git.oblomov.eu Git - linux-2.6/blob - sound/core/info.c

   1 /*
   2  *  Information interface for ALSA driver
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/time.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/string.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <sound/version.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/devfs_fs_kernel.h>
  34 #include <linux/mutex.h>
  35 #include <stdarg.h>
  36
  37 /*
  38  *
  39  */
  40
  41 #ifdef CONFIG_PROC_FS
  42
  43 int snd_info_check_reserved_words(const char *str)
  44 {
  45         static char *reserved[] =
  46         {
  47                 "version",
  48                 "meminfo",
  49                 "memdebug",
  50                 "detect",
  51                 "devices",
  52                 "oss",
  53                 "cards",
  54                 "timers",
  55                 "synth",
  56                 "pcm",
  57                 "seq",
  58                 NULL
  59         };
  60         char **xstr = reserved;
  61
  62         while (*xstr) {
  63                 if (!strcmp(*xstr, str))
  64                         return 0;
  65                 xstr++;
  66         }
  67         if (!strncmp(str, "card", 4))
  68                 return 0;
  69         return 1;
  70 }
  71
  72 static DEFINE_MUTEX(info_mutex);
  73
  74 struct snd_info_private_data {
  75         struct snd_info_buffer *rbuffer;
  76         struct snd_info_buffer *wbuffer;
  77         struct snd_info_entry *entry;
  78         void *file_private_data;
  79 };
  80
  81 static int snd_info_version_init(void);
  82 static int snd_info_version_done(void);
  83
  84
  85 /**
  86  * snd_iprintf - printf on the procfs buffer
  87  * @buffer: the procfs buffer
  88  * @fmt: the printf format
  89  *
  90  * Outputs the string on the procfs buffer just like printf().
  91  *
  92  * Returns the size of output string.
  93  */
  94 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
  95 {
  96         va_list args;
  97         int len, res;
  98
  99         if (buffer->stop || buffer->error)
 100                 return 0;
 101         len = buffer->len - buffer->size;
 102         va_start(args, fmt);
 103         res = vsnprintf(buffer->curr, len, fmt, args);
 104         va_end(args);
 105         if (res >= len) {
 106                 buffer->stop = 1;
 107                 return 0;
 108         }
 109         buffer->curr += res;
 110         buffer->size += res;
 111         return res;
 112 }
 113
 114 /*
 115
 116  */
 117
 118 static struct proc_dir_entry *snd_proc_root = NULL;
 119 struct snd_info_entry *snd_seq_root = NULL;
 120 #ifdef CONFIG_SND_OSSEMUL
 121 struct snd_info_entry *snd_oss_root = NULL;
 122 #endif
 123
 124 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 125 {
 126         de->owner = THIS_MODULE;
 127 }
 128
 129 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 130                                   struct proc_dir_entry *de)
 131 {
 132         if (de)
 133                 remove_proc_entry(de->name, parent);
 134 }
 135
 136 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 137 {
 138         struct snd_info_private_data *data;
 139         struct snd_info_entry *entry;
 140         loff_t ret;
 141
 142         data = file->private_data;
 143         entry = data->entry;
 144         lock_kernel();
 145         switch (entry->content) {
 146         case SNDRV_INFO_CONTENT_TEXT:
 147                 switch (orig) {
 148                 case 0: /* SEEK_SET */
 149                         file->f_pos = offset;
 150                         ret = file->f_pos;
 151                         goto out;
 152                 case 1: /* SEEK_CUR */
 153                         file->f_pos += offset;
 154                         ret = file->f_pos;
 155                         goto out;
 156                 case 2: /* SEEK_END */
 157                 default:
 158                         ret = -EINVAL;
 159                         goto out;
 160                 }
 161                 break;
 162         case SNDRV_INFO_CONTENT_DATA:
 163                 if (entry->c.ops->llseek) {
 164                         ret = entry->c.ops->llseek(entry,
 165                                                     data->file_private_data,
 166                                                     file, offset, orig);
 167                         goto out;
 168                 }
 169                 break;
 170         }
 171         ret = -ENXIO;
 172 out:
 173         unlock_kernel();
 174         return ret;
 175 }
 176
 177 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 178                                    size_t count, loff_t * offset)
 179 {
