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 <linux/module.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <linux/utsname.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/mutex.h>
  34 #include <stdarg.h>
  35
  36 /*
  37  *
  38  */
  39
  40 #ifdef CONFIG_PROC_FS
  41
  42 int snd_info_check_reserved_words(const char *str)
  43 {
  44         static char *reserved[] =
  45         {
  46                 "version",
  47                 "meminfo",
  48                 "memdebug",
  49                 "detect",
  50                 "devices",
  51                 "oss",
  52                 "cards",
  53                 "timers",
  54                 "synth",
  55                 "pcm",
  56                 "seq",
  57                 NULL
  58         };
  59         char **xstr = reserved;
  60
  61         while (*xstr) {
  62                 if (!strcmp(*xstr, str))
  63                         return 0;
  64                 xstr++;
  65         }
  66         if (!strncmp(str, "card", 4))
  67                 return 0;
  68         return 1;
  69 }
  70
  71 static DEFINE_MUTEX(info_mutex);
  72
  73 struct snd_info_private_data {
  74         struct snd_info_buffer *rbuffer;
  75         struct snd_info_buffer *wbuffer;
  76         struct snd_info_entry *entry;
  77         void *file_private_data;
  78 };
  79
  80 static int snd_info_version_init(void);
  81 static int snd_info_version_done(void);
  82 static void snd_info_disconnect(struct snd_info_entry *entry);
  83
  84
  85 /* resize the proc r/w buffer */
  86 static int resize_info_buffer(struct snd_info_buffer *buffer,
  87                               unsigned int nsize)
  88 {
  89         char *nbuf;
  90
  91         nsize = PAGE_ALIGN(nsize);
  92         nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL);
  93         if (! nbuf)
  94                 return -ENOMEM;
  95
  96         buffer->buffer = nbuf;
  97         buffer->len = nsize;
  98         return 0;
  99 }
 100
 101 /**
 102  * snd_iprintf - printf on the procfs buffer
 103  * @buffer: the procfs buffer
 104  * @fmt: the printf format
 105  *
 106  * Outputs the string on the procfs buffer just like printf().
 107  *
 108  * Returns the size of output string.
 109  */
 110 int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
 111 {
 112         va_list args;
 113         int len, res;
 114         int err = 0;
 115
 116         might_sleep();
 117         if (buffer->stop || buffer->error)
 118                 return 0;
 119         len = buffer->len - buffer->size;
 120         va_start(args, fmt);
 121         for (;;) {
 122                 va_list ap;
 123                 va_copy(ap, args);
 124                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
 125                 va_end(ap);
 126                 if (res < len)
 127                         break;
 128                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
 129                 if (err < 0)
 130                         break;
 131                 len = buffer->len - buffer->size;
 132         }
 133         va_end(args);
 134
 135         if (err < 0)
 136                 return err;
 137         buffer->curr += res;
 138         buffer->size += res;
 139         return res;
 140 }
 141
 142 EXPORT_SYMBOL(snd_iprintf);
 143
 144 /*
 145
 146  */
 147
 148 static struct proc_dir_entry *snd_proc_root;
 149 struct snd_info_entry *snd_seq_root;
 150 EXPORT_SYMBOL(snd_seq_root);
 151
 152 #ifdef CONFIG_SND_OSSEMUL
 153 struct snd_info_entry *snd_oss_root;
 154 #endif
 155
 156 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 157                                   struct proc_dir_entry *de)
 158 {
 159         if (de)
 160                 remove_proc_entry(de->name, parent);
 161 }
 162
 163 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 164 {
 165         struct snd_info_private_data *data;
 166         struct snd_info_entry *entry;
 167         loff_t ret = -EINVAL, size;
 168
 169         data = file->private_data;
 170         entry = data->entry;
 171         mutex_lock(&entry->access);
 172         if (entry->content == SNDRV_INFO_CONTENT_DATA &&
 173             entry->c.ops->llseek) {
 174                 offset = entry->c.ops->llseek(entry,
 175                                               data->file_private_data,
 176                                               file, offset, orig);
 177                 goto out;
 178         }
 179         if (entry->content == SNDRV_INFO_CONTENT_DATA)
 180                 size = entry->size;
 181         else
 182                 size = 0;
 183         switch (orig) {
 184         case SEEK_SET:
 185                 break;
 186         case SEEK_CUR:
 187                 offset += file->f_pos;
 188                 break;
 189         case SEEK_END:
 190                 if (!size)
 191                         goto out;
 192                 offset += size;
