sound/core/info.c

   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 int snd_info_check_reserved_words(const char *str)
  37 {
  38         static char *reserved[] =
  39         {
  40                 "version",
  41                 "meminfo",
  42                 "memdebug",
  43                 "detect",
  44                 "devices",
  45                 "oss",
  46                 "cards",
  47                 "timers",
  48                 "synth",
  49                 "pcm",
  50                 "seq",
  51                 NULL
  52         };
  53         char **xstr = reserved;
  54
  55         while (*xstr) {
  56                 if (!strcmp(*xstr, str))
  57                         return 0;
  58                 xstr++;
  59         }
  60         if (!strncmp(str, "card", 4))
  61                 return 0;
  62         return 1;
  63 }
  64
  65 static DEFINE_MUTEX(info_mutex);
  66
  67 struct snd_info_private_data {
  68         struct snd_info_buffer *rbuffer;
  69         struct snd_info_buffer *wbuffer;
  70         struct snd_info_entry *entry;
  71         void *file_private_data;
  72 };
  73
  74 static int snd_info_version_init(void);
  75 static void snd_info_disconnect(struct snd_info_entry *entry);
  76
  77 /*
  78
  79  */
  80
  81 static struct snd_info_entry *snd_proc_root;
  82 struct snd_info_entry *snd_seq_root;
  83 EXPORT_SYMBOL(snd_seq_root);
  84
  85 #ifdef CONFIG_SND_OSSEMUL
  86 struct snd_info_entry *snd_oss_root;
  87 #endif
  88
  89 static int alloc_info_private(struct snd_info_entry *entry,
  90                               struct snd_info_private_data **ret)
  91 {
  92         struct snd_info_private_data *data;
  93
  94         if (!entry || !entry->p)
  95                 return -ENODEV;
  96         if (!try_module_get(entry->module))
  97                 return -EFAULT;
  98         data = kzalloc(sizeof(*data), GFP_KERNEL);
  99         if (!data) {
 100                 module_put(entry->module);
 101                 return -ENOMEM;
 102         }
 103         data->entry = entry;
 104         *ret = data;
 105         return 0;
 106 }
 107
 108 static bool valid_pos(loff_t pos, size_t count)
 109 {
 110         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 111                 return false;
 112         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 113                 return false;
 114         return true;
 115 }
 116
 117 /*
 118  * file ops for binary proc files
 119  */
 120 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 121 {
 122         struct snd_info_private_data *data;
 123         struct snd_info_entry *entry;
 124         loff_t ret = -EINVAL, size;
 125
 126         data = file->private_data;
 127         entry = data->entry;
 128         mutex_lock(&entry->access);
 129         if (entry->c.ops->llseek) {
 130                 offset = entry->c.ops->llseek(entry,
 131                                               data->file_private_data,
 132                                               file, offset, orig);
 133                 goto out;
 134         }
 135
 136         size = entry->size;
 137         switch (orig) {
 138         case SEEK_SET:
 139                 break;
 140         case SEEK_CUR:
 141                 offset += file->f_pos;
 142                 break;
 143         case SEEK_END:
 144                 if (!size)
 145                         goto out;
 146                 offset += size;
 147                 break;
 148         default:
 149                 goto out;
 150         }
 151         if (offset < 0)
 152                 goto out;
 153         if (size && offset > size)
 154                 offset = size;
 155         file->f_pos = offset;
 156         ret = offset;
 157  out:
 158         mutex_unlock(&entry->access);
 159         return ret;
 160 }
 161
 162 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 163                                    size_t count, loff_t * offset)
 164 {
 165         struct snd_info_private_data *data = file->private_data;
 166         struct snd_info_entry *entry = data->entry;
 167         size_t size;
 168         loff_t pos;
 169
 170         pos = *offset;
 171         if (!valid_pos(pos, count))
 172                 return -EIO;
 173         if (pos >= entry->size)
 174                 return 0;
 175         size = entry->size - pos;
 176         size = min(count, size);
 177         size = entry->c.ops->read(entry, data->file_private_data,
 178                                   file, buffer, size, pos);
 179         if ((ssize_t) size > 0)
 180                 *offset = pos + size;
 181         return size;
 182 }
 183
 184 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 185                                     size_t count, loff_t * offset)
 186 {
 187         struct snd_info_private_data *data = file->private_data;
 188         struct snd_info_entry *entry = data->entry;
 189         ssize_t size = 0;
 190         loff_t pos;
