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@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 static void snd_info_disconnect(struct snd_info_entry *entry);
  82
  83
  84 /* resize the proc r/w buffer */
  85 static int resize_info_buffer(struct snd_info_buffer *buffer,
  86                               unsigned int nsize)
  87 {
  88         char *nbuf;
  89
  90         nsize = PAGE_ALIGN(nsize);
  91         nbuf = kmalloc(nsize, GFP_KERNEL);
  92         if (! nbuf)
  93                 return -ENOMEM;
  94
  95         memcpy(nbuf, buffer->buffer, buffer->len);
  96         kfree(buffer->buffer);
  97         buffer->buffer = nbuf;
  98         buffer->len = nsize;
  99         return 0;
 100 }
 101
 102 /**
 103  * snd_iprintf - printf on the procfs buffer
 104  * @buffer: the procfs buffer
 105  * @fmt: the printf format
 106  *
 107  * Outputs the string on the procfs buffer just like printf().
 108  *
 109  * Returns the size of output string.
 110  */
 111 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
 112 {
 113         va_list args;
 114         int len, res;
 115         int err = 0;
 116
 117         might_sleep();
 118         if (buffer->stop || buffer->error)
 119                 return 0;
 120         len = buffer->len - buffer->size;
 121         va_start(args, fmt);
 122         for (;;) {
 123                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, args);
 124                 if (res < len)
 125                         break;
 126                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
 127                 if (err < 0)
 128                         break;
 129                 len = buffer->len - buffer->size;
 130         }
 131         va_end(args);
 132
 133         if (err < 0)
 134                 return err;
 135         buffer->curr += res;
 136         buffer->size += res;
 137         return res;
 138 }
 139
 140 EXPORT_SYMBOL(snd_iprintf);
 141
 142 /*
 143
 144  */
 145
 146 static struct proc_dir_entry *snd_proc_root;
 147 struct snd_info_entry *snd_seq_root;
 148 EXPORT_SYMBOL(snd_seq_root);
 149
 150 #ifdef CONFIG_SND_OSSEMUL
 151 struct snd_info_entry *snd_oss_root;
 152 #endif
 153
 154 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 155 {
 156         de->owner = THIS_MODULE;
 157 }
 158
 159 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 160                                   struct proc_dir_entry *de)
 161 {
 162         if (de)
 163                 remove_proc_entry(de->name, parent);
 164 }
 165
 166 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 167 {
 168         struct snd_info_private_data *data;
 169         struct snd_info_entry *entry;
 170         loff_t ret;
 171
 172         data = file->private_data;
 173         entry = data->entry;
 174         lock_kernel();
 175         switch (entry->content) {
 176         case SNDRV_INFO_CONTENT_TEXT:
 177                 switch (orig) {
 178                 case SEEK_SET:
 179                         file->f_pos = offset;
 180                         ret = file->f_pos;
 181                         goto out;
 182                 case SEEK_CUR:
 183                         file->f_pos += offset;
 184                         ret = file->f_pos;
 185                         goto out;
 186                 case SEEK_END:
 187                 default:
 188                         ret = -EINVAL;
 189                         goto out;
 190                 }
 191                 break;
 192         case SNDRV_INFO_CONTENT_DATA:
 193                 if (entry->c.ops->llseek) {
 194                         ret = entry->c.ops->llseek(entry,
 195                                                     data->file_private_data,
 196                                                     file, offset, orig);
 197                         goto out;
 198                 }
 199                 break;
 200         }
 201         ret = -ENXIO;
 202 out:
 203         unlock_kernel();
 204         return ret;
 205 }
 206
 207 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 208                                    size_t count, loff_t * offset)
 209 {
 210         struct snd_info_private_data *data;
 211         struct snd_info_entry *entry;
 212         struct snd_info_buffer *buf;
 213         size_t size = 0;
 214         loff_t pos;
 215
 216         data = file->private_data;
 217         snd_assert(data != NULL, return -ENXIO);
 218         pos = *offset;
 219         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 220                 return -EIO;
 221         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 222                 return -EIO;
 223         entry = data->entry;
 224         switch (entry->content) {
 225         case SNDRV_INFO_CONTENT_TEXT:
 226                 buf = data->rbuffer;
 227                 if (buf == NULL)
 228                         return -EIO;
 229                 if (pos >= buf->size)
