git.oblomov.eu Git - linux-2.6/blob - 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/smp_lock.h>
  25 #include <linux/string.h>
  26 #include <sound/core.h>
  27 #include <sound/minors.h>
  28 #include <sound/info.h>
  29 #include <sound/version.h>
  30 #include <linux/proc_fs.h>
  31 #include <linux/mutex.h>
  32 #include <stdarg.h>
  33
  34 /*
  35  *
  36  */
  37
  38 #ifdef CONFIG_PROC_FS
  39
  40 int snd_info_check_reserved_words(const char *str)
  41 {
  42         static char *reserved[] =
  43         {
  44                 "version",
  45                 "meminfo",
  46                 "memdebug",
  47                 "detect",
  48                 "devices",
  49                 "oss",
  50                 "cards",
  51                 "timers",
  52                 "synth",
  53                 "pcm",
  54                 "seq",
  55                 NULL
  56         };
  57         char **xstr = reserved;
  58
  59         while (*xstr) {
  60                 if (!strcmp(*xstr, str))
  61                         return 0;
  62                 xstr++;
  63         }
  64         if (!strncmp(str, "card", 4))
  65                 return 0;
  66         return 1;
  67 }
  68
  69 static DEFINE_MUTEX(info_mutex);
  70
  71 struct snd_info_private_data {
  72         struct snd_info_buffer *rbuffer;
  73         struct snd_info_buffer *wbuffer;
  74         struct snd_info_entry *entry;
  75         void *file_private_data;
  76 };
  77
  78 static int snd_info_version_init(void);
  79 static int snd_info_version_done(void);
  80 static void snd_info_disconnect(struct snd_info_entry *entry);
  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 SEEK_SET:
 181                         file->f_pos = offset;
 182                         ret = file->f_pos;
 183                         goto out;
 184                 case SEEK_CUR:
 185                         file->f_pos += offset;
 186                         ret = file->f_pos;
 187                         goto out;
 188                 case 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->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 = 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_path.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 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 /**
 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, NULL);
 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_free_entry(snd_seq_root);
 593 #endif
 594 #ifdef CONFIG_SND_OSSEMUL
 595                 snd_info_free_entry(snd_oss_root);
 596 #endif
 597                 snd_remove_proc_entry(NULL, 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 void snd_info_card_disconnect(struct snd_card *card)
 655 {
 656         snd_assert(card != NULL, return);
 657         mutex_lock(&info_mutex);
 658         if (card->proc_root_link) {
 659                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 660                 card->proc_root_link = NULL;
 661         }
 662         if (card->proc_root)
 663                 snd_info_disconnect(card->proc_root);
 664         mutex_unlock(&info_mutex);
 665 }
 666
 667 /*
 668  * release the card proc file resources
 669  * called from init.c
 670  */
 671 int snd_info_card_free(struct snd_card *card)
 672 {
 673         snd_assert(card != NULL, return -ENXIO);
 674         snd_info_free_entry(card->proc_root);
 675         card->proc_root = NULL;
 676         return 0;
 677 }
 678
 679
 680 /**
 681  * snd_info_get_line - read one line from the procfs buffer
 682  * @buffer: the procfs buffer
 683  * @line: the buffer to store
 684  * @len: the max. buffer size - 1
 685  *
 686  * Reads one line from the buffer and stores the string.
 687  *
 688  * Returns zero if successful, or 1 if error or EOF.
 689  */
 690 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 691 {
 692         int c = -1;
 693
 694         if (len <= 0 || buffer->stop || buffer->error)
 695                 return 1;
 696         while (--len > 0) {
 697                 c = buffer->buffer[buffer->curr++];
 698                 if (c == '\n') {
 699                         if (buffer->curr >= buffer->size)
 700                                 buffer->stop = 1;
 701                         break;
 702                 }
 703                 *line++ = c;
 704                 if (buffer->curr >= buffer->size) {
 705                         buffer->stop = 1;
 706                         break;
 707                 }
 708         }
 709         while (c != '\n' && !buffer->stop) {
 710                 c = buffer->buffer[buffer->curr++];
 711                 if (buffer->curr >= buffer->size)
 712                         buffer->stop = 1;
 713         }
 714         *line = '\0';
 715         return 0;
 716 }
 717
 718 EXPORT_SYMBOL(snd_info_get_line);
 719
 720 /**
 721  * snd_info_get_str - parse a string token
 722  * @dest: the buffer to store the string token
 723  * @src: the original string
 724  * @len: the max. length of token - 1
 725  *
 726  * Parses the original string and copy a token to the given
 727  * string buffer.
