sound/core/info.c

   1 /*
   2  *  Information interface for ALSA driver
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/time.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/string.h>
  27 #include <sound/core.h>
  28 #include <sound/minors.h>
  29 #include <sound/info.h>
  30 #include <sound/version.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/mutex.h>
  33 #include <stdarg.h>
  34
  35 /*
  36  *
  37  */
  38
  39 #ifdef CONFIG_PROC_FS
  40
  41 int snd_info_check_reserved_words(const char *str)
  42 {
  43         static char *reserved[] =
  44         {
  45                 "version",
  46                 "meminfo",
  47                 "memdebug",
  48                 "detect",
  49                 "devices",
  50                 "oss",
  51                 "cards",
  52                 "timers",
  53                 "synth",
  54                 "pcm",
  55                 "seq",
  56                 NULL
  57         };
  58         char **xstr = reserved;
  59
  60         while (*xstr) {
  61                 if (!strcmp(*xstr, str))
  62                         return 0;
  63                 xstr++;
  64         }
  65         if (!strncmp(str, "card", 4))
  66                 return 0;
  67         return 1;
  68 }
  69
  70 static DEFINE_MUTEX(info_mutex);
  71
  72 struct snd_info_private_data {
  73         struct snd_info_buffer *rbuffer;
  74         struct snd_info_buffer *wbuffer;
  75         struct snd_info_entry *entry;
  76         void *file_private_data;
  77 };
  78
  79 static int snd_info_version_init(void);
  80 static int snd_info_version_done(void);
  81
  82
  83 /* resize the proc r/w buffer */
  84 static int resize_info_buffer(struct snd_info_buffer *buffer,
  85                               unsigned int nsize)
  86 {
  87         char *nbuf;
  88
  89         nsize = PAGE_ALIGN(nsize);
  90         nbuf = kmalloc(nsize, GFP_KERNEL);
  91         if (! nbuf)
  92                 return -ENOMEM;
  93
  94         memcpy(nbuf, buffer->buffer, buffer->len);
  95         kfree(buffer->buffer);
  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  * Returns the size of output string.
 109  */
 110 int snd_iprintf(struct snd_info_buffer *buffer, 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 inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 157 {
 158         de->owner = THIS_MODULE;
 159 }
 160
 161 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 162                                   struct proc_dir_entry *de)
 163 {
 164         if (de)
 165                 remove_proc_entry(de->name, parent);
 166 }
 167
 168 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 169 {
 170         struct snd_info_private_data *data;
 171         struct snd_info_entry *entry;
 172         loff_t ret;
 173
 174         data = file->private_data;
 175         entry = data->entry;
 176         lock_kernel();
 177         switch (entry->content) {
 178         case SNDRV_INFO_CONTENT_TEXT:
 179                 switch (orig) {
 180                 case 0: /* SEEK_SET */
 181                         file->f_pos = offset;
 182                         ret = file->f_pos;
 183                         goto out;
 184                 case 1: /* SEEK_CUR */
 185                         file->f_pos += offset;
 186                         ret = file->f_pos;
 187                         goto out;
 188                 case 2: /* SEEK_END */
 189                 default:
 190                         ret = -EINVAL;
 191                         goto out;
 192                 }
 193                 break;
 194         case SNDRV_INFO_CONTENT_DATA:
 195                 if (entry->c.ops->llseek) {
 196                         ret = entry->c.ops->llseek(entry,
 197                                                     data->file_private_data,
 198                                                     file, offset, orig);
 199                         goto out;
 200                 }
 201                 break;
 202         }
 203         ret = -ENXIO;
 204 out:
 205         unlock_kernel();
 206         return ret;
 207 }
 208
 209 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 210                                    size_t count, loff_t * offset)
 211 {
 212         struct snd_info_private_data *data;
 213         struct snd_info_entry *entry;
 214         struct snd_info_buffer *buf;
 215         size_t size = 0;
 216         loff_t pos;
 217
 218         data = file->private_data;
 219         snd_assert(data != NULL, return -ENXIO);
 220         pos = *offset;
 221         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 222                 return -EIO;
 223         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 224                 return -EIO;
 225         entry = data->entry;
 226         switch (entry->content) {
 227         case SNDRV_INFO_CONTENT_TEXT:
 228                 buf = data->rbuffer;
 229                 if (buf == NULL)
 230                         return -EIO;
 231                 if (pos >= buf->size)
 232                         return 0;
 233                 size = buf->size - pos;
 234                 size = min(count, size);
 235                 if (copy_to_user(buffer, buf->buffer + pos, size))
 236                         return -EFAULT;
 237                 break;
 238         case SNDRV_INFO_CONTENT_DATA:
 239                 if (entry->c.ops->read)
 240                         size = entry->c.ops->read(entry,
 241                                                   data->file_private_data,
 242                                                   file, buffer, count, pos);
 243                 break;
 244         }
 245         if ((ssize_t) size > 0)
 246                 *offset = pos + size;
 247         return size;
 248 }
 249
 250 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 251                                     size_t count, loff_t * offset)
 252 {
 253         struct snd_info_private_data *data;
 254         struct snd_info_entry *entry;
 255         struct snd_info_buffer *buf;
 256         ssize_t size = 0;
 257         loff_t pos;
 258
 259         data = file->private_data;
 260         snd_assert(data != NULL, return -ENXIO);
 261         entry = data->entry;
 262         pos = *offset;
 263         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 264                 return -EIO;
 265         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 266                 return -EIO;
 267         switch (entry->content) {
 268         case SNDRV_INFO_CONTENT_TEXT:
 269                 buf = data->wbuffer;
 270                 if (buf == NULL)
 271                         return -EIO;
 272                 mutex_lock(&entry->access);
 273                 if (pos + count >= buf->len) {
 274                         if (resize_info_buffer(buf, pos + count)) {
 275                                 mutex_unlock(&entry->access);
 276                                 return -ENOMEM;
 277                         }
 278                 }
 279                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
 280                         mutex_unlock(&entry->access);
 281                         return -EFAULT;
 282                 }
 283                 buf->size = pos + count;
 284                 mutex_unlock(&entry->access);
 285                 size = count;
 286                 break;
 287         case SNDRV_INFO_CONTENT_DATA:
 288                 if (entry->c.ops->write)
 289                         size = entry->c.ops->write(entry,
 290                                                    data->file_private_data,
 291                                                    file, buffer, count, pos);
 292                 break;
 293         }
 294         if ((ssize_t) size > 0)
 295                 *offset = pos + size;
 296         return size;
 297 }
 298
 299 static int snd_info_entry_open(struct inode *inode, struct file *file)
 300 {
 301         struct snd_info_entry *entry;
 302         struct snd_info_private_data *data;
 303         struct snd_info_buffer *buffer;
 304         struct proc_dir_entry *p;
 305         int mode, err;
 306
 307         mutex_lock(&info_mutex);
 308         p = PDE(inode);
 309         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 310         if (entry == NULL || entry->disconnected) {
 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 = kmalloc(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->f_dentry->d_inode;
 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 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 /**
 523  * snd_create_proc_entry - create a procfs entry
 524  * @name: the name of the proc file
 525  * @mode: the file permission bits, S_Ixxx
 526  * @parent: the parent proc-directory entry
 527  *
 528  * Creates a new proc file entry with the given name and permission
 529  * on the given directory.
 530  *
 531  * Returns the pointer of new instance or NULL on failure.
 532  */
 533 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 534                                                     struct proc_dir_entry *parent)
 535 {
 536         struct proc_dir_entry *p;
 537         p = create_proc_entry(name, mode, parent);
 538         if (p)
 539                 snd_info_entry_prepare(p);
 540         return p;
 541 }
 542
 543 int __init snd_info_init(void)
 544 {
 545         struct proc_dir_entry *p;
 546
 547         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 548         if (p == NULL)
 549                 return -ENOMEM;
 550         snd_proc_root = p;
 551 #ifdef CONFIG_SND_OSSEMUL
 552         {
 553                 struct snd_info_entry *entry;
 554                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 555                         return -ENOMEM;
 556                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 557                 if (snd_info_register(entry) < 0) {
 558                         snd_info_free_entry(entry);
 559                         return -ENOMEM;
 560                 }
 561                 snd_oss_root = entry;
 562         }
 563 #endif
 564 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 565         {
 566                 struct snd_info_entry *entry;
 567                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 568                         return -ENOMEM;
 569                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 570                 if (snd_info_register(entry) < 0) {
 571                         snd_info_free_entry(entry);
 572                         return -ENOMEM;
 573                 }
 574                 snd_seq_root = entry;
 575         }
 576 #endif
 577         snd_info_version_init();