 230                         return 0;
 231                 size = buf->size - pos;
 232                 size = min(count, size);
 233                 if (copy_to_user(buffer, buf->buffer + pos, size))
 234                         return -EFAULT;
 235                 break;
 236         case SNDRV_INFO_CONTENT_DATA:
 237                 if (entry->c.ops->read)
 238                         size = entry->c.ops->read(entry,
 239                                                   data->file_private_data,
 240                                                   file, buffer, count, pos);
 241                 break;
 242         }
 243         if ((ssize_t) size > 0)
 244                 *offset = pos + size;
 245         return size;
 246 }
 247
 248 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 249                                     size_t count, loff_t * offset)
 250 {
 251         struct snd_info_private_data *data;
 252         struct snd_info_entry *entry;
 253         struct snd_info_buffer *buf;
 254         ssize_t size = 0;
 255         loff_t pos;
 256
 257         data = file->private_data;
 258         snd_assert(data != NULL, return -ENXIO);
 259         entry = data->entry;
 260         pos = *offset;
 261         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 262                 return -EIO;
 263         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 264                 return -EIO;
 265         switch (entry->content) {
 266         case SNDRV_INFO_CONTENT_TEXT:
 267                 buf = data->wbuffer;
 268                 if (buf == NULL)
 269                         return -EIO;
 270                 mutex_lock(&entry->access);
 271                 if (pos + count >= buf->len) {
 272                         if (resize_info_buffer(buf, pos + count)) {
 273                                 mutex_unlock(&entry->access);
 274                                 return -ENOMEM;
 275                         }
 276                 }
 277                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
 278                         mutex_unlock(&entry->access);
 279                         return -EFAULT;
 280                 }
 281                 buf->size = pos + count;
 282                 mutex_unlock(&entry->access);
 283                 size = count;
 284                 break;
 285         case SNDRV_INFO_CONTENT_DATA:
 286                 if (entry->c.ops->write)
 287                         size = entry->c.ops->write(entry,
 288                                                    data->file_private_data,
 289                                                    file, buffer, count, pos);
 290                 break;
 291         }
 292         if ((ssize_t) size > 0)
 293                 *offset = pos + size;
 294         return size;
 295 }
 296
 297 static int snd_info_entry_open(struct inode *inode, struct file *file)
 298 {
 299         struct snd_info_entry *entry;
 300         struct snd_info_private_data *data;
 301         struct snd_info_buffer *buffer;
 302         struct proc_dir_entry *p;
 303         int mode, err;
 304
 305         mutex_lock(&info_mutex);
 306         p = PDE(inode);
 307         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 308         if (entry == NULL || ! entry->p) {
 309                 mutex_unlock(&info_mutex);
 310                 return -ENODEV;
 311         }
 312         if (!try_module_get(entry->module)) {
 313                 err = -EFAULT;
 314                 goto __error1;
 315         }
 316         mode = file->f_flags & O_ACCMODE;
 317         if (mode == O_RDONLY || mode == O_RDWR) {
 318                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 319                      entry->c.ops->read == NULL)) {
 320                         err = -ENODEV;
 321                         goto __error;
 322                 }
 323         }
 324         if (mode == O_WRONLY || mode == O_RDWR) {
 325                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 326                      entry->c.ops->write == NULL)) {
 327                         err = -ENODEV;
 328                         goto __error;
 329                 }
 330         }
 331         data = kzalloc(sizeof(*data), GFP_KERNEL);
 332         if (data == NULL) {
 333                 err = -ENOMEM;
 334                 goto __error;
 335         }
 336         data->entry = entry;
 337         switch (entry->content) {
 338         case SNDRV_INFO_CONTENT_TEXT:
 339                 if (mode == O_RDONLY || mode == O_RDWR) {
 340                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 341                         if (buffer == NULL)
 342                                 goto __nomem;
 343                         data->rbuffer = buffer;
 344                         buffer->len = PAGE_SIZE;
 345                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 346                         if (buffer->buffer == NULL)