 193                 break;
 194         default:
 195                 goto out;
 196         }
 197         if (offset < 0)
 198                 goto out;
 199         if (size && offset > size)
 200                 offset = size;
 201         file->f_pos = offset;
 202         ret = offset;
 203  out:
 204         mutex_unlock(&entry->access);
 205         return ret;
 206 }
 207
 208 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 209                                    size_t count, loff_t * offset)
 210 {
 211         struct snd_info_private_data *data;
 212         struct snd_info_entry *entry;
 213         struct snd_info_buffer *buf;
 214         size_t size = 0;
 215         loff_t pos;
 216
 217         data = file->private_data;
 218         if (snd_BUG_ON(!data))
 219                 return -ENXIO;
 220         pos = *offset;
 221         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 222                 return -EIO;
 223         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 224                 return -EIO;
 225         entry = data->entry;
 226         switch (entry->content) {
 227         case SNDRV_INFO_CONTENT_TEXT:
 228                 buf = data->rbuffer;
 229                 if (buf == NULL)
 230                         return -EIO;
 231                 if (pos >= buf->size)
 232                         return 0;
 233                 size = buf->size - pos;
 234                 size = min(count, size);
 235                 if (copy_to_user(buffer, buf->buffer + pos, size))
 236                         return -EFAULT;
 237                 break;
 238         case SNDRV_INFO_CONTENT_DATA:
 239                 if (pos >= entry->size)
 240                         return 0;
 241                 if (entry->c.ops->read) {
 242                         size = entry->size - pos;
 243                         size = min(count, size);
 244                         size = entry->c.ops->read(entry,
 245                                                   data->file_private_data,
 246                                                   file, buffer, size, pos);
 247                 }
 248                 break;
 249         }
 250         if ((ssize_t) size > 0)
 251                 *offset = pos + size;
 252         return size;
 253 }
 254
 255 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 256                                     size_t count, loff_t * offset)
 257 {
 258         struct snd_info_private_data *data;
 259         struct snd_info_entry *entry;
 260         struct snd_info_buffer *buf;
 261         ssize_t size = 0;
 262         loff_t pos;
 263
 264         data = file->private_data;
 265         if (snd_BUG_ON(!data))
 266                 return -ENXIO;
 267         entry = data->entry;
 268         pos = *offset;
 269         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 270                 return -EIO;
 271         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 272                 return -EIO;
 273         switch (entry->content) {
 274         case SNDRV_INFO_CONTENT_TEXT:
 275                 buf = data->wbuffer;
 276                 if (buf == NULL)
 277                         return -EIO;
 278                 mutex_lock(&entry->access);
 279                 if (pos + count >= buf->len) {
 280                         if (resize_info_buffer(buf, pos + count)) {
 281                                 mutex_unlock(&entry->access);
 282                                 return -ENOMEM;
 283                         }
 284                 }
 285                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
 286                         mutex_unlock(&entry->access);
 287                         return -EFAULT;
 288                 }
 289                 buf->size = pos + count;
 290                 mutex_unlock(&entry->access);
 291                 size = count;
 292                 break;
 293         case SNDRV_INFO_CONTENT_DATA:
 294                 if (entry->c.ops->write && count > 0) {
 295                         size_t maxsize = entry->size - pos;
 296                         count = min(count, maxsize);
 297                         size = entry->c.ops->write(entry,
 298                                                    data->file_private_data,
 299                                                    file, buffer, count, pos);
 300                 }
 301                 break;
 302         }
 303         if ((ssize_t) size > 0)
 304                 *offset = pos + size;
 305         return size;
 306 }
 307
 308 static int snd_info_entry_open(struct inode *inode, struct file *file)
 309 {
 310         struct snd_info_entry *entry;
 311         struct snd_info_private_data *data;
 312         struct snd_info_buffer *buffer;
 313         int mode, err;
 314
 315         mutex_lock(&info_mutex);
 316         entry = PDE_DATA(inode);
 317         if (entry == NULL || ! entry->p) {
