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_clear_entries(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 size; |
109 | |
110 | data = file->private_data; |
111 | entry = data->entry; |
112 | guard(mutex)(T: &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 | |
141 | static 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 | |
163 | static 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 | |
185 | static __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 | |
202 | static 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 | |
214 | static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma) |
215 | { |
216 | struct inode *inode = file_inode(f: 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 | |
230 | static 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)(T: &info_mutex); |
237 | err = alloc_info_private(entry, ret: &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(objp: data); |
259 | module_put(module: entry->module); |
260 | return err; |
261 | } |
262 | |
263 | static 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(module: entry->module); |
272 | kfree(objp: data); |
273 | return 0; |
274 | } |
275 | |
276 | static 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 | */ |
291 | static 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)(T: &entry->access); |
312 | buf = data->wbuffer; |
313 | if (!buf) { |
314 | data->wbuffer = buf = kzalloc(size: 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(addr: buf->buffer); |
323 | buf->buffer = nbuf; |
324 | buf->len = PAGE_ALIGN(next); |
325 | } |
326 | if (copy_from_user(to: buf->buffer + pos, from: buffer, n: count)) |
327 | return -EFAULT; |
328 | buf->size = next; |
329 | *offset = next; |
330 | return count; |
331 | } |
332 | |
333 | static 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 | |
347 | static 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)(T: &info_mutex); |
354 | err = alloc_info_private(entry, ret: &data); |
355 | if (err < 0) |
356 | return err; |
357 | |
358 | data->rbuffer = kzalloc(size: 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(objp: data->rbuffer); |
374 | kfree(objp: data); |
375 | module_put(module: entry->module); |
376 | return err; |
377 | } |
378 | |
379 | static 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(objp: data->rbuffer); |
390 | if (data->wbuffer) { |
391 | kvfree(addr: data->wbuffer->buffer); |
392 | kfree(objp: data->wbuffer); |
393 | } |
394 | |
395 | module_put(module: entry->module); |
396 | kfree(objp: data); |
397 | return 0; |
398 | } |
399 | |
400 | static 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 | |
409 | static 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(module: 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 | |
425 | static struct snd_info_entry * |
426 | snd_info_create_entry(const char *name, struct snd_info_entry *parent, |
427 | struct module *module); |
428 | |
429 | int __init snd_info_init(void) |
430 | { |
431 | snd_proc_root = snd_info_create_entry(name: "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, name: "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, name: "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(entry: snd_proc_root); |
458 | return -ENOMEM; |
459 | } |
460 | |
461 | int __exit snd_info_done(void) |
462 | { |
463 | snd_info_free_entry(entry: snd_proc_root); |
464 | return 0; |
465 | } |
466 | |
467 | static 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 | */ |
479 | int 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(buf: str, fmt: "card%i" , card->number); |
488 | entry = create_subdir(mod: card->module, name: str); |
489 | if (!entry) |
490 | return -ENOMEM; |
491 | card->proc_root = entry; |
492 | |
493 | return snd_card_ro_proc_new(card, name: "id" , private_data: card, read: 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 | */ |
501 | int 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(entry: 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 | */ |
528 | void snd_info_card_id_change(struct snd_card *card) |
529 | { |
530 | guard(mutex)(T: &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 | */ |
545 | void 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)(T: &info_mutex); |
555 | if (card->proc_root) |
556 | snd_info_clear_entries(entry: 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 | */ |
565 | int snd_info_card_free(struct snd_card *card) |
566 | { |
567 | if (!card) |
568 | return 0; |
569 | snd_info_free_entry(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 | */ |
585 | int 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 | } |
609 | EXPORT_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 | */ |
623 | const 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 | } |
646 | EXPORT_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 | */ |
661 | static struct snd_info_entry * |
662 | snd_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(size: sizeof(*entry), GFP_KERNEL); |
667 | if (entry == NULL) |
668 | return NULL; |
669 | entry->name = kstrdup(s: name, GFP_KERNEL); |
670 | if (entry->name == NULL) { |
671 | kfree(objp: 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(list: &entry->children); |
678 | INIT_LIST_HEAD(list: &entry->list); |
679 | entry->parent = parent; |
680 | entry->module = module; |
681 | if (parent) { |
682 | guard(mutex)(T: &parent->access); |
683 | list_add_tail(new: &entry->list, head: &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 | */ |
698 | struct 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 | } |
706 | EXPORT_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 | */ |
718 | struct 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, module: card->module); |
725 | } |
726 | EXPORT_SYMBOL(snd_info_create_card_entry); |
727 | |
728 | static 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(entry: 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 | */ |
745 | void 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)(T: &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(entry: p); |
760 | |
761 | p = entry->parent; |
762 | if (p) { |
763 | guard(mutex)(T: &p->access); |
764 | list_del(entry: &entry->list); |
765 | } |
766 | kfree(objp: entry->name); |
767 | if (entry->private_free) |
768 | entry->private_free(entry); |
769 | kfree(objp: entry); |
770 | } |
771 | EXPORT_SYMBOL(snd_info_free_entry); |
772 | |
773 | static 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)(T: &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 | */ |
812 | int 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(entry: p); |
825 | if (err < 0) |
826 | return err; |
827 | } |
828 | |
829 | return 0; |
830 | } |
831 | EXPORT_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 | */ |
846 | int 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 | } |
865 | EXPORT_SYMBOL_GPL(snd_card_rw_proc_new); |
866 | |
867 | /* |
868 | |
869 | */ |
870 | |
871 | static 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 | |
878 | static 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 | } |
888 | |