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