 180         struct snd_info_private_data *data;
 181         struct snd_info_entry *entry;
 182         struct snd_info_buffer *buf;
 183         size_t size = 0;
 184         loff_t pos;
 185
 186         data = file->private_data;
 187         snd_assert(data != NULL, return -ENXIO);
 188         pos = *offset;
 189         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 190                 return -EIO;
 191         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 192                 return -EIO;
 193         entry = data->entry;
 194         switch (entry->content) {
 195         case SNDRV_INFO_CONTENT_TEXT:
 196                 buf = data->rbuffer;
 197                 if (buf == NULL)
 198                         return -EIO;
 199                 if (pos >= buf->size)
 200                         return 0;
 201                 size = buf->size - pos;
 202                 size = min(count, size);
 203                 if (copy_to_user(buffer, buf->buffer + pos, size))
 204                         return -EFAULT;
 205                 break;
 206         case SNDRV_INFO_CONTENT_DATA:
 207                 if (entry->c.ops->read)
 208                         size = entry->c.ops->read(entry,
 209                                                   data->file_private_data,
 210                                                   file, buffer, count, pos);
 211                 break;
 212         }
 213         if ((ssize_t) size > 0)
 214                 *offset = pos + size;
 215         return size;
 216 }
 217
 218 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 219                                     size_t count, loff_t * offset)
 220 {
 221         struct snd_info_private_data *data;
 222         struct snd_info_entry *entry;
 223         struct snd_info_buffer *buf;
 224         size_t size = 0;
 225         loff_t pos;
 226
 227         data = file->private_data;
 228         snd_assert(data != NULL, return -ENXIO);
 229         entry = data->entry;
 230         pos = *offset;
 231         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 232                 return -EIO;
 233         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 234                 return -EIO;
 235         switch (entry->content) {
 236         case SNDRV_INFO_CONTENT_TEXT:
 237                 buf = data->wbuffer;
 238                 if (buf == NULL)
 239                         return -EIO;
 240                 if (pos >= buf->len)
 241                         return -ENOMEM;
 242                 size = buf->len - pos;
 243                 size = min(count, size);
 244                 if (copy_from_user(buf->buffer + pos, buffer, size))
 245                         return -EFAULT;
 246                 if ((long)buf->size < pos + size)
 247                         buf->size = pos + size;
 248                 break;
 249         case SNDRV_INFO_CONTENT_DATA:
 250                 if (entry->c.ops->write)
 251                         size = entry->c.ops->write(entry,
 252                                                    data->file_private_data,
 253                                                    file, buffer, count, pos);
 254                 break;
 255         }
 256         if ((ssize_t) size > 0)
 257                 *offset = pos + size;
 258         return size;
 259 }
 260
 261 static int snd_info_entry_open(struct inode *inode, struct file *file)
 262 {
 263         struct snd_info_entry *entry;
 264         struct snd_info_private_data *data;
 265         struct snd_info_buffer *buffer;
 266         struct proc_dir_entry *p;
 267         int mode, err;
 268
 269         mutex_lock(&info_mutex);
 270         p = PDE(inode);
 271         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 272         if (entry == NULL || entry->disconnected) {
 273                 mutex_unlock(&info_mutex);
 274                 return -ENODEV;
 275         }
 276         if (!try_module_get(entry->module)) {
 277                 err = -EFAULT;
 278                 goto __error1;
 279         }
 280         mode = file->f_flags & O_ACCMODE;
 281         if (mode == O_RDONLY || mode == O_RDWR) {
 282                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 283                      !entry->c.text.read_size) ||
 284                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 285                      entry->c.ops->read == NULL)) {
 286                         err = -ENODEV;
 287                         goto __error;
 288                 }
 289         }
 290         if (mode == O_WRONLY || mode == O_RDWR) {
 291                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 292                      !entry->c.text.write_size) ||
