | return -EIO; |
316 | next = pos + count; |
317 | /* don't handle too large text inputs */ |
318 | if (next > 16 * 1024) |
319 | return -EIO; |
320 | mutex_lock(&entry->access); |
321 | buf = data->wbuffer; |
322 | if (!buf) { |
323 | data->wbuffer = buf = kzalloc(size: sizeof(*buf), GFP_KERNEL); |
324 | if (!buf) { |
325 | err = -ENOMEM; |
326 | goto error; |
327 | } |
328 | } |
329 | if (next > buf->len) { |
330 | char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL); |
331 | if (!nbuf) { |
332 | err = -ENOMEM; |
333 | goto error; |
334 | } |
335 | kvfree(addr: buf->buffer); |
336 | buf->buffer = nbuf; |
337 | buf->len = PAGE_ALIGN(next); |
338 | } |
339 | if (copy_from_user(to: buf->buffer + pos, from: buffer, n: count)) { |
340 | err = -EFAULT; |
341 | goto error; |
342 | } |
343 | buf->size = next; |
344 | error: |
345 | mutex_unlock(lock: &entry->access); |
346 | if (err < 0) |
347 | return err; |
348 | *offset = next; |
349 | return count; |
350 | } |
351 | |
352 | static int snd_info_seq_show(struct seq_file *seq, void *p) |
353 | { |
354 | struct snd_info_private_data *data = seq->private; |
355 | struct snd_info_entry *entry = data->entry; |
356 | |
357 | if (!entry->c.text.read) { |
358 | return -EIO; |
359 | } else { |
360 | data->rbuffer->buffer = (char *)seq; /* XXX hack! */ |
361 | entry->c.text.read(entry, data->rbuffer); |
362 | } |
363 | return 0; |
364 | } |
365 | |
366 | static int snd_info_text_entry_open(struct inode *inode, struct file *file) |
367 | { |
368 | struct snd_info_entry *entry = pde_data(inode); |
369 | struct snd_info_private_data *data; |
370 | int err; |
371 | |
372 | mutex_lock(&info_mutex); |
373 | err = alloc_info_private(entry, ret: &data); |
374 | if (err < 0) |
375 | goto unlock; |
376 | |
377 | data->rbuffer = kzalloc(size: sizeof(*data->rbuffer), GFP_KERNEL); |
378 | if (!data->rbuffer) { |
379 | err = -ENOMEM; |
380 | goto error; |
381 | } |
382 | if (entry->size) |
383 | err = single_open_size(file, snd_info_seq_show, data, |
384 | entry->size); |
385 | else |
386 | err = single_open(file, snd_info_seq_show, data); |
387 | if (err < 0) |
388 | goto error; |
389 | mutex_unlock(lock: &info_mutex); |
390 | return 0; |
391 | |
392 | error: |
393 | kfree(objp: data->rbuffer); |
394 | kfree(objp: data); |
395 | module_put(module: entry->module); |
396 | unlock: |
397 | mutex_unlock(lock: &info_mutex); |
398 | return err; |
399 | } |
400 | |
401 | static int snd_info_text_entry_release(struct inode *inode, struct file *file) |
402 | { |
403 | struct seq_file *m = file->private_data; |
404 | struct snd_info_private_data *data = m->private; |
405 | struct snd_info_entry *entry = data->entry; |
406 | |
407 | if (data->wbuffer && entry->c.text.write) |
408 | entry->c.text.write(entry, data->wbuffer); |
409 | |
410 | single_release(inode, file); |
411 | kfree(objp: data->rbuffer); |
412 | if (data->wbuffer) { |
413 | kvfree(addr: data->wbuffer->buffer); |
414 | kfree(objp: data->wbuffer); |
415 | } |
416 | |
417 | module_put(module: entry->module); |
418 | kfree(objp: data); |
419 | return 0; |
420 | } |
421 | |
422 | static const struct proc_ops snd_info_text_entry_ops = |
423 | { |
424 | .proc_open = snd_info_text_entry_open, |
425 | .proc_release = snd_info_text_entry_release, |
426 | .proc_write = snd_info_text_entry_write, |
427 | .proc_lseek = seq_lseek, |
428 | .proc_read = seq_read, |
429 | }; |
430 | |
431 | static struct snd_info_entry *create_subdir(struct module *mod, |
432 | const char *name) |
433 | { |
434 | struct snd_info_entry *entry; |
435 | |
436 | entry = snd_info_create_module_entry(module: mod, name, NULL); |
