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