 293                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 294                      entry->c.ops->write == NULL)) {
 295                         err = -ENODEV;
 296                         goto __error;
 297                 }
 298         }
 299         data = kzalloc(sizeof(*data), GFP_KERNEL);
 300         if (data == NULL) {
 301                 err = -ENOMEM;
 302                 goto __error;
 303         }
 304         data->entry = entry;
 305         switch (entry->content) {
 306         case SNDRV_INFO_CONTENT_TEXT:
 307                 if (mode == O_RDONLY || mode == O_RDWR) {
 308                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 309                         if (buffer == NULL) {
 310                                 kfree(data);
 311                                 err = -ENOMEM;
 312                                 goto __error;
 313                         }
 314                         buffer->len = (entry->c.text.read_size +
 315                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 316                         buffer->buffer = vmalloc(buffer->len);
 317                         if (buffer->buffer == NULL) {
 318                                 kfree(buffer);
 319                                 kfree(data);
 320                                 err = -ENOMEM;
 321                                 goto __error;
 322                         }
 323                         buffer->curr = buffer->buffer;
 324                         data->rbuffer = buffer;
 325                 }
 326                 if (mode == O_WRONLY || mode == O_RDWR) {
 327                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 328                         if (buffer == NULL) {
 329                                 if (mode == O_RDWR) {
 330                                         vfree(data->rbuffer->buffer);
 331                                         kfree(data->rbuffer);
 332                                 }
 333                                 kfree(data);
 334                                 err = -ENOMEM;
 335                                 goto __error;
 336                         }
 337                         buffer->len = (entry->c.text.write_size +
 338                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 339                         buffer->buffer = vmalloc(buffer->len);
 340                         if (buffer->buffer == NULL) {
 341                                 if (mode == O_RDWR) {
 342                                         vfree(data->rbuffer->buffer);
 343                                         kfree(data->rbuffer);
 344                                 }
 345                                 kfree(buffer);
 346                                 kfree(data);
 347                                 err = -ENOMEM;
 348                                 goto __error;
 349                         }
 350                         buffer->curr = buffer->buffer;
 351                         data->wbuffer = buffer;
 352                 }
 353                 break;
 354         case SNDRV_INFO_CONTENT_DATA:   /* data */
 355                 if (entry->c.ops->open) {
 356                         if ((err = entry->c.ops->open(entry, mode,
 357                                                       &data->file_private_data)) < 0) {
 358                                 kfree(data);
 359                                 goto __error;
 360                         }
 361                 }
 362                 break;
 363         }
 364         file->private_data = data;
 365         mutex_unlock(&info_mutex);
 366         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 367             (mode == O_RDONLY || mode == O_RDWR)) {
 368                 if (entry->c.text.read) {
 369                         mutex_lock(&entry->access);
 370                         entry->c.text.read(entry, data->rbuffer);
 371                         mutex_unlock(&entry->access);
 372                 }
 373         }
 374         return 0;
 375
 376       __error:
 377         module_put(entry->module);
 378       __error1:
 379         mutex_unlock(&info_mutex);
 380         return err;
 381 }
 382
 383 static int snd_info_entry_release(struct inode *inode, struct file *file)
 384 {
 385         struct snd_info_entry *entry;
 386         struct snd_info_private_data *data;
 387         int mode;
 388
 389         mode = file->f_flags & O_ACCMODE;
 390         data = file->private_data;
 391         entry = data->entry;
 392         switch (entry->content) {
 393         case SNDRV_INFO_CONTENT_TEXT:
 394                 if (mode == O_RDONLY || mode == O_RDWR) {
 395                         vfree(data->rbuffer->buffer);