437 | if (!entry) |
438 | return NULL; |
439 | entry->mode = S_IFDIR | 0555; |
440 | if (snd_info_register(entry) < 0) { |
441 | snd_info_free_entry(entry); |
442 | return NULL; |
443 | } |
444 | return entry; |
445 | } |
446 | |
447 | static struct snd_info_entry * |
448 | snd_info_create_entry(const char *name, struct snd_info_entry *parent, |
449 | struct module *module); |
450 | |
451 | int __init snd_info_init(void) |
452 | { |
453 | snd_proc_root = snd_info_create_entry(name: "asound" , NULL, THIS_MODULE); |
454 | if (!snd_proc_root) |
455 | return -ENOMEM; |
456 | snd_proc_root->mode = S_IFDIR | 0555; |
457 | snd_proc_root->p = proc_mkdir("asound" , NULL); |
458 | if (!snd_proc_root->p) |
459 | goto error; |
460 | #ifdef CONFIG_SND_OSSEMUL |
461 | snd_oss_root = create_subdir(THIS_MODULE, name: "oss" ); |
462 | if (!snd_oss_root) |
463 | goto error; |
464 | #endif |
465 | #if IS_ENABLED(CONFIG_SND_SEQUENCER) |
466 | snd_seq_root = create_subdir(THIS_MODULE, name: "seq" ); |
467 | if (!snd_seq_root) |
468 | goto error; |
469 | #endif |
470 | if (snd_info_version_init() < 0 || |
471 | snd_minor_info_init() < 0 || |
472 | snd_minor_info_oss_init() < 0 || |
473 | snd_card_info_init() < 0 || |
474 | snd_info_minor_register() < 0) |
475 | goto error; |
476 | return 0; |
477 | |
478 | error: |
479 | snd_info_free_entry(entry: snd_proc_root); |
480 | return -ENOMEM; |
481 | } |
482 | |
483 | int __exit snd_info_done(void) |
484 | { |
485 | snd_info_free_entry(entry: snd_proc_root); |
486 | return 0; |
487 | } |
488 | |
489 | static void snd_card_id_read(struct snd_info_entry *entry, |
490 | struct snd_info_buffer *buffer) |
491 | { |
492 | struct snd_card *card = entry->private_data; |
493 | |
494 | snd_iprintf(buffer, "%s\n" , card->id); |
495 | } |
496 | |
497 | /* |
498 | * create a card proc file |
499 | * called from init.c |
500 | */ |
501 | int snd_info_card_create(struct snd_card *card) |
502 | { |
503 | char str[8]; |
504 | struct snd_info_entry *entry; |
505 | |
506 | if (snd_BUG_ON(!card)) |
507 | return -ENXIO; |
508 | |
509 | sprintf(buf: str, fmt: "card%i" , card->number); |
510 | entry = create_subdir(mod: card->module, name: str); |
511 | if (!entry) |
512 | return -ENOMEM; |
513 | card->proc_root = entry; |
514 | |
515 | return snd_card_ro_proc_new(card, name: "id" , private_data: card, read: snd_card_id_read); |
516 | } |
517 | |
518 | /* |
519 | * register the card proc file |
520 | * called from init.c |
521 | * can be called multiple times for reinitialization |
522 | */ |
523 | int snd_info_card_register(struct snd_card *card) |
524 | { |
525 | struct proc_dir_entry *p; |
526 | int err; |
527 | |
528 | if (snd_BUG_ON(!card)) |
529 | return -ENXIO; |
530 | |
531 | err = snd_info_register(entry: card->proc_root); |
532 | if (err < 0) |
533 | return err; |
534 | |
535 | if (!strcmp(card->id, card->proc_root->name)) |
536 | return 0; |
537 | |
538 | if (card->proc_root_link) |
539 | return 0; |
540 | p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name); |
541 | if (!p) |
542 | return -ENOMEM; |
543 | card->proc_root_link = p; |
544 | return 0; |
545 | } |
546 | |
547 | /* |
548 | * called on card->id change |
549 | */ |
550 | void snd_info_card_id_change(struct snd_card *card) |
551 | { |
552 | mutex_lock(&info_mutex); |
553 | if (card->proc_root_link) { |
554 | proc_remove(card->proc_root_link); |
555 | card->proc_root_link = NULL; |
556 | } |
557 | if (strcmp(card->id, card->proc_root->name)) |
558 | card->proc_root_link = proc_symlink(card->id, |
559 | snd_proc_root->p, |
