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 <stdarg.h>
  35
  36 /*
  37  *
  38  */
  39
  40 int snd_info_check_reserved_words(const char *str)
  41 {
  42         static char *reserved[] =
  43         {
  44                 "version",
  45                 "meminfo",
  46                 "memdebug",
  47                 "detect",
  48                 "devices",
  49                 "oss",
  50                 "cards",
  51                 "timers",
  52                 "synth",
  53                 "pcm",
  54                 "seq",
  55                 NULL
  56         };
  57         char **xstr = reserved;
  58
  59         while (*xstr) {
  60                 if (!strcmp(*xstr, str))
  61                         return 0;
  62                 xstr++;
  63         }
  64         if (!strncmp(str, "card", 4))
  65                 return 0;
  66         return 1;
  67 }
  68
  69 #ifdef CONFIG_PROC_FS
  70
  71 static DECLARE_MUTEX(info_mutex);
  72
  73 typedef struct _snd_info_private_data {
  74         snd_info_buffer_t *rbuffer;
  75         snd_info_buffer_t *wbuffer;
  76         snd_info_entry_t *entry;
  77         void *file_private_data;
  78 } snd_info_private_data_t;
  79
  80 static int snd_info_version_init(void);
  81 static int snd_info_version_done(void);
  82
  83
  84 /**
  85  * snd_iprintf - printf on the procfs buffer
  86  * @buffer: the procfs buffer
  87  * @fmt: the printf format
  88  *
  89  * Outputs the string on the procfs buffer just like printf().
  90  *
  91  * Returns the size of output string.
  92  */
  93 int snd_iprintf(snd_info_buffer_t * buffer, char *fmt,...)
  94 {
  95         va_list args;
  96         int len, res;
  97
  98         if (buffer->stop || buffer->error)
  99                 return 0;
 100         len = buffer->len - buffer->size;
 101         va_start(args, fmt);
 102         res = vsnprintf(buffer->curr, len, fmt, args);
 103         va_end(args);
 104         if (res >= len) {
 105                 buffer->stop = 1;
 106                 return 0;
 107         }
 108         buffer->curr += res;
 109         buffer->size += res;
 110         return res;
 111 }
 112
 113 /*
 114
 115  */
 116
 117 static struct proc_dir_entry *snd_proc_root = NULL;
 118 snd_info_entry_t *snd_seq_root = NULL;
 119 #ifdef CONFIG_SND_OSSEMUL
 120 snd_info_entry_t *snd_oss_root = NULL;
 121 #endif
 122
 123 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 124 {
 125         de->owner = THIS_MODULE;
 126 }
 127
 128 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 129                                   struct proc_dir_entry *de)
 130 {
 131         if (de)
 132                 remove_proc_entry(de->name, parent);
 133 }
 134
 135 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 136 {
 137         snd_info_private_data_t *data;
 138         struct snd_info_entry *entry;
 139         loff_t ret;
 140
 141         data = file->private_data;
 142         entry = data->entry;
 143         lock_kernel();
 144         switch (entry->content) {
 145         case SNDRV_INFO_CONTENT_TEXT:
 146                 switch (orig) {
 147                 case 0: /* SEEK_SET */
 148                         file->f_pos = offset;
 149                         ret = file->f_pos;
 150                         goto out;
 151                 case 1: /* SEEK_CUR */
 152                         file->f_pos += offset;
 153                         ret = file->f_pos;
 154                         goto out;
 155                 case 2: /* SEEK_END */
 156                 default:
 157                         ret = -EINVAL;
 158                         goto out;
 159                 }
 160                 break;
 161         case SNDRV_INFO_CONTENT_DATA:
 162                 if (entry->c.ops->llseek) {
 163                         ret = entry->c.ops->llseek(entry,
 164                                                     data->file_private_data,
 165                                                     file, offset, orig);
 166                         goto out;
 167                 }
 168                 break;
 169         }
 170         ret = -ENXIO;
 171 out:
 172         unlock_kernel();
 173         return ret;
 174 }
 175
 176 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 177                                    size_t count, loff_t * offset)
 178 {
 179         snd_info_private_data_t *data;
 180         struct snd_info_entry *entry;
 181         snd_info_buffer_t *buf;
 182         size_t size = 0;
 183         loff_t pos;
 184
 185         data = file->private_data;
 186         snd_assert(data != NULL, return -ENXIO);
 187         pos = *offset;
