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 = vsnprintf(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 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 *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         long size = 0, size1;
 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 < count ? buf->size : count;
 196                 size1 = buf->size - file->f_pos;
 197                 if (size1 < size)
 198                         size = size1;
 199                 if (copy_to_user(buffer, buf->buffer + file->f_pos, size))
 200                         return -EFAULT;
 201                 file->f_pos += size;
 202                 break;
 203         case SNDRV_INFO_CONTENT_DATA:
 204                 if (entry->c.ops->read)
 205                         return entry->c.ops->read(entry,
 206                                                   data->file_private_data,
 207                                                   file, buffer, count);
 208                 if (size > 0)
 209                         file->f_pos += size;
 210                 break;
 211         }
 212         return size;
 213 }
 214
 215 static ssize_t snd_info_entry_write(struct file *file, const char *buffer,
 216                                     size_t count, loff_t * offset)
 217 {
 218         snd_info_private_data_t *data;
 219         struct snd_info_entry *entry;
 220         snd_info_buffer_t *buf;
 221         long size = 0, size1;
 222
 223         data = snd_magic_cast(snd_info_private_data_t, file->private_data, return -ENXIO);
 224         snd_assert(data != NULL, return -ENXIO);
 225         entry = data->entry;
 226         switch (entry->content) {
 227         case SNDRV_INFO_CONTENT_TEXT:
 228                 buf = data->wbuffer;
 229                 if (buf == NULL)
 230                         return -EIO;
 231                 if (file->f_pos < 0)
 232                         return -EINVAL;
 233                 if (file->f_pos >= (long)buf->len)
 234                         return -ENOMEM;
 235                 size = buf->len < count ? buf->len : count;
 236                 size1 = buf->len - file->f_pos;
 237                 if (size1 < size)
 238                         size = size1;
 239                 if (copy_from_user(buf->buffer + file->f_pos, buffer, size))
 240                         return -EFAULT;
 241                 if ((long)buf->size < file->f_pos + size)
 242                         buf->size = file->f_pos + size;
 243                 file->f_pos += size;
 244                 break;
 245         case SNDRV_INFO_CONTENT_DATA:
 246                 if (entry->c.ops->write)
 247                         return entry->c.ops->write(entry,
 248                                                    data->file_private_data,
 249                                                    file, buffer, count);
 250                 if (size > 0)
 251                         file->f_pos += size;
 252                 break;
 253         }
 254         return size;
 255 }
 256
 257 static int snd_info_entry_open(struct inode *inode, struct file *file)
 258 {
 259         snd_info_entry_t *entry;
 260         snd_info_private_data_t *data;
 261         snd_info_buffer_t *buffer;
 262         struct proc_dir_entry *p;
 263         int mode, err;
 264
 265         down(&info_mutex);
 266         p = PDE(inode);
 267         entry = p == NULL ? NULL : (snd_info_entry_t *)p->data;
 268         if (entry == NULL || entry->disconnected) {
 269                 up(&info_mutex);
 270                 return -ENODEV;
 271         }
 272         if (!try_module_get(entry->module)) {
 273                 err = -EFAULT;
 274                 goto __error1;
 275         }
 276         mode = file->f_flags & O_ACCMODE;
 277         if (mode == O_RDONLY || mode == O_RDWR) {
 278                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 279                      !entry->c.text.read_size) ||
 280                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 281                      entry->c.ops->read == NULL) ||
 282                     entry->content == SNDRV_INFO_CONTENT_DEVICE) {
 283                         err = -ENODEV;
 284                         goto __error;
 285                 }
 286         }
 287         if (mode == O_WRONLY || mode == O_RDWR) {
 288                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 289                                         !entry->c.text.write_size) ||
 290                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 291                                         entry->c.ops->write == NULL) ||
 292                     entry->content == SNDRV_INFO_CONTENT_DEVICE) {
 293                         err = -ENODEV;
 294                         goto __error;
 295                 }