 396                         kfree(data->rbuffer);
 397                 }
 398                 if (mode == O_WRONLY || mode == O_RDWR) {
 399                         if (entry->c.text.write) {
 400                                 entry->c.text.write(entry, data->wbuffer);
 401                                 if (data->wbuffer->error) {
 402                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 403                                                 entry->name,
 404                                                 data->wbuffer->error);
 405                                 }
 406                         }
 407                         vfree(data->wbuffer->buffer);
 408                         kfree(data->wbuffer);
 409                 }
 410                 break;
 411         case SNDRV_INFO_CONTENT_DATA:
 412                 if (entry->c.ops->release)
 413                         entry->c.ops->release(entry, mode,
 414                                               data->file_private_data);
 415                 break;
 416         }
 417         module_put(entry->module);
 418         kfree(data);
 419         return 0;
 420 }
 421
 422 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 423 {
 424         struct snd_info_private_data *data;
 425         struct snd_info_entry *entry;
 426         unsigned int mask;
 427
 428         data = file->private_data;
 429         if (data == NULL)
 430                 return 0;
 431         entry = data->entry;
 432         mask = 0;
 433         switch (entry->content) {
 434         case SNDRV_INFO_CONTENT_DATA:
 435                 if (entry->c.ops->poll)
 436                         return entry->c.ops->poll(entry,
 437                                                   data->file_private_data,
 438                                                   file, wait);
 439                 if (entry->c.ops->read)
 440                         mask |= POLLIN | POLLRDNORM;
 441                 if (entry->c.ops->write)
 442                         mask |= POLLOUT | POLLWRNORM;
 443                 break;
 444         }
 445         return mask;
 446 }
 447
 448 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 449                                 unsigned long arg)
 450 {
 451         struct snd_info_private_data *data;
 452         struct snd_info_entry *entry;
 453
 454         data = file->private_data;
 455         if (data == NULL)
 456                 return 0;
 457         entry = data->entry;
 458         switch (entry->content) {
 459         case SNDRV_INFO_CONTENT_DATA:
 460                 if (entry->c.ops->ioctl)
 461                         return entry->c.ops->ioctl(entry,
 462                                                    data->file_private_data,
 463                                                    file, cmd, arg);
 464                 break;
 465         }
 466         return -ENOTTY;
 467 }
 468
 469 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 470 {
 471         struct inode *inode = file->f_dentry->d_inode;
 472         struct snd_info_private_data *data;
 473         struct snd_info_entry *entry;
 474
 475         data = file->private_data;
 476         if (data == NULL)
 477                 return 0;
 478         entry = data->entry;
 479         switch (entry->content) {
 480         case SNDRV_INFO_CONTENT_DATA:
 481                 if (entry->c.ops->mmap)
 482                         return entry->c.ops->mmap(entry,
 483                                                   data->file_private_data,
 484                                                   inode, file, vma);
 485                 break;
 486         }
 487         return -ENXIO;
 488 }
 489
 490 static struct file_operations snd_info_entry_operations =
 491 {
 492         .owner =                THIS_MODULE,
 493         .llseek =               snd_info_entry_llseek,
 494         .read =                 snd_info_entry_read,
 495         .write =                snd_info_entry_write,
 496         .poll =                 snd_info_entry_poll,
 497         .unlocked_ioctl =       snd_info_entry_ioctl,
 498         .mmap =                 snd_info_entry_mmap,
 499         .open =                 snd_info_entry_open,
 500         .release =              snd_info_entry_release,
 501 };
 502
 503 /**
 504  * snd_create_proc_entry - create a procfs entry
 505  * @name: the name of the proc file
 506  * @mode: the file permission bits, S_Ixxx
 507  * @parent: the parent proc-directory entry
 508  *
 509  * Creates a new proc file entry with the given name and permission
 510  * on the given directory.
 511  *
 512  * Returns the pointer of new instance or NULL on failure.
