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                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 422                                                 entry->name,
 423                                                 data->wbuffer->error);
 424                                 }
 425                         }
 426                         kfree(data->wbuffer->buffer);
 427                         kfree(data->wbuffer);
 428                 }
 429                 break;
 430         case SNDRV_INFO_CONTENT_DATA:
 431                 if (entry->c.ops->release)
 432                         entry->c.ops->release(entry, mode,
 433                                               data->file_private_data);
 434                 break;
 435         }
 436         module_put(entry->module);
 437         kfree(data);
 438         return 0;
 439 }
 440
 441 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 442 {
 443         struct snd_info_private_data *data;
 444         struct snd_info_entry *entry;
 445         unsigned int mask;
 446
 447         data = file->private_data;
 448         if (data == NULL)
 449                 return 0;
 450         entry = data->entry;
 451         mask = 0;
 452         switch (entry->content) {
 453         case SNDRV_INFO_CONTENT_DATA:
 454                 if (entry->c.ops->poll)
 455                         return entry->c.ops->poll(entry,
 456                                                   data->file_private_data,
 457                                                   file, wait);
 458                 if (entry->c.ops->read)
 459                         mask |= POLLIN | POLLRDNORM;
 460                 if (entry->c.ops->write)
 461                         mask |= POLLOUT | POLLWRNORM;
 462                 break;
 463         }
 464         return mask;
 465 }
 466
 467 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 468                                 unsigned long arg)
 469 {
 470         struct snd_info_private_data *data;
 471         struct snd_info_entry *entry;
 472
 473         data = file->private_data;
 474         if (data == NULL)
 475                 return 0;
 476         entry = data->entry;
 477         switch (entry->content) {
 478         case SNDRV_INFO_CONTENT_DATA:
 479                 if (entry->c.ops->ioctl)
 480                         return entry->c.ops->ioctl(entry,
 481                                                    data->file_private_data,
 482                                                    file, cmd, arg);
 483                 break;
 484         }
 485         return -ENOTTY;
 486 }
 487
 488 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 489 {
 490         struct inode *inode = file_inode(file);
 491         struct snd_info_private_data *data;
 492         struct snd_info_entry *entry;
 493
 494         data = file->private_data;
 495         if (data == NULL)
 496                 return 0;
 497         entry = data->entry;
 498         switch (entry->content) {
 499         case SNDRV_INFO_CONTENT_DATA:
 500                 if (entry->c.ops->mmap)
 501                         return entry->c.ops->mmap(entry,
 502                                                   data->file_private_data,
 503                                                   inode, file, vma);
 504                 break;
 505         }
 506         return -ENXIO;
 507 }
 508
 509 static const struct file_operations snd_info_entry_operations =
 510 {
 511         .owner =                THIS_MODULE,
 512         .llseek =               snd_info_entry_llseek,
 513         .read =                 snd_info_entry_read,
 514         .write =                snd_info_entry_write,
 515         .poll =                 snd_info_entry_poll,
 516         .unlocked_ioctl =       snd_info_entry_ioctl,
 517         .mmap =                 snd_info_entry_mmap,
 518         .open =                 snd_info_entry_open,
 519         .release =              snd_info_entry_release,
 520 };
 521
 522 int __init snd_info_init(void)
 523 {
 524         struct proc_dir_entry *p;
 525
 526         p = proc_mkdir("asound", NULL);
 527         if (p == NULL)
 528                 return -ENOMEM;
 529         snd_proc_root = p;
 530 #ifdef CONFIG_SND_OSSEMUL
 531         {
 532                 struct snd_info_entry *entry;
 533                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 534                         return -ENOMEM;
 535                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 536                 if (snd_info_register(entry) < 0) {
 537                         snd_info_free_entry(entry);
 538                         return -ENOMEM;
 539                 }
 540                 snd_oss_root = entry;
 541         }
 542 #endif
 543 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 544         {
 545                 struct snd_info_entry *entry;
 546                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 547                         return -ENOMEM;
 548                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 549                 if (snd_info_register(entry) < 0) {
 550                         snd_info_free_entry(entry);