 296         }
 297         data = snd_magic_kcalloc(snd_info_private_data_t, 0, GFP_KERNEL);
 298         if (data == NULL) {
 299                 err = -ENOMEM;
 300                 goto __error;
 301         }
 302         data->entry = entry;
 303         switch (entry->content) {
 304         case SNDRV_INFO_CONTENT_TEXT:
 305                 if (mode == O_RDONLY || mode == O_RDWR) {
 306                         buffer = (snd_info_buffer_t *)
 307                                         snd_kcalloc(sizeof(snd_info_buffer_t), GFP_KERNEL);
 308                         if (buffer == NULL) {
 309                                 snd_magic_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                                 snd_magic_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 = (snd_info_buffer_t *)
 327                                         snd_kcalloc(sizeof(snd_info_buffer_t), GFP_KERNEL);
 328                         if (buffer == NULL) {
 329                                 if (mode == O_RDWR) {
 330                                         vfree(data->rbuffer->buffer);
 331                                         kfree(data->rbuffer);
 332                                 }
 333                                 snd_magic_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                                 snd_magic_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                                 snd_magic_kfree(data);
 359                                 goto __error;
 360                         }
 361                 }
 362                 break;
 363         }
 364         file->private_data = data;
 365         up(&info_mutex);
 366         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 367             (mode == O_RDONLY || mode == O_RDWR)) {
 368                 if (entry->c.text.read) {
 369                         down(&entry->access);
 370                         entry->c.text.read(entry, data->rbuffer);
 371                         up(&entry->access);
 372                 }
 373         }
 374         return 0;
 375
 376       __error:
 377         module_put(entry->module);
 378       __error1:
 379         up(&info_mutex);
 380         return err;
 381 }
 382
 383 static int snd_info_entry_release(struct inode *inode, struct file *file)
 384 {
 385         snd_info_entry_t *entry;
 386         snd_info_private_data_t *data;
 387         int mode;
 388
 389         mode = file->f_flags & O_ACCMODE;
 390         data = snd_magic_cast(snd_info_private_data_t, file->private_data, return -ENXIO);
 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         snd_magic_kfree(data);
 419         return 0;
 420 }
 421
 422 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 423 {
 424         snd_info_private_data_t *data;
 425         struct snd_info_entry *entry;
 426         unsigned int mask;
 427
 428         data = snd_magic_cast(snd_info_private_data_t, file->private_data, return -ENXIO);
 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 int snd_info_entry_ioctl(struct inode *inode, struct file *file,
 449                                 unsigned int cmd, unsigned long arg)
 450 {
 451         snd_info_private_data_t *data;
 452         struct snd_info_entry *entry;
 453
 454         data = snd_magic_cast(snd_info_private_data_t, file->private_data, return -ENXIO);
 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         snd_info_private_data_t *data;
 473         struct snd_info_entry *entry;
 474
 475         data = snd_magic_cast(snd_info_private_data_t, file->private_data, return -ENXIO);
 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         .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 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                 snd_info_entry_t *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                 snd_info_entry_t *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_memory_info_init();
 560         snd_minor_info_init();
 561         snd_minor_info_oss_init();
 562         snd_card_info_init();
 563         return 0;
 564 }
 565
 566 int __exit snd_info_done(void)
 567 {
 568         snd_card_info_done();
 569         snd_minor_info_oss_done();
 570         snd_minor_info_done();
 571         snd_memory_info_done();
 572         snd_info_version_done();
 573         if (snd_proc_root) {
 574 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 575                 if (snd_seq_root)
 576                         snd_info_unregister(snd_seq_root);
 577 #endif
 578 #ifdef CONFIG_SND_OSSEMUL
 579                 if (snd_oss_root)
 580                         snd_info_unregister(snd_oss_root);
 581 #endif
 582                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 583         }
 584         return 0;
 585 }
