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 = file->private_data;
 143         entry = data->entry;
 144         lock_kernel();
 145         switch (entry->content) {
 146         case SNDRV_INFO_CONTENT_TEXT:
 147                 switch (orig) {
 148                 case 0: /* SEEK_SET */
 149                         file->f_pos = offset;
 150                         ret = file->f_pos;
 151                         goto out;
 152                 case 1: /* SEEK_CUR */
 153                         file->f_pos += offset;
 154                         ret = file->f_pos;
 155                         goto out;
 156                 case 2: /* SEEK_END */
 157                 default:
 158                         ret = -EINVAL;
 159                         goto out;
 160                 }
 161                 break;
 162         case SNDRV_INFO_CONTENT_DATA:
 163                 if (entry->c.ops->llseek) {
 164                         ret = entry->c.ops->llseek(entry,
 165                                                     data->file_private_data,
 166                                                     file, offset, orig);
 167                         goto out;
 168                 }
 169                 break;
 170         }
 171         ret = -ENXIO;
 172 out:
 173         unlock_kernel();
 174         return ret;
 175 }
 176
 177 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 178                                    size_t count, loff_t * offset)
 179 {
 180         snd_info_private_data_t *data;
 181         struct snd_info_entry *entry;
 182         snd_info_buffer_t *buf;
 183         size_t size = 0;
 184         loff_t pos;
 185
 186         data = file->private_data;
 187         snd_assert(data != NULL, return -ENXIO);
 188         pos = *offset;
 189         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 190                 return -EIO;
 191         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 192                 return -EIO;
 193         entry = data->entry;
 194         switch (entry->content) {
 195         case SNDRV_INFO_CONTENT_TEXT:
 196                 buf = data->rbuffer;
 197                 if (buf == NULL)
 198                         return -EIO;
 199                 if (pos >= buf->size)
 200                         return 0;
 201                 size = buf->size - pos;
 202                 size = min(count, size);
 203                 if (copy_to_user(buffer, buf->buffer + pos, size))
 204                         return -EFAULT;
 205                 break;
 206         case SNDRV_INFO_CONTENT_DATA:
 207                 if (entry->c.ops->read)
 208                         size = entry->c.ops->read(entry,
 209                                                   data->file_private_data,
 210                                                   file, buffer, count, pos);
 211                 break;
 212         }
 213         if ((ssize_t) size > 0)
 214                 *offset = pos + size;
 215         return size;
 216 }
 217
 218 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 219                                     size_t count, loff_t * offset)
 220 {
 221         snd_info_private_data_t *data;
 222         struct snd_info_entry *entry;
 223         snd_info_buffer_t *buf;
 224         size_t size = 0;
 225         loff_t pos;
 226
 227         data = file->private_data;
 228         snd_assert(data != NULL, return -ENXIO);
 229         entry = data->entry;
 230         pos = *offset;
 231         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 232                 return -EIO;
 233         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 234                 return -EIO;
 235         switch (entry->content) {
 236         case SNDRV_INFO_CONTENT_TEXT:
 237                 buf = data->wbuffer;
 238                 if (buf == NULL)
 239                         return -EIO;
 240                 if (pos >= buf->len)
 241                         return -ENOMEM;
 242                 size = buf->len - pos;
 243                 size = min(count, size);
 244                 if (copy_from_user(buf->buffer + pos, buffer, size))
 245                         return -EFAULT;
 246                 if ((long)buf->size < pos + size)
 247                         buf->size = pos + size;
 248                 break;
 249         case SNDRV_INFO_CONTENT_DATA:
 250                 if (entry->c.ops->write)
 251                         size = entry->c.ops->write(entry,
 252                                                    data->file_private_data,
 253                                                    file, buffer, count, pos);
 254                 break;
 255         }
 256         if ((ssize_t) size > 0)
 257                 *offset = pos + size;
 258         return size;
 259 }
 260
 261 static int snd_info_entry_open(struct inode *inode, struct file *file)
 262 {
 263         snd_info_entry_t *entry;
 264         snd_info_private_data_t *data;
 265         snd_info_buffer_t *buffer;
 266         struct proc_dir_entry *p;
 267         int mode, err;
 268
 269         down(&info_mutex);
 270         p = PDE(inode);
 271         entry = p == NULL ? NULL : (snd_info_entry_t *)p->data;
 272         if (entry == NULL || entry->disconnected) {
 273                 up(&info_mutex);
 274                 return -ENODEV;
 275         }
 276         if (!try_module_get(entry->module)) {
 277                 err = -EFAULT;
 278                 goto __error1;
 279         }
 280         mode = file->f_flags & O_ACCMODE;
