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/vmalloc.h>
  25 #include <linux/time.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/string.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <sound/version.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/devfs_fs_kernel.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 DECLARE_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
  83
  84 /**
  85  * snd_iprintf - printf on the procfs buffer
  86  * @buffer: the procfs buffer
  87  * @fmt: the printf format
  88  *
  89  * Outputs the string on the procfs buffer just like printf().
  90  *
  91  * Returns the size of output string.
  92  */
  93 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
  94 {
  95         va_list args;
  96         int len, res;
  97
  98         if (buffer->stop || buffer->error)
  99                 return 0;
 100         len = buffer->len - buffer->size;
 101         va_start(args, fmt);
 102         res = vsnprintf(buffer->curr, len, fmt, args);
 103         va_end(args);
 104         if (res >= len) {
 105                 buffer->stop = 1;
 106                 return 0;
 107         }
 108         buffer->curr += res;
 109         buffer->size += res;
 110         return res;
 111 }
 112
 113 /*
 114
 115  */
 116
 117 static struct proc_dir_entry *snd_proc_root = NULL;
 118 struct snd_info_entry *snd_seq_root = NULL;
 119 #ifdef CONFIG_SND_OSSEMUL
 120 struct snd_info_entry *snd_oss_root = NULL;
 121 #endif
 122
 123 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 124 {
 125         de->owner = THIS_MODULE;
 126 }
 127
 128 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 129                                   struct proc_dir_entry *de)
 130 {
 131         if (de)
 132                 remove_proc_entry(de->name, parent);
 133 }
 134
 135 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 136 {
 137         struct snd_info_private_data *data;
 138         struct snd_info_entry *entry;
 139         loff_t ret;
 140
 141         data = file->private_data;
 142         entry = data->entry;
 143         lock_kernel();
 144         switch (entry->content) {
 145         case SNDRV_INFO_CONTENT_TEXT:
 146                 switch (orig) {
 147                 case 0: /* SEEK_SET */
 148                         file->f_pos = offset;
 149                         ret = file->f_pos;
 150                         goto out;
 151                 case 1: /* SEEK_CUR */
 152                         file->f_pos += offset;
 153                         ret = file->f_pos;
 154                         goto out;
 155                 case 2: /* SEEK_END */
 156                 default:
 157                         ret = -EINVAL;
 158                         goto out;
 159                 }
 160                 break;
 161         case SNDRV_INFO_CONTENT_DATA:
 162                 if (entry->c.ops->llseek) {
 163                         ret = entry->c.ops->llseek(entry,
 164                                                     data->file_private_data,
 165                                                     file, offset, orig);
 166                         goto out;
 167                 }
 168                 break;
 169         }
 170         ret = -ENXIO;
 171 out:
 172         unlock_kernel();
 173         return ret;
 174 }
 175
 176 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 177                                    size_t count, loff_t * offset)
 178 {
 179         struct snd_info_private_data *data;
 180         struct snd_info_entry *entry;
 181         struct snd_info_buffer *buf;
 182         size_t size = 0;
 183         loff_t pos;
 184
 185         data = file->private_data;
 186         snd_assert(data != NULL, return -ENXIO);
 187         pos = *offset;
 188         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 189                 return -EIO;
 190         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 191                 return -EIO;
 192         entry = data->entry;
 193         switch (entry->content) {
 194         case SNDRV_INFO_CONTENT_TEXT:
 195                 buf = data->rbuffer;
 196                 if (buf == NULL)
 197                         return -EIO;
 198                 if (pos >= buf->size)
 199                         return 0;
 200                 size = buf->size - pos;
 201                 size = min(count, size);
 202                 if (copy_to_user(buffer, buf->buffer + pos, size))
 203                         return -EFAULT;
 204                 break;
 205         case SNDRV_INFO_CONTENT_DATA:
 206                 if (entry->c.ops->read)
 207                         size = entry->c.ops->read(entry,
 208                                                   data->file_private_data,
 209                                                   file, buffer, count, pos);
 210                 break;
 211         }
 212         if ((ssize_t) size > 0)
 213                 *offset = pos + size;
 214         return size;
 215 }
 216
