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/mm.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                 va_list ap;
 124                 va_copy(ap, args);
 125                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
 126                 va_end(ap);
 127                 if (res < len)
 128                         break;
 129                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
 130                 if (err < 0)
 131                         break;
 132                 len = buffer->len - buffer->size;
 133         }
 134         va_end(args);
 135
 136         if (err < 0)
 137                 return err;
 138         buffer->curr += res;
 139         buffer->size += res;
 140         return res;
 141 }
 142
 143 EXPORT_SYMBOL(snd_iprintf);
 144
 145 /*
 146
 147  */
 148
 149 static struct proc_dir_entry *snd_proc_root;
 150 struct snd_info_entry *snd_seq_root;
 151 EXPORT_SYMBOL(snd_seq_root);
 152
 153 #ifdef CONFIG_SND_OSSEMUL
 154 struct snd_info_entry *snd_oss_root;
 155 #endif
 156
 157 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 158 {
 159         de->owner = THIS_MODULE;
 160 }
 161
 162 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 163                                   struct proc_dir_entry *de)
 164 {
 165         if (de)
 166                 remove_proc_entry(de->name, parent);
 167 }
 168
 169 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 170 {
 171         struct snd_info_private_data *data;
 172         struct snd_info_entry *entry;
 173         loff_t ret;
 174
 175         data = file->private_data;
 176         entry = data->entry;
 177         lock_kernel();
 178         switch (entry->content) {
 179         case SNDRV_INFO_CONTENT_TEXT:
 180                 switch (orig) {
 181                 case SEEK_SET:
 182                         file->f_pos = offset;
 183                         ret = file->f_pos;
 184                         goto out;
 185                 case SEEK_CUR:
 186                         file->f_pos += offset;
 187                         ret = file->f_pos;
 188                         goto out;
 189                 case SEEK_END:
 190                 default:
 191                         ret = -EINVAL;
 192                         goto out;
 193                 }
 194                 break;
 195         case SNDRV_INFO_CONTENT_DATA:
 196                 if (entry->c.ops->llseek) {
 197                         ret = entry->c.ops->llseek(entry,
 198                                                     data->file_private_data,
 199                                                     file, offset, orig);
 200                         goto out;
 201                 }
 202                 break;
 203         }
 204         ret = -ENXIO;
 205 out:
 206         unlock_kernel();
 207         return ret;
 208 }
 209
 210 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 211                                    size_t count, loff_t * offset)
 212 {
 213         struct snd_info_private_data *data;
 214         struct snd_info_entry *entry;
 215         struct snd_info_buffer *buf;
 216         size_t size = 0;
 217         loff_t pos;
 218
 219         data = file->private_data;
 220         if (snd_BUG_ON(!data))
 221                 return -ENXIO;
 222         pos = *offset;
 223         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 224                 return -EIO;
 225         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 226                 return -EIO;
 227         entry = data->entry;
 228         switch (entry->content) {
 229         case SNDRV_INFO_CONTENT_TEXT:
 230                 buf = data->rbuffer;
 231                 if (buf == NULL)
 232                         return -EIO;
 233                 if (pos >= buf->size)
 234                         return 0;
 235                 size = buf->size - pos;
 236                 size = min(count, size);
 237                 if (copy_to_user(buffer, buf->buffer + pos, size))
 238                         return -EFAULT;
 239                 break;
 240         case SNDRV_INFO_CONTENT_DATA:
 241                 if (entry->c.ops->read)
 242                         size = entry->c.ops->read(entry,
 243                                                   data->file_private_data,
 244                                                   file, buffer, count, pos);
 245                 break;
 246         }
 247         if ((ssize_t) size > 0)
 248                 *offset = pos + size;
 249         return size;
 250 }
 251
 252 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 253                                     size_t count, loff_t * offset)
 254 {