 728  *
 729  * Returns the updated pointer of the original string so that
 730  * it can be used for the next call.
 731  */
 732 char *snd_info_get_str(char *dest, char *src, int len)
 733 {
 734         int c;
 735
 736         while (*src == ' ' || *src == '\t')
 737                 src++;
 738         if (*src == '"' || *src == '\'') {
 739                 c = *src++;
 740                 while (--len > 0 && *src && *src != c) {
 741                         *dest++ = *src++;
 742                 }
 743                 if (*src == c)
 744                         src++;
 745         } else {
 746                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 747                         *dest++ = *src++;
 748                 }
 749         }
 750         *dest = 0;
 751         while (*src == ' ' || *src == '\t')
 752                 src++;
 753         return src;
 754 }
 755
 756 EXPORT_SYMBOL(snd_info_get_str);
 757
 758 /**
 759  * snd_info_create_entry - create an info entry
 760  * @name: the proc file name
 761  *
 762  * Creates an info entry with the given file name and initializes as
 763  * the default state.
 764  *
 765  * Usually called from other functions such as
 766  * snd_info_create_card_entry().
 767  *
 768  * Returns the pointer of the new instance, or NULL on failure.
 769  */
 770 static struct snd_info_entry *snd_info_create_entry(const char *name)
 771 {
 772         struct snd_info_entry *entry;
 773         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 774         if (entry == NULL)
 775                 return NULL;
 776         entry->name = kstrdup(name, GFP_KERNEL);
 777         if (entry->name == NULL) {
 778                 kfree(entry);
 779                 return NULL;
 780         }
 781         entry->mode = S_IFREG | S_IRUGO;
 782         entry->content = SNDRV_INFO_CONTENT_TEXT;
 783         mutex_init(&entry->access);
 784         INIT_LIST_HEAD(&entry->children);
 785         INIT_LIST_HEAD(&entry->list);
 786         return entry;
 787 }
 788
 789 /**
 790  * snd_info_create_module_entry - create an info entry for the given module
 791  * @module: the module pointer
 792  * @name: the file name
 793  * @parent: the parent directory
 794  *
 795  * Creates a new info entry and assigns it to the given module.
 796  *
 797  * Returns the pointer of the new instance, or NULL on failure.
 798  */
 799 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 800                                                const char *name,
 801                                                struct snd_info_entry *parent)
 802 {
 803         struct snd_info_entry *entry = snd_info_create_entry(name);
 804         if (entry) {
 805                 entry->module = module;
 806                 entry->parent = parent;
 807         }
 808         return entry;
 809 }
 810
 811 EXPORT_SYMBOL(snd_info_create_module_entry);
 812
 813 /**
 814  * snd_info_create_card_entry - create an info entry for the given card
 815  * @card: the card instance
 816  * @name: the file name
 817  * @parent: the parent directory
 818  *
 819  * Creates a new info entry and assigns it to the given card.
 820  *
 821  * Returns the pointer of the new instance, or NULL on failure.
 822  */
 823 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 824                                              const char *name,
 825                                              struct snd_info_entry * parent)
 826 {
 827         struct snd_info_entry *entry = snd_info_create_entry(name);
 828         if (entry) {
 829                 entry->module = card->module;
 830                 entry->card = card;
 831                 entry->parent = parent;
 832         }
 833         return entry;
 834 }
 835
 836 EXPORT_SYMBOL(snd_info_create_card_entry);
 837
 838 static void snd_info_disconnect(struct snd_info_entry *entry)
 839 {
 840         struct list_head *p, *n;
 841         struct proc_dir_entry *root;
 842
 843         list_for_each_safe(p, n, &entry->children) {
 844                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 845         }
 846
 847         if (! entry->p)
 848                 return;
 849         list_del_init(&entry->list);
 850         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 851         snd_assert(root, return);
 852         snd_remove_proc_entry(root, entry->p);
 853         entry->p = NULL;
 854 }
 855
 856 static int snd_info_dev_free_entry(struct snd_device *device)
 857 {
 858         struct snd_info_entry *entry = device->device_data;
 859         snd_info_free_entry(entry);
 860         return 0;
 861 }
 862
 863 static int snd_info_dev_register_entry(struct snd_device *device)
 864 {
 865         struct snd_info_entry *entry = device->device_data;
 866         return snd_info_register(entry);
 867 }
 868
 869 /**
 870  * snd_card_proc_new - create an info entry for the given card
 871  * @card: the card instance
 872  * @name: the file name
 873  * @entryp: the pointer to store the new info entry
 874  *
 875  * Creates a new info entry and assigns it to the given card.