560 | card->proc_root->name); |
561 | mutex_unlock(lock: &info_mutex); |
562 | } |
563 | |
564 | /* |
565 | * de-register the card proc file |
566 | * called from init.c |
567 | */ |
568 | void snd_info_card_disconnect(struct snd_card *card) |
569 | { |
570 | if (!card) |
571 | return; |
572 | mutex_lock(&info_mutex); |
573 | proc_remove(card->proc_root_link); |
574 | card->proc_root_link = NULL; |
575 | if (card->proc_root) |
576 | snd_info_disconnect(entry: card->proc_root); |
577 | mutex_unlock(lock: &info_mutex); |
578 | } |
579 | |
580 | /* |
581 | * release the card proc file resources |
582 | * called from init.c |
583 | */ |
584 | int snd_info_card_free(struct snd_card *card) |
585 | { |
586 | if (!card) |
587 | return 0; |
588 | snd_info_free_entry(entry: card->proc_root); |
589 | card->proc_root = NULL; |
590 | return 0; |
591 | } |
592 | |
593 | |
594 | /** |
595 | * snd_info_get_line - read one line from the procfs buffer |
596 | * @buffer: the procfs buffer |
597 | * @line: the buffer to store |
598 | * @len: the max. buffer size |
599 | * |
600 | * Reads one line from the buffer and stores the string. |
601 | * |
602 | * Return: Zero if successful, or 1 if error or EOF. |
603 | */ |
604 | int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len) |
605 | { |
606 | int c; |
607 | |
608 | if (snd_BUG_ON(!buffer)) |
609 | return 1; |
610 | if (!buffer->buffer) |
611 | return 1; |
612 | if (len <= 0 || buffer->stop || buffer->error) |
613 | return 1; |
614 | while (!buffer->stop) { |
615 | c = buffer->buffer[buffer->curr++]; |
616 | if (buffer->curr >= buffer->size) |
617 | buffer->stop = 1; |
618 | if (c == '\n') |
619 | break; |
620 | if (len > 1) { |
621 | len--; |
622 | *line++ = c; |
623 | } |
624 | } |
625 | *line = '\0'; |
626 | return 0; |
627 | } |
628 | EXPORT_SYMBOL(snd_info_get_line); |
629 | |
630 | /** |
631 | * snd_info_get_str - parse a string token |
632 | * @dest: the buffer to store the string token |
633 | * @src: the original string |
634 | * @len: the max. length of token - 1 |
635 | * |
636 | * Parses the original string and copy a token to the given |
637 | * string buffer. |
638 | * |
639 | * Return: The updated pointer of the original string so that |
640 | * it can be used for the next call. |
641 | */ |
642 | const char *snd_info_get_str(char *dest, const char *src, int len) |
643 | { |
644 | int c; |
645 | |
646 | while (*src == ' ' || *src == '\t') |
647 | src++; |
648 | if (*src == '"' || *src == '\'') { |
649 | c = *src++; |
650 | while (--len > 0 && *src && *src != c) { |
651 | *dest++ = *src++; |
652 | } |
653 | if (*src == c) |
654 | src++; |
655 | } else { |
656 | while (--len > 0 && *src && *src != ' ' && *src != '\t') { |
657 | *dest++ = *src++; |
658 | } |
659 | } |
660 | *dest = 0; |
661 | while (*src == ' ' || *src == '\t') |
662 | src++; |
663 | return src; |
664 | } |
665 | EXPORT_SYMBOL(snd_info_get_str); |
666 | |
667 | /* |
668 | * snd_info_create_entry - create an info entry |
669 | * @name: the proc file name |
670 | * @parent: the parent directory |
671 | * |
672 | * Creates an info entry with the given file name and initializes as |
673 | * the default state. |
674 | * |
675 | * Usually called from other functions such as |
676 | * snd_info_create_card_entry(). |
677 | * |
678 | * Return: The pointer of the new instance, or %NULL on failure. |
679 | */ |
680 | static struct snd_info_entry * |
681 | snd_info_create_entry(const char *name, struct snd_info_entry *parent, |
682 | struct module *module) |
683 | { |
684 | struct snd_info_entry *entry; |
685 | entry = kzalloc(size: sizeof(*entry), GFP_KERNEL); |