 188         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 189                 return -EIO;
 190         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 191                 return -EIO;
 192         entry = data->entry;
 193         switch (entry->content) {
 194         case SNDRV_INFO_CONTENT_TEXT:
 195                 buf = data->rbuffer;
 196                 if (buf == NULL)
 197                         return -EIO;
 198                 if (pos >= buf->size)
 199                         return 0;
 200                 size = buf->size - pos;
 201                 size = min(count, size);
 202                 if (copy_to_user(buffer, buf->buffer + pos, size))
 203                         return -EFAULT;
 204                 break;
 205         case SNDRV_INFO_CONTENT_DATA:
 206                 if (entry->c.ops->read)
 207                         size = entry->c.ops->read(entry,
 208                                                   data->file_private_data,
 209                                                   file, buffer, count, pos);
 210                 break;
 211         }
 212         if ((ssize_t) size > 0)
 213                 *offset = pos + size;
 214         return size;
 215 }
 216
 217 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 218                                     size_t count, loff_t * offset)
 219 {
 220         snd_info_private_data_t *data;
 221         struct snd_info_entry *entry;
 222         snd_info_buffer_t *buf;
 223         size_t size = 0;
 224         loff_t pos;
 225
 226         data = file->private_data;
 227         snd_assert(data != NULL, return -ENXIO);
 228         entry = data->entry;
 229         pos = *offset;
 230         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 231                 return -EIO;
 232         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 233                 return -EIO;
 234         switch (entry->content) {
 235         case SNDRV_INFO_CONTENT_TEXT:
 236                 buf = data->wbuffer;
 237                 if (buf == NULL)
 238                         return -EIO;
 239                 if (pos >= buf->len)
 240                         return -ENOMEM;
 241                 size = buf->len - pos;
 242                 size = min(count, size);
 243                 if (copy_from_user(buf->buffer + pos, buffer, size))
 244                         return -EFAULT;
 245                 if ((long)buf->size < pos + size)
 246                         buf->size = pos + size;
 247                 break;
 248         case SNDRV_INFO_CONTENT_DATA:
 249                 if (entry->c.ops->write)
 250                         size = entry->c.ops->write(entry,
 251                                                    data->file_private_data,
 252                                                    file, buffer, count, pos);
 253                 break;
 254         }
 255         if ((ssize_t) size > 0)
 256                 *offset = pos + size;
 257         return size;
 258 }
 259
 260 static int snd_info_entry_open(struct inode *inode, struct file *file)
 261 {
 262         snd_info_entry_t *entry;
 263         snd_info_private_data_t *data;
 264         snd_info_buffer_t *buffer;
 265         struct proc_dir_entry *p;
 266         int mode, err;
 267
 268         down(&info_mutex);
 269         p = PDE(inode);
 270         entry = p == NULL ? NULL : (snd_info_entry_t *)p->data;
 271         if (entry == NULL || entry->disconnected) {
 272                 up(&info_mutex);
 273                 return -ENODEV;
 274         }
 275         if (!try_module_get(entry->module)) {
 276                 err = -EFAULT;
 277                 goto __error1;
 278         }
 279         mode = file->f_flags & O_ACCMODE;
 280         if (mode == O_RDONLY || mode == O_RDWR) {
 281                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 282                      !entry->c.text.read_size) ||
 283                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 284                      entry->c.ops->read == NULL)) {
 285                         err = -ENODEV;
 286                         goto __error;
 287                 }
 288         }
 289         if (mode == O_WRONLY || mode == O_RDWR) {
 290                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 291                      !entry->c.text.write_size) ||
 292                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 293                      entry->c.ops->write == NULL)) {
 294                         err = -ENODEV;
 295                         goto __error;
 296                 }
 297         }
 298         data = kcalloc(1, sizeof(*data), GFP_KERNEL);
 299         if (data == NULL) {