 255         struct snd_info_private_data *data;
 256         struct snd_info_entry *entry;
 257         struct snd_info_buffer *buf;
 258         ssize_t size = 0;
 259         loff_t pos;
 260
 261         data = file->private_data;
 262         if (snd_BUG_ON(!data))
 263                 return -ENXIO;
 264         entry = data->entry;
 265         pos = *offset;
 266         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 267                 return -EIO;
 268         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 269                 return -EIO;
 270         switch (entry->content) {
 271         case SNDRV_INFO_CONTENT_TEXT:
 272                 buf = data->wbuffer;
 273                 if (buf == NULL)
 274                         return -EIO;
 275                 mutex_lock(&entry->access);
 276                 if (pos + count >= buf->len) {
 277                         if (resize_info_buffer(buf, pos + count)) {
 278                                 mutex_unlock(&entry->access);
 279                                 return -ENOMEM;
 280                         }
 281                 }
 282                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
 283                         mutex_unlock(&entry->access);
 284                         return -EFAULT;
 285                 }
 286                 buf->size = pos + count;
 287                 mutex_unlock(&entry->access);
 288                 size = count;
 289                 break;
 290         case SNDRV_INFO_CONTENT_DATA:
 291                 if (entry->c.ops->write)
 292                         size = entry->c.ops->write(entry,
 293                                                    data->file_private_data,
 294                                                    file, buffer, count, pos);
 295                 break;
 296         }
 297         if ((ssize_t) size > 0)
 298                 *offset = pos + size;
 299         return size;
 300 }
 301
 302 static int snd_info_entry_open(struct inode *inode, struct file *file)
 303 {
 304         struct snd_info_entry *entry;
 305         struct snd_info_private_data *data;
 306         struct snd_info_buffer *buffer;
 307         struct proc_dir_entry *p;
 308         int mode, err;
 309
 310         mutex_lock(&info_mutex);
 311         p = PDE(inode);
 312         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 313         if (entry == NULL || ! entry->p) {
 314                 mutex_unlock(&info_mutex);
 315                 return -ENODEV;
 316         }
 317         if (!try_module_get(entry->module)) {
 318                 err = -EFAULT;
 319                 goto __error1;
 320         }
 321         mode = file->f_flags & O_ACCMODE;
 322         if (mode == O_RDONLY || mode == O_RDWR) {
 323                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 324                      entry->c.ops->read == NULL)) {
 325                         err = -ENODEV;
 326                         goto __error;
 327                 }
 328         }
 329         if (mode == O_WRONLY || mode == O_RDWR) {
 330                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 331                      entry->c.ops->write == NULL)) {
 332                         err = -ENODEV;
 333                         goto __error;
 334                 }
 335         }
 336         data = kzalloc(sizeof(*data), GFP_KERNEL);
 337         if (data == NULL) {
 338                 err = -ENOMEM;
 339                 goto __error;
 340         }
 341         data->entry = entry;
 342         switch (entry->content) {
 343         case SNDRV_INFO_CONTENT_TEXT:
 344                 if (mode == O_RDONLY || mode == O_RDWR) {
 345                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 346                         if (buffer == NULL)
 347                                 goto __nomem;
 348                         data->rbuffer = buffer;
 349                         buffer->len = PAGE_SIZE;
 350                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 351                         if (buffer->buffer == NULL)
 352                                 goto __nomem;
 353                 }
 354                 if (mode == O_WRONLY || mode == O_RDWR) {
 355                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 356                         if (buffer == NULL)
 357                                 goto __nomem;
 358                         data->wbuffer = buffer;
 359                         buffer->len = PAGE_SIZE;
 360                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 361                         if (buffer->buffer == NULL)
 362                                 goto __nomem;
 363                 }
