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  * called on card->id change
 657  */
 658 void snd_info_card_id_change(struct snd_card *card)
 659 {
 660         mutex_lock(&info_mutex);
 661         if (card->proc_root_link) {
 662                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 663                 card->proc_root_link = NULL;
 664         }
 665         if (strcmp(card->id, card->proc_root->name))
 666                 card->proc_root_link = proc_symlink(card->id,
 667                                                     snd_proc_root,
 668                                                     card->proc_root->name);
 669         mutex_unlock(&info_mutex);
 670 }
 671
 672 /*
 673  * de-register the card proc file
 674  * called from init.c
 675  */
 676 void snd_info_card_disconnect(struct snd_card *card)
 677 {
 678         if (!card)
 679                 return;
 680         mutex_lock(&info_mutex);
 681         if (card->proc_root_link) {
 682                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 683                 card->proc_root_link = NULL;
 684         }
 685         if (card->proc_root)
 686                 snd_info_disconnect(card->proc_root);
 687         mutex_unlock(&info_mutex);
 688 }
 689
 690 /*
 691  * release the card proc file resources
 692  * called from init.c
 693  */
 694 int snd_info_card_free(struct snd_card *card)
 695 {
 696         if (!card)
 697                 return 0;
 698         snd_info_free_entry(card->proc_root);
 699         card->proc_root = NULL;
 700         return 0;
 701 }
 702
 703
 704 /**
 705  * snd_info_get_line - read one line from the procfs buffer
 706  * @buffer: the procfs buffer
 707  * @line: the buffer to store
 708  * @len: the max. buffer size - 1
 709  *
 710  * Reads one line from the buffer and stores the string.
 711  *
 712  * Returns zero if successful, or 1 if error or EOF.
 713  */
 714 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 715 {
 716         int c = -1;
 717
 718         if (len <= 0 || buffer->stop || buffer->error)
 719                 return 1;
 720         while (--len > 0) {
 721                 c = buffer->buffer[buffer->curr++];
 722                 if (c == '\n') {
 723                         if (buffer->curr >= buffer->size)
 724                                 buffer->stop = 1;
 725                         break;
 726                 }
 727                 *line++ = c;
 728                 if (buffer->curr >= buffer->size) {
 729                         buffer->stop = 1;
 730                         break;
 731                 }
 732         }
 733         while (c != '\n' && !buffer->stop) {
 734                 c = buffer->buffer[buffer->curr++];
 735                 if (buffer->curr >= buffer->size)
 736                         buffer->stop = 1;
 737         }
 738         *line = '\0';
 739         return 0;
 740 }
 741
 742 EXPORT_SYMBOL(snd_info_get_line);
 743
 744 /**
 745  * snd_info_get_str - parse a string token
 746  * @dest: the buffer to store the string token
 747  * @src: the original string
 748  * @len: the max. length of token - 1
 749  *
 750  * Parses the original string and copy a token to the given
 751  * string buffer.
 752  *
 753  * Returns the updated pointer of the original string so that
 754  * it can be used for the next call.
 755  */
 756 char *snd_info_get_str(char *dest, char *src, int len)
 757 {
 758         int c;
 759
 760         while (*src == ' ' || *src == '\t')
 761                 src++;
 762         if (*src == '"' || *src == '\'') {
 763                 c = *src++;
 764                 while (--len > 0 && *src && *src != c) {
 765                         *dest++ = *src++;
 766                 }
 767                 if (*src == c)
 768                         src++;
 769         } else {
 770                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 771                         *dest++ = *src++;
 772                 }
 773         }
 774         *dest = 0;
 775         while (*src == ' ' || *src == '\t')
 776                 src++;
 777         return src;
 778 }
 779
 780 EXPORT_SYMBOL(snd_info_get_str);
 781
 782 /**
 783  * snd_info_create_entry - create an info entry
 784  * @name: the proc file name
 785  *
 786  * Creates an info entry with the given file name and initializes as
 787  * the default state.