686 | if (entry == NULL) |
687 | return NULL; |
688 | entry->name = kstrdup(s: name, GFP_KERNEL); |
689 | if (entry->name == NULL) { |
690 | kfree(objp: entry); |
691 | return NULL; |
692 | } |
693 | entry->mode = S_IFREG | 0444; |
694 | entry->content = SNDRV_INFO_CONTENT_TEXT; |
695 | mutex_init(&entry->access); |
696 | INIT_LIST_HEAD(list: &entry->children); |
697 | INIT_LIST_HEAD(list: &entry->list); |
698 | entry->parent = parent; |
699 | entry->module = module; |
700 | if (parent) { |
701 | mutex_lock(&parent->access); |
702 | list_add_tail(new: &entry->list, head: &parent->children); |
703 | mutex_unlock(lock: &parent->access); |
704 | } |
705 | return entry; |
706 | } |
707 | |
708 | /** |
709 | * snd_info_create_module_entry - create an info entry for the given module |
710 | * @module: the module pointer |
711 | * @name: the file name |
712 | * @parent: the parent directory |
713 | * |
714 | * Creates a new info entry and assigns it to the given module. |
715 | * |
716 | * Return: The pointer of the new instance, or %NULL on failure. |
717 | */ |
718 | struct snd_info_entry *snd_info_create_module_entry(struct module * module, |
719 | const char *name, |
720 | struct snd_info_entry *parent) |
721 | { |
722 | if (!parent) |
723 | parent = snd_proc_root; |
724 | return snd_info_create_entry(name, parent, module); |
725 | } |
726 | EXPORT_SYMBOL(snd_info_create_module_entry); |
727 | |
728 | /** |
729 | * snd_info_create_card_entry - create an info entry for the given card |
730 | * @card: the card instance |
731 | * @name: the file name |
732 | * @parent: the parent directory |
733 | * |
734 | * Creates a new info entry and assigns it to the given card. |
735 | * |
736 | * Return: The pointer of the new instance, or %NULL on failure. |
737 | */ |
738 | struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card, |
739 | const char *name, |
740 | struct snd_info_entry * parent) |
741 | { |
742 | if (!parent) |
743 | parent = card->proc_root; |
744 | return snd_info_create_entry(name, parent, module: card->module); |
745 | } |
746 | EXPORT_SYMBOL(snd_info_create_card_entry); |
747 | |
748 | static void snd_info_disconnect(struct snd_info_entry *entry) |
749 | { |
750 | struct snd_info_entry *p; |
751 | |
752 | if (!entry->p) |
753 | return; |
754 | list_for_each_entry(p, &entry->children, list) |
755 | snd_info_disconnect(entry: p); |
756 | proc_remove(entry->p); |
757 | entry->p = NULL; |
758 | } |
759 | |
760 | /** |
761 | * snd_info_free_entry - release the info entry |
762 | * @entry: the info entry |
763 | * |
764 | * Releases the info entry. |
765 | */ |
766 | void snd_info_free_entry(struct snd_info_entry * entry) |
767 | { |
768 | struct snd_info_entry *p, *n; |
769 | |
770 | if (!entry) |
771 | return; |
772 | if (entry->p) { |
773 | mutex_lock(&info_mutex); |
774 | snd_info_disconnect(entry); |
775 | mutex_unlock(lock: &info_mutex); |
776 | } |
777 | |
778 | /* free all children at first */ |
779 | list_for_each_entry_safe(p, n, &entry->children, list) |
780 | snd_info_free_entry(entry: p); |
781 | |
782 | p = entry->parent; |
783 | if (p) { |
784 | mutex_lock(&p->access); |
785 | list_del(entry: &entry->list); |
786 | mutex_unlock(lock: &p->access); |
787 | } |
788 | kfree(objp: entry->name); |
789 | if (entry->private_free) |
790 | entry->private_free(entry); |
791 | kfree(objp: entry); |
792 | } |
793 | EXPORT_SYMBOL(snd_info_free_entry); |
794 | |
795 | static int __snd_info_register(struct snd_info_entry *entry) |
796 | { |
797 | struct proc_dir_entry *root, *p = NULL; |
798 | |
799 | if (snd_BUG_ON(!entry)) |