 364                 break;
 365         case SNDRV_INFO_CONTENT_DATA:   /* data */
 366                 if (entry->c.ops->open) {
 367                         if ((err = entry->c.ops->open(entry, mode,
 368                                                       &data->file_private_data)) < 0) {
 369                                 kfree(data);
 370                                 goto __error;
 371                         }
 372                 }
 373                 break;
 374         }
 375         file->private_data = data;
 376         mutex_unlock(&info_mutex);
 377         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 378             (mode == O_RDONLY || mode == O_RDWR)) {
 379                 if (entry->c.text.read) {
 380                         mutex_lock(&entry->access);
 381                         entry->c.text.read(entry, data->rbuffer);
 382                         mutex_unlock(&entry->access);
 383                 }
 384         }
 385         return 0;
 386
 387  __nomem:
 388         if (data->rbuffer) {
 389                 kfree(data->rbuffer->buffer);
 390                 kfree(data->rbuffer);
 391         }
 392         if (data->wbuffer) {
 393                 kfree(data->wbuffer->buffer);
 394                 kfree(data->wbuffer);
 395         }
 396         kfree(data);
 397         err = -ENOMEM;
 398       __error:
 399         module_put(entry->module);
 400       __error1:
 401         mutex_unlock(&info_mutex);
 402         return err;
 403 }
 404
 405 static int snd_info_entry_release(struct inode *inode, struct file *file)
 406 {
 407         struct snd_info_entry *entry;
 408         struct snd_info_private_data *data;
 409         int mode;
 410
 411         mode = file->f_flags & O_ACCMODE;
 412         data = file->private_data;
 413         entry = data->entry;
 414         switch (entry->content) {
 415         case SNDRV_INFO_CONTENT_TEXT:
 416                 if (data->rbuffer) {
 417                         kfree(data->rbuffer->buffer);
 418                         kfree(data->rbuffer);
 419                 }
 420                 if (data->wbuffer) {
 421                         if (entry->c.text.write) {
 422                                 entry->c.text.write(entry, data->wbuffer);
 423                                 if (data->wbuffer->error) {
 424                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 425                                                 entry->name,
 426                                                 data->wbuffer->error);
 427                                 }
 428                         }
 429                         kfree(data->wbuffer->buffer);
 430                         kfree(data->wbuffer);
 431                 }
 432                 break;
 433         case SNDRV_INFO_CONTENT_DATA:
 434                 if (entry->c.ops->release)
 435                         entry->c.ops->release(entry, mode,
 436                                               data->file_private_data);
 437                 break;
 438         }
 439         module_put(entry->module);
 440         kfree(data);
 441         return 0;
 442 }
 443
 444 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 445 {
 446         struct snd_info_private_data *data;
 447         struct snd_info_entry *entry;
 448         unsigned int mask;
 449
 450         data = file->private_data;
 451         if (data == NULL)
 452                 return 0;
 453         entry = data->entry;
 454         mask = 0;
 455         switch (entry->content) {
 456         case SNDRV_INFO_CONTENT_DATA:
 457                 if (entry->c.ops->poll)
 458                         return entry->c.ops->poll(entry,
 459                                                   data->file_private_data,
 460                                                   file, wait);
 461                 if (entry->c.ops->read)
 462                         mask |= POLLIN | POLLRDNORM;
 463                 if (entry->c.ops->write)
 464                         mask |= POLLOUT | POLLWRNORM;
 465                 break;
 466         }
 467         return mask;
 468 }
 469
 470 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 471                                 unsigned long arg)
 472 {
 473         struct snd_info_private_data *data;
 474         struct snd_info_entry *entry;
 475
 476         data = file->private_data;
 477         if (data == NULL)
 478                 return 0;
 479         entry = data->entry;
 480         switch (entry->content) {
 481         case SNDRV_INFO_CONTENT_DATA:
 482                 if (entry->c.ops->ioctl)
 483                         return entry->c.ops->ioctl(entry,
 484                                                    data->file_private_data,