 347                                 goto __nomem;
 348                 }
 349                 if (mode == O_WRONLY || mode == O_RDWR) {
 350                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 351                         if (buffer == NULL)
 352                                 goto __nomem;
 353                         data->wbuffer = buffer;
 354                         buffer->len = PAGE_SIZE;
 355                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 356                         if (buffer->buffer == NULL)
 357                                 goto __nomem;
 358                 }
 359                 break;
 360         case SNDRV_INFO_CONTENT_DATA:   /* data */
 361                 if (entry->c.ops->open) {
 362                         if ((err = entry->c.ops->open(entry, mode,
 363                                                       &data->file_private_data)) < 0) {
 364                                 kfree(data);
 365                                 goto __error;
 366                         }
 367                 }
 368                 break;
 369         }
 370         file->private_data = data;
 371         mutex_unlock(&info_mutex);
 372         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 373             (mode == O_RDONLY || mode == O_RDWR)) {
 374                 if (entry->c.text.read) {
 375                         mutex_lock(&entry->access);
 376                         entry->c.text.read(entry, data->rbuffer);
 377                         mutex_unlock(&entry->access);
 378                 }
 379         }
 380         return 0;
 381
 382  __nomem:
 383         if (data->rbuffer) {
 384                 kfree(data->rbuffer->buffer);
 385                 kfree(data->rbuffer);
 386         }
 387         if (data->wbuffer) {
 388                 kfree(data->wbuffer->buffer);
 389                 kfree(data->wbuffer);
 390         }
 391         kfree(data);
 392         err = -ENOMEM;
 393       __error:
 394         module_put(entry->module);
 395       __error1:
 396         mutex_unlock(&info_mutex);
 397         return err;
 398 }
 399
 400 static int snd_info_entry_release(struct inode *inode, struct file *file)
 401 {
 402         struct snd_info_entry *entry;
 403         struct snd_info_private_data *data;
 404         int mode;
 405
 406         mode = file->f_flags & O_ACCMODE;
 407         data = file->private_data;
 408         entry = data->entry;
 409         switch (entry->content) {
 410         case SNDRV_INFO_CONTENT_TEXT:
 411                 if (data->rbuffer) {
 412                         kfree(data->rbuffer->buffer);
 413                         kfree(data->rbuffer);
 414                 }
 415                 if (data->wbuffer) {
 416                         if (entry->c.text.write) {
 417                                 entry->c.text.write(entry, data->wbuffer);
 418                                 if (data->wbuffer->error) {
 419                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 420                                                 entry->name,
 421                                                 data->wbuffer->error);
 422                                 }
 423                         }
 424                         kfree(data->wbuffer->buffer);
 425                         kfree(data->wbuffer);
 426                 }
 427                 break;
 428         case SNDRV_INFO_CONTENT_DATA:
 429                 if (entry->c.ops->release)
 430                         entry->c.ops->release(entry, mode,
 431                                               data->file_private_data);
 432                 break;
 433         }
 434         module_put(entry->module);
 435         kfree(data);
 436         return 0;
 437 }
 438
 439 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 440 {
 441         struct snd_info_private_data *data;
 442         struct snd_info_entry *entry;
 443         unsigned int mask;
 444
 445         data = file->private_data;
 446         if (data == NULL)
 447                 return 0;
 448         entry = data->entry;
 449         mask = 0;
 450         switch (entry->content) {
 451         case SNDRV_INFO_CONTENT_DATA:
 452                 if (entry->c.ops->poll)
 453                         return entry->c.ops->poll(entry,
 454                                                   data->file_private_data,
 455                                                   file, wait);
 456                 if (entry->c.ops->read)
 457                         mask |= POLLIN | POLLRDNORM;
 458                 if (entry->c.ops->write)
 459                         mask |= POLLOUT | POLLWRNORM;
 460                 break;
 461         }
 462         return mask;
 463 }
 464
 465 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 466                                 unsigned long arg)
 467 {