 281         if (mode == O_RDONLY || mode == O_RDWR) {
 282                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 283                      !entry->c.text.read_size) ||
 284                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 285                      entry->c.ops->read == NULL)) {
 286                         err = -ENODEV;
 287                         goto __error;
 288                 }
 289         }
 290         if (mode == O_WRONLY || mode == O_RDWR) {
 291                 if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
 292                      !entry->c.text.write_size) ||
 293                     (entry->content == SNDRV_INFO_CONTENT_DATA &&
 294                      entry->c.ops->write == NULL)) {
 295                         err = -ENODEV;
 296                         goto __error;
 297                 }
 298         }
 299         data = kcalloc(1, sizeof(*data), GFP_KERNEL);
 300         if (data == NULL) {
 301                 err = -ENOMEM;
 302                 goto __error;
 303         }
 304         data->entry = entry;
 305         switch (entry->content) {
 306         case SNDRV_INFO_CONTENT_TEXT:
 307                 if (mode == O_RDONLY || mode == O_RDWR) {
 308                         buffer = kcalloc(1, sizeof(*buffer), GFP_KERNEL);
 309                         if (buffer == NULL) {
 310                                 kfree(data);
 311                                 err = -ENOMEM;
 312                                 goto __error;
 313                         }
 314                         buffer->len = (entry->c.text.read_size +
 315                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 316                         buffer->buffer = vmalloc(buffer->len);
 317                         if (buffer->buffer == NULL) {
 318                                 kfree(buffer);
 319                                 kfree(data);
 320                                 err = -ENOMEM;
 321                                 goto __error;
 322                         }
 323                         buffer->curr = buffer->buffer;
 324                         data->rbuffer = buffer;
 325                 }
 326                 if (mode == O_WRONLY || mode == O_RDWR) {
 327                         buffer = kcalloc(1, sizeof(*buffer), GFP_KERNEL);
 328                         if (buffer == NULL) {
 329                                 if (mode == O_RDWR) {
 330                                         vfree(data->rbuffer->buffer);
 331                                         kfree(data->rbuffer);
 332                                 }
 333                                 kfree(data);
 334                                 err = -ENOMEM;
 335                                 goto __error;
 336                         }
 337                         buffer->len = (entry->c.text.write_size +
 338                                       (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 339                         buffer->buffer = vmalloc(buffer->len);
 340                         if (buffer->buffer == NULL) {
 341                                 if (mode == O_RDWR) {
 342                                         vfree(data->rbuffer->buffer);
 343                                         kfree(data->rbuffer);
 344                                 }
 345                                 kfree(buffer);
 346                                 kfree(data);
 347                                 err = -ENOMEM;
 348                                 goto __error;
 349                         }
 350                         buffer->curr = buffer->buffer;
 351                         data->wbuffer = buffer;
 352                 }
 353                 break;
 354         case SNDRV_INFO_CONTENT_DATA:   /* data */
 355                 if (entry->c.ops->open) {
 356                         if ((err = entry->c.ops->open(entry, mode,
 357                                                       &data->file_private_data)) < 0) {
 358                                 kfree(data);
 359                                 goto __error;
 360                         }
 361                 }
 362                 break;
 363         }
 364         file->private_data = data;
 365         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 = file->private_data;
 391         entry = data->entry;
 392         switch (entry->content) {
 393         case SNDRV_INFO_CONTENT_TEXT:
 394                 if (mode == O_RDONLY || mode == O_RDWR) {
 395                         vfree(data->rbuffer->buffer);
 396                         kfree(data->rbuffer);
 397                 }
 398                 if (mode == O_WRONLY || mode == O_RDWR) {
 399                         if (entry->c.text.write) {
 400                                 entry->c.text.write(entry, data->wbuffer);
 401                                 if (data->wbuffer->error) {
 402                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 403                                                 entry->name,
 404                                                 data->wbuffer->error);
 405                                 }
 406                         }
 407                         vfree(data->wbuffer->buffer);
 408                         kfree(data->wbuffer);
 409                 }
 410                 break;
 411         case SNDRV_INFO_CONTENT_DATA:
 412                 if (entry->c.ops->release)
 413                         entry->c.ops->release(entry, mode,
 414                                               data->file_private_data);