 191
 192         pos = *offset;
 193         if (!valid_pos(pos, count))
 194                 return -EIO;
 195         if (count > 0) {
 196                 size_t maxsize = entry->size - pos;
 197                 count = min(count, maxsize);
 198                 size = entry->c.ops->write(entry, data->file_private_data,
 199                                            file, buffer, count, pos);
 200         }
 201         if (size > 0)
 202                 *offset = pos + size;
 203         return size;
 204 }
 205
 206 static unsigned int snd_info_entry_poll(struct file *file, poll_table *wait)
 207 {
 208         struct snd_info_private_data *data = file->private_data;
 209         struct snd_info_entry *entry = data->entry;
 210         unsigned int mask = 0;
 211
 212         if (entry->c.ops->poll)
 213                 return entry->c.ops->poll(entry,
 214                                           data->file_private_data,
 215                                           file, wait);
 216         if (entry->c.ops->read)
 217                 mask |= POLLIN | POLLRDNORM;
 218         if (entry->c.ops->write)
 219                 mask |= POLLOUT | POLLWRNORM;
 220         return mask;
 221 }
 222
 223 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 224                                 unsigned long arg)
 225 {
 226         struct snd_info_private_data *data = file->private_data;
 227         struct snd_info_entry *entry = data->entry;
 228
 229         if (!entry->c.ops->ioctl)
 230                 return -ENOTTY;
 231         return entry->c.ops->ioctl(entry, data->file_private_data,
 232                                    file, cmd, arg);
 233 }
 234
 235 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 236 {
 237         struct inode *inode = file_inode(file);
 238         struct snd_info_private_data *data;
 239         struct snd_info_entry *entry;
 240
 241         data = file->private_data;
 242         if (data == NULL)
 243                 return 0;
 244         entry = data->entry;
 245         if (!entry->c.ops->mmap)
 246                 return -ENXIO;
 247         return entry->c.ops->mmap(entry, data->file_private_data,
 248                                   inode, file, vma);
 249 }
 250
 251 static int snd_info_entry_open(struct inode *inode, struct file *file)
 252 {
 253         struct snd_info_entry *entry = PDE_DATA(inode);
 254         struct snd_info_private_data *data;
 255         int mode, err;
 256
 257         mutex_lock(&info_mutex);
 258         err = alloc_info_private(entry, &data);
 259         if (err < 0)
 260                 goto unlock;
 261
 262         mode = file->f_flags & O_ACCMODE;
 263         if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
 264             ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
 265                 err = -ENODEV;
 266                 goto error;
 267         }
 268
 269         if (entry->c.ops->open) {
 270                 err = entry->c.ops->open(entry, mode, &data->file_private_data);
 271                 if (err < 0)
 272                         goto error;
 273         }
 274
 275         file->private_data = data;
 276         mutex_unlock(&info_mutex);
 277         return 0;
 278
 279  error:
 280         kfree(data);
 281         module_put(entry->module);
 282  unlock:
 283         mutex_unlock(&info_mutex);
 284         return err;
 285 }
 286
 287 static int snd_info_entry_release(struct inode *inode, struct file *file)
 288 {
 289         struct snd_info_private_data *data = file->private_data;
 290         struct snd_info_entry *entry = data->entry;
 291
 292         if (entry->c.ops->release)
 293                 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
 294                                       data->file_private_data);
 295         module_put(entry->module);
 296         kfree(data);
 297         return 0;
 298 }
 299
 300 static const struct file_operations snd_info_entry_operations =
 301 {
 302         .owner =                THIS_MODULE,
 303         .llseek =               snd_info_entry_llseek,
 304         .read =                 snd_info_entry_read,
 305         .write =                snd_info_entry_write,
 306         .poll =                 snd_info_entry_poll,
 307         .unlocked_ioctl =       snd_info_entry_ioctl,
 308         .mmap =                 snd_info_entry_mmap,
 309         .open =                 snd_info_entry_open,
 310         .release =              snd_info_entry_release,
 311 };
 312
 313 /*
 314  * file ops for text proc files
 315  */
 316 static ssize_t snd_info_text_entry_write(struct file *file,
 317                                          const char __user *buffer,
 318                                          size_t count, loff_t *offset)
 319 {
 320         struct seq_file *m = file->private_data;
 321         struct snd_info_private_data *data = m->private;
 322         struct snd_info_entry *entry = data->entry;