 468         struct snd_info_private_data *data;
 469         struct snd_info_entry *entry;
 470
 471         data = file->private_data;
 472         if (data == NULL)
 473                 return 0;
 474         entry = data->entry;
 475         switch (entry->content) {
 476         case SNDRV_INFO_CONTENT_DATA:
 477                 if (entry->c.ops->ioctl)
 478                         return entry->c.ops->ioctl(entry,
 479                                                    data->file_private_data,
 480                                                    file, cmd, arg);
 481                 break;
 482         }
 483         return -ENOTTY;
 484 }
 485
 486 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 487 {
 488         struct inode *inode = file->f_dentry->d_inode;
 489         struct snd_info_private_data *data;
 490         struct snd_info_entry *entry;
 491
 492         data = file->private_data;
 493         if (data == NULL)
 494                 return 0;
 495         entry = data->entry;
 496         switch (entry->content) {
 497         case SNDRV_INFO_CONTENT_DATA:
 498                 if (entry->c.ops->mmap)
 499                         return entry->c.ops->mmap(entry,
 500                                                   data->file_private_data,
 501                                                   inode, file, vma);
 502                 break;
 503         }
 504         return -ENXIO;
 505 }
 506
 507 static struct file_operations snd_info_entry_operations =
 508 {
 509         .owner =                THIS_MODULE,
 510         .llseek =               snd_info_entry_llseek,
 511         .read =                 snd_info_entry_read,
 512         .write =                snd_info_entry_write,
 513         .poll =                 snd_info_entry_poll,
 514         .unlocked_ioctl =       snd_info_entry_ioctl,
 515         .mmap =                 snd_info_entry_mmap,
 516         .open =                 snd_info_entry_open,
 517         .release =              snd_info_entry_release,
 518 };
 519
 520 /**
 521  * snd_create_proc_entry - create a procfs entry
 522  * @name: the name of the proc file
 523  * @mode: the file permission bits, S_Ixxx
 524  * @parent: the parent proc-directory entry
 525  *
 526  * Creates a new proc file entry with the given name and permission
 527  * on the given directory.
 528  *
 529  * Returns the pointer of new instance or NULL on failure.
 530  */
 531 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 532                                                     struct proc_dir_entry *parent)
 533 {
 534         struct proc_dir_entry *p;
 535         p = create_proc_entry(name, mode, parent);
 536         if (p)
 537                 snd_info_entry_prepare(p);
 538         return p;
 539 }
 540
 541 int __init snd_info_init(void)
 542 {
 543         struct proc_dir_entry *p;
 544
 545         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 546         if (p == NULL)
 547                 return -ENOMEM;
 548         snd_proc_root = p;
 549 #ifdef CONFIG_SND_OSSEMUL
 550         {
 551                 struct snd_info_entry *entry;
 552                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 553                         return -ENOMEM;
 554                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 555                 if (snd_info_register(entry) < 0) {
 556                         snd_info_free_entry(entry);
 557                         return -ENOMEM;
 558                 }
 559                 snd_oss_root = entry;
 560         }
 561 #endif
 562 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 563         {
 564                 struct snd_info_entry *entry;
 565                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 566                         return -ENOMEM;
 567                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 568                 if (snd_info_register(entry) < 0) {
 569                         snd_info_free_entry(entry);
 570                         return -ENOMEM;
 571                 }
 572                 snd_seq_root = entry;
 573         }
 574 #endif
 575         snd_info_version_init();
 576         snd_minor_info_init();
 577         snd_minor_info_oss_init();
 578         snd_card_info_init();
 579         return 0;
 580 }
 581
 582 int __exit snd_info_done(void)
 583 {
 584         snd_card_info_done();
 585         snd_minor_info_oss_done();
 586         snd_minor_info_done();
 587         snd_info_version_done();
 588         if (snd_proc_root) {
 589 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 590                 snd_info_free_entry(snd_seq_root);
 591 #endif
 592 #ifdef CONFIG_SND_OSSEMUL
 593                 snd_info_free_entry(snd_oss_root);
 594 #endif
 595                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 596         }
 597         return 0;
 598 }
 599
 600 /*
 601
 602  */
 603