 217 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 218                                     size_t count, loff_t * offset)
 219 {
 220         struct snd_info_private_data *data;
 221         struct snd_info_entry *entry;
 222         struct snd_info_buffer *buf;
 223         size_t size = 0;
 224         loff_t pos;
 225
 226         data = file->private_data;
 227         snd_assert(data != NULL, return -ENXIO);
 228         entry = data->entry;
 229         pos = *offset;
 230         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 231                 return -EIO;
 232         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 233                 return -EIO;
 234         switch (entry->content) {
 235         case SNDRV_INFO_CONTENT_TEXT:
 236                 buf = data->wbuffer;
 237                 if (buf == NULL)
 238                         return -EIO;
 239                 if (pos >= buf->len)
 240                         return -ENOMEM;
 241                 size = buf->len - pos;
 242                 size = min(count, size);
 243                 if (copy_from_user(buf->buffer + pos, buffer, size))
 244                         return -EFAULT;
 245                 if ((long)buf->size < pos + size)
 246                         buf->size = pos + size;
 247                 break;
 248         case SNDRV_INFO_CONTENT_DATA:
 249                 if (entry->c.ops->write)
 250                         size = entry->c.ops->write(entry,
 251                                                    data->file_private_data,
 252                                                    file, buffer, count, pos);
 253                 break;
 254         }
 255         if ((ssize_t) size > 0)
 256                 *offset = pos + size;
 257         return size;
 258 }
 259
 260 static int snd_info_entry_open(struct inode *inode, struct file *file)
 261 {
 262         struct snd_info_entry *entry;
 263         struct snd_info_private_data *data;
 264         struct snd_info_buffer *buffer;
 265         struct proc_dir_entry *p;
 266         int mode, err;
 267
 268         down(&info_mutex);
 269         p = PDE(inode);
 270         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 271         if (entry == NULL || entry->disconnected) {
 272                 up(&info_mutex);
 273                 return -ENODEV;
 274         }
 275         if (!try_module_get(entry->module)) {
 276                 err = -EFAULT;
 277                 goto __error1;
 278         }
 279         mode = file->f_flags & O_ACCMODE;
 280         if (mode == O_RDONLY || mode == O_RDWR) {
 281                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 282                      !entry->c.text.read_size) ||
 283                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 284                      entry->c.ops->read == NULL)) {
 285                         err = -ENODEV;
 286                         goto __error;
 287                 }
 288         }
 289         if (mode == O_WRONLY || mode == O_RDWR) {
 290                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 291                      !entry->c.text.write_size) ||
 292                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 293                      entry->c.ops->write == NULL)) {
 294                         err = -ENODEV;
 295                         goto __error;
 296                 }
 297         }
 298         data = kzalloc(sizeof(*data), GFP_KERNEL);
 299         if (data == NULL) {
 300                 err = -ENOMEM;
 301                 goto __error;
 302         }
 303         data->entry = entry;
 304         switch (entry->content) {
 305         case SNDRV_INFO_CONTENT_TEXT:
 306                 if (mode == O_RDONLY || mode == O_RDWR) {
 307                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 308                         if (buffer == NULL) {
 309                                 kfree(data);
 310                                 err = -ENOMEM;
 311                                 goto __error;
 312                         }
 313                         buffer->len = (entry->c.text.read_size +
 314                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 315                         buffer->buffer = vmalloc(buffer->len);
 316                         if (buffer->buffer == NULL) {
 317                                 kfree(buffer);
 318                                 kfree(data);
 319                                 err = -ENOMEM;
 320                                 goto __error;
 321                         }
 322                         buffer->curr = buffer->buffer;
 323                         data->rbuffer = buffer;
 324                 }
 325                 if (mode == O_WRONLY || mode == O_RDWR) {
 326                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 327                         if (buffer == NULL) {
 328                                 if (mode == O_RDWR) {