 551                         return -ENOMEM;
 552                 }
 553                 snd_seq_root = entry;
 554         }
 555 #endif
 556         snd_info_version_init();
 557         snd_minor_info_init();
 558         snd_minor_info_oss_init();
 559         snd_card_info_init();
 560         return 0;
 561 }
 562
 563 int __exit snd_info_done(void)
 564 {
 565         snd_card_info_done();
 566         snd_minor_info_oss_done();
 567         snd_minor_info_done();
 568         snd_info_version_done();
 569         if (snd_proc_root) {
 570 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 571                 snd_info_free_entry(snd_seq_root);
 572 #endif
 573 #ifdef CONFIG_SND_OSSEMUL
 574                 snd_info_free_entry(snd_oss_root);
 575 #endif
 576                 proc_remove(snd_proc_root);
 577         }
 578         return 0;
 579 }
 580
 581 /*
 582
 583  */
 584
 585
 586 /*
 587  * create a card proc file
 588  * called from init.c
 589  */
 590 int snd_info_card_create(struct snd_card *card)
 591 {
 592         char str[8];
 593         struct snd_info_entry *entry;
 594
 595         if (snd_BUG_ON(!card))
 596                 return -ENXIO;
 597
 598         sprintf(str, "card%i", card->number);
 599         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 600                 return -ENOMEM;
 601         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 602         if (snd_info_register(entry) < 0) {
 603                 snd_info_free_entry(entry);
 604                 return -ENOMEM;
 605         }
 606         card->proc_root = entry;
 607         return 0;
 608 }
 609
 610 /*
 611  * register the card proc file
 612  * called from init.c
 613  */
 614 int snd_info_card_register(struct snd_card *card)
 615 {
 616         struct proc_dir_entry *p;
 617
 618         if (snd_BUG_ON(!card))
 619                 return -ENXIO;
 620
 621         if (!strcmp(card->id, card->proc_root->name))
 622                 return 0;
 623
 624         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 625         if (p == NULL)
 626                 return -ENOMEM;
 627         card->proc_root_link = p;
 628         return 0;
 629 }
 630
 631 /*
 632  * called on card->id change
 633  */
 634 void snd_info_card_id_change(struct snd_card *card)
 635 {
 636         mutex_lock(&info_mutex);
 637         if (card->proc_root_link) {
 638                 proc_remove(card->proc_root_link);
 639                 card->proc_root_link = NULL;
 640         }
 641         if (strcmp(card->id, card->proc_root->name))
 642                 card->proc_root_link = proc_symlink(card->id,
 643                                                     snd_proc_root,
 644                                                     card->proc_root->name);
 645         mutex_unlock(&info_mutex);
 646 }
 647
 648 /*
 649  * de-register the card proc file
 650  * called from init.c
 651  */
 652 void snd_info_card_disconnect(struct snd_card *card)
 653 {
 654         if (!card)
 655                 return;
 656         mutex_lock(&info_mutex);
 657         proc_remove(card->proc_root_link);
 658         card->proc_root_link = NULL;
 659         if (card->proc_root)
 660                 snd_info_disconnect(card->proc_root);
 661         mutex_unlock(&info_mutex);
 662 }
 663
 664 /*
 665  * release the card proc file resources
 666  * called from init.c
 667  */
 668 int snd_info_card_free(struct snd_card *card)
 669 {
 670         if (!card)
 671                 return 0;
 672         snd_info_free_entry(card->proc_root);
 673         card->proc_root = NULL;
 674         return 0;
 675 }
 676
 677
 678 /**
 679  * snd_info_get_line - read one line from the procfs buffer
 680  * @buffer: the procfs buffer
 681  * @line: the buffer to store
 682  * @len: the max. buffer size - 1
 683  *
 684  * Reads one line from the buffer and stores the string.
 685  *
 686  * Return: Zero if successful, or 1 if error or EOF.
 687  */
 688 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 689 {
 690         int c = -1;
 691
 692         if (snd_BUG_ON(!buffer || !buffer->buffer))
 693                 return 1;
 694         if (len <= 0 || buffer->stop || buffer->error)
 695                 return 1;
 696         while (!buffer->stop) {
 697                 c = buffer->buffer[buffer->curr++];
 698                 if (buffer->curr >= buffer->size)
 699                         buffer->stop = 1;
 700                 if (c == '\n')
 701                         break;
 702                 if (len) {
 703                         len--;
 704                         *line++ = c;
 705                 }
 706         }
 707         *line = '\0';
 708         return 0;
 709 }
 710
 711 EXPORT_SYMBOL(snd_info_get_line);
 712
 713 /**
 714  * snd_info_get_str - parse a string token
 715  * @dest: the buffer to store the string token
 716  * @src: the original string
 717  * @len: the max. length of token - 1
 718  *
 719  * Parses the original string and copy a token to the given
 720  * string buffer.
 721  *
 722  * Return: The updated pointer of the original string so that
 723  * it can be used for the next call.