 586
 587 /*
 588
 589  */
 590
 591
 592 /*
 593  * create a card proc file
 594  * called from init.c
 595  */
 596 int snd_info_card_create(snd_card_t * card)
 597 {
 598         char str[8];
 599         snd_info_entry_t *entry;
 600
 601         snd_assert(card != NULL, return -ENXIO);
 602
 603         sprintf(str, "card%i", card->number);
 604         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 605                 return -ENOMEM;
 606         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 607         if (snd_info_register(entry) < 0) {
 608                 snd_info_free_entry(entry);
 609                 return -ENOMEM;
 610         }
 611         card->proc_root = entry;
 612         return 0;
 613 }
 614
 615 /*
 616  * register the card proc file
 617  * called from init.c
 618  */
 619 int snd_info_card_register(snd_card_t * card)
 620 {
 621         struct proc_dir_entry *p;
 622
 623         snd_assert(card != NULL, return -ENXIO);
 624
 625         if (!strcmp(card->id, card->proc_root->name))
 626                 return 0;
 627
 628         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 629         if (p == NULL)
 630                 return -ENOMEM;
 631         card->proc_root_link = p;
 632         return 0;
 633 }
 634
 635 /*
 636  * de-register the card proc file
 637  * called from init.c
 638  */
 639 int snd_info_card_free(snd_card_t * card)
 640 {
 641         snd_assert(card != NULL, return -ENXIO);
 642         if (card->proc_root_link) {
 643                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 644                 card->proc_root_link = NULL;
 645         }
 646         if (card->proc_root) {
 647                 snd_info_unregister(card->proc_root);
 648                 card->proc_root = NULL;
 649         }
 650         return 0;
 651 }
 652
 653
 654 /**
 655  * snd_info_get_line - read one line from the procfs buffer
 656  * @buffer: the procfs buffer
 657  * @line: the buffer to store
 658  * @len: the max. buffer size - 1
 659  *
 660  * Reads one line from the buffer and stores the string.
 661  *
 662  * Returns zero if successful, or 1 if error or EOF.
 663  */
 664 int snd_info_get_line(snd_info_buffer_t * buffer, char *line, int len)
 665 {
 666         int c = -1;
 667
 668         if (len <= 0 || buffer->stop || buffer->error)
 669                 return 1;
 670         while (--len > 0) {
 671                 c = *buffer->curr++;
 672                 if (c == '\n') {
 673                         if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 674                                 buffer->stop = 1;
 675                         }
 676                         break;
 677                 }
 678                 *line++ = c;
 679                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 680                         buffer->stop = 1;
 681                         break;
 682                 }
 683         }
 684         while (c != '\n' && !buffer->stop) {
 685                 c = *buffer->curr++;
 686                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 687                         buffer->stop = 1;
 688                 }
 689         }
 690         *line = '\0';
 691         return 0;
 692 }
 693
 694 /**
 695  * snd_info_get_line - parse a string token
 696  * @dest: the buffer to store the string token
 697  * @src: the original string
 698  * @len: the max. length of token - 1
 699  *
 700  * Parses the original string and copy a token to the given
 701  * string buffer.
 702  *
 703  * Returns the updated pointer of the original string so that
 704  * it can be used for the next call.
 705  */
 706 char *snd_info_get_str(char *dest, char *src, int len)
 707 {
 708         int c;
 709
 710         while (*src == ' ' || *src == '\t')
 711                 src++;
 712         if (*src == '"' || *src == '\'') {
 713                 c = *src++;
 714                 while (--len > 0 && *src && *src != c) {
 715                         *dest++ = *src++;
 716                 }
 717                 if (*src == c)
 718                         src++;
 719         } else {
 720                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 721                         *dest++ = *src++;
 722                 }
 723         }
 724         *dest = 0;
 725         while (*src == ' ' || *src == '\t')
 726                 src++;
 727         return src;
 728 }
 729
 730 /**
 731  * snd_info_create_entry - create an info entry
 732  * @name: the proc file name
 733  *
 734  * Creates an info entry with the given file name and initializes as
 735  * the default state.
 736  *
 737  * Usually called from other functions such as
 738  * snd_info_create_card_entry().
 739  *
 740  * Returns the pointer of the new instance, or NULL on failure.