 578         snd_minor_info_init();
 579         snd_minor_info_oss_init();
 580         snd_card_info_init();
 581         return 0;
 582 }
 583
 584 int __exit snd_info_done(void)
 585 {
 586         snd_card_info_done();
 587         snd_minor_info_oss_done();
 588         snd_minor_info_done();
 589         snd_info_version_done();
 590         if (snd_proc_root) {
 591 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 592                 snd_info_unregister(snd_seq_root);
 593 #endif
 594 #ifdef CONFIG_SND_OSSEMUL
 595                 snd_info_unregister(snd_oss_root);
 596 #endif
 597                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 598         }
 599         return 0;
 600 }
 601
 602 /*
 603
 604  */
 605
 606
 607 /*
 608  * create a card proc file
 609  * called from init.c
 610  */
 611 int snd_info_card_create(struct snd_card *card)
 612 {
 613         char str[8];
 614         struct snd_info_entry *entry;
 615
 616         snd_assert(card != NULL, return -ENXIO);
 617
 618         sprintf(str, "card%i", card->number);
 619         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 620                 return -ENOMEM;
 621         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 622         if (snd_info_register(entry) < 0) {
 623                 snd_info_free_entry(entry);
 624                 return -ENOMEM;
 625         }
 626         card->proc_root = entry;
 627         return 0;
 628 }
 629
 630 /*
 631  * register the card proc file
 632  * called from init.c
 633  */
 634 int snd_info_card_register(struct snd_card *card)
 635 {
 636         struct proc_dir_entry *p;
 637
 638         snd_assert(card != NULL, return -ENXIO);
 639
 640         if (!strcmp(card->id, card->proc_root->name))
 641                 return 0;
 642
 643         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 644         if (p == NULL)
 645                 return -ENOMEM;
 646         card->proc_root_link = p;
 647         return 0;
 648 }
 649
 650 /*
 651  * de-register the card proc file
 652  * called from init.c
 653  */
 654 int snd_info_card_free(struct snd_card *card)
 655 {
 656         snd_assert(card != NULL, return -ENXIO);
 657         if (card->proc_root_link) {
 658                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 659                 card->proc_root_link = NULL;
 660         }
 661         if (card->proc_root) {
 662                 snd_info_unregister(card->proc_root);
 663                 card->proc_root = NULL;
 664         }
 665         return 0;
 666 }
 667
 668
 669 /**
 670  * snd_info_get_line - read one line from the procfs buffer
 671  * @buffer: the procfs buffer
 672  * @line: the buffer to store
 673  * @len: the max. buffer size - 1
 674  *
 675  * Reads one line from the buffer and stores the string.
 676  *
 677  * Returns zero if successful, or 1 if error or EOF.
 678  */
 679 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 680 {
 681         int c = -1;
 682
 683         if (len <= 0 || buffer->stop || buffer->error)
 684                 return 1;
 685         while (--len > 0) {
 686                 c = buffer->buffer[buffer->curr++];
 687                 if (c == '\n') {
 688                         if (buffer->curr >= buffer->size)
 689                                 buffer->stop = 1;
 690                         break;
 691                 }
 692                 *line++ = c;
 693                 if (buffer->curr >= buffer->size) {
 694                         buffer->stop = 1;
 695                         break;
 696                 }
 697         }
 698         while (c != '\n' && !buffer->stop) {
 699                 c = buffer->buffer[buffer->curr++];
 700                 if (buffer->curr >= buffer->size)
 701                         buffer->stop = 1;
 702         }
 703         *line = '\0';
 704         return 0;
 705 }
 706
 707 EXPORT_SYMBOL(snd_info_get_line);
 708
 709 /**
 710  * snd_info_get_str - parse a string token
 711  * @dest: the buffer to store the string token
 712  * @src: the original string
 713  * @len: the max. length of token - 1
 714  *
 715  * Parses the original string and copy a token to the given
 716  * string buffer.
 717  *
 718  * Returns the updated pointer of the original string so that
 719  * it can be used for the next call.
 720  */
 721 char *snd_info_get_str(char *dest, char *src, int len)
 722 {
 723         int c;
 724
 725         while (*src == ' ' || *src == '\t')
 726                 src++;
 727         if (*src == '"' || *src == '\'') {
 728                 c = *src++;
 729                 while (--len > 0 && *src && *src != c) {
 730                         *dest++ = *src++;
 731                 }
 732                 if (*src == c)
 733                         src++;
 734         } else {
 735                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 736                         *dest++ = *src++;
 737                 }
 738         }
 739         *dest = 0;
 740         while (*src == ' ' || *src == '\t')
 741                 src++;
 742         return src;
 743 }
 744
 745 EXPORT_SYMBOL(snd_info_get_str);
 746
 747 /**
 748  * snd_info_create_entry - create an info entry
 749  * @name: the proc file name
 750  *
 751  * Creates an info entry with the given file name and initializes as
 752  * the default state.