 485                                                    file, cmd, arg);
 486                 break;
 487         }
 488         return -ENOTTY;
 489 }
 490
 491 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 492 {
 493         struct inode *inode = file->f_path.dentry->d_inode;
 494         struct snd_info_private_data *data;
 495         struct snd_info_entry *entry;
 496
 497         data = file->private_data;
 498         if (data == NULL)
 499                 return 0;
 500         entry = data->entry;
 501         switch (entry->content) {
 502         case SNDRV_INFO_CONTENT_DATA:
 503                 if (entry->c.ops->mmap)
 504                         return entry->c.ops->mmap(entry,
 505                                                   data->file_private_data,
 506                                                   inode, file, vma);
 507                 break;
 508         }
 509         return -ENXIO;
 510 }
 511
 512 static const struct file_operations snd_info_entry_operations =
 513 {
 514         .owner =                THIS_MODULE,
 515         .llseek =               snd_info_entry_llseek,
 516         .read =                 snd_info_entry_read,
 517         .write =                snd_info_entry_write,
 518         .poll =                 snd_info_entry_poll,
 519         .unlocked_ioctl =       snd_info_entry_ioctl,
 520         .mmap =                 snd_info_entry_mmap,
 521         .open =                 snd_info_entry_open,
 522         .release =              snd_info_entry_release,
 523 };
 524
 525 /**
 526  * snd_create_proc_entry - create a procfs entry
 527  * @name: the name of the proc file
 528  * @mode: the file permission bits, S_Ixxx
 529  * @parent: the parent proc-directory entry
 530  *
 531  * Creates a new proc file entry with the given name and permission
 532  * on the given directory.
 533  *
 534  * Returns the pointer of new instance or NULL on failure.
 535  */
 536 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 537                                                     struct proc_dir_entry *parent)
 538 {
 539         struct proc_dir_entry *p;
 540         p = create_proc_entry(name, mode, parent);
 541         if (p)
 542                 snd_info_entry_prepare(p);
 543         return p;
 544 }
 545
 546 int __init snd_info_init(void)
 547 {
 548         struct proc_dir_entry *p;
 549
 550         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
 551         if (p == NULL)
 552                 return -ENOMEM;
 553         snd_proc_root = p;
 554 #ifdef CONFIG_SND_OSSEMUL
 555         {
 556                 struct snd_info_entry *entry;
 557                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 558                         return -ENOMEM;
 559                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 560                 if (snd_info_register(entry) < 0) {
 561                         snd_info_free_entry(entry);
 562                         return -ENOMEM;
 563                 }
 564                 snd_oss_root = entry;
 565         }
 566 #endif
 567 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 568         {
 569                 struct snd_info_entry *entry;
 570                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 571                         return -ENOMEM;
 572                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 573                 if (snd_info_register(entry) < 0) {
 574                         snd_info_free_entry(entry);
 575                         return -ENOMEM;
 576                 }
 577                 snd_seq_root = entry;
 578         }
 579 #endif
 580         snd_info_version_init();
 581         snd_minor_info_init();
 582         snd_minor_info_oss_init();
 583         snd_card_info_init();
 584         return 0;
 585 }
 586
 587 int __exit snd_info_done(void)
 588 {
 589         snd_card_info_done();
 590         snd_minor_info_oss_done();
 591         snd_minor_info_done();
 592         snd_info_version_done();
 593         if (snd_proc_root) {
 594 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 595                 snd_info_free_entry(snd_seq_root);
 596 #endif
 597 #ifdef CONFIG_SND_OSSEMUL
 598                 snd_info_free_entry(snd_oss_root);
 599 #endif
 600                 snd_remove_proc_entry(NULL, snd_proc_root);
 601         }
 602         return 0;
 603 }
 604
 605 /*
 606
 607  */
 608
 609
 610 /*
 611  * create a card proc file
 612  * called from init.c
 613  */
 614 int snd_info_card_create(struct snd_card *card)
 615 {
 616         char str[8];
 617         struct snd_info_entry *entry;
 618
 619         if (snd_BUG_ON(!card))