 329                                         vfree(data->rbuffer->buffer);
 330                                         kfree(data->rbuffer);
 331                                 }
 332                                 kfree(data);
 333                                 err = -ENOMEM;
 334                                 goto __error;
 335                         }
 336                         buffer->len = (entry->c.text.write_size +
 337                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 338                         buffer->buffer = vmalloc(buffer->len);
 339                         if (buffer->buffer == NULL) {
 340                                 if (mode == O_RDWR) {
 341                                         vfree(data->rbuffer->buffer);
 342                                         kfree(data->rbuffer);
 343                                 }
 344                                 kfree(buffer);
 345                                 kfree(data);
 346                                 err = -ENOMEM;
 347                                 goto __error;
 348                         }
 349                         buffer->curr = buffer->buffer;
 350                         data->wbuffer = buffer;
 351                 }
 352                 break;
 353         case SNDRV_INFO_CONTENT_DATA:   /* data */
 354                 if (entry->c.ops->open) {
 355                         if ((err = entry->c.ops->open(entry, mode,
 356                                                       &data->file_private_data)) < 0) {
 357                                 kfree(data);
 358                                 goto __error;
 359                         }
 360                 }
 361                 break;
 362         }
 363         file->private_data = data;
 364         up(&info_mutex);
 365         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 366             (mode == O_RDONLY || mode == O_RDWR)) {
 367                 if (entry->c.text.read) {
 368                         down(&entry->access);
 369                         entry->c.text.read(entry, data->rbuffer);
 370                         up(&entry->access);
 371                 }
 372         }
 373         return 0;
 374
 375       __error:
 376         module_put(entry->module);
 377       __error1:
 378         up(&info_mutex);
 379         return err;
 380 }
 381
 382 static int snd_info_entry_release(struct inode *inode, struct file *file)
 383 {
 384         struct snd_info_entry *entry;
 385         struct snd_info_private_data *data;
 386         int mode;
 387
 388         mode = file->f_flags & O_ACCMODE;
 389         data = file->private_data;
 390         entry = data->entry;
 391         switch (entry->content) {
 392         case SNDRV_INFO_CONTENT_TEXT:
 393                 if (mode == O_RDONLY || mode == O_RDWR) {
 394                         vfree(data->rbuffer->buffer);
 395                         kfree(data->rbuffer);
 396                 }
 397                 if (mode == O_WRONLY || mode == O_RDWR) {
 398                         if (entry->c.text.write) {
 399                                 entry->c.text.write(entry, data->wbuffer);
 400                                 if (data->wbuffer->error) {
 401                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 402                                                 entry->name,
 403                                                 data->wbuffer->error);
 404                                 }
 405                         }
 406                         vfree(data->wbuffer->buffer);
 407                         kfree(data->wbuffer);
 408                 }
 409                 break;
 410         case SNDRV_INFO_CONTENT_DATA:
 411                 if (entry->c.ops->release)
 412                         entry->c.ops->release(entry, mode,
 413                                               data->file_private_data);
 414                 break;
 415         }
 416         module_put(entry->module);
 417         kfree(data);
 418         return 0;
 419 }
 420
 421 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 422 {
 423         struct snd_info_private_data *data;
 424         struct snd_info_entry *entry;
 425         unsigned int mask;
 426
 427         data = file->private_data;
 428         if (data == NULL)
 429                 return 0;
 430         entry = data->entry;
 431         mask = 0;
 432         switch (entry->content) {
 433         case SNDRV_INFO_CONTENT_DATA:
 434                 if (entry->c.ops->poll)
 435                         return entry->c.ops->poll(entry,
 436                                                   data->file_private_data,
 437                                                   file, wait);
 438                 if (entry->c.ops->read)
 439                         mask |= POLLIN | POLLRDNORM;
 440                 if (entry->c.ops->write)
 441                         mask |= POLLOUT | POLLWRNORM;
 442                 break;
 443         }
 444         return mask;
 445 }
 446