 753  *
 754  * Usually called from other functions such as
 755  * snd_info_create_card_entry().
 756  *
 757  * Returns the pointer of the new instance, or NULL on failure.
 758  */
 759 static struct snd_info_entry *snd_info_create_entry(const char *name)
 760 {
 761         struct snd_info_entry *entry;
 762         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 763         if (entry == NULL)
 764                 return NULL;
 765         entry->name = kstrdup(name, GFP_KERNEL);
 766         if (entry->name == NULL) {
 767                 kfree(entry);
 768                 return NULL;
 769         }
 770         entry->mode = S_IFREG | S_IRUGO;
 771         entry->content = SNDRV_INFO_CONTENT_TEXT;
 772         mutex_init(&entry->access);
 773         return entry;
 774 }
 775
 776 /**
 777  * snd_info_create_module_entry - create an info entry for the given module
 778  * @module: the module pointer
 779  * @name: the file name
 780  * @parent: the parent directory
 781  *
 782  * Creates a new info entry and assigns it to the given module.
 783  *
 784  * Returns the pointer of the new instance, or NULL on failure.
 785  */
 786 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 787                                                const char *name,
 788                                                struct snd_info_entry *parent)
 789 {
 790         struct snd_info_entry *entry = snd_info_create_entry(name);
 791         if (entry) {
 792                 entry->module = module;
 793                 entry->parent = parent;
 794         }
 795         return entry;
 796 }
 797
 798 EXPORT_SYMBOL(snd_info_create_module_entry);
 799
 800 /**
 801  * snd_info_create_card_entry - create an info entry for the given card
 802  * @card: the card instance
 803  * @name: the file name
 804  * @parent: the parent directory
 805  *
 806  * Creates a new info entry and assigns it to the given card.
 807  *
 808  * Returns the pointer of the new instance, or NULL on failure.
 809  */
 810 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 811                                              const char *name,
 812                                              struct snd_info_entry * parent)
 813 {
 814         struct snd_info_entry *entry = snd_info_create_entry(name);
 815         if (entry) {
 816                 entry->module = card->module;
 817                 entry->card = card;
 818                 entry->parent = parent;
 819         }
 820         return entry;
 821 }
 822
 823 EXPORT_SYMBOL(snd_info_create_card_entry);
 824
 825 static int snd_info_dev_free_entry(struct snd_device *device)
 826 {
 827         struct snd_info_entry *entry = device->device_data;
 828         snd_info_free_entry(entry);
 829         return 0;
 830 }
 831
 832 static int snd_info_dev_register_entry(struct snd_device *device)
 833 {
 834         struct snd_info_entry *entry = device->device_data;
 835         return snd_info_register(entry);
 836 }
 837
 838 static int snd_info_dev_disconnect_entry(struct snd_device *device)
 839 {
 840         struct snd_info_entry *entry = device->device_data;
 841         entry->disconnected = 1;
 842         return 0;
 843 }
 844
 845 static int snd_info_dev_unregister_entry(struct snd_device *device)
 846 {
 847         struct snd_info_entry *entry = device->device_data;
 848         return snd_info_unregister(entry);
 849 }
 850
 851 /**
 852  * snd_card_proc_new - create an info entry for the given card
 853  * @card: the card instance
 854  * @name: the file name
 855  * @entryp: the pointer to store the new info entry
 856  *
 857  * Creates a new info entry and assigns it to the given card.
 858  * Unlike snd_info_create_card_entry(), this function registers the
 859  * info entry as an ALSA device component, so that it can be
 860  * unregistered/released without explicit call.
 861  * Also, you don't have to register this entry via snd_info_register(),
 862  * since this will be registered by snd_card_register() automatically.
 863  *
 864  * The parent is assumed as card->proc_root.
 865  *
 866  * For releasing this entry, use snd_device_free() instead of
 867  * snd_info_free_entry().
 868  *
 869  * Returns zero if successful, or a negative error code on failure.