 741  */
 742 static snd_info_entry_t *snd_info_create_entry(const char *name)
 743 {
 744         snd_info_entry_t *entry;
 745         entry = snd_magic_kcalloc(snd_info_entry_t, 0, GFP_KERNEL);
 746         if (entry == NULL)
 747                 return NULL;
 748         entry->name = snd_kmalloc_strdup(name, GFP_KERNEL);
 749         if (entry->name == NULL) {
 750                 snd_magic_kfree(entry);
 751                 return NULL;
 752         }
 753         entry->mode = S_IFREG | S_IRUGO;
 754         entry->content = SNDRV_INFO_CONTENT_TEXT;
 755         init_MUTEX(&entry->access);
 756         return entry;
 757 }
 758
 759 /**
 760  * snd_info_create_module_entry - create an info entry for the given module
 761  * @module: the module pointer
 762  * @name: the file name
 763  * @parent: the parent directory
 764  *
 765  * Creates a new info entry and assigns it to the given module.
 766  *
 767  * Returns the pointer of the new instance, or NULL on failure.
 768  */
 769 snd_info_entry_t *snd_info_create_module_entry(struct module * module,
 770                                                const char *name,
 771                                                snd_info_entry_t *parent)
 772 {
 773         snd_info_entry_t *entry = snd_info_create_entry(name);
 774         if (entry) {
 775                 entry->module = module;
 776                 entry->parent = parent;
 777         }
 778         return entry;
 779 }
 780
 781 /**
 782  * snd_info_create_card_entry - create an info entry for the given card
 783  * @card: the card instance
 784  * @name: the file name
 785  * @parent: the parent directory
 786  *
 787  * Creates a new info entry and assigns it to the given card.
 788  *
 789  * Returns the pointer of the new instance, or NULL on failure.
 790  */
 791 snd_info_entry_t *snd_info_create_card_entry(snd_card_t * card,
 792                                              const char *name,
 793                                              snd_info_entry_t * parent)
 794 {
 795         snd_info_entry_t *entry = snd_info_create_entry(name);
 796         if (entry) {
 797                 entry->module = card->module;
 798                 entry->card = card;
 799                 entry->parent = parent;
 800         }
 801         return entry;
 802 }
 803
 804 static int snd_info_dev_free_entry(snd_device_t *device)
 805 {
 806         snd_info_entry_t *entry = snd_magic_cast(snd_info_entry_t, device->device_data, return -ENXIO);
 807         snd_info_free_entry(entry);
 808         return 0;
 809 }
 810
 811 static int snd_info_dev_register_entry(snd_device_t *device)
 812 {
 813         snd_info_entry_t *entry = snd_magic_cast(snd_info_entry_t, device->device_data, return -ENXIO);
 814         return snd_info_register(entry);
 815 }
 816
 817 static int snd_info_dev_disconnect_entry(snd_device_t *device)
 818 {
 819         snd_info_entry_t *entry = snd_magic_cast(snd_info_entry_t, device->device_data, return -ENXIO);
 820         entry->disconnected = 1;
 821         return 0;
 822 }
 823
 824 static int snd_info_dev_unregister_entry(snd_device_t *device)
 825 {
 826         snd_info_entry_t *entry = snd_magic_cast(snd_info_entry_t, device->device_data, return -ENXIO);
 827         return snd_info_unregister(entry);
 828 }
 829
 830 /**
 831  * snd_card_proc_new - create an info entry for the given card
 832  * @card: the card instance
 833  * @name: the file name
 834  * @entryp: the pointer to store the new info entry
 835  *
 836  * Creates a new info entry and assigns it to the given card.
 837  * Unlike snd_info_create_card_entry(), this function registers the
 838  * info entry as an ALSA device component, so that it can be
 839  * unregistered/released without explicit call.
 840  * Also, you don't have to register this entry via snd_info_register(),
 841  * since this will be registered by snd_card_register() automatically.
 842  *
 843  * The parent is assumed as card->proc_root.
 844  *
 845  * For releasing this entry, use snd_device_free() instead of
 846  * snd_info_free_entry().
 847  *
 848  * Returns zero if successful, or a negative error code on failure.