 447 static inline int _snd_info_entry_ioctl(struct inode *inode, struct file *file,
 448                                         unsigned int cmd, unsigned long arg)
 449 {
 450         struct snd_info_private_data *data;
 451         struct snd_info_entry *entry;
 452
 453         data = file->private_data;
 454         if (data == NULL)
 455                 return 0;
 456         entry = data->entry;
 457         switch (entry->content) {
 458         case SNDRV_INFO_CONTENT_DATA:
 459                 if (entry->c.ops->ioctl)
 460                         return entry->c.ops->ioctl(entry,
 461                                                    data->file_private_data,
 462                                                    file, cmd, arg);
 463                 break;
 464         }
 465         return -ENOTTY;
 466 }
 467
 468 /* FIXME: need to unlock BKL to allow preemption */
 469 static int snd_info_entry_ioctl(struct inode *inode, struct file *file,
 470                                 unsigned int cmd, unsigned long arg)
 471 {
 472         int err;
 473         unlock_kernel();
 474         err = _snd_info_entry_ioctl(inode, file, cmd, arg);
 475         lock_kernel();
 476         return err;
 477 }
 478
 479 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 480 {
 481         struct inode *inode = file->f_dentry->d_inode;
 482         struct snd_info_private_data *data;
 483         struct snd_info_entry *entry;
 484
 485         data = file->private_data;
 486         if (data == NULL)
 487                 return 0;
 488         entry = data->entry;
 489         switch (entry->content) {
 490         case SNDRV_INFO_CONTENT_DATA:
 491                 if (entry->c.ops->mmap)
 492                         return entry->c.ops->mmap(entry,
 493                                                   data->file_private_data,
 494                                                   inode, file, vma);
 495                 break;
 496         }
 497         return -ENXIO;
 498 }
 499
 500 static struct file_operations snd_info_entry_operations =
 501 {
 502         .owner =        THIS_MODULE,
 503         .llseek =       snd_info_entry_llseek,
 504         .read =         snd_info_entry_read,
 505         .write =        snd_info_entry_write,
 506         .poll =         snd_info_entry_poll,
 507         .ioctl =        snd_info_entry_ioctl,
 508         .mmap =         snd_info_entry_mmap,
 509         .open =         snd_info_entry_open,
 510         .release =      snd_info_entry_release,
 511 };
 512
 513 /**
 514  * snd_create_proc_entry - create a procfs entry
 515  * @name: the name of the proc file
 516  * @mode: the file permission bits, S_Ixxx
 517  * @parent: the parent proc-directory entry
 518  *
 519  * Creates a new proc file entry with the given name and permission
 520  * on the given directory.
 521  *
 522  * Returns the pointer of new instance or NULL on failure.
 523  */
 524 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 525                                                     struct proc_dir_entry *parent)
 526 {
 527         struct proc_dir_entry *p;
 528         p = create_proc_entry(name, mode, parent);
 529         if (p)
 530                 snd_info_entry_prepare(p);
 531         return p;
 532 }
 533
 534 int __init snd_info_init(void)
 535 {
 536         struct proc_dir_entry *p;
 537
 538         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 539         if (p == NULL)
 540                 return -ENOMEM;
 541         snd_proc_root = p;
 542 #ifdef CONFIG_SND_OSSEMUL
 543         {
 544                 struct snd_info_entry *entry;
 545                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 546                         return -ENOMEM;
 547                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 548                 if (snd_info_register(entry) < 0) {
 549                         snd_info_free_entry(entry);
 550                         return -ENOMEM;
 551                 }
 552                 snd_oss_root = entry;
 553         }
 554 #endif
 555 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 556         {
 557                 struct snd_info_entry *entry;
 558                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 559                         return -ENOMEM;
 560                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 561                 if (snd_info_register(entry) < 0) {
 562                         snd_info_free_entry(entry);
 563                         return -ENOMEM;
 564                 }
 565                 snd_seq_root = entry;
 566         }
 567 #endif
 568         snd_info_version_init();
 569         snd_minor_info_init();
 570         snd_minor_info_oss_init();
 571         snd_card_info_init();
 572         return 0;
 573 }
 574
 575 int __exit snd_info_done(void)
 576 {
 577         snd_card_info_done();
 578         snd_minor_info_oss_done();
 579         snd_minor_info_done();
 580         snd_info_version_done();