 323         struct snd_info_buffer *buf;
 324         loff_t pos;
 325         size_t next;
 326         int err = 0;
 327
 328         if (!entry->c.text.write)
 329                 return -EIO;
 330         pos = *offset;
 331         if (!valid_pos(pos, count))
 332                 return -EIO;
 333         next = pos + count;
 334         /* don't handle too large text inputs */
 335         if (next > 16 * 1024)
 336                 return -EIO;
 337         mutex_lock(&entry->access);
 338         buf = data->wbuffer;
 339         if (!buf) {
 340                 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 341                 if (!buf) {
 342                         err = -ENOMEM;
 343                         goto error;
 344                 }
 345         }
 346         if (next > buf->len) {
 347                 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
 348                 if (!nbuf) {
 349                         err = -ENOMEM;
 350                         goto error;
 351                 }
 352                 kvfree(buf->buffer);
 353                 buf->buffer = nbuf;
 354                 buf->len = PAGE_ALIGN(next);
 355         }
 356         if (copy_from_user(buf->buffer + pos, buffer, count)) {
 357                 err = -EFAULT;
 358                 goto error;
 359         }
 360         buf->size = next;
 361  error:
 362         mutex_unlock(&entry->access);
 363         if (err < 0)
 364                 return err;
 365         *offset = next;
 366         return count;
 367 }
 368
 369 static int snd_info_seq_show(struct seq_file *seq, void *p)
 370 {
 371         struct snd_info_private_data *data = seq->private;
 372         struct snd_info_entry *entry = data->entry;
 373
 374         if (!entry->c.text.read) {
 375                 return -EIO;
 376         } else {
 377                 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
 378                 entry->c.text.read(entry, data->rbuffer);
 379         }
 380         return 0;
 381 }
 382
 383 static int snd_info_text_entry_open(struct inode *inode, struct file *file)
 384 {
 385         struct snd_info_entry *entry = PDE_DATA(inode);
 386         struct snd_info_private_data *data;
 387         int err;
 388
 389         mutex_lock(&info_mutex);
 390         err = alloc_info_private(entry, &data);
 391         if (err < 0)
 392                 goto unlock;
 393
 394         data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
 395         if (!data->rbuffer) {
 396                 err = -ENOMEM;
 397                 goto error;
 398         }
 399         if (entry->size)
 400                 err = single_open_size(file, snd_info_seq_show, data,
 401                                        entry->size);
 402         else
 403                 err = single_open(file, snd_info_seq_show, data);
 404         if (err < 0)
 405                 goto error;
 406         mutex_unlock(&info_mutex);
 407         return 0;
 408
 409  error:
 410         kfree(data->rbuffer);
 411         kfree(data);
 412         module_put(entry->module);
 413  unlock:
 414         mutex_unlock(&info_mutex);
 415         return err;
 416 }
 417
 418 static int snd_info_text_entry_release(struct inode *inode, struct file *file)
 419 {
 420         struct seq_file *m = file->private_data;
 421         struct snd_info_private_data *data = m->private;
 422         struct snd_info_entry *entry = data->entry;
 423
 424         if (data->wbuffer && entry->c.text.write)
 425                 entry->c.text.write(entry, data->wbuffer);
 426
 427         single_release(inode, file);
 428         kfree(data->rbuffer);
 429         if (data->wbuffer) {
 430                 kvfree(data->wbuffer->buffer);
 431                 kfree(data->wbuffer);
 432         }
 433
 434         module_put(entry->module);
 435         kfree(data);
 436         return 0;
 437 }
 438
 439 static const struct file_operations snd_info_text_entry_ops =
 440 {
 441         .owner =                THIS_MODULE,
 442         .open =                 snd_info_text_entry_open,
 443         .release =              snd_info_text_entry_release,
 444         .write =                snd_info_text_entry_write,
 445         .llseek =               seq_lseek,
 446         .read =                 seq_read,
 447 };
 448
 449 static struct snd_info_entry *create_subdir(struct module *mod,
 450                                             const char *name)
 451 {
 452         struct snd_info_entry *entry;
 453
 454         entry = snd_info_create_module_entry(mod, name, NULL);
 455         if (!entry)
 456                 return NULL;
 457         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 458         if (snd_info_register(entry) < 0) {
 459                 snd_info_free_entry(entry);
 460                 return NULL;
 461         }
 462         return entry;
 463 }
 464
 465 static struct snd_info_entry *
 466 snd_info_create_entry(const char *name, struct snd_info_entry *parent);