 620                 return -ENXIO;
 621
 622         sprintf(str, "card%i", card->number);
 623         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 624                 return -ENOMEM;
 625         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 626         if (snd_info_register(entry) < 0) {
 627                 snd_info_free_entry(entry);
 628                 return -ENOMEM;
 629         }
 630         card->proc_root = entry;
 631         return 0;
 632 }
 633
 634 /*
 635  * register the card proc file
 636  * called from init.c
 637  */
 638 int snd_info_card_register(struct snd_card *card)
 639 {
 640         struct proc_dir_entry *p;
 641
 642         if (snd_BUG_ON(!card))
 643                 return -ENXIO;
 644
 645         if (!strcmp(card->id, card->proc_root->name))
 646                 return 0;
 647
 648         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 649         if (p == NULL)
 650                 return -ENOMEM;
 651         card->proc_root_link = p;
 652         return 0;
 653 }
 654
 655 /*
 656  * de-register the card proc file
 657  * called from init.c
 658  */
 659 void snd_info_card_disconnect(struct snd_card *card)
 660 {
 661         if (!card)
 662                 return;
 663         mutex_lock(&info_mutex);
 664         if (card->proc_root_link) {
 665                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 666                 card->proc_root_link = NULL;
 667         }
 668         if (card->proc_root)
 669                 snd_info_disconnect(card->proc_root);
 670         mutex_unlock(&info_mutex);
 671 }
 672
 673 /*
 674  * release the card proc file resources
 675  * called from init.c
 676  */
 677 int snd_info_card_free(struct snd_card *card)
 678 {
 679         if (!card)
 680                 return 0;
 681         snd_info_free_entry(card->proc_root);
 682         card->proc_root = NULL;
 683         return 0;
 684 }
 685
 686
 687 /**
 688  * snd_info_get_line - read one line from the procfs buffer
 689  * @buffer: the procfs buffer
 690  * @line: the buffer to store
 691  * @len: the max. buffer size - 1
 692  *
 693  * Reads one line from the buffer and stores the string.
 694  *
 695  * Returns zero if successful, or 1 if error or EOF.
 696  */
 697 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 698 {
 699         int c = -1;
 700
 701         if (len <= 0 || buffer->stop || buffer->error)
 702                 return 1;
 703         while (--len > 0) {
 704                 c = buffer->buffer[buffer->curr++];
 705                 if (c == '\n') {
 706                         if (buffer->curr >= buffer->size)
 707                                 buffer->stop = 1;
 708                         break;
 709                 }
 710                 *line++ = c;
 711                 if (buffer->curr >= buffer->size) {
 712                         buffer->stop = 1;
 713                         break;
 714                 }
 715         }
 716         while (c != '\n' && !buffer->stop) {
 717                 c = buffer->buffer[buffer->curr++];
 718                 if (buffer->curr >= buffer->size)
 719                         buffer->stop = 1;
 720         }
 721         *line = '\0';
 722         return 0;
 723 }
 724
 725 EXPORT_SYMBOL(snd_info_get_line);
 726
 727 /**
 728  * snd_info_get_str - parse a string token
 729  * @dest: the buffer to store the string token
 730  * @src: the original string
 731  * @len: the max. length of token - 1
 732  *
 733  * Parses the original string and copy a token to the given
 734  * string buffer.
 735  *
 736  * Returns the updated pointer of the original string so that
 737  * it can be used for the next call.
 738  */
 739 char *snd_info_get_str(char *dest, char *src, int len)
 740 {
 741         int c;
 742
 743         while (*src == ' ' || *src == '\t')
 744                 src++;
 745         if (*src == '"' || *src == '\'') {
 746                 c = *src++;
 747                 while (--len > 0 && *src && *src != c) {
 748                         *dest++ = *src++;
 749                 }
 750                 if (*src == c)
 751                         src++;
 752         } else {
 753                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 754                         *dest++ = *src++;
 755                 }
 756         }
 757         *dest = 0;
 758         while (*src == ' ' || *src == '\t')
 759                 src++;
 760         return src;
 761 }
 762
 763 EXPORT_SYMBOL(snd_info_get_str);
 764
 765 /**
 766  * snd_info_create_entry - create an info entry
 767  * @name: the proc file name
 768  *
 769  * Creates an info entry with the given file name and initializes as
 770  * the default state.