 581         if (snd_proc_root) {
 582 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 583                 snd_info_unregister(snd_seq_root);
 584 #endif
 585 #ifdef CONFIG_SND_OSSEMUL
 586                 snd_info_unregister(snd_oss_root);
 587 #endif
 588                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 589         }
 590         return 0;
 591 }
 592
 593 /*
 594
 595  */
 596
 597
 598 /*
 599  * create a card proc file
 600  * called from init.c
 601  */
 602 int snd_info_card_create(struct snd_card *card)
 603 {
 604         char str[8];
 605         struct snd_info_entry *entry;
 606
 607         snd_assert(card != NULL, return -ENXIO);
 608
 609         sprintf(str, "card%i", card->number);
 610         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 611                 return -ENOMEM;
 612         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 613         if (snd_info_register(entry) < 0) {
 614                 snd_info_free_entry(entry);
 615                 return -ENOMEM;
 616         }
 617         card->proc_root = entry;
 618         return 0;
 619 }
 620
 621 /*
 622  * register the card proc file
 623  * called from init.c
 624  */
 625 int snd_info_card_register(struct snd_card *card)
 626 {
 627         struct proc_dir_entry *p;
 628
 629         snd_assert(card != NULL, return -ENXIO);
 630
 631         if (!strcmp(card->id, card->proc_root->name))
 632                 return 0;
 633
 634         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 635         if (p == NULL)
 636                 return -ENOMEM;
 637         card->proc_root_link = p;
 638         return 0;
 639 }
 640
 641 /*
 642  * de-register the card proc file
 643  * called from init.c
 644  */
 645 int snd_info_card_free(struct snd_card *card)
 646 {
 647         snd_assert(card != NULL, return -ENXIO);
 648         if (card->proc_root_link) {
 649                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 650                 card->proc_root_link = NULL;
 651         }
 652         if (card->proc_root) {
 653                 snd_info_unregister(card->proc_root);
 654                 card->proc_root = NULL;
 655         }
 656         return 0;
 657 }
 658
 659
 660 /**
 661  * snd_info_get_line - read one line from the procfs buffer
 662  * @buffer: the procfs buffer
 663  * @line: the buffer to store
 664  * @len: the max. buffer size - 1
 665  *
 666  * Reads one line from the buffer and stores the string.
 667  *
 668  * Returns zero if successful, or 1 if error or EOF.
 669  */
 670 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 671 {
 672         int c = -1;
 673
 674         if (len <= 0 || buffer->stop || buffer->error)
 675                 return 1;
 676         while (--len > 0) {
 677                 c = *buffer->curr++;
 678                 if (c == '\n') {
 679                         if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 680                                 buffer->stop = 1;
 681                         }
 682                         break;
 683                 }
 684                 *line++ = c;
 685                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 686                         buffer->stop = 1;
 687                         break;
 688                 }
 689         }
 690         while (c != '\n' && !buffer->stop) {
 691                 c = *buffer->curr++;
 692                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 693                         buffer->stop = 1;
 694                 }
 695         }
 696         *line = '\0';
 697         return 0;
 698 }
 699
 700 /**
 701  * snd_info_get_str - parse a string token
 702  * @dest: the buffer to store the string token
 703  * @src: the original string
 704  * @len: the max. length of token - 1
 705  *
 706  * Parses the original string and copy a token to the given
 707  * string buffer.
 708  *
 709  * Returns the updated pointer of the original string so that
 710  * it can be used for the next call.
 711  */
 712 char *snd_info_get_str(char *dest, char *src, int len)
 713 {
 714         int c;
 715
 716         while (*src == ' ' || *src == '\t')
 717                 src++;
 718         if (*src == '"' || *src == '\'') {
 719                 c = *src++;
 720                 while (--len > 0 && *src && *src != c) {
 721                         *dest++ = *src++;
 722                 }
 723                 if (*src == c)
 724                         src++;
 725         } else {
 726                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 727                         *dest++ = *src++;
 728                 }
 729         }
 730         *dest = 0;
 731         while (*src == ' ' || *src == '\t')
 732                 src++;
 733         return src;
 734 }
 735
 736 /**
 737  * snd_info_create_entry - create an info entry
 738  * @name: the proc file name
 739  *
 740  * Creates an info entry with the given file name and initializes as
 741  * the default state.