 415                 break;
 416         }
 417         module_put(entry->module);
 418         kfree(data);
 419         return 0;
 420 }
 421
 422 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 423 {
 424         snd_info_private_data_t *data;
 425         struct snd_info_entry *entry;
 426         unsigned int mask;
 427
 428         data = file->private_data;
 429         if (data == NULL)
 430                 return 0;
 431         entry = data->entry;
 432         mask = 0;
 433         switch (entry->content) {
 434         case SNDRV_INFO_CONTENT_DATA:
 435                 if (entry->c.ops->poll)
 436                         return entry->c.ops->poll(entry,
 437                                                   data->file_private_data,
 438                                                   file, wait);
 439                 if (entry->c.ops->read)
 440                         mask |= POLLIN | POLLRDNORM;
 441                 if (entry->c.ops->write)
 442                         mask |= POLLOUT | POLLWRNORM;
 443                 break;
 444         }
 445         return mask;
 446 }
 447
 448 static inline 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 = file->private_data;
 455         if (data == NULL)
 456                 return 0;
 457         entry = data->entry;
 458         switch (entry->content) {
 459         case SNDRV_INFO_CONTENT_DATA:
 460                 if (entry->c.ops->ioctl)
 461                         return entry->c.ops->ioctl(entry,
 462                                                    data->file_private_data,
 463                                                    file, cmd, arg);
 464                 break;
 465         }
 466         return -ENOTTY;
 467 }
 468
 469 /* FIXME: need to unlock BKL to allow preemption */
 470 static int snd_info_entry_ioctl(struct inode *inode, struct file *file,
 471                                 unsigned int cmd, unsigned long arg)
 472 {
 473         int err;
 474         unlock_kernel();
 475         err = _snd_info_entry_ioctl(inode, file, cmd, arg);
 476         lock_kernel();
 477         return err;
 478 }
 479
 480 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 481 {
 482         struct inode *inode = file->f_dentry->d_inode;
 483         snd_info_private_data_t *data;
 484         struct snd_info_entry *entry;
 485
 486         data = file->private_data;
 487         if (data == NULL)
 488                 return 0;
 489         entry = data->entry;
 490         switch (entry->content) {
 491         case SNDRV_INFO_CONTENT_DATA:
 492                 if (entry->c.ops->mmap)
 493                         return entry->c.ops->mmap(entry,
 494                                                   data->file_private_data,
 495                                                   inode, file, vma);
 496                 break;
 497         }
 498         return -ENXIO;
 499 }
 500
 501 static struct file_operations snd_info_entry_operations =
 502 {
 503         .owner =        THIS_MODULE,
 504         .llseek =       snd_info_entry_llseek,
 505         .read =         snd_info_entry_read,
 506         .write =        snd_info_entry_write,
 507         .poll =         snd_info_entry_poll,
 508         .ioctl =        snd_info_entry_ioctl,
 509         .mmap =         snd_info_entry_mmap,
 510         .open =         snd_info_entry_open,
 511         .release =      snd_info_entry_release,
 512 };
 513
 514 /**
 515  * snd_create_proc_entry - create a procfs entry
 516  * @name: the name of the proc file
 517  * @mode: the file permission bits, S_Ixxx
 518  * @parent: the parent proc-directory entry
 519  *
 520  * Creates a new proc file entry with the given name and permission
 521  * on the given directory.
 522  *
 523  * Returns the pointer of new instance or NULL on failure.
 524  */
 525 struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 526                                              struct proc_dir_entry *parent)
 527 {
 528         struct proc_dir_entry *p;
 529         p = create_proc_entry(name, mode, parent);
 530         if (p)
 531                 snd_info_entry_prepare(p);
 532         return p;
 533 }
 534
 535 int __init snd_info_init(void)
 536 {
 537         struct proc_dir_entry *p;
 538
 539         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 540         if (p == NULL)
 541                 return -ENOMEM;
 542         snd_proc_root = p;
 543 #ifdef CONFIG_SND_OSSEMUL
 544         {
 545                 snd_info_entry_t *entry;
 546                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 547                         return -ENOMEM;
 548                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 549                 if (snd_info_register(entry) < 0) {
 550                         snd_info_free_entry(entry);
 551                         return -ENOMEM;
 552                 }
 553                 snd_oss_root = entry;
 554         }
 555 #endif
 556 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 557         {
 558                 snd_info_entry_t *entry;
 559                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 560                         return -ENOMEM;
 561                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 562                 if (snd_info_register(entry) < 0) {
 563                         snd_info_free_entry(entry);
 564                         return -ENOMEM;
 565                 }
 566                 snd_seq_root = entry;
 567         }
 568 #endif