 604
 605 /*
 606  * create a card proc file
 607  * called from init.c
 608  */
 609 int snd_info_card_create(struct snd_card *card)
 610 {
 611         char str[8];
 612         struct snd_info_entry *entry;
 613
 614         snd_assert(card != NULL, return -ENXIO);
 615
 616         sprintf(str, "card%i", card->number);
 617         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 618                 return -ENOMEM;
 619         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 620         if (snd_info_register(entry) < 0) {
 621                 snd_info_free_entry(entry);
 622                 return -ENOMEM;
 623         }
 624         card->proc_root = entry;
 625         return 0;
 626 }
 627
 628 /*
 629  * register the card proc file
 630  * called from init.c
 631  */
 632 int snd_info_card_register(struct snd_card *card)
 633 {
 634         struct proc_dir_entry *p;
 635
 636         snd_assert(card != NULL, return -ENXIO);
 637
 638         if (!strcmp(card->id, card->proc_root->name))
 639                 return 0;
 640
 641         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 642         if (p == NULL)
 643                 return -ENOMEM;
 644         card->proc_root_link = p;
 645         return 0;
 646 }
 647
 648 /*
 649  * de-register the card proc file
 650  * called from init.c
 651  */
 652 void snd_info_card_disconnect(struct snd_card *card)
 653 {
 654         snd_assert(card != NULL, return);
 655         mutex_lock(&info_mutex);
 656         if (card->proc_root_link) {
 657                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 658                 card->proc_root_link = NULL;
 659         }
 660         if (card->proc_root)
 661                 snd_info_disconnect(card->proc_root);
 662         mutex_unlock(&info_mutex);
 663 }
 664
 665 /*
 666  * release the card proc file resources
 667  * called from init.c
 668  */
 669 int snd_info_card_free(struct snd_card *card)
 670 {
 671         snd_assert(card != NULL, return -ENXIO);
 672         snd_info_free_entry(card->proc_root);
 673         card->proc_root = NULL;
 674         return 0;
 675 }
 676
 677
 678 /**
 679  * snd_info_get_line - read one line from the procfs buffer
 680  * @buffer: the procfs buffer
 681  * @line: the buffer to store
 682  * @len: the max. buffer size - 1
 683  *
 684  * Reads one line from the buffer and stores the string.
 685  *
 686  * Returns zero if successful, or 1 if error or EOF.
 687  */
 688 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 689 {
 690         int c = -1;
 691
 692         if (len <= 0 || buffer->stop || buffer->error)
 693                 return 1;
 694         while (--len > 0) {
 695                 c = buffer->buffer[buffer->curr++];
 696                 if (c == '\n') {
 697                         if (buffer->curr >= buffer->size)
 698                                 buffer->stop = 1;
 699                         break;
 700                 }
 701                 *line++ = c;
 702                 if (buffer->curr >= buffer->size) {
 703                         buffer->stop = 1;
 704                         break;
 705                 }
 706         }
 707         while (c != '\n' && !buffer->stop) {
 708                 c = buffer->buffer[buffer->curr++];
 709                 if (buffer->curr >= buffer->size)
 710                         buffer->stop = 1;
 711         }
 712         *line = '\0';
 713         return 0;
 714 }
 715
 716 EXPORT_SYMBOL(snd_info_get_line);
 717
 718 /**
 719  * snd_info_get_str - parse a string token
 720  * @dest: the buffer to store the string token
 721  * @src: the original string
 722  * @len: the max. length of token - 1
 723  *
 724  * Parses the original string and copy a token to the given
 725  * string buffer.
 726  *
 727  * Returns the updated pointer of the original string so that
 728  * it can be used for the next call.
 729  */
 730 char *snd_info_get_str(char *dest, char *src, int len)
 731 {
 732         int c;
 733
 734         while (*src == ' ' || *src == '\t')
 735                 src++;
 736         if (*src == '"' || *src == '\'') {
 737                 c = *src++;
 738                 while (--len > 0 && *src && *src != c) {
 739                         *dest++ = *src++;
 740                 }
 741                 if (*src == c)
 742                         src++;
 743         } else {
 744                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 745                         *dest++ = *src++;
 746                 }
 747         }
 748         *dest = 0;
 749         while (*src == ' ' || *src == '\t')
 750                 src++;
 751         return src;
 752 }
 753
 754 EXPORT_SYMBOL(snd_info_get_str);
 755
 756 /**
 757  * snd_info_create_entry - create an info entry
 758  * @name: the proc file name
 759  *
 760  * Creates an info entry with the given file name and initializes as
 761  * the default state.