 742  *
 743  * Usually called from other functions such as
 744  * snd_info_create_card_entry().
 745  *
 746  * Returns the pointer of the new instance, or NULL on failure.
 747  */
 748 static struct snd_info_entry *snd_info_create_entry(const char *name)
 749 {
 750         struct snd_info_entry *entry;
 751         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 752         if (entry == NULL)
 753                 return NULL;
 754         entry->name = kstrdup(name, GFP_KERNEL);
 755         if (entry->name == NULL) {
 756                 kfree(entry);
 757                 return NULL;
 758         }
 759         entry->mode = S_IFREG | S_IRUGO;
 760         entry->content = SNDRV_INFO_CONTENT_TEXT;
 761         init_MUTEX(&entry->access);
 762         return entry;
 763 }
 764
 765 /**
 766  * snd_info_create_module_entry - create an info entry for the given module
 767  * @module: the module pointer
 768  * @name: the file name
 769  * @parent: the parent directory
 770  *
 771  * Creates a new info entry and assigns it to the given module.
 772  *
 773  * Returns the pointer of the new instance, or NULL on failure.
 774  */
 775 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 776                                                const char *name,
 777                                                struct snd_info_entry *parent)
 778 {
 779         struct snd_info_entry *entry = snd_info_create_entry(name);
 780         if (entry) {
 781                 entry->module = module;
 782                 entry->parent = parent;
 783         }
 784         return entry;
 785 }
 786
 787 /**
 788  * snd_info_create_card_entry - create an info entry for the given card
 789  * @card: the card instance
 790  * @name: the file name
 791  * @parent: the parent directory
 792  *
 793  * Creates a new info entry and assigns it to the given card.
 794  *
 795  * Returns the pointer of the new instance, or NULL on failure.
 796  */
 797 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 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 = card->module;
 804                 entry->card = card;
 805                 entry->parent = parent;
 806         }
 807         return entry;
 808 }
 809
 810 static int snd_info_dev_free_entry(struct snd_device *device)
 811 {
 812         struct snd_info_entry *entry = device->device_data;
 813         snd_info_free_entry(entry);
 814         return 0;
 815 }
 816
 817 static int snd_info_dev_register_entry(struct snd_device *device)
 818 {
 819         struct snd_info_entry *entry = device->device_data;
 820         return snd_info_register(entry);
 821 }
 822
 823 static int snd_info_dev_disconnect_entry(struct snd_device *device)
 824 {
 825         struct snd_info_entry *entry = device->device_data;
 826         entry->disconnected = 1;
 827         return 0;
 828 }
 829
 830 static int snd_info_dev_unregister_entry(struct snd_device *device)
 831 {
 832         struct snd_info_entry *entry = device->device_data;
 833         return snd_info_unregister(entry);
 834 }
 835
 836 /**
 837  * snd_card_proc_new - create an info entry for the given card
 838  * @card: the card instance
 839  * @name: the file name
 840  * @entryp: the pointer to store the new info entry
 841  *
 842  * Creates a new info entry and assigns it to the given card.
 843  * Unlike snd_info_create_card_entry(), this function registers the
 844  * info entry as an ALSA device component, so that it can be
 845  * unregistered/released without explicit call.
 846  * Also, you don't have to register this entry via snd_info_register(),
 847  * since this will be registered by snd_card_register() automatically.
 848  *
 849  * The parent is assumed as card->proc_root.
 850  *
 851  * For releasing this entry, use snd_device_free() instead of
 852  * snd_info_free_entry().
 853  *
 854  * Returns zero if successful, or a negative error code on failure.