 724  */
 725 const char *snd_info_get_str(char *dest, const char *src, int len)
 726 {
 727         int c;
 728
 729         while (*src == ' ' || *src == '\t')
 730                 src++;
 731         if (*src == '"' || *src == '\'') {
 732                 c = *src++;
 733                 while (--len > 0 && *src && *src != c) {
 734                         *dest++ = *src++;
 735                 }
 736                 if (*src == c)
 737                         src++;
 738         } else {
 739                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 740                         *dest++ = *src++;
 741                 }
 742         }
 743         *dest = 0;
 744         while (*src == ' ' || *src == '\t')
 745                 src++;
 746         return src;
 747 }
 748
 749 EXPORT_SYMBOL(snd_info_get_str);
 750
 751 /**
 752  * snd_info_create_entry - create an info entry
 753  * @name: the proc file name
 754  *
 755  * Creates an info entry with the given file name and initializes as
 756  * the default state.
 757  *
 758  * Usually called from other functions such as
 759  * snd_info_create_card_entry().
 760  *
 761  * Return: The pointer of the new instance, or %NULL on failure.
 762  */
 763 static struct snd_info_entry *snd_info_create_entry(const char *name)
 764 {
 765         struct snd_info_entry *entry;
 766         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 767         if (entry == NULL)
 768                 return NULL;
 769         entry->name = kstrdup(name, GFP_KERNEL);
 770         if (entry->name == NULL) {
 771                 kfree(entry);
 772                 return NULL;
 773         }
 774         entry->mode = S_IFREG | S_IRUGO;
 775         entry->content = SNDRV_INFO_CONTENT_TEXT;
 776         mutex_init(&entry->access);
 777         INIT_LIST_HEAD(&entry->children);
 778         INIT_LIST_HEAD(&entry->list);
 779         return entry;
 780 }
 781
 782 /**
 783  * snd_info_create_module_entry - create an info entry for the given module
 784  * @module: the module pointer
 785  * @name: the file name
 786  * @parent: the parent directory
 787  *
 788  * Creates a new info entry and assigns it to the given module.
 789  *
 790  * Return: The pointer of the new instance, or %NULL on failure.
 791  */
 792 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 793                                                const char *name,
 794                                                struct snd_info_entry *parent)
 795 {
 796         struct snd_info_entry *entry = snd_info_create_entry(name);
 797         if (entry) {
 798                 entry->module = module;
 799                 entry->parent = parent;
 800         }
 801         return entry;
 802 }
 803
 804 EXPORT_SYMBOL(snd_info_create_module_entry);
 805
 806 /**
 807  * snd_info_create_card_entry - create an info entry for the given card
 808  * @card: the card instance
 809  * @name: the file name
 810  * @parent: the parent directory
 811  *
 812  * Creates a new info entry and assigns it to the given card.
 813  *
 814  * Return: The pointer of the new instance, or %NULL on failure.
 815  */
 816 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 817                                              const char *name,
 818                                              struct snd_info_entry * parent)
 819 {
 820         struct snd_info_entry *entry = snd_info_create_entry(name);
 821         if (entry) {
 822                 entry->module = card->module;
 823                 entry->card = card;
 824                 entry->parent = parent;
 825         }
 826         return entry;
 827 }
 828
 829 EXPORT_SYMBOL(snd_info_create_card_entry);
 830
 831 static void snd_info_disconnect(struct snd_info_entry *entry)
 832 {
 833         struct list_head *p, *n;
 834         struct proc_dir_entry *root;
 835
 836         list_for_each_safe(p, n, &entry->children) {
 837                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 838         }
 839
 840         if (! entry->p)
 841                 return;
 842         list_del_init(&entry->list);
 843         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 844         snd_BUG_ON(!root);
 845         proc_remove(entry->p);
 846         entry->p = NULL;
 847 }
 848
 849 static int snd_info_dev_free_entry(struct snd_device *device)
 850 {
 851         struct snd_info_entry *entry = device->device_data;
 852         snd_info_free_entry(entry);
 853         return 0;
 854 }
 855
 856 static int snd_info_dev_register_entry(struct snd_device *device)
 857 {
 858         struct snd_info_entry *entry = device->device_data;
 859         return snd_info_register(entry);
 860 }
 861
 862 /**
 863  * snd_card_proc_new - create an info entry for the given card
 864  * @card: the card instance
 865  * @name: the file name
 866  * @entryp: the pointer to store the new info entry
 867  *
 868  * Creates a new info entry and assigns it to the given card.