 300                 err = -ENOMEM;
 301                 goto __error;
 302         }
 303         data->entry = entry;
 304         switch (entry->content) {
 305         case SNDRV_INFO_CONTENT_TEXT:
 306                 if (mode == O_RDONLY || mode == O_RDWR) {
 307                         buffer = kcalloc(1, sizeof(*buffer), GFP_KERNEL);
 308                         if (buffer == NULL) {
 309                                 kfree(data);
 310                                 err = -ENOMEM;
 311                                 goto __error;
 312                         }
 313                         buffer->len = (entry->c.text.read_size +
 314                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 315                         buffer->buffer = vmalloc(buffer->len);
 316                         if (buffer->buffer == NULL) {
 317                                 kfree(buffer);
 318                                 kfree(data);
 319                                 err = -ENOMEM;
 320                                 goto __error;
 321                         }
 322                         buffer->curr = buffer->buffer;
 323                         data->rbuffer = buffer;
 324                 }
 325                 if (mode == O_WRONLY || mode == O_RDWR) {
 326                         buffer = kcalloc(1, sizeof(*buffer), GFP_KERNEL);
 327                         if (buffer == NULL) {
 328                                 if (mode == O_RDWR) {
 329                                         vfree(data->rbuffer->buffer);
 330                                         kfree(data->rbuffer);
 331                                 }
 332                                 kfree(data);
 333                                 err = -ENOMEM;
 334                                 goto __error;
 335                         }
 336                         buffer->len = (entry->c.text.write_size +
 337                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 338                         buffer->buffer = vmalloc(buffer->len);
 339                         if (buffer->buffer == NULL) {
 340                                 if (mode == O_RDWR) {
 341                                         vfree(data->rbuffer->buffer);
 342                                         kfree(data->rbuffer);
 343                                 }
 344                                 kfree(buffer);
 345                                 kfree(data);
 346                                 err = -ENOMEM;
 347                                 goto __error;
 348                         }
 349                         buffer->curr = buffer->buffer;
 350                         data->wbuffer = buffer;
 351                 }
 352                 break;
 353         case SNDRV_INFO_CONTENT_DATA:   /* data */
 354                 if (entry->c.ops->open) {
 355                         if ((err = entry->c.ops->open(entry, mode,
 356                                                       &data->file_private_data)) < 0) {
 357                                 kfree(data);
 358                                 goto __error;
 359                         }
 360                 }
 361                 break;
 362         }
 363         file->private_data = data;
 364         up(&info_mutex);
 365         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 366             (mode == O_RDONLY || mode == O_RDWR)) {
 367                 if (entry->c.text.read) {
 368                         down(&entry->access);
 369                         entry->c.text.read(entry, data->rbuffer);
 370                         up(&entry->access);
 371                 }
 372         }
 373         return 0;
 374
 375       __error:
 376         module_put(entry->module);
 377       __error1:
 378         up(&info_mutex);
 379         return err;
 380 }
 381
 382 static int snd_info_entry_release(struct inode *inode, struct file *file)
 383 {
 384         snd_info_entry_t *entry;
 385         snd_info_private_data_t *data;
 386         int mode;
 387
 388         mode = file->f_flags & O_ACCMODE;
 389         data = file->private_data;
 390         entry = data->entry;
 391         switch (entry->content) {
 392         case SNDRV_INFO_CONTENT_TEXT:
 393                 if (mode == O_RDONLY || mode == O_RDWR) {
 394                         vfree(data->rbuffer->buffer);
 395                         kfree(data->rbuffer);
 396                 }
 397                 if (mode == O_WRONLY || mode == O_RDWR) {
 398                         if (entry->c.text.write) {
 399                                 entry->c.text.write(entry, data->wbuffer);
 400                                 if (data->wbuffer->error) {