 771  *
 772  * Usually called from other functions such as
 773  * snd_info_create_card_entry().
 774  *
 775  * Returns the pointer of the new instance, or NULL on failure.
 776  */
 777 static struct snd_info_entry *snd_info_create_entry(const char *name)
 778 {
 779         struct snd_info_entry *entry;
 780         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 781         if (entry == NULL)
 782                 return NULL;
 783         entry->name = kstrdup(name, GFP_KERNEL);
 784         if (entry->name == NULL) {
 785                 kfree(entry);
 786                 return NULL;
 787         }
 788         entry->mode = S_IFREG | S_IRUGO;
 789         entry->content = SNDRV_INFO_CONTENT_TEXT;
 790         mutex_init(&entry->access);
 791         INIT_LIST_HEAD(&entry->children);
 792         INIT_LIST_HEAD(&entry->list);
 793         return entry;
 794 }
 795
 796 /**
 797  * snd_info_create_module_entry - create an info entry for the given module
 798  * @module: the module pointer
 799  * @name: the file name
 800  * @parent: the parent directory
 801  *
 802  * Creates a new info entry and assigns it to the given module.
 803  *
 804  * Returns the pointer of the new instance, or NULL on failure.
 805  */
 806 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 807                                                const char *name,
 808                                                struct snd_info_entry *parent)
 809 {
 810         struct snd_info_entry *entry = snd_info_create_entry(name);
 811         if (entry) {
 812                 entry->module = module;
 813                 entry->parent = parent;
 814         }
 815         return entry;
 816 }
 817
 818 EXPORT_SYMBOL(snd_info_create_module_entry);
 819
 820 /**
 821  * snd_info_create_card_entry - create an info entry for the given card
 822  * @card: the card instance
 823  * @name: the file name
 824  * @parent: the parent directory
 825  *
 826  * Creates a new info entry and assigns it to the given card.
 827  *
 828  * Returns the pointer of the new instance, or NULL on failure.
 829  */
 830 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 831                                              const char *name,
 832                                              struct snd_info_entry * parent)
 833 {
 834         struct snd_info_entry *entry = snd_info_create_entry(name);
 835         if (entry) {
 836                 entry->module = card->module;
 837                 entry->card = card;
 838                 entry->parent = parent;
 839         }
 840         return entry;
 841 }
 842
 843 EXPORT_SYMBOL(snd_info_create_card_entry);
 844
 845 static void snd_info_disconnect(struct snd_info_entry *entry)
 846 {
 847         struct list_head *p, *n;
 848         struct proc_dir_entry *root;
 849
 850         list_for_each_safe(p, n, &entry->children) {
 851                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 852         }
 853
 854         if (! entry->p)
 855                 return;
 856         list_del_init(&entry->list);
 857         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 858         snd_BUG_ON(!root);
 859         snd_remove_proc_entry(root, entry->p);
 860         entry->p = NULL;
 861 }
 862
 863 static int snd_info_dev_free_entry(struct snd_device *device)
 864 {
 865         struct snd_info_entry *entry = device->device_data;
 866         snd_info_free_entry(entry);
 867         return 0;
 868 }
 869
 870 static int snd_info_dev_register_entry(struct snd_device *device)
 871 {
 872         struct snd_info_entry *entry = device->device_data;
 873         return snd_info_register(entry);
 874 }
 875
 876 /**
 877  * snd_card_proc_new - create an info entry for the given card
 878  * @card: the card instance
 879  * @name: the file name
 880  * @entryp: the pointer to store the new info entry
 881  *
 882  * Creates a new info entry and assigns it to the given card.
 883  * Unlike snd_info_create_card_entry(), this function registers the
 884  * info entry as an ALSA device component, so that it can be
 885  * unregistered/released without explicit call.
 886  * Also, you don't have to register this entry via snd_info_register(),
 887  * since this will be registered by snd_card_register() automatically.
 888  *
 889  * The parent is assumed as card->proc_root.