 855  */
 856 int snd_card_proc_new(struct snd_card *card, const char *name,
 857                       struct snd_info_entry **entryp)
 858 {
 859         static struct snd_device_ops ops = {
 860                 .dev_free = snd_info_dev_free_entry,
 861                 .dev_register = snd_info_dev_register_entry,
 862                 .dev_disconnect = snd_info_dev_disconnect_entry,
 863                 .dev_unregister = snd_info_dev_unregister_entry
 864         };
 865         struct snd_info_entry *entry;
 866         int err;
 867
 868         entry = snd_info_create_card_entry(card, name, card->proc_root);
 869         if (! entry)
 870                 return -ENOMEM;
 871         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 872                 snd_info_free_entry(entry);
 873                 return err;
 874         }
 875         if (entryp)
 876                 *entryp = entry;
 877         return 0;
 878 }
 879
 880 /**
 881  * snd_info_free_entry - release the info entry
 882  * @entry: the info entry
 883  *
 884  * Releases the info entry.  Don't call this after registered.
 885  */
 886 void snd_info_free_entry(struct snd_info_entry * entry)
 887 {
 888         if (entry == NULL)
 889                 return;
 890         kfree(entry->name);
 891         if (entry->private_free)
 892                 entry->private_free(entry);
 893         kfree(entry);
 894 }
 895
 896 /**
 897  * snd_info_register - register the info entry
 898  * @entry: the info entry
 899  *
 900  * Registers the proc info entry.
 901  *
 902  * Returns zero if successful, or a negative error code on failure.
 903  */
 904 int snd_info_register(struct snd_info_entry * entry)
 905 {
 906         struct proc_dir_entry *root, *p = NULL;
 907
 908         snd_assert(entry != NULL, return -ENXIO);
 909         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 910         down(&info_mutex);
 911         p = snd_create_proc_entry(entry->name, entry->mode, root);
 912         if (!p) {
 913                 up(&info_mutex);
 914                 return -ENOMEM;
 915         }
 916         p->owner = entry->module;
 917         if (!S_ISDIR(entry->mode))
 918                 p->proc_fops = &snd_info_entry_operations;
 919         p->size = entry->size;
 920         p->data = entry;
 921         entry->p = p;
 922         up(&info_mutex);
 923         return 0;
 924 }
 925
 926 /**
 927  * snd_info_unregister - de-register the info entry
 928  * @entry: the info entry
 929  *
 930  * De-registers the info entry and releases the instance.
 931  *
 932  * Returns zero if successful, or a negative error code on failure.
 933  */
 934 int snd_info_unregister(struct snd_info_entry * entry)
 935 {
 936         struct proc_dir_entry *root;
 937
 938         if (! entry)
 939                 return 0;
 940         snd_assert(entry->p != NULL, return -ENXIO);
 941         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 942         snd_assert(root, return -ENXIO);
 943         down(&info_mutex);
 944         snd_remove_proc_entry(root, entry->p);
 945         up(&info_mutex);
 946         snd_info_free_entry(entry);
 947         return 0;
 948 }
 949
 950 /*
 951
 952  */
 953
 954 static struct snd_info_entry *snd_info_version_entry = NULL;
 955
 956 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 957 {
 958         snd_iprintf(buffer,
 959                     "Advanced Linux Sound Architecture Driver Version "
 960                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 961                    );
 962 }
 963
 964 static int __init snd_info_version_init(void)
 965 {
 966         struct snd_info_entry *entry;
 967
 968         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 969         if (entry == NULL)
 970                 return -ENOMEM;
 971         entry->c.text.read_size = 256;
 972         entry->c.text.read = snd_info_version_read;
 973         if (snd_info_register(entry) < 0) {
 974                 snd_info_free_entry(entry);
 975                 return -ENOMEM;
 976         }
 977         snd_info_version_entry = entry;
 978         return 0;
 979 }
 980
 981 static int __exit snd_info_version_done(void)
 982 {
 983         if (snd_info_version_entry)
 984                 snd_info_unregister(snd_info_version_entry);
 985         return 0;
 986 }
 987
 988 #endif /* CONFIG_PROC_FS */