 876  * Unlike snd_info_create_card_entry(), this function registers the
 877  * info entry as an ALSA device component, so that it can be
 878  * unregistered/released without explicit call.
 879  * Also, you don't have to register this entry via snd_info_register(),
 880  * since this will be registered by snd_card_register() automatically.
 881  *
 882  * The parent is assumed as card->proc_root.
 883  *
 884  * For releasing this entry, use snd_device_free() instead of
 885  * snd_info_free_entry().
 886  *
 887  * Returns zero if successful, or a negative error code on failure.
 888  */
 889 int snd_card_proc_new(struct snd_card *card, const char *name,
 890                       struct snd_info_entry **entryp)
 891 {
 892         static struct snd_device_ops ops = {
 893                 .dev_free = snd_info_dev_free_entry,
 894                 .dev_register = snd_info_dev_register_entry,
 895                 /* disconnect is done via snd_info_card_disconnect() */
 896         };
 897         struct snd_info_entry *entry;
 898         int err;
 899
 900         entry = snd_info_create_card_entry(card, name, card->proc_root);
 901         if (! entry)
 902                 return -ENOMEM;
 903         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 904                 snd_info_free_entry(entry);
 905                 return err;
 906         }
 907         if (entryp)
 908                 *entryp = entry;
 909         return 0;
 910 }
 911
 912 EXPORT_SYMBOL(snd_card_proc_new);
 913
 914 /**
 915  * snd_info_free_entry - release the info entry
 916  * @entry: the info entry
 917  *
 918  * Releases the info entry.  Don't call this after registered.
 919  */
 920 void snd_info_free_entry(struct snd_info_entry * entry)
 921 {
 922         if (entry == NULL)
 923                 return;
 924         if (entry->p) {
 925                 mutex_lock(&info_mutex);
 926                 snd_info_disconnect(entry);
 927                 mutex_unlock(&info_mutex);
 928         }
 929         kfree(entry->name);
 930         if (entry->private_free)
 931                 entry->private_free(entry);
 932         kfree(entry);
 933 }
 934
 935 EXPORT_SYMBOL(snd_info_free_entry);
 936
 937 /**
 938  * snd_info_register - register the info entry
 939  * @entry: the info entry
 940  *
 941  * Registers the proc info entry.
 942  *
 943  * Returns zero if successful, or a negative error code on failure.
 944  */
 945 int snd_info_register(struct snd_info_entry * entry)
 946 {
 947         struct proc_dir_entry *root, *p = NULL;
 948
 949         snd_assert(entry != NULL, return -ENXIO);
 950         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 951         mutex_lock(&info_mutex);
 952         p = snd_create_proc_entry(entry->name, entry->mode, root);
 953         if (!p) {
 954                 mutex_unlock(&info_mutex);
 955                 return -ENOMEM;
 956         }
 957         p->owner = entry->module;
 958         if (!S_ISDIR(entry->mode))
 959                 p->proc_fops = &snd_info_entry_operations;
 960         p->size = entry->size;
 961         p->data = entry;
 962         entry->p = p;
 963         if (entry->parent)
 964                 list_add_tail(&entry->list, &entry->parent->children);
 965         mutex_unlock(&info_mutex);
 966         return 0;
 967 }
 968
 969 EXPORT_SYMBOL(snd_info_register);
 970
 971 /*
 972
 973  */
 974
 975 static struct snd_info_entry *snd_info_version_entry;
 976
 977 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 978 {
 979         snd_iprintf(buffer,
 980                     "Advanced Linux Sound Architecture Driver Version "
 981                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 982                    );
 983 }
 984
 985 static int __init snd_info_version_init(void)
 986 {
 987         struct snd_info_entry *entry;
 988
 989         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 990         if (entry == NULL)
 991                 return -ENOMEM;
 992         entry->c.text.read = snd_info_version_read;
 993         if (snd_info_register(entry) < 0) {
 994                 snd_info_free_entry(entry);
 995                 return -ENOMEM;
 996         }
 997         snd_info_version_entry = entry;
 998         return 0;
 999 }
1000
1001 static int __exit snd_info_version_done(void)
1002 {
1003         snd_info_free_entry(snd_info_version_entry);
1004         return 0;
1005 }
1006
1007 #endif /* CONFIG_PROC_FS */