 788  *
 789  * Usually called from other functions such as
 790  * snd_info_create_card_entry().
 791  *
 792  * Returns the pointer of the new instance, or NULL on failure.
 793  */
 794 static struct snd_info_entry *snd_info_create_entry(const char *name)
 795 {
 796         struct snd_info_entry *entry;
 797         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 798         if (entry == NULL)
 799                 return NULL;
 800         entry->name = kstrdup(name, GFP_KERNEL);
 801         if (entry->name == NULL) {
 802                 kfree(entry);
 803                 return NULL;
 804         }
 805         entry->mode = S_IFREG | S_IRUGO;
 806         entry->content = SNDRV_INFO_CONTENT_TEXT;
 807         mutex_init(&entry->access);
 808         INIT_LIST_HEAD(&entry->children);
 809         INIT_LIST_HEAD(&entry->list);
 810         return entry;
 811 }
 812
 813 /**
 814  * snd_info_create_module_entry - create an info entry for the given module
 815  * @module: the module pointer
 816  * @name: the file name
 817  * @parent: the parent directory
 818  *
 819  * Creates a new info entry and assigns it to the given module.
 820  *
 821  * Returns the pointer of the new instance, or NULL on failure.
 822  */
 823 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 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 = module;
 830                 entry->parent = parent;
 831         }
 832         return entry;
 833 }
 834
 835 EXPORT_SYMBOL(snd_info_create_module_entry);
 836
 837 /**
 838  * snd_info_create_card_entry - create an info entry for the given card
 839  * @card: the card instance
 840  * @name: the file name
 841  * @parent: the parent directory
 842  *
 843  * Creates a new info entry and assigns it to the given card.
 844  *
 845  * Returns the pointer of the new instance, or NULL on failure.
 846  */
 847 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 848                                              const char *name,
 849                                              struct snd_info_entry * parent)
 850 {
 851         struct snd_info_entry *entry = snd_info_create_entry(name);
 852         if (entry) {
 853                 entry->module = card->module;
 854                 entry->card = card;
 855                 entry->parent = parent;
 856         }
 857         return entry;
 858 }
 859
 860 EXPORT_SYMBOL(snd_info_create_card_entry);
 861
 862 static void snd_info_disconnect(struct snd_info_entry *entry)
 863 {
 864         struct list_head *p, *n;
 865         struct proc_dir_entry *root;
 866
 867         list_for_each_safe(p, n, &entry->children) {
 868                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 869         }
 870
 871         if (! entry->p)
 872                 return;
 873         list_del_init(&entry->list);
 874         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 875         snd_BUG_ON(!root);
 876         snd_remove_proc_entry(root, entry->p);
 877         entry->p = NULL;
 878 }
 879
 880 static int snd_info_dev_free_entry(struct snd_device *device)
 881 {
 882         struct snd_info_entry *entry = device->device_data;
 883         snd_info_free_entry(entry);
 884         return 0;
 885 }
 886
 887 static int snd_info_dev_register_entry(struct snd_device *device)
 888 {
 889         struct snd_info_entry *entry = device->device_data;
 890         return snd_info_register(entry);
 891 }
 892
 893 /**
 894  * snd_card_proc_new - create an info entry for the given card
 895  * @card: the card instance
 896  * @name: the file name
 897  * @entryp: the pointer to store the new info entry
 898  *
 899  * Creates a new info entry and assigns it to the given card.
 900  * Unlike snd_info_create_card_entry(), this function registers the
 901  * info entry as an ALSA device component, so that it can be
 902  * unregistered/released without explicit call.
 903  * Also, you don't have to register this entry via snd_info_register(),
 904  * since this will be registered by snd_card_register() automatically.
 905  *
 906  * The parent is assumed as card->proc_root.
 907  *
 908  * For releasing this entry, use snd_device_free() instead of
 909  * snd_info_free_entry().