800 | return -ENXIO; |
801 | root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p; |
802 | mutex_lock(&info_mutex); |
803 | if (entry->p || !root) |
804 | goto unlock; |
805 | if (S_ISDIR(entry->mode)) { |
806 | p = proc_mkdir_mode(entry->name, entry->mode, root); |
807 | if (!p) { |
808 | mutex_unlock(lock: &info_mutex); |
809 | return -ENOMEM; |
810 | } |
811 | } else { |
812 | const struct proc_ops *ops; |
813 | if (entry->content == SNDRV_INFO_CONTENT_DATA) |
814 | ops = &snd_info_entry_operations; |
815 | else |
816 | ops = &snd_info_text_entry_ops; |
817 | p = proc_create_data(entry->name, entry->mode, root, |
818 | ops, entry); |
819 | if (!p) { |
820 | mutex_unlock(lock: &info_mutex); |
821 | return -ENOMEM; |
822 | } |
823 | proc_set_size(p, entry->size); |
824 | } |
825 | entry->p = p; |
826 | unlock: |
827 | mutex_unlock(lock: &info_mutex); |
828 | return 0; |
829 | } |
830 | |
831 | /** |
832 | * snd_info_register - register the info entry |
833 | * @entry: the info entry |
834 | * |
835 | * Registers the proc info entry. |
836 | * The all children entries are registered recursively. |
837 | * |
838 | * Return: Zero if successful, or a negative error code on failure. |
839 | */ |
840 | int snd_info_register(struct snd_info_entry *entry) |
841 | { |
842 | struct snd_info_entry *p; |
843 | int err; |
844 | |
845 | if (!entry->p) { |
846 | err = __snd_info_register(entry); |
847 | if (err < 0) |
848 | return err; |
849 | } |
850 | |
851 | list_for_each_entry(p, &entry->children, list) { |
852 | err = snd_info_register(entry: p); |
853 | if (err < 0) |
854 | return err; |
855 | } |
856 | |
857 | return 0; |
858 | } |
859 | EXPORT_SYMBOL(snd_info_register); |
860 | |
861 | /** |
862 | * snd_card_rw_proc_new - Create a read/write text proc file entry for the card |
863 | * @card: the card instance |
864 | * @name: the file name |
865 | * @private_data: the arbitrary private data |
866 | * @read: the read callback |
867 | * @write: the write callback, NULL for read-only |
868 | * |
869 | * This proc file entry will be registered via snd_card_register() call, and |
870 | * it will be removed automatically at the card removal, too. |
871 | * |
872 | * Return: zero if successful, or a negative error code |
873 | */ |
874 | int snd_card_rw_proc_new(struct snd_card *card, const char *name, |
875 | void *private_data, |
876 | void (*read)(struct snd_info_entry *, |
877 | struct snd_info_buffer *), |
878 | void (*write)(struct snd_info_entry *entry, |
879 | struct snd_info_buffer *buffer)) |
880 | { |
881 | struct snd_info_entry *entry; |
882 | |
883 | entry = snd_info_create_card_entry(card, name, card->proc_root); |
884 | if (!entry) |
885 | return -ENOMEM; |
886 | snd_info_set_text_ops(entry, private_data, read); |
887 | if (write) { |
888 | entry->mode |= 0200; |
889 | entry->c.text.write = write; |
890 | } |
891 | return 0; |
892 | } |
893 | EXPORT_SYMBOL_GPL(snd_card_rw_proc_new); |
894 | |
895 | /* |
896 | |
897 | */ |
898 | |
899 | static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) |
900 | { |
901 | snd_iprintf(buffer, |
902 | "Advanced Linux Sound Architecture Driver Version k%s.\n" , |
903 | init_utsname()->release); |
904 | } |
905 | |
906 | static int __init snd_info_version_init(void) |
907 | { |
908 | struct snd_info_entry *entry; |
909 | |
910 | entry = snd_info_create_module_entry(THIS_MODULE, "version" , NULL); |
911 | if (entry == NULL) |
912 | return -ENOMEM; |
913 | entry->c.text.read = snd_info_version_read; |
914 | return snd_info_register(entry); /* freed in error path */ |
915 | } |
916 | |