 870  */
 871 int snd_card_proc_new(struct snd_card *card, const char *name,
 872                       struct snd_info_entry **entryp)
 873 {
 874         static struct snd_device_ops ops = {
 875                 .dev_free = snd_info_dev_free_entry,
 876                 .dev_register = snd_info_dev_register_entry,
 877                 .dev_disconnect = snd_info_dev_disconnect_entry,
 878                 .dev_unregister = snd_info_dev_unregister_entry
 879         };
 880         struct snd_info_entry *entry;
 881         int err;
 882
 883         entry = snd_info_create_card_entry(card, name, card->proc_root);
 884         if (! entry)
 885                 return -ENOMEM;
 886         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 887                 snd_info_free_entry(entry);
 888                 return err;
 889         }
 890         if (entryp)
 891                 *entryp = entry;
 892         return 0;
 893 }
 894
 895 EXPORT_SYMBOL(snd_card_proc_new);
 896
 897 /**
 898  * snd_info_free_entry - release the info entry
 899  * @entry: the info entry
 900  *
 901  * Releases the info entry.  Don't call this after registered.
 902  */
 903 void snd_info_free_entry(struct snd_info_entry * entry)
 904 {
 905         if (entry == NULL)
 906                 return;
 907         kfree(entry->name);
 908         if (entry->private_free)
 909                 entry->private_free(entry);
 910         kfree(entry);
 911 }
 912
 913 EXPORT_SYMBOL(snd_info_free_entry);
 914
 915 /**
 916  * snd_info_register - register the info entry
 917  * @entry: the info entry
 918  *
 919  * Registers the proc info entry.
 920  *
 921  * Returns zero if successful, or a negative error code on failure.
 922  */
 923 int snd_info_register(struct snd_info_entry * entry)
 924 {
 925         struct proc_dir_entry *root, *p = NULL;
 926
 927         snd_assert(entry != NULL, return -ENXIO);
 928         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 929         mutex_lock(&info_mutex);
 930         p = snd_create_proc_entry(entry->name, entry->mode, root);
 931         if (!p) {
 932                 mutex_unlock(&info_mutex);
 933                 return -ENOMEM;
 934         }
 935         p->owner = entry->module;
 936         if (!S_ISDIR(entry->mode))
 937                 p->proc_fops = &snd_info_entry_operations;
 938         p->size = entry->size;
 939         p->data = entry;
 940         entry->p = p;
 941         mutex_unlock(&info_mutex);
 942         return 0;
 943 }
 944
 945 EXPORT_SYMBOL(snd_info_register);
 946
 947 /**
 948  * snd_info_unregister - de-register the info entry
 949  * @entry: the info entry
 950  *
 951  * De-registers the info entry and releases the instance.
 952  *
 953  * Returns zero if successful, or a negative error code on failure.
 954  */
 955 int snd_info_unregister(struct snd_info_entry * entry)
 956 {
 957         struct proc_dir_entry *root;
 958
 959         if (! entry)
 960                 return 0;
 961         snd_assert(entry->p != NULL, return -ENXIO);
 962         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 963         snd_assert(root, return -ENXIO);
 964         mutex_lock(&info_mutex);
 965         snd_remove_proc_entry(root, entry->p);
 966         mutex_unlock(&info_mutex);
 967         snd_info_free_entry(entry);
 968         return 0;
 969 }
 970
 971 EXPORT_SYMBOL(snd_info_unregister);
 972
 973 /*
 974
 975  */
 976
 977 static struct snd_info_entry *snd_info_version_entry;
 978
 979 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 980 {
 981         snd_iprintf(buffer,
 982                     "Advanced Linux Sound Architecture Driver Version "
 983                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 984                    );
 985 }
 986
 987 static int __init snd_info_version_init(void)
 988 {
 989         struct snd_info_entry *entry;
 990
 991         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 992         if (entry == NULL)
 993                 return -ENOMEM;
 994         entry->c.text.read = snd_info_version_read;
 995         if (snd_info_register(entry) < 0) {
 996                 snd_info_free_entry(entry);
 997                 return -ENOMEM;
 998         }
 999         snd_info_version_entry = entry;
1000         return 0;
1001 }
1002
1003 static int __exit snd_info_version_done(void)
1004 {
1005         if (snd_info_version_entry)
1006                 snd_info_unregister(snd_info_version_entry);
1007         return 0;
1008 }
1009
1010 #endif /* CONFIG_PROC_FS */