 513  */
 514 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 515                                                     struct proc_dir_entry *parent)
 516 {
 517         struct proc_dir_entry *p;
 518         p = create_proc_entry(name, mode, parent);
 519         if (p)
 520                 snd_info_entry_prepare(p);
 521         return p;
 522 }
 523
 524 int __init snd_info_init(void)
 525 {
 526         struct proc_dir_entry *p;
 527
 528         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 529         if (p == NULL)
 530                 return -ENOMEM;
 531         snd_proc_root = p;
 532 #ifdef CONFIG_SND_OSSEMUL
 533         {
 534                 struct snd_info_entry *entry;
 535                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 536                         return -ENOMEM;
 537                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 538                 if (snd_info_register(entry) < 0) {
 539                         snd_info_free_entry(entry);
 540                         return -ENOMEM;
 541                 }
 542                 snd_oss_root = entry;
 543         }
 544 #endif
 545 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 546         {
 547                 struct snd_info_entry *entry;
 548                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 549                         return -ENOMEM;
 550                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 551                 if (snd_info_register(entry) < 0) {
 552                         snd_info_free_entry(entry);
 553                         return -ENOMEM;
 554                 }
 555                 snd_seq_root = entry;
 556         }
 557 #endif
 558         snd_info_version_init();
 559         snd_minor_info_init();
 560         snd_minor_info_oss_init();
 561         snd_card_info_init();
 562         return 0;
 563 }
 564
 565 int __exit snd_info_done(void)
 566 {
 567         snd_card_info_done();
 568         snd_minor_info_oss_done();
 569         snd_minor_info_done();
 570         snd_info_version_done();
 571         if (snd_proc_root) {
 572 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 573                 snd_info_unregister(snd_seq_root);
 574 #endif
 575 #ifdef CONFIG_SND_OSSEMUL
 576                 snd_info_unregister(snd_oss_root);
 577 #endif
 578                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 579         }
 580         return 0;
 581 }
 582
 583 /*
 584
 585  */
 586
 587
 588 /*
 589  * create a card proc file
 590  * called from init.c
 591  */
 592 int snd_info_card_create(struct snd_card *card)
 593 {
 594         char str[8];
 595         struct snd_info_entry *entry;
 596
 597         snd_assert(card != NULL, return -ENXIO);
 598
 599         sprintf(str, "card%i", card->number);
 600         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 601                 return -ENOMEM;
 602         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 603         if (snd_info_register(entry) < 0) {
 604                 snd_info_free_entry(entry);
 605                 return -ENOMEM;
 606         }
 607         card->proc_root = entry;
 608         return 0;
 609 }
 610
 611 /*
 612  * register the card proc file
 613  * called from init.c
 614  */
 615 int snd_info_card_register(struct snd_card *card)
 616 {
 617         struct proc_dir_entry *p;
 618
 619         snd_assert(card != NULL, return -ENXIO);
 620
 621         if (!strcmp(card->id, card->proc_root->name))
 622                 return 0;
 623
 624         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 625         if (p == NULL)
 626                 return -ENOMEM;
 627         card->proc_root_link = p;
 628         return 0;
 629 }
 630
 631 /*
 632  * de-register the card proc file
 633  * called from init.c
 634  */
 635 int snd_info_card_free(struct snd_card *card)
 636 {
 637         snd_assert(card != NULL, return -ENXIO);
 638         if (card->proc_root_link) {
 639                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 640                 card->proc_root_link = NULL;
 641         }
 642         if (card->proc_root) {
 643                 snd_info_unregister(card->proc_root);
 644                 card->proc_root = NULL;
 645         }
 646         return 0;
 647 }
 648
 649
 650 /**
 651  * snd_info_get_line - read one line from the procfs buffer
 652  * @buffer: the procfs buffer
 653  * @line: the buffer to store
 654  * @len: the max. buffer size - 1
 655  *
 656  * Reads one line from the buffer and stores the string.
 657  *
 658  * Returns zero if successful, or 1 if error or EOF.
 659  */
 660 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 661 {
 662         int c = -1;
 663
 664         if (len <= 0 || buffer->stop || buffer->error)
 665                 return 1;
 666         while (--len > 0) {
 667                 c = *buffer->curr++;
 668                 if (c == '\n') {
 669                         if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 670                                 buffer->stop = 1;
 671                         }
 672                         break;
 673                 }
 674                 *line++ = c;
 675                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 676                         buffer->stop = 1;
 677                         break;
 678                 }
 679         }
 680         while (c != '\n' && !buffer->stop) {
 681                 c = *buffer->curr++;
 682                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 683                         buffer->stop = 1;
 684                 }
 685         }
 686         *line = '\0';
 687         return 0;
 688 }
 689
 690 /**
 691  * snd_info_get_str - parse a string token
 692  * @dest: the buffer to store the string token
 693  * @src: the original string
 694  * @len: the max. length of token - 1
 695  *
 696  * Parses the original string and copy a token to the given
 697  * string buffer.
 698  *
 699  * Returns the updated pointer of the original string so that
 700  * it can be used for the next call.