 401                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 402                                                 entry->name,
 403                                                 data->wbuffer->error);
 404                                 }
 405                         }
 406                         vfree(data->wbuffer->buffer);
 407                         kfree(data->wbuffer);
 408                 }
 409                 break;
 410         case SNDRV_INFO_CONTENT_DATA:
 411                 if (entry->c.ops->release)
 412                         entry->c.ops->release(entry, mode,
 413                                               data->file_private_data);
 414                 break;
 415         }
 416         module_put(entry->module);
 417         kfree(data);
 418         return 0;
 419 }
 420
 421 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 422 {
 423         snd_info_private_data_t *data;
 424         struct snd_info_entry *entry;
 425         unsigned int mask;
 426
 427         data = file->private_data;
 428         if (data == NULL)
 429                 return 0;
 430         entry = data->entry;
 431         mask = 0;
 432         switch (entry->content) {
 433         case SNDRV_INFO_CONTENT_DATA:
 434                 if (entry->c.ops->poll)
 435                         return entry->c.ops->poll(entry,
 436                                                   data->file_private_data,
 437                                                   file, wait);
 438                 if (entry->c.ops->read)
 439                         mask |= POLLIN | POLLRDNORM;
 440                 if (entry->c.ops->write)
 441                         mask |= POLLOUT | POLLWRNORM;
 442                 break;
 443         }
 444         return mask;
 445 }
 446
 447 static inline int _snd_info_entry_ioctl(struct inode *inode, struct file *file,
 448                                         unsigned int cmd, unsigned long arg)
 449 {
 450         snd_info_private_data_t *data;
 451         struct snd_info_entry *entry;
 452
 453         data = file->private_data;
 454         if (data == NULL)
 455                 return 0;
 456         entry = data->entry;
 457         switch (entry->content) {
 458         case SNDRV_INFO_CONTENT_DATA:
 459                 if (entry->c.ops->ioctl)
 460                         return entry->c.ops->ioctl(entry,
 461                                                    data->file_private_data,
 462                                                    file, cmd, arg);
 463                 break;
 464         }
 465         return -ENOTTY;
 466 }
 467
 468 /* FIXME: need to unlock BKL to allow preemption */
 469 static int snd_info_entry_ioctl(struct inode *inode, struct file *file,
 470                                 unsigned int cmd, unsigned long arg)
 471 {
 472         int err;
 473         unlock_kernel();
 474         err = _snd_info_entry_ioctl(inode, file, cmd, arg);
 475         lock_kernel();
 476         return err;
 477 }
 478
 479 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 480 {
 481         struct inode *inode = file->f_dentry->d_inode;
 482         snd_info_private_data_t *data;
 483         struct snd_info_entry *entry;
 484
 485         data = file->private_data;
 486         if (data == NULL)
 487                 return 0;
 488         entry = data->entry;
 489         switch (entry->content) {
 490         case SNDRV_INFO_CONTENT_DATA:
 491                 if (entry->c.ops->mmap)
 492                         return entry->c.ops->mmap(entry,
 493                                                   data->file_private_data,
 494                                                   inode, file, vma);
 495                 break;
 496         }
 497         return -ENXIO;
 498 }
 499
 500 static struct file_operations snd_info_entry_operations =
 501 {
 502         .owner =        THIS_MODULE,
 503         .llseek =       snd_info_entry_llseek,
 504         .read =         snd_info_entry_read,
 505         .write =        snd_info_entry_write,
 506         .poll =         snd_info_entry_poll,
 507         .ioctl =        snd_info_entry_ioctl,
 508         .mmap =         snd_info_entry_mmap,
 509         .open =         snd_info_entry_open,
 510         .release =      snd_info_entry_release,
 511 };
 512
 513 /**
 514  * snd_create_proc_entry - create a procfs entry
 515  * @name: the name of the proc file
 516  * @mode: the file permission bits, S_Ixxx
 517  * @parent: the parent proc-directory entry
 518  *
 519  * Creates a new proc file entry with the given name and permission
 520  * on the given directory.
 521  *
 522  * Returns the pointer of new instance or NULL on failure.