 910  *
 911  * Returns zero if successful, or a negative error code on failure.
 912  */
 913 int snd_card_proc_new(struct snd_card *card, const char *name,
 914                       struct snd_info_entry **entryp)
 915 {
 916         static struct snd_device_ops ops = {
 917                 .dev_free = snd_info_dev_free_entry,
 918                 .dev_register = snd_info_dev_register_entry,
 919                 /* disconnect is done via snd_info_card_disconnect() */
 920         };
 921         struct snd_info_entry *entry;
 922         int err;
 923
 924         entry = snd_info_create_card_entry(card, name, card->proc_root);
 925         if (! entry)
 926                 return -ENOMEM;
 927         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 928                 snd_info_free_entry(entry);
 929                 return err;
 930         }
 931         if (entryp)
 932                 *entryp = entry;
 933         return 0;
 934 }
 935
 936 EXPORT_SYMBOL(snd_card_proc_new);
 937
 938 /**
 939  * snd_info_free_entry - release the info entry
 940  * @entry: the info entry
 941  *
 942  * Releases the info entry.  Don't call this after registered.
 943  */
 944 void snd_info_free_entry(struct snd_info_entry * entry)
 945 {
 946         if (entry == NULL)
 947                 return;
 948         if (entry->p) {
 949                 mutex_lock(&info_mutex);
 950                 snd_info_disconnect(entry);
 951                 mutex_unlock(&info_mutex);
 952         }
 953         kfree(entry->name);
 954         if (entry->private_free)
 955                 entry->private_free(entry);
 956         kfree(entry);
 957 }
 958
 959 EXPORT_SYMBOL(snd_info_free_entry);
 960
 961 /**
 962  * snd_info_register - register the info entry
 963  * @entry: the info entry
 964  *
 965  * Registers the proc info entry.
 966  *
 967  * Returns zero if successful, or a negative error code on failure.
 968  */
 969 int snd_info_register(struct snd_info_entry * entry)
 970 {
 971         struct proc_dir_entry *root, *p = NULL;
 972
 973         if (snd_BUG_ON(!entry))
 974                 return -ENXIO;
 975         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 976         mutex_lock(&info_mutex);
 977         p = snd_create_proc_entry(entry->name, entry->mode, root);
 978         if (!p) {
 979                 mutex_unlock(&info_mutex);
 980                 return -ENOMEM;
 981         }
 982         p->owner = entry->module;
 983         if (!S_ISDIR(entry->mode))
 984                 p->proc_fops = &snd_info_entry_operations;
 985         p->size = entry->size;
 986         p->data = entry;
 987         entry->p = p;
 988         if (entry->parent)
 989                 list_add_tail(&entry->list, &entry->parent->children);
 990         mutex_unlock(&info_mutex);
 991         return 0;
 992 }
 993
 994 EXPORT_SYMBOL(snd_info_register);
 995
 996 /*
 997
 998  */
 999
1000 static struct snd_info_entry *snd_info_version_entry;
1001
1002 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
1003 {
1004         snd_iprintf(buffer,
1005                     "Advanced Linux Sound Architecture Driver Version "
1006                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
1007                    );
1008 }
1009
1010 static int __init snd_info_version_init(void)
1011 {
1012         struct snd_info_entry *entry;
1013
1014         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
1015         if (entry == NULL)
1016                 return -ENOMEM;
1017         entry->c.text.read = snd_info_version_read;
1018         if (snd_info_register(entry) < 0) {
1019                 snd_info_free_entry(entry);
1020                 return -ENOMEM;
1021         }
1022         snd_info_version_entry = entry;
1023         return 0;
1024 }
1025
1026 static int __exit snd_info_version_done(void)
1027 {
1028         snd_info_free_entry(snd_info_version_entry);
1029         return 0;
1030 }
1031
1032 #endif /* CONFIG_PROC_FS */