 318                 mutex_unlock(&info_mutex);
 319                 return -ENODEV;
 320         }
 321         if (!try_module_get(entry->module)) {
 322                 err = -EFAULT;
 323                 goto __error1;
 324         }
 325         mode = file->f_flags & O_ACCMODE;
 326         if (mode == O_RDONLY || mode == O_RDWR) {
 327                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 328                      entry->c.ops->read == NULL)) {
 329                         err = -ENODEV;
 330                         goto __error;
 331                 }
 332         }
 333         if (mode == O_WRONLY || mode == O_RDWR) {
 334                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 335                      entry->c.ops->write == NULL)) {
 336                         err = -ENODEV;
 337                         goto __error;
 338                 }
 339         }
 340         data = kzalloc(sizeof(*data), GFP_KERNEL);
 341         if (data == NULL) {
 342                 err = -ENOMEM;
 343                 goto __error;
 344         }
 345         data->entry = entry;
 346         switch (entry->content) {
 347         case SNDRV_INFO_CONTENT_TEXT:
 348                 if (mode == O_RDONLY || mode == O_RDWR) {
 349                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 350                         if (buffer == NULL)
 351                                 goto __nomem;
 352                         data->rbuffer = buffer;
 353                         buffer->len = PAGE_SIZE;
 354                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 355                         if (buffer->buffer == NULL)
 356                                 goto __nomem;
 357                 }
 358                 if (mode == O_WRONLY || mode == O_RDWR) {
 359                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 360                         if (buffer == NULL)
 361                                 goto __nomem;
 362                         data->wbuffer = buffer;
 363                         buffer->len = PAGE_SIZE;
 364                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 365                         if (buffer->buffer == NULL)
 366                                 goto __nomem;
 367                 }
 368                 break;
 369         case SNDRV_INFO_CONTENT_DATA:   /* data */
 370                 if (entry->c.ops->open) {
 371                         if ((err = entry->c.ops->open(entry, mode,
 372                                                       &data->file_private_data)) < 0) {
 373                                 kfree(data);
 374                                 goto __error;
 375                         }
 376                 }
 377                 break;
 378         }
 379         file->private_data = data;
 380         mutex_unlock(&info_mutex);
 381         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 382             (mode == O_RDONLY || mode == O_RDWR)) {
 383                 if (entry->c.text.read) {
 384                         mutex_lock(&entry->access);
 385                         entry->c.text.read(entry, data->rbuffer);
 386                         mutex_unlock(&entry->access);
 387                 }
 388         }
 389         return 0;
 390
 391  __nomem:
 392         if (data->rbuffer) {
 393                 kfree(data->rbuffer->buffer);
 394                 kfree(data->rbuffer);
 395         }
 396         if (data->wbuffer) {
 397                 kfree(data->wbuffer->buffer);
 398                 kfree(data->wbuffer);
 399         }
 400         kfree(data);
 401         err = -ENOMEM;
 402       __error:
 403         module_put(entry->module);
 404       __error1:
 405         mutex_unlock(&info_mutex);
 406         return err;
 407 }
 408
 409 static int snd_info_entry_release(struct inode *inode, struct file *file)
 410 {
 411         struct snd_info_entry *entry;
 412         struct snd_info_private_data *data;
 413         int mode;
 414
 415         mode = file->f_flags & O_ACCMODE;
 416         data = file->private_data;
 417         entry = data->entry;
 418         switch (entry->content) {
 419         case SNDRV_INFO_CONTENT_TEXT:
 420                 if (data->rbuffer) {
 421                         kfree(data->rbuffer->buffer);
 422                         kfree(data->rbuffer);
 423                 }
 424                 if (data->wbuffer) {
 425                         if (entry->c.text.write) {
 426                                 entry->c.text.write(entry, data->wbuffer);
 427                                 if (data->wbuffer->error) {
 428                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 429                                                 entry->name,
 430                                                 data->wbuffer->error);
 431                                 }
 432                         }