 467
 468 int __init snd_info_init(void)
 469 {
 470         snd_proc_root = snd_info_create_entry("asound", NULL);
 471         if (!snd_proc_root)
 472                 return -ENOMEM;
 473         snd_proc_root->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 474         snd_proc_root->p = proc_mkdir("asound", NULL);
 475         if (!snd_proc_root->p)
 476                 goto error;
 477 #ifdef CONFIG_SND_OSSEMUL
 478         snd_oss_root = create_subdir(THIS_MODULE, "oss");
 479         if (!snd_oss_root)
 480                 goto error;
 481 #endif
 482 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
 483         snd_seq_root = create_subdir(THIS_MODULE, "seq");
 484         if (!snd_seq_root)
 485                 goto error;
 486 #endif
 487         if (snd_info_version_init() < 0 ||
 488             snd_minor_info_init() < 0 ||
 489             snd_minor_info_oss_init() < 0 ||
 490             snd_card_info_init() < 0 ||
 491             snd_info_minor_register() < 0)
 492                 goto error;
 493         return 0;
 494
 495  error:
 496         snd_info_free_entry(snd_proc_root);
 497         return -ENOMEM;
 498 }
 499
 500 int __exit snd_info_done(void)
 501 {
 502         snd_info_free_entry(snd_proc_root);
 503         return 0;
 504 }
 505
 506 /*
 507  * create a card proc file
 508  * called from init.c
 509  */
 510 int snd_info_card_create(struct snd_card *card)
 511 {
 512         char str[8];
 513         struct snd_info_entry *entry;
 514
 515         if (snd_BUG_ON(!card))
 516                 return -ENXIO;
 517
 518         sprintf(str, "card%i", card->number);
 519         entry = create_subdir(card->module, str);
 520         if (!entry)
 521                 return -ENOMEM;
 522         card->proc_root = entry;
 523         return 0;
 524 }
 525
 526 /* register all pending info entries */
 527 static int snd_info_register_recursive(struct snd_info_entry *entry)
 528 {
 529         struct snd_info_entry *p;
 530         int err;
 531
 532         if (!entry->p) {
 533                 err = snd_info_register(entry);
 534                 if (err < 0)
 535                         return err;
 536         }
 537
 538         list_for_each_entry(p, &entry->children, list) {
 539                 err = snd_info_register_recursive(p);
 540                 if (err < 0)
 541                         return err;
 542         }
 543
 544         return 0;
 545 }
 546
 547 /*
 548  * register the card proc file
 549  * called from init.c
 550  * can be called multiple times for reinitialization
 551  */
 552 int snd_info_card_register(struct snd_card *card)
 553 {
 554         struct proc_dir_entry *p;
 555         int err;
 556
 557         if (snd_BUG_ON(!card))
 558                 return -ENXIO;
 559
 560         err = snd_info_register_recursive(card->proc_root);
 561         if (err < 0)
 562                 return err;
 563
 564         if (!strcmp(card->id, card->proc_root->name))
 565                 return 0;
 566
 567         if (card->proc_root_link)
 568                 return 0;
 569         p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
 570         if (!p)
 571                 return -ENOMEM;
 572         card->proc_root_link = p;
 573         return 0;
 574 }
 575
 576 /*
 577  * called on card->id change
 578  */
 579 void snd_info_card_id_change(struct snd_card *card)
 580 {
 581         mutex_lock(&info_mutex);
 582         if (card->proc_root_link) {
 583                 proc_remove(card->proc_root_link);
 584                 card->proc_root_link = NULL;
 585         }
 586         if (strcmp(card->id, card->proc_root->name))
 587                 card->proc_root_link = proc_symlink(card->id,
 588                                                     snd_proc_root->p,
 589                                                     card->proc_root->name);
 590         mutex_unlock(&info_mutex);
 591 }
 592
 593 /*
 594  * de-register the card proc file
 595  * called from init.c
 596  */
 597 void snd_info_card_disconnect(struct snd_card *card)
 598 {
 599         if (!card)
 600                 return;
 601         mutex_lock(&info_mutex);
 602         proc_remove(card->proc_root_link);
 603         card->proc_root_link = NULL;
 604         if (card->proc_root)
 605                 snd_info_disconnect(card->proc_root);
 606         mutex_unlock(&info_mutex);
 607 }
 608
 609 /*
 610  * release the card proc file resources
 611  * called from init.c
 612  */
 613 int snd_info_card_free(struct snd_card *card)
 614 {
 615         if (!card)
 616                 return 0;
 617         snd_info_free_entry(card->proc_root);
 618         card->proc_root = NULL;
 619         return 0;
 620 }
 621
 622
 623 /**
 624  * snd_info_get_line - read one line from the procfs buffer
 625  * @buffer: the procfs buffer
 626  * @line: the buffer to store
 627  * @len: the max. buffer size
 628  *
 629  * Reads one line from the buffer and stores the string.