 762  *
 763  * Usually called from other functions such as
 764  * snd_info_create_card_entry().
 765  *
 766  * Returns the pointer of the new instance, or NULL on failure.
 767  */
 768 static struct snd_info_entry *snd_info_create_entry(const char *name)
 769 {
 770         struct snd_info_entry *entry;
 771         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 772         if (entry == NULL)
 773                 return NULL;
 774         entry->name = kstrdup(name, GFP_KERNEL);
 775         if (entry->name == NULL) {
 776                 kfree(entry);
 777                 return NULL;
 778         }
 779         entry->mode = S_IFREG | S_IRUGO;
 780         entry->content = SNDRV_INFO_CONTENT_TEXT;
 781         mutex_init(&entry->access);
 782         INIT_LIST_HEAD(&entry->children);
 783         INIT_LIST_HEAD(&entry->list);
 784         return entry;
 785 }
 786
 787 /**
 788  * snd_info_create_module_entry - create an info entry for the given module
 789  * @module: the module pointer
 790  * @name: the file name
 791  * @parent: the parent directory
 792  *
 793  * Creates a new info entry and assigns it to the given module.
 794  *
 795  * Returns the pointer of the new instance, or NULL on failure.
 796  */
 797 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 798                                                const char *name,
 799                                                struct snd_info_entry *parent)
 800 {
 801         struct snd_info_entry *entry = snd_info_create_entry(name);
 802         if (entry) {
 803                 entry->module = module;
 804                 entry->parent = parent;
 805         }
 806         return entry;
 807 }
 808
 809 EXPORT_SYMBOL(snd_info_create_module_entry);
 810
 811 /**
 812  * snd_info_create_card_entry - create an info entry for the given card
 813  * @card: the card instance
 814  * @name: the file name
 815  * @parent: the parent directory
 816  *
 817  * Creates a new info entry and assigns it to the given card.
 818  *
 819  * Returns the pointer of the new instance, or NULL on failure.
 820  */
 821 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 822                                              const char *name,
 823                                              struct snd_info_entry * parent)
 824 {
 825         struct snd_info_entry *entry = snd_info_create_entry(name);
 826         if (entry) {
 827                 entry->module = card->module;
 828                 entry->card = card;
 829                 entry->parent = parent;
 830         }
 831         return entry;
 832 }
 833
 834 EXPORT_SYMBOL(snd_info_create_card_entry);
 835
 836 static void snd_info_disconnect(struct snd_info_entry *entry)
 837 {
 838         struct list_head *p, *n;
 839         struct proc_dir_entry *root;
 840
 841         list_for_each_safe(p, n, &entry->children) {
 842                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 843         }
 844
 845         if (! entry->p)
 846                 return;
 847         list_del_init(&entry->list);
 848         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 849         snd_assert(root, return);
 850         snd_remove_proc_entry(root, entry->p);
 851         entry->p = NULL;
 852 }
 853
 854 static int snd_info_dev_free_entry(struct snd_device *device)
 855 {
 856         struct snd_info_entry *entry = device->device_data;
 857         snd_info_free_entry(entry);
 858         return 0;
 859 }
 860
 861 static int snd_info_dev_register_entry(struct snd_device *device)
 862 {
 863         struct snd_info_entry *entry = device->device_data;
 864         return snd_info_register(entry);
 865 }
 866
 867 /**
 868  * snd_card_proc_new - create an info entry for the given card
 869  * @card: the card instance
 870  * @name: the file name
 871  * @entryp: the pointer to store the new info entry
 872  *
 873  * Creates a new info entry and assigns it to the given card.
 874  * Unlike snd_info_create_card_entry(), this function registers the
 875  * info entry as an ALSA device component, so that it can be
 876  * unregistered/released without explicit call.