 433                         kfree(data->wbuffer->buffer);
 434                         kfree(data->wbuffer);
 435                 }
 436                 break;
 437         case SNDRV_INFO_CONTENT_DATA:
 438                 if (entry->c.ops->release)
 439                         entry->c.ops->release(entry, mode,
 440                                               data->file_private_data);
 441                 break;
 442         }
 443         module_put(entry->module);
 444         kfree(data);
 445         return 0;
 446 }
 447
 448 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 449 {
 450         struct snd_info_private_data *data;
 451         struct snd_info_entry *entry;
 452         unsigned int mask;
 453
 454         data = file->private_data;
 455         if (data == NULL)
 456                 return 0;
 457         entry = data->entry;
 458         mask = 0;
 459         switch (entry->content) {
 460         case SNDRV_INFO_CONTENT_DATA:
 461                 if (entry->c.ops->poll)
 462                         return entry->c.ops->poll(entry,
 463                                                   data->file_private_data,
 464                                                   file, wait);
 465                 if (entry->c.ops->read)
 466                         mask |= POLLIN | POLLRDNORM;
 467                 if (entry->c.ops->write)
 468                         mask |= POLLOUT | POLLWRNORM;
 469                 break;
 470         }
 471         return mask;
 472 }
 473
 474 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 475                                 unsigned long arg)
 476 {
 477         struct snd_info_private_data *data;
 478         struct snd_info_entry *entry;
 479
 480         data = file->private_data;
 481         if (data == NULL)
 482                 return 0;
 483         entry = data->entry;
 484         switch (entry->content) {
 485         case SNDRV_INFO_CONTENT_DATA:
 486                 if (entry->c.ops->ioctl)
 487                         return entry->c.ops->ioctl(entry,
 488                                                    data->file_private_data,
 489                                                    file, cmd, arg);
 490                 break;
 491         }
 492         return -ENOTTY;
 493 }
 494
 495 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 496 {
 497         struct inode *inode = file_inode(file);
 498         struct snd_info_private_data *data;
 499         struct snd_info_entry *entry;
 500
 501         data = file->private_data;
 502         if (data == NULL)
 503                 return 0;
 504         entry = data->entry;
 505         switch (entry->content) {
 506         case SNDRV_INFO_CONTENT_DATA:
 507                 if (entry->c.ops->mmap)
 508                         return entry->c.ops->mmap(entry,
 509                                                   data->file_private_data,
 510                                                   inode, file, vma);
 511                 break;
 512         }
 513         return -ENXIO;
 514 }
 515
 516 static const struct file_operations snd_info_entry_operations =
 517 {
 518         .owner =                THIS_MODULE,
 519         .llseek =               snd_info_entry_llseek,
 520         .read =                 snd_info_entry_read,
 521         .write =                snd_info_entry_write,
 522         .poll =                 snd_info_entry_poll,
 523         .unlocked_ioctl =       snd_info_entry_ioctl,
 524         .mmap =                 snd_info_entry_mmap,
 525         .open =                 snd_info_entry_open,
 526         .release =              snd_info_entry_release,
 527 };
 528
 529 int __init snd_info_init(void)
 530 {
 531         struct proc_dir_entry *p;
 532
 533         p = proc_mkdir("asound", NULL);
 534         if (p == NULL)
 535                 return -ENOMEM;
 536         snd_proc_root = p;
 537 #ifdef CONFIG_SND_OSSEMUL
 538         {
 539                 struct snd_info_entry *entry;
 540                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 541                         return -ENOMEM;
 542                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 543                 if (snd_info_register(entry) < 0) {
 544                         snd_info_free_entry(entry);
 545                         return -ENOMEM;
 546                 }
 547                 snd_oss_root = entry;
 548         }
 549 #endif
 550 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 551         {
 552                 struct snd_info_entry *entry;
 553                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 554                         return -ENOMEM;
 555                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 556                 if (snd_info_register(entry) < 0) {
 557                         snd_info_free_entry(entry);
 558                         return -ENOMEM;