 890  *
 891  * For releasing this entry, use snd_device_free() instead of
 892  * snd_info_free_entry().
 893  *
 894  * Returns zero if successful, or a negative error code on failure.
 895  */
 896 int snd_card_proc_new(struct snd_card *card, const char *name,
 897                       struct snd_info_entry **entryp)
 898 {
 899         static struct snd_device_ops ops = {
 900                 .dev_free = snd_info_dev_free_entry,
 901                 .dev_register = snd_info_dev_register_entry,
 902                 /* disconnect is done via snd_info_card_disconnect() */
 903         };
 904         struct snd_info_entry *entry;
 905         int err;
 906
 907         entry = snd_info_create_card_entry(card, name, card->proc_root);
 908         if (! entry)
 909                 return -ENOMEM;
 910         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 911                 snd_info_free_entry(entry);
 912                 return err;
 913         }
 914         if (entryp)
 915                 *entryp = entry;
 916         return 0;
 917 }
 918
 919 EXPORT_SYMBOL(snd_card_proc_new);
 920
 921 /**
 922  * snd_info_free_entry - release the info entry
 923  * @entry: the info entry
 924  *
 925  * Releases the info entry.  Don't call this after registered.
 926  */
 927 void snd_info_free_entry(struct snd_info_entry * entry)
 928 {
 929         if (entry == NULL)
 930                 return;
 931         if (entry->p) {
 932                 mutex_lock(&info_mutex);
 933                 snd_info_disconnect(entry);
 934                 mutex_unlock(&info_mutex);
 935         }
 936         kfree(entry->name);
 937         if (entry->private_free)
 938                 entry->private_free(entry);
 939         kfree(entry);
 940 }
 941
 942 EXPORT_SYMBOL(snd_info_free_entry);
 943
 944 /**
 945  * snd_info_register - register the info entry
 946  * @entry: the info entry
 947  *
 948  * Registers the proc info entry.
 949  *
 950  * Returns zero if successful, or a negative error code on failure.
 951  */
 952 int snd_info_register(struct snd_info_entry * entry)
 953 {
 954         struct proc_dir_entry *root, *p = NULL;
 955
 956         if (snd_BUG_ON(!entry))
 957                 return -ENXIO;
 958         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 959         mutex_lock(&info_mutex);
 960         p = snd_create_proc_entry(entry->name, entry->mode, root);
 961         if (!p) {
 962                 mutex_unlock(&info_mutex);
 963                 return -ENOMEM;
 964         }
 965         p->owner = entry->module;
 966         if (!S_ISDIR(entry->mode))
 967                 p->proc_fops = &snd_info_entry_operations;
 968         p->size = entry->size;
 969         p->data = entry;
 970         entry->p = p;
 971         if (entry->parent)
 972                 list_add_tail(&entry->list, &entry->parent->children);
 973         mutex_unlock(&info_mutex);
 974         return 0;
 975 }
 976
 977 EXPORT_SYMBOL(snd_info_register);
 978
 979 /*
 980
 981  */
 982
 983 static struct snd_info_entry *snd_info_version_entry;
 984
 985 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 986 {
 987         snd_iprintf(buffer,
 988                     "Advanced Linux Sound Architecture Driver Version "
 989                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 990                    );
 991 }
 992
 993 static int __init snd_info_version_init(void)
 994 {
 995         struct snd_info_entry *entry;
 996
 997         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 998         if (entry == NULL)
 999                 return -ENOMEM;
1000         entry->c.text.read = snd_info_version_read;
1001         if (snd_info_register(entry) < 0) {
1002                 snd_info_free_entry(entry);
1003                 return -ENOMEM;
1004         }
1005         snd_info_version_entry = entry;
1006         return 0;
1007 }
1008
1009 static int __exit snd_info_version_done(void)
1010 {
1011         snd_info_free_entry(snd_info_version_entry);
1012         return 0;
1013 }
1014
1015 #endif /* CONFIG_PROC_FS */