 523  */
 524 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 525                                                     struct proc_dir_entry *parent)
 526 {
 527         struct proc_dir_entry *p;
 528         p = create_proc_entry(name, mode, parent);
 529         if (p)
 530                 snd_info_entry_prepare(p);
 531         return p;
 532 }
 533
 534 int __init snd_info_init(void)
 535 {
 536         struct proc_dir_entry *p;
 537
 538         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 539         if (p == NULL)
 540                 return -ENOMEM;
 541         snd_proc_root = p;
 542 #ifdef CONFIG_SND_OSSEMUL
 543         {
 544                 snd_info_entry_t *entry;
 545                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 546                         return -ENOMEM;
 547                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 548                 if (snd_info_register(entry) < 0) {
 549                         snd_info_free_entry(entry);
 550                         return -ENOMEM;
 551                 }
 552                 snd_oss_root = entry;
 553         }
 554 #endif
 555 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 556         {
 557                 snd_info_entry_t *entry;
 558                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 559                         return -ENOMEM;
 560                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 561                 if (snd_info_register(entry) < 0) {
 562                         snd_info_free_entry(entry);
 563                         return -ENOMEM;
 564                 }
 565                 snd_seq_root = entry;
 566         }
 567 #endif
 568         snd_info_version_init();
 569         snd_memory_info_init();
 570         snd_minor_info_init();
 571         snd_minor_info_oss_init();
 572         snd_card_info_init();
 573         return 0;
 574 }
 575
 576 int __exit snd_info_done(void)
 577 {
 578         snd_card_info_done();
 579         snd_minor_info_oss_done();
 580         snd_minor_info_done();
 581         snd_memory_info_done();
 582         snd_info_version_done();
 583         if (snd_proc_root) {
 584 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 585                 if (snd_seq_root)
 586                         snd_info_unregister(snd_seq_root);
 587 #endif
 588 #ifdef CONFIG_SND_OSSEMUL
 589                 if (snd_oss_root)
 590                         snd_info_unregister(snd_oss_root);
 591 #endif
 592                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 593         }
 594         return 0;
 595 }
 596
 597 /*
 598
 599  */
 600
 601
 602 /*
 603  * create a card proc file
 604  * called from init.c
 605  */
 606 int snd_info_card_create(snd_card_t * card)
 607 {
 608         char str[8];
 609         snd_info_entry_t *entry;
 610
 611         snd_assert(card != NULL, return -ENXIO);
 612
 613         sprintf(str, "card%i", card->number);
 614         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 615                 return -ENOMEM;
 616         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 617         if (snd_info_register(entry) < 0) {
 618                 snd_info_free_entry(entry);
 619                 return -ENOMEM;
 620         }
 621         card->proc_root = entry;
 622         return 0;
 623 }
 624
 625 /*
 626  * register the card proc file
 627  * called from init.c
 628  */
 629 int snd_info_card_register(snd_card_t * card)
 630 {
 631         struct proc_dir_entry *p;
 632
 633         snd_assert(card != NULL, return -ENXIO);
 634
 635         if (!strcmp(card->id, card->proc_root->name))
 636                 return 0;
 637
 638         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 639         if (p == NULL)
 640                 return -ENOMEM;
 641         card->proc_root_link = p;
 642         return 0;
 643 }
 644
 645 /*
 646  * de-register the card proc file
 647  * called from init.c
 648  */
 649 int snd_info_card_free(snd_card_t * card)
 650 {
 651         snd_assert(card != NULL, return -ENXIO);
 652         if (card->proc_root_link) {
 653                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 654                 card->proc_root_link = NULL;
 655         }
 656         if (card->proc_root) {
 657                 snd_info_unregister(card->proc_root);
 658                 card->proc_root = NULL;
 659         }
 660         return 0;
 661 }
 662
 663
 664 /**
 665  * snd_info_get_line - read one line from the procfs buffer
 666  * @buffer: the procfs buffer
 667  * @line: the buffer to store
 668  * @len: the max. buffer size - 1
 669  *
 670  * Reads one line from the buffer and stores the string.
 671  *
 672  * Returns zero if successful, or 1 if error or EOF.
 673  */
 674 int snd_info_get_line(snd_info_buffer_t * buffer, char *line, int len)
 675 {
 676         int c = -1;
 677
 678         if (len <= 0 || buffer->stop || buffer->error)
 679                 return 1;
 680         while (--len > 0) {
 681                 c = *buffer->curr++;
 682                 if (c == '\n') {
 683                         if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 684                                 buffer->stop = 1;
 685                         }
 686                         break;
 687                 }
 688                 *line++ = c;
 689                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 690                         buffer->stop = 1;
 691                         break;
 692                 }
 693         }
 694         while (c != '\n' && !buffer->stop) {
 695                 c = *buffer->curr++;
 696                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 697                         buffer->stop = 1;
 698                 }
 699         }
 700         *line = '\0';
 701         return 0;
 702 }
 703
 704 /**
 705  * snd_info_get_str - parse a string token
 706  * @dest: the buffer to store the string token
 707  * @src: the original string
 708  * @len: the max. length of token - 1
 709  *
 710  * Parses the original string and copy a token to the given
 711  * string buffer.
 712  *
 713  * Returns the updated pointer of the original string so that
 714  * it can be used for the next call.