 701  */
 702 char *snd_info_get_str(char *dest, char *src, int len)
 703 {
 704         int c;
 705
 706         while (*src == ' ' || *src == '\t')
 707                 src++;
 708         if (*src == '"' || *src == '\'') {
 709                 c = *src++;
 710                 while (--len > 0 && *src && *src != c) {
 711                         *dest++ = *src++;
 712                 }
 713                 if (*src == c)
 714                         src++;
 715         } else {
 716                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 717                         *dest++ = *src++;
 718                 }
 719         }
 720         *dest = 0;
 721         while (*src == ' ' || *src == '\t')
 722                 src++;
 723         return src;
 724 }
 725
 726 /**
 727  * snd_info_create_entry - create an info entry
 728  * @name: the proc file name
 729  *
 730  * Creates an info entry with the given file name and initializes as
 731  * the default state.
 732  *
 733  * Usually called from other functions such as
 734  * snd_info_create_card_entry().
 735  *
 736  * Returns the pointer of the new instance, or NULL on failure.
 737  */
 738 static struct snd_info_entry *snd_info_create_entry(const char *name)
 739 {
 740         struct snd_info_entry *entry;
 741         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 742         if (entry == NULL)
 743                 return NULL;
 744         entry->name = kstrdup(name, GFP_KERNEL);
 745         if (entry->name == NULL) {
 746                 kfree(entry);
 747                 return NULL;
 748         }
 749         entry->mode = S_IFREG | S_IRUGO;
 750         entry->content = SNDRV_INFO_CONTENT_TEXT;
 751         mutex_init(&entry->access);
 752         return entry;
 753 }
 754
 755 /**
 756  * snd_info_create_module_entry - create an info entry for the given module
 757  * @module: the module pointer
 758  * @name: the file name
 759  * @parent: the parent directory
 760  *
 761  * Creates a new info entry and assigns it to the given module.
 762  *
 763  * Returns the pointer of the new instance, or NULL on failure.
 764  */
 765 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 766                                                const char *name,
 767                                                struct snd_info_entry *parent)
 768 {
 769         struct snd_info_entry *entry = snd_info_create_entry(name);
 770         if (entry) {
 771                 entry->module = module;
 772                 entry->parent = parent;
 773         }
 774         return entry;
 775 }
 776
 777 /**
 778  * snd_info_create_card_entry - create an info entry for the given card
 779  * @card: the card instance
 780  * @name: the file name
 781  * @parent: the parent directory
 782  *
 783  * Creates a new info entry and assigns it to the given card.
 784  *
 785  * Returns the pointer of the new instance, or NULL on failure.
 786  */
 787 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 788                                              const char *name,
 789                                              struct snd_info_entry * parent)
 790 {
 791         struct snd_info_entry *entry = snd_info_create_entry(name);
 792         if (entry) {
 793                 entry->module = card->module;
 794                 entry->card = card;
 795                 entry->parent = parent;
 796         }
 797         return entry;
 798 }
 799
 800 static int snd_info_dev_free_entry(struct snd_device *device)
 801 {
 802         struct snd_info_entry *entry = device->device_data;
 803         snd_info_free_entry(entry);
 804         return 0;
 805 }
 806
 807 static int snd_info_dev_register_entry(struct snd_device *device)
 808 {
 809         struct snd_info_entry *entry = device->device_data;
 810         return snd_info_register(entry);
 811 }
 812
 813 static int snd_info_dev_disconnect_entry(struct snd_device *device)
 814 {
 815         struct snd_info_entry *entry = device->device_data;
 816         entry->disconnected = 1;
 817         return 0;
 818 }
 819
 820 static int snd_info_dev_unregister_entry(struct snd_device *device)
 821 {
 822         struct snd_info_entry *entry = device->device_data;
 823         return snd_info_unregister(entry);
 824 }
 825
 826 /**
 827  * snd_card_proc_new - create an info entry for the given card
 828  * @card: the card instance
 829  * @name: the file name
 830  * @entryp: the pointer to store the new info entry
 831  *
 832  * Creates a new info entry and assigns it to the given card.
 833  * Unlike snd_info_create_card_entry(), this function registers the
 834  * info entry as an ALSA device component, so that it can be
 835  * unregistered/released without explicit call.
 836  * Also, you don't have to register this entry via snd_info_register(),
 837  * since this will be registered by snd_card_register() automatically.
 838  *
 839  * The parent is assumed as card->proc_root.
 840  *
 841  * For releasing this entry, use snd_device_free() instead of
 842  * snd_info_free_entry().
 843  *
 844  * Returns zero if successful, or a negative error code on failure.