 630  *
 631  * Return: Zero if successful, or 1 if error or EOF.
 632  */
 633 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 634 {
 635         int c = -1;
 636
 637         if (snd_BUG_ON(!buffer || !buffer->buffer))
 638                 return 1;
 639         if (len <= 0 || buffer->stop || buffer->error)
 640                 return 1;
 641         while (!buffer->stop) {
 642                 c = buffer->buffer[buffer->curr++];
 643                 if (buffer->curr >= buffer->size)
 644                         buffer->stop = 1;
 645                 if (c == '\n')
 646                         break;
 647                 if (len > 1) {
 648                         len--;
 649                         *line++ = c;
 650                 }
 651         }
 652         *line = '\0';
 653         return 0;
 654 }
 655 EXPORT_SYMBOL(snd_info_get_line);
 656
 657 /**
 658  * snd_info_get_str - parse a string token
 659  * @dest: the buffer to store the string token
 660  * @src: the original string
 661  * @len: the max. length of token - 1
 662  *
 663  * Parses the original string and copy a token to the given
 664  * string buffer.
 665  *
 666  * Return: The updated pointer of the original string so that
 667  * it can be used for the next call.
 668  */
 669 const char *snd_info_get_str(char *dest, const char *src, int len)
 670 {
 671         int c;
 672
 673         while (*src == ' ' || *src == '\t')
 674                 src++;
 675         if (*src == '"' || *src == '\'') {
 676                 c = *src++;
 677                 while (--len > 0 && *src && *src != c) {
 678                         *dest++ = *src++;
 679                 }
 680                 if (*src == c)
 681                         src++;
 682         } else {
 683                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 684                         *dest++ = *src++;
 685                 }
 686         }
 687         *dest = 0;
 688         while (*src == ' ' || *src == '\t')
 689                 src++;
 690         return src;
 691 }
 692 EXPORT_SYMBOL(snd_info_get_str);
 693
 694 /*
 695  * snd_info_create_entry - create an info entry
 696  * @name: the proc file name
 697  * @parent: the parent directory
 698  *
 699  * Creates an info entry with the given file name and initializes as
 700  * the default state.
 701  *
 702  * Usually called from other functions such as
 703  * snd_info_create_card_entry().
 704  *
 705  * Return: The pointer of the new instance, or %NULL on failure.
 706  */
 707 static struct snd_info_entry *
 708 snd_info_create_entry(const char *name, struct snd_info_entry *parent)
 709 {
 710         struct snd_info_entry *entry;
 711         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 712         if (entry == NULL)
 713                 return NULL;
 714         entry->name = kstrdup(name, GFP_KERNEL);
 715         if (entry->name == NULL) {
 716                 kfree(entry);
 717                 return NULL;
 718         }
 719         entry->mode = S_IFREG | S_IRUGO;
 720         entry->content = SNDRV_INFO_CONTENT_TEXT;
 721         mutex_init(&entry->access);
 722         INIT_LIST_HEAD(&entry->children);
 723         INIT_LIST_HEAD(&entry->list);
 724         entry->parent = parent;
 725         if (parent)
 726                 list_add_tail(&entry->list, &parent->children);
 727         return entry;
 728 }
 729
 730 /**
 731  * snd_info_create_module_entry - create an info entry for the given module
 732  * @module: the module pointer
 733  * @name: the file name
 734  * @parent: the parent directory
 735  *
 736  * Creates a new info entry and assigns it to the given module.
 737  *
 738  * Return: The pointer of the new instance, or %NULL on failure.
