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 /*
  37  *
  38  */
  39
  40 #ifdef CONFIG_PROC_FS
  41
  42 int 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
  71 static DEFINE_MUTEX(info_mutex);
  72
  73 struct 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
  80 static int snd_info_version_init(void);
  81 static int snd_info_version_done(void);
  82 static void snd_info_disconnect(struct snd_info_entry *entry);
  83
  84
  85 /* resize the proc r/w buffer */
  86 static 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  */
 110 int 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
 142 EXPORT_SYMBOL(snd_iprintf);
 143
 144 /*
 145
 146  */
 147
 148 static struct proc_dir_entry *snd_proc_root;
 149 struct snd_info_entry *snd_seq_root;
 150 EXPORT_SYMBOL(snd_seq_root);
 151
 152 #ifdef CONFIG_SND_OSSEMUL
 153 struct snd_info_entry *snd_oss_root;
 154 #endif
 155
 156 static 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
 201 static 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
 248 static 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
 301 static 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
 402 static 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
 446 static 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
 472 static 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
 493 static 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
 514 static 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
 527 int __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
 568 int __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  */
 595 int 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  */
 619 int 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  */
 639 void 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  */
 657 void 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  */
 673 int 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  */
 693 int 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
 716 EXPORT_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  */
 730 const 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
 754 EXPORT_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  */
 768 static 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  */
 797 struct 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
 809 EXPORT_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  */
 821 struct 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
 834 EXPORT_SYMBOL(snd_info_create_card_entry);
 835
 836 static 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
 854 static 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
 861 static 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  */
 887 int 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
 910 EXPORT_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  */
 918 void 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
 933 EXPORT_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  */
 943 int 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
 973 EXPORT_SYMBOL(snd_info_register);
 974
 975 /*
 976
 977  */
 978
 979 static struct snd_info_entry *snd_info_version_entry;
 980
 981 static 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
 988 static 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
1004 static 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 */