 845  */
 846 int snd_card_proc_new(struct snd_card *card, const char *name,
 847                       struct snd_info_entry **entryp)
 848 {
 849         static struct snd_device_ops ops = {
 850                 .dev_free = snd_info_dev_free_entry,
 851                 .dev_register = snd_info_dev_register_entry,
 852                 .dev_disconnect = snd_info_dev_disconnect_entry,
 853                 .dev_unregister = snd_info_dev_unregister_entry
 854         };
 855         struct snd_info_entry *entry;
 856         int err;
 857
 858         entry = snd_info_create_card_entry(card, name, card->proc_root);
 859         if (! entry)
 860                 return -ENOMEM;
 861         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 862                 snd_info_free_entry(entry);
 863                 return err;
 864         }
 865         if (entryp)
 866                 *entryp = entry;
 867         return 0;
 868 }
 869
 870 /**
 871  * snd_info_free_entry - release the info entry
 872  * @entry: the info entry
 873  *
 874  * Releases the info entry.  Don't call this after registered.
 875  */
 876 void snd_info_free_entry(struct snd_info_entry * entry)
 877 {
 878         if (entry == NULL)
 879                 return;
 880         kfree(entry->name);
 881         if (entry->private_free)
 882                 entry->private_free(entry);
 883         kfree(entry);
 884 }
 885
 886 /**
 887  * snd_info_register - register the info entry
 888  * @entry: the info entry
 889  *
 890  * Registers the proc info entry.
 891  *
 892  * Returns zero if successful, or a negative error code on failure.
 893  */
 894 int snd_info_register(struct snd_info_entry * entry)
 895 {
 896         struct proc_dir_entry *root, *p = NULL;
 897
 898         snd_assert(entry != NULL, return -ENXIO);
 899         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 900         mutex_lock(&info_mutex);
 901         p = snd_create_proc_entry(entry->name, entry->mode, root);
 902         if (!p) {
 903                 mutex_unlock(&info_mutex);
 904                 return -ENOMEM;
 905         }
 906         p->owner = entry->module;
 907         if (!S_ISDIR(entry->mode))
 908                 p->proc_fops = &snd_info_entry_operations;
 909         p->size = entry->size;
 910         p->data = entry;
 911         entry->p = p;
 912         mutex_unlock(&info_mutex);
 913         return 0;
 914 }
 915
 916 /**
 917  * snd_info_unregister - de-register the info entry
 918  * @entry: the info entry
 919  *
 920  * De-registers the info entry and releases the instance.
 921  *
 922  * Returns zero if successful, or a negative error code on failure.
 923  */
 924 int snd_info_unregister(struct snd_info_entry * entry)
 925 {
 926         struct proc_dir_entry *root;
 927
 928         if (! entry)
 929                 return 0;
 930         snd_assert(entry->p != NULL, return -ENXIO);
 931         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 932         snd_assert(root, return -ENXIO);
 933         mutex_lock(&info_mutex);
 934         snd_remove_proc_entry(root, entry->p);
 935         mutex_unlock(&info_mutex);
 936         snd_info_free_entry(entry);
 937         return 0;
 938 }
 939
 940 /*
 941
 942  */
 943
 944 static struct snd_info_entry *snd_info_version_entry = NULL;
 945
 946 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 947 {
 948         snd_iprintf(buffer,
 949                     "Advanced Linux Sound Architecture Driver Version "
 950                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 951                    );
 952 }
 953
 954 static int __init snd_info_version_init(void)
 955 {
 956         struct snd_info_entry *entry;
 957
 958         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 959         if (entry == NULL)
 960                 return -ENOMEM;
 961         entry->c.text.read_size = 256;
 962         entry->c.text.read = snd_info_version_read;
 963         if (snd_info_register(entry) < 0) {
 964                 snd_info_free_entry(entry);
 965                 return -ENOMEM;
 966         }
 967         snd_info_version_entry = entry;
 968         return 0;
 969 }
 970
 971 static int __exit snd_info_version_done(void)
 972 {
 973         if (snd_info_version_entry)
 974                 snd_info_unregister(snd_info_version_entry);
 975         return 0;
 976 }
 977
 978 #endif /* CONFIG_PROC_FS */