 715  */
 716 char *snd_info_get_str(char *dest, char *src, int len)
 717 {
 718         int c;
 719
 720         while (*src == ' ' || *src == '\t')
 721                 src++;
 722         if (*src == '"' || *src == '\'') {
 723                 c = *src++;
 724                 while (--len > 0 && *src && *src != c) {
 725                         *dest++ = *src++;
 726                 }
 727                 if (*src == c)
 728                         src++;
 729         } else {
 730                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 731                         *dest++ = *src++;
 732                 }
 733         }
 734         *dest = 0;
 735         while (*src == ' ' || *src == '\t')
 736                 src++;
 737         return src;
 738 }
 739
 740 /**
 741  * snd_info_create_entry - create an info entry
 742  * @name: the proc file name
 743  *
 744  * Creates an info entry with the given file name and initializes as
 745  * the default state.
 746  *
 747  * Usually called from other functions such as
 748  * snd_info_create_card_entry().
 749  *
 750  * Returns the pointer of the new instance, or NULL on failure.
 751  */
 752 static snd_info_entry_t *snd_info_create_entry(const char *name)
 753 {
 754         snd_info_entry_t *entry;
 755         entry = kcalloc(1, sizeof(*entry), GFP_KERNEL);
 756         if (entry == NULL)
 757                 return NULL;
 758         entry->name = kstrdup(name, GFP_KERNEL);
 759         if (entry->name == NULL) {
 760                 kfree(entry);
 761                 return NULL;
 762         }
 763         entry->mode = S_IFREG | S_IRUGO;
 764         entry->content = SNDRV_INFO_CONTENT_TEXT;
 765         init_MUTEX(&entry->access);
 766         return entry;
 767 }
 768
 769 /**
 770  * snd_info_create_module_entry - create an info entry for the given module
 771  * @module: the module pointer
 772  * @name: the file name
 773  * @parent: the parent directory
 774  *
 775  * Creates a new info entry and assigns it to the given module.
 776  *
 777  * Returns the pointer of the new instance, or NULL on failure.
 778  */
 779 snd_info_entry_t *snd_info_create_module_entry(struct module * module,
 780                                                const char *name,
 781                                                snd_info_entry_t *parent)
 782 {
 783         snd_info_entry_t *entry = snd_info_create_entry(name);
 784         if (entry) {
 785                 entry->module = module;
 786                 entry->parent = parent;
 787         }
 788         return entry;
 789 }
 790
 791 /**
 792  * snd_info_create_card_entry - create an info entry for the given card
 793  * @card: the card instance
 794  * @name: the file name
 795  * @parent: the parent directory
 796  *
 797  * Creates a new info entry and assigns it to the given card.
 798  *
 799  * Returns the pointer of the new instance, or NULL on failure.
 800  */
 801 snd_info_entry_t *snd_info_create_card_entry(snd_card_t * card,
 802                                              const char *name,
 803                                              snd_info_entry_t * parent)
 804 {
 805         snd_info_entry_t *entry = snd_info_create_entry(name);
 806         if (entry) {
 807                 entry->module = card->module;
 808                 entry->card = card;
 809                 entry->parent = parent;
 810         }
 811         return entry;
 812 }
 813
 814 static int snd_info_dev_free_entry(snd_device_t *device)
 815 {
 816         snd_info_entry_t *entry = device->device_data;
 817         snd_info_free_entry(entry);
 818         return 0;
 819 }
 820
 821 static int snd_info_dev_register_entry(snd_device_t *device)
 822 {
 823         snd_info_entry_t *entry = device->device_data;
 824         return snd_info_register(entry);
 825 }
 826
 827 static int snd_info_dev_disconnect_entry(snd_device_t *device)
 828 {
 829         snd_info_entry_t *entry = device->device_data;
 830         entry->disconnected = 1;
 831         return 0;
 832 }
 833
 834 static int snd_info_dev_unregister_entry(snd_device_t *device)
 835 {
 836         snd_info_entry_t *entry = device->device_data;
 837         return snd_info_unregister(entry);
 838 }
 839
 840 /**
 841  * snd_card_proc_new - create an info entry for the given card
 842  * @card: the card instance
 843  * @name: the file name
 844  * @entryp: the pointer to store the new info entry
 845  *
 846  * Creates a new info entry and assigns it to the given card.
 847  * Unlike snd_info_create_card_entry(), this function registers the
 848  * info entry as an ALSA device component, so that it can be
 849  * unregistered/released without explicit call.
 850  * Also, you don't have to register this entry via snd_info_register(),
 851  * since this will be registered by snd_card_register() automatically.
 852  *
 853  * The parent is assumed as card->proc_root.