 559                 }
 560                 snd_seq_root = entry;
 561         }
 562 #endif
 563         snd_info_version_init();
 564         snd_minor_info_init();
 565         snd_minor_info_oss_init();
 566         snd_card_info_init();
 567         return 0;
 568 }
 569
 570 int __exit snd_info_done(void)
 571 {
 572         snd_card_info_done();
 573         snd_minor_info_oss_done();
 574         snd_minor_info_done();
 575         snd_info_version_done();
 576         if (snd_proc_root) {
 577 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 578                 snd_info_free_entry(snd_seq_root);
 579 #endif
 580 #ifdef CONFIG_SND_OSSEMUL
 581                 snd_info_free_entry(snd_oss_root);
 582 #endif
 583                 snd_remove_proc_entry(NULL, snd_proc_root);
 584         }
 585         return 0;
 586 }
 587
 588 /*
 589
 590  */
 591
 592
 593 /*
 594  * create a card proc file
 595  * called from init.c
 596  */
 597 int snd_info_card_create(struct snd_card *card)
 598 {
 599         char str[8];
 600         struct snd_info_entry *entry;
 601
 602         if (snd_BUG_ON(!card))
 603                 return -ENXIO;
 604
 605         sprintf(str, "card%i", card->number);
 606         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 607                 return -ENOMEM;
 608         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 609         if (snd_info_register(entry) < 0) {
 610                 snd_info_free_entry(entry);
 611                 return -ENOMEM;
 612         }
 613         card->proc_root = entry;
 614         return 0;
 615 }
 616
 617 /*
 618  * register the card proc file
 619  * called from init.c
 620  */
 621 int snd_info_card_register(struct snd_card *card)
 622 {
 623         struct proc_dir_entry *p;
 624
 625         if (snd_BUG_ON(!card))
 626                 return -ENXIO;
 627
 628         if (!strcmp(card->id, card->proc_root->name))
 629                 return 0;
 630
 631         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 632         if (p == NULL)
 633                 return -ENOMEM;
 634         card->proc_root_link = p;
 635         return 0;
 636 }
 637
 638 /*
 639  * called on card->id change
 640  */
 641 void snd_info_card_id_change(struct snd_card *card)
 642 {
 643         mutex_lock(&info_mutex);
 644         if (card->proc_root_link) {
 645                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 646                 card->proc_root_link = NULL;
 647         }
 648         if (strcmp(card->id, card->proc_root->name))
 649                 card->proc_root_link = proc_symlink(card->id,
 650                                                     snd_proc_root,
 651                                                     card->proc_root->name);
 652         mutex_unlock(&info_mutex);
 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 const char *snd_info_get_str(char *dest, const 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         if (S_ISDIR(entry->mode)) {
 961                 p = proc_mkdir_mode(entry->name, entry->mode, root);
 962                 if (!p) {
 963                         mutex_unlock(&info_mutex);
 964                         return -ENOMEM;
 965                 }
 966         } else {
 967                 p = proc_create_data(entry->name, entry->mode, root,
 968                                         &snd_info_entry_operations, entry);
 969                 if (!p) {
 970                         mutex_unlock(&info_mutex);
 971                         return -ENOMEM;
 972                 }
 973                 p->size = entry->size;
 974         }
 975         entry->p = p;
 976         if (entry->parent)
 977                 list_add_tail(&entry->list, &entry->parent->children);
 978         mutex_unlock(&info_mutex);
 979         return 0;
 980 }
 981
 982 EXPORT_SYMBOL(snd_info_register);
 983
 984 /*
 985
 986  */
 987
 988 static struct snd_info_entry *snd_info_version_entry;
 989
 990 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 991 {
 992         snd_iprintf(buffer,
 993                     "Advanced Linux Sound Architecture Driver Version k%s.\n",
 994                     init_utsname()->release);
 995 }
 996
 997 static int __init snd_info_version_init(void)
 998 {
 999         struct snd_info_entry *entry;
1000
1001         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
1002         if (entry == NULL)
1003                 return -ENOMEM;
1004         entry->c.text.read = snd_info_version_read;
1005         if (snd_info_register(entry) < 0) {
1006                 snd_info_free_entry(entry);
1007                 return -ENOMEM;
1008         }
1009         snd_info_version_entry = entry;
1010         return 0;
1011 }
1012
1013 static int __exit snd_info_version_done(void)
1014 {
1015         snd_info_free_entry(snd_info_version_entry);
1016         return 0;
1017 }
1018
1019 #endif /* CONFIG_PROC_FS */