 849  */
 850 int snd_card_proc_new(snd_card_t *card, const char *name,
 851                       snd_info_entry_t **entryp)
 852 {
 853         static snd_device_ops_t ops = {
 854                 .dev_free = snd_info_dev_free_entry,
 855                 .dev_register = snd_info_dev_register_entry,
 856                 .dev_disconnect = snd_info_dev_disconnect_entry,
 857                 .dev_unregister = snd_info_dev_unregister_entry
 858         };
 859         snd_info_entry_t *entry;
 860         int err;
 861
 862         entry = snd_info_create_card_entry(card, name, card->proc_root);
 863         if (! entry)
 864                 return -ENOMEM;
 865         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 866                 snd_info_free_entry(entry);
 867                 return err;
 868         }
 869         if (entryp)
 870                 *entryp = entry;
 871         return 0;
 872 }
 873
 874 /**
 875  * snd_info_free_entry - release the info entry
 876  * @entry: the info entry
 877  *
 878  * Releases the info entry.  Don't call this after registered.
 879  */
 880 void snd_info_free_entry(snd_info_entry_t * entry)
 881 {
 882         if (entry == NULL)
 883                 return;
 884         if (entry->name)
 885                 kfree((char *)entry->name);
 886         if (entry->private_free)
 887                 entry->private_free(entry);
 888         snd_magic_kfree(entry);
 889 }
 890
 891 /**
 892  * snd_info_register - register the info entry
 893  * @entry: the info entry
 894  *
 895  * Registers the proc info entry.
 896  *
 897  * Returns zero if successful, or a negative error code on failure.
 898  */
 899 int snd_info_register(snd_info_entry_t * entry)
 900 {
 901         struct proc_dir_entry *root, *p = NULL;
 902
 903         snd_assert(entry != NULL, return -ENXIO);
 904         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 905         down(&info_mutex);
 906         p = snd_create_proc_entry(entry->name, entry->mode, root);
 907         if (!p) {
 908                 up(&info_mutex);
 909                 return -ENOMEM;
 910         }
 911         p->owner = entry->module;
 912         if (!S_ISDIR(entry->mode))
 913                 p->proc_fops = &snd_info_entry_operations;
 914         p->size = entry->size;
 915         p->data = entry;
 916         entry->p = p;
 917         up(&info_mutex);
 918         return 0;
 919 }
 920
 921 /**
 922  * snd_info_unregister - de-register the info entry
 923  * @entry: the info entry
 924  *
 925  * De-registers the info entry and releases the instance.
 926  *
 927  * Returns zero if successful, or a negative error code on failure.
 928  */
 929 int snd_info_unregister(snd_info_entry_t * entry)
 930 {
 931         struct proc_dir_entry *root;
 932
 933         snd_assert(entry != NULL && entry->p != NULL, return -ENXIO);
 934         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 935         snd_assert(root, return -ENXIO);
 936         down(&info_mutex);
 937         snd_remove_proc_entry(root, entry->p);
 938         up(&info_mutex);
 939         snd_info_free_entry(entry);
 940         return 0;
 941 }
 942
 943 /*
 944
 945  */
 946
 947 static snd_info_entry_t *snd_info_version_entry = NULL;
 948
 949 static void snd_info_version_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 950 {
 951         static char *kernel_version = UTS_RELEASE;
 952
 953         snd_iprintf(buffer,
 954                     "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 955                     "Compiled on " __DATE__ " for kernel %s"
 956 #ifdef CONFIG_SMP
 957                     " (SMP)"
 958 #endif
 959 #ifdef MODVERSIONS
 960                     " with versioned symbols"
 961 #endif
 962                     ".\n", kernel_version);
 963 }
 964
 965 static int __init snd_info_version_init(void)
 966 {
 967         snd_info_entry_t *entry;
 968
 969         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 970         if (entry == NULL)
 971                 return -ENOMEM;
 972         entry->c.text.read_size = 256;
 973         entry->c.text.read = snd_info_version_read;
 974         if (snd_info_register(entry) < 0) {
 975                 snd_info_free_entry(entry);
 976                 return -ENOMEM;
 977         }
 978         snd_info_version_entry = entry;
 979         return 0;
 980 }
 981
 982 static int __exit snd_info_version_done(void)
 983 {
 984         if (snd_info_version_entry)
 985                 snd_info_unregister(snd_info_version_entry);
 986         return 0;
 987 }
 988
 989 #endif /* CONFIG_PROC_FS */