 569         snd_info_version_init();
 570         snd_memory_info_init();
 571         snd_minor_info_init();
 572         snd_minor_info_oss_init();
 573         snd_card_info_init();
 574         return 0;
 575 }
 576
 577 int __exit snd_info_done(void)
 578 {
 579         snd_card_info_done();
 580         snd_minor_info_oss_done();
 581         snd_minor_info_done();
 582         snd_memory_info_done();
 583         snd_info_version_done();
 584         if (snd_proc_root) {
 585 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 586                 if (snd_seq_root)
 587                         snd_info_unregister(snd_seq_root);
 588 #endif
 589 #ifdef CONFIG_SND_OSSEMUL
 590                 if (snd_oss_root)
 591                         snd_info_unregister(snd_oss_root);
 592 #endif
 593                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 594         }
 595         return 0;
 596 }
 597
 598 /*
 599
 600  */
 601
 602
 603 /*
 604  * create a card proc file
 605  * called from init.c
 606  */
 607 int snd_info_card_create(snd_card_t * card)
 608 {
 609         char str[8];
 610         snd_info_entry_t *entry;
 611
 612         snd_assert(card != NULL, return -ENXIO);
 613
 614         sprintf(str, "card%i", card->number);
 615         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 616                 return -ENOMEM;
 617         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 618         if (snd_info_register(entry) < 0) {
 619                 snd_info_free_entry(entry);
 620                 return -ENOMEM;
 621         }
 622         card->proc_root = entry;
 623         return 0;
 624 }
 625
 626 /*
 627  * register the card proc file
 628  * called from init.c
 629  */
 630 int snd_info_card_register(snd_card_t * card)
 631 {
 632         struct proc_dir_entry *p;
 633
 634         snd_assert(card != NULL, return -ENXIO);
 635
 636         if (!strcmp(card->id, card->proc_root->name))
 637                 return 0;
 638
 639         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 640         if (p == NULL)
 641                 return -ENOMEM;
 642         card->proc_root_link = p;
 643         return 0;
 644 }
 645
 646 /*
 647  * de-register the card proc file
 648  * called from init.c
 649  */
 650 int snd_info_card_free(snd_card_t * card)
 651 {
 652         snd_assert(card != NULL, return -ENXIO);
 653         if (card->proc_root_link) {
 654                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 655                 card->proc_root_link = NULL;
 656         }
 657         if (card->proc_root) {
 658                 snd_info_unregister(card->proc_root);
 659                 card->proc_root = NULL;
 660         }
 661         return 0;
 662 }
 663
 664
 665 /**
 666  * snd_info_get_line - read one line from the procfs buffer
 667  * @buffer: the procfs buffer
 668  * @line: the buffer to store
 669  * @len: the max. buffer size - 1
 670  *
 671  * Reads one line from the buffer and stores the string.
 672  *
 673  * Returns zero if successful, or 1 if error or EOF.
 674  */
 675 int snd_info_get_line(snd_info_buffer_t * buffer, char *line, int len)
 676 {
 677         int c = -1;
 678
 679         if (len <= 0 || buffer->stop || buffer->error)
 680                 return 1;
 681         while (--len > 0) {
 682                 c = *buffer->curr++;
 683                 if (c == '\n') {
 684                         if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 685                                 buffer->stop = 1;
 686                         }
 687                         break;
 688                 }
 689                 *line++ = c;
 690                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 691                         buffer->stop = 1;
 692                         break;
 693                 }
 694         }
 695         while (c != '\n' && !buffer->stop) {
 696                 c = *buffer->curr++;
 697                 if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
 698                         buffer->stop = 1;
 699                 }
 700         }
 701         *line = '\0';
 702         return 0;
 703 }
 704
 705 /**
 706  * snd_info_get_line - parse a string token
 707  * @dest: the buffer to store the string token
 708  * @src: the original string
 709  * @len: the max. length of token - 1
 710  *
 711  * Parses the original string and copy a token to the given
 712  * string buffer.
 713  *
 714  * Returns the updated pointer of the original string so that
 715  * it can be used for the next call.
 716  */
 717 char *snd_info_get_str(char *dest, char *src, int len)
 718 {
 719         int c;
 720
 721         while (*src == ' ' || *src == '\t')
 722                 src++;
 723         if (*src == '"' || *src == '\'') {
 724                 c = *src++;
 725                 while (--len > 0 && *src && *src != c) {
 726                         *dest++ = *src++;
 727                 }
 728                 if (*src == c)
 729                         src++;
 730         } else {
 731                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 732                         *dest++ = *src++;
 733                 }
 734         }
 735         *dest = 0;
 736         while (*src == ' ' || *src == '\t')
 737                 src++;
 738         return src;
 739 }
 740
 741 /**
 742  * snd_info_create_entry - create an info entry
 743  * @name: the proc file name
 744  *
 745  * Creates an info entry with the given file name and initializes as
 746  * the default state.