 877  * Also, you don't have to register this entry via snd_info_register(),
 878  * since this will be registered by snd_card_register() automatically.
 879  *
 880  * The parent is assumed as card->proc_root.
 881  *
 882  * For releasing this entry, use snd_device_free() instead of
 883  * snd_info_free_entry().
 884  *
 885  * Returns zero if successful, or a negative error code on failure.
 886  */
 887 int snd_card_proc_new(struct snd_card *card, const char *name,
 888                       struct snd_info_entry **entryp)
 889 {
 890         static struct snd_device_ops ops = {
 891                 .dev_free = snd_info_dev_free_entry,
 892                 .dev_register = snd_info_dev_register_entry,
 893                 /* disconnect is done via snd_info_card_disconnect() */
 894         };
 895         struct snd_info_entry *entry;
 896         int err;
 897
 898         entry = snd_info_create_card_entry(card, name, card->proc_root);
 899         if (! entry)
 900                 return -ENOMEM;
 901         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 902                 snd_info_free_entry(entry);
 903                 return err;
 904         }
 905         if (entryp)
 906                 *entryp = entry;
 907         return 0;
 908 }
 909
 910 EXPORT_SYMBOL(snd_card_proc_new);
 911
 912 /**
 913  * snd_info_free_entry - release the info entry
 914  * @entry: the info entry
 915  *
 916  * Releases the info entry.  Don't call this after registered.
 917  */
 918 void snd_info_free_entry(struct snd_info_entry * entry)
 919 {
 920         if (entry == NULL)
 921                 return;
 922         if (entry->p) {
 923                 mutex_lock(&info_mutex);
 924                 snd_info_disconnect(entry);
 925                 mutex_unlock(&info_mutex);
 926         }
 927         kfree(entry->name);
 928         if (entry->private_free)
 929                 entry->private_free(entry);
 930         kfree(entry);
 931 }
 932
 933 EXPORT_SYMBOL(snd_info_free_entry);
 934
 935 /**
 936  * snd_info_register - register the info entry
 937  * @entry: the info entry
 938  *
 939  * Registers the proc info entry.
 940  *
 941  * Returns zero if successful, or a negative error code on failure.
 942  */
 943 int snd_info_register(struct snd_info_entry * entry)
 944 {
 945         struct proc_dir_entry *root, *p = NULL;
 946
 947         snd_assert(entry != NULL, return -ENXIO);
 948         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 949         mutex_lock(&info_mutex);
 950         p = snd_create_proc_entry(entry->name, entry->mode, root);
 951         if (!p) {
 952                 mutex_unlock(&info_mutex);
 953                 return -ENOMEM;
 954         }
 955         p->owner = entry->module;
 956         if (!S_ISDIR(entry->mode))
 957                 p->proc_fops = &snd_info_entry_operations;
 958         p->size = entry->size;
 959         p->data = entry;
 960         entry->p = p;
 961         if (entry->parent)
 962                 list_add_tail(&entry->list, &entry->parent->children);
 963         mutex_unlock(&info_mutex);
 964         return 0;
 965 }
 966
 967 EXPORT_SYMBOL(snd_info_register);
 968
 969 /*
 970
 971  */
 972
 973 static struct snd_info_entry *snd_info_version_entry;
 974
 975 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 976 {
 977         snd_iprintf(buffer,
 978                     "Advanced Linux Sound Architecture Driver Version "
 979                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 980                    );
 981 }
 982
 983 static int __init snd_info_version_init(void)
 984 {
 985         struct snd_info_entry *entry;
 986
 987         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 988         if (entry == NULL)
 989                 return -ENOMEM;
 990         entry->c.text.read = snd_info_version_read;
 991         if (snd_info_register(entry) < 0) {
 992                 snd_info_free_entry(entry);
 993                 return -ENOMEM;
 994         }
 995         snd_info_version_entry = entry;
 996         return 0;
 997 }
 998
 999 static int __exit snd_info_version_done(void)
1000 {
1001         snd_info_free_entry(snd_info_version_entry);
1002         return 0;
1003 }
1004
1005 #endif /* CONFIG_PROC_FS */