 869  * Unlike snd_info_create_card_entry(), this function registers the
 870  * info entry as an ALSA device component, so that it can be
 871  * unregistered/released without explicit call.
 872  * Also, you don't have to register this entry via snd_info_register(),
 873  * since this will be registered by snd_card_register() automatically.
 874  *
 875  * The parent is assumed as card->proc_root.
 876  *
 877  * For releasing this entry, use snd_device_free() instead of
 878  * snd_info_free_entry().
 879  *
 880  * Return: Zero if successful, or a negative error code on failure.
 881  */
 882 int snd_card_proc_new(struct snd_card *card, const char *name,
 883                       struct snd_info_entry **entryp)
 884 {
 885         static struct snd_device_ops ops = {
 886                 .dev_free = snd_info_dev_free_entry,
 887                 .dev_register = snd_info_dev_register_entry,
 888                 /* disconnect is done via snd_info_card_disconnect() */
 889         };
 890         struct snd_info_entry *entry;
 891         int err;
 892
 893         entry = snd_info_create_card_entry(card, name, card->proc_root);
 894         if (! entry)
 895                 return -ENOMEM;
 896         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 897                 snd_info_free_entry(entry);
 898                 return err;
 899         }
 900         if (entryp)
 901                 *entryp = entry;
 902         return 0;
 903 }
 904
 905 EXPORT_SYMBOL(snd_card_proc_new);
 906
 907 /**
 908  * snd_info_free_entry - release the info entry
 909  * @entry: the info entry
 910  *
 911  * Releases the info entry.  Don't call this after registered.
 912  */
 913 void snd_info_free_entry(struct snd_info_entry * entry)
 914 {
 915         if (entry == NULL)
 916                 return;
 917         if (entry->p) {
 918                 mutex_lock(&info_mutex);
 919                 snd_info_disconnect(entry);
 920                 mutex_unlock(&info_mutex);
 921         }
 922         kfree(entry->name);
 923         if (entry->private_free)
 924                 entry->private_free(entry);
 925         kfree(entry);
 926 }
 927
 928 EXPORT_SYMBOL(snd_info_free_entry);
 929
 930 /**
 931  * snd_info_register - register the info entry
 932  * @entry: the info entry
 933  *
 934  * Registers the proc info entry.
 935  *
 936  * Return: Zero if successful, or a negative error code on failure.
 937  */
 938 int snd_info_register(struct snd_info_entry * entry)
 939 {
 940         struct proc_dir_entry *root, *p = NULL;
 941
 942         if (snd_BUG_ON(!entry))
 943                 return -ENXIO;
 944         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 945         mutex_lock(&info_mutex);
 946         if (S_ISDIR(entry->mode)) {
 947                 p = proc_mkdir_mode(entry->name, entry->mode, root);
 948                 if (!p) {
 949                         mutex_unlock(&info_mutex);
 950                         return -ENOMEM;
 951                 }
 952         } else {
 953                 p = proc_create_data(entry->name, entry->mode, root,
 954                                         &snd_info_entry_operations, entry);
 955                 if (!p) {
 956                         mutex_unlock(&info_mutex);
 957                         return -ENOMEM;
 958                 }
 959                 proc_set_size(p, entry->size);
 960         }
 961         entry->p = p;
 962         if (entry->parent)
 963                 list_add_tail(&entry->list, &entry->parent->children);
 964         mutex_unlock(&info_mutex);
 965         return 0;
 966 }
 967
 968 EXPORT_SYMBOL(snd_info_register);
 969
 970 /*
 971
 972  */
 973
 974 static struct snd_info_entry *snd_info_version_entry;
 975
 976 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 977 {
 978         snd_iprintf(buffer,
 979                     "Advanced Linux Sound Architecture Driver Version k%s.\n",
 980                     init_utsname()->release);
 981 }
 982
 983 static int __init snd_info_version_init(void)
 984 {
 985         struct snd_info_entry *entry;
 986
 987         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 988         if (entry == NULL)
 989                 return -ENOMEM;
 990         entry->c.text.read = snd_info_version_read;
 991         if (snd_info_register(entry) < 0) {
 992                 snd_info_free_entry(entry);
 993                 return -ENOMEM;
 994         }
 995         snd_info_version_entry = entry;
 996         return 0;
 997 }
 998
 999 static int __exit snd_info_version_done(void)
1000 {
1001         snd_info_free_entry(snd_info_version_entry);
1002         return 0;
1003 }
1004
1005 #endif /* CONFIG_PROC_FS */