 747  *
 748  * Usually called from other functions such as
 749  * snd_info_create_card_entry().
 750  *
 751  * Returns the pointer of the new instance, or NULL on failure.
 752  */
 753 static snd_info_entry_t *snd_info_create_entry(const char *name)
 754 {
 755         snd_info_entry_t *entry;
 756         entry = kcalloc(1, sizeof(*entry), GFP_KERNEL);
 757         if (entry == NULL)
 758                 return NULL;
 759         entry->name = snd_kmalloc_strdup(name, GFP_KERNEL);
 760         if (entry->name == NULL) {
 761                 kfree(entry);
 762                 return NULL;
 763         }
 764         entry->mode = S_IFREG | S_IRUGO;
 765         entry->content = SNDRV_INFO_CONTENT_TEXT;
 766         init_MUTEX(&entry->access);
 767         return entry;
 768 }
 769
 770 /**
 771  * snd_info_create_module_entry - create an info entry for the given module
 772  * @module: the module pointer
 773  * @name: the file name
 774  * @parent: the parent directory
 775  *
 776  * Creates a new info entry and assigns it to the given module.
 777  *
 778  * Returns the pointer of the new instance, or NULL on failure.
 779  */
 780 snd_info_entry_t *snd_info_create_module_entry(struct module * module,
 781                                                const char *name,
 782                                                snd_info_entry_t *parent)
 783 {
 784         snd_info_entry_t *entry = snd_info_create_entry(name);
 785         if (entry) {
 786                 entry->module = module;
 787                 entry->parent = parent;
 788         }
 789         return entry;
 790 }
 791
 792 /**
 793  * snd_info_create_card_entry - create an info entry for the given card
 794  * @card: the card instance
 795  * @name: the file name
 796  * @parent: the parent directory
 797  *
 798  * Creates a new info entry and assigns it to the given card.
 799  *
 800  * Returns the pointer of the new instance, or NULL on failure.
 801  */
 802 snd_info_entry_t *snd_info_create_card_entry(snd_card_t * card,
 803                                              const char *name,
 804                                              snd_info_entry_t * parent)
 805 {
 806         snd_info_entry_t *entry = snd_info_create_entry(name);
 807         if (entry) {
 808                 entry->module = card->module;
 809                 entry->card = card;
 810                 entry->parent = parent;
 811         }
 812         return entry;
 813 }
 814
 815 static int snd_info_dev_free_entry(snd_device_t *device)
 816 {
 817         snd_info_entry_t *entry = device->device_data;
 818         snd_info_free_entry(entry);
 819         return 0;
 820 }
 821
 822 static int snd_info_dev_register_entry(snd_device_t *device)
 823 {
 824         snd_info_entry_t *entry = device->device_data;
 825         return snd_info_register(entry);
 826 }
 827
 828 static int snd_info_dev_disconnect_entry(snd_device_t *device)
 829 {
 830         snd_info_entry_t *entry = device->device_data;
 831         entry->disconnected = 1;
 832         return 0;
 833 }
 834
 835 static int snd_info_dev_unregister_entry(snd_device_t *device)
 836 {
 837         snd_info_entry_t *entry = device->device_data;
 838         return snd_info_unregister(entry);
 839 }
 840
 841 /**
 842  * snd_card_proc_new - create an info entry for the given card
 843  * @card: the card instance
 844  * @name: the file name
 845  * @entryp: the pointer to store the new info entry
 846  *
 847  * Creates a new info entry and assigns it to the given card.
 848  * Unlike snd_info_create_card_entry(), this function registers the
 849  * info entry as an ALSA device component, so that it can be
 850  * unregistered/released without explicit call.
 851  * Also, you don't have to register this entry via snd_info_register(),
 852  * since this will be registered by snd_card_register() automatically.
 853  *
 854  * The parent is assumed as card->proc_root.
 855  *
 856  * For releasing this entry, use snd_device_free() instead of
 857  * snd_info_free_entry().
 858  *
 859  * Returns zero if successful, or a negative error code on failure.
 860  */
 861 int snd_card_proc_new(snd_card_t *card, const char *name,
 862                       snd_info_entry_t **entryp)
 863 {
 864         static snd_device_ops_t ops = {
 865                 .dev_free = snd_info_dev_free_entry,
 866                 .dev_register = snd_info_dev_register_entry,
 867                 .dev_disconnect = snd_info_dev_disconnect_entry,
 868                 .dev_unregister = snd_info_dev_unregister_entry
 869         };
 870         snd_info_entry_t *entry;
 871         