 854  *
 855  * For releasing this entry, use snd_device_free() instead of
 856  * snd_info_free_entry().
 857  *
 858  * Returns zero if successful, or a negative error code on failure.
 859  */
 860 int snd_card_proc_new(snd_card_t *card, const char *name,
 861                       snd_info_entry_t **entryp)
 862 {
 863         static snd_device_ops_t ops = {
 864                 .dev_free = snd_info_dev_free_entry,
 865                 .dev_register = snd_info_dev_register_entry,
 866                 .dev_disconnect = snd_info_dev_disconnect_entry,
 867                 .dev_unregister = snd_info_dev_unregister_entry
 868         };
 869         snd_info_entry_t *entry;
 870         int err;
 871
 872         entry = snd_info_create_card_entry(card, name, card->proc_root);
 873         if (! entry)
 874                 return -ENOMEM;
 875         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 876                 snd_info_free_entry(entry);
 877                 return err;
 878         }
 879         if (entryp)
 880                 *entryp = entry;
 881         return 0;
 882 }
 883
 884 /**
 885  * snd_info_free_entry - release the info entry
 886  * @entry: the info entry
 887  *
 888  * Releases the info entry.  Don't call this after registered.
 889  */
 890 void snd_info_free_entry(snd_info_entry_t * entry)
 891 {
 892         if (entry == NULL)
 893                 return;
 894         kfree(entry->name);
 895         if (entry->private_free)
 896                 entry->private_free(entry);
 897         kfree(entry);
 898 }
 899
 900 /**
 901  * snd_info_register - register the info entry
 902  * @entry: the info entry
 903  *
 904  * Registers the proc info entry.
 905  *
 906  * Returns zero if successful, or a negative error code on failure.
 907  */
 908 int snd_info_register(snd_info_entry_t * entry)
 909 {
 910         struct proc_dir_entry *root, *p = NULL;
 911
 912         snd_assert(entry != NULL, return -ENXIO);
 913         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 914         down(&info_mutex);
 915         p = snd_create_proc_entry(entry->name, entry->mode, root);
 916         if (!p) {
 917                 up(&info_mutex);
 918                 return -ENOMEM;
 919         }
 920         p->owner = entry->module;
 921         if (!S_ISDIR(entry->mode))
 922                 p->proc_fops = &snd_info_entry_operations;
 923         p->size = entry->size;
 924         p->data = entry;
 925         entry->p = p;
 926         up(&info_mutex);
 927         return 0;
 928 }
 929
 930 /**
 931  * snd_info_unregister - de-register the info entry
 932  * @entry: the info entry
 933  *
 934  * De-registers the info entry and releases the instance.
 935  *
 936  * Returns zero if successful, or a negative error code on failure.
 937  */
 938 int snd_info_unregister(snd_info_entry_t * entry)
 939 {
 940         struct proc_dir_entry *root;
 941
 942         snd_assert(entry != NULL, return -ENXIO);
 943         snd_assert(entry->p != NULL, return -ENXIO);
 944         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 945         snd_assert(root, return -ENXIO);
 946         down(&info_mutex);
 947         snd_remove_proc_entry(root, entry->p);
 948         up(&info_mutex);
 949         snd_info_free_entry(entry);
 950         return 0;
 951 }
 952
 953 /*
 954
 955  */
 956
 957 static snd_info_entry_t *snd_info_version_entry = NULL;
 958
 959 static void snd_info_version_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 960 {
 961         snd_iprintf(buffer,
 962                     "Advanced Linux Sound Architecture Driver Version "
 963                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 964                    );
 965 }
 966
 967 static int __init snd_info_version_init(void)
 968 {
 969         snd_info_entry_t *entry;
 970
 971         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 972         if (entry == NULL)
 973                 return -ENOMEM;
 974         entry->c.text.read_size = 256;
 975         entry->c.text.read = snd_info_version_read;
 976         if (snd_info_register(entry) < 0) {
 977                 snd_info_free_entry(entry);
 978                 return -ENOMEM;
 979         }
 980         snd_info_version_entry = entry;
 981         return 0;
 982 }
 983
 984 static int __exit snd_info_version_done(void)
 985 {
 986         if (snd_info_version_entry)
 987                 snd_info_unregister(snd_info_version_entry);
 988         return 0;
 989 }
 990
 991 #endif /* CONFIG_PROC_FS */