 739  */
 740 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 741                                                const char *name,
 742                                                struct snd_info_entry *parent)
 743 {
 744         struct snd_info_entry *entry = snd_info_create_entry(name, parent);
 745         if (entry)
 746                 entry->module = module;
 747         return entry;
 748 }
 749 EXPORT_SYMBOL(snd_info_create_module_entry);
 750
 751 /**
 752  * snd_info_create_card_entry - create an info entry for the given card
 753  * @card: the card instance
 754  * @name: the file name
 755  * @parent: the parent directory
 756  *
 757  * Creates a new info entry and assigns it to the given card.
 758  *
 759  * Return: The pointer of the new instance, or %NULL on failure.
 760  */
 761 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 762                                              const char *name,
 763                                              struct snd_info_entry * parent)
 764 {
 765         struct snd_info_entry *entry = snd_info_create_entry(name, parent);
 766         if (entry) {
 767                 entry->module = card->module;
 768                 entry->card = card;
 769         }
 770         return entry;
 771 }
 772 EXPORT_SYMBOL(snd_info_create_card_entry);
 773
 774 static void snd_info_disconnect(struct snd_info_entry *entry)
 775 {
 776         struct snd_info_entry *p;
 777
 778         if (!entry->p)
 779                 return;
 780         list_for_each_entry(p, &entry->children, list)
 781                 snd_info_disconnect(p);
 782         proc_remove(entry->p);
 783         entry->p = NULL;
 784 }
 785
 786 /**
 787  * snd_info_free_entry - release the info entry
 788  * @entry: the info entry
 789  *
 790  * Releases the info entry.
 791  */
 792 void snd_info_free_entry(struct snd_info_entry * entry)
 793 {
 794         struct snd_info_entry *p, *n;
 795
 796         if (!entry)
 797                 return;
 798         if (entry->p) {
 799                 mutex_lock(&info_mutex);
 800                 snd_info_disconnect(entry);
 801                 mutex_unlock(&info_mutex);
 802         }
 803
 804         /* free all children at first */
 805         list_for_each_entry_safe(p, n, &entry->children, list)
 806                 snd_info_free_entry(p);
 807
 808         list_del(&entry->list);
 809         kfree(entry->name);
 810         if (entry->private_free)
 811                 entry->private_free(entry);
 812         kfree(entry);
 813 }
 814 EXPORT_SYMBOL(snd_info_free_entry);
 815
 816 /**
 817  * snd_info_register - register the info entry
 818  * @entry: the info entry
 819  *
 820  * Registers the proc info entry.
 821  *
 822  * Return: Zero if successful, or a negative error code on failure.
 823  */
 824 int snd_info_register(struct snd_info_entry * entry)
 825 {
 826         struct proc_dir_entry *root, *p = NULL;
 827
 828         if (snd_BUG_ON(!entry))
 829                 return -ENXIO;
 830         root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
 831         mutex_lock(&info_mutex);
 832         if (S_ISDIR(entry->mode)) {
 833                 p = proc_mkdir_mode(entry->name, entry->mode, root);
 834                 if (!p) {
 835                         mutex_unlock(&info_mutex);
 836                         return -ENOMEM;
 837                 }
 838         } else {
 839                 const struct file_operations *ops;
 840                 if (entry->content == SNDRV_INFO_CONTENT_DATA)
 841                         ops = &snd_info_entry_operations;
 842                 else
 843                         ops = &snd_info_text_entry_ops;
 844                 p = proc_create_data(entry->name, entry->mode, root,
 845                                      ops, entry);
 846                 if (!p) {
 847                         mutex_unlock(&info_mutex);
 848                         return -ENOMEM;
 849                 }
 850                 proc_set_size(p, entry->size);
 851         }
 852         entry->p = p;
 853         mutex_unlock(&info_mutex);
 854         return 0;
 855 }
 856 EXPORT_SYMBOL(snd_info_register);
 857
 858 /*
 859
 860  */
 861
 862 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 863 {
 864         snd_iprintf(buffer,
 865                     "Advanced Linux Sound Architecture Driver Version k%s.\n",
 866                     init_utsname()->release);
 867 }
 868
 869 static int __init snd_info_version_init(void)
 870 {
 871         struct snd_info_entry *entry;
 872
 873         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 874         if (entry == NULL)
 875                 return -ENOMEM;
 876         entry->c.text.read = snd_info_version_read;
 877         return snd_info_register(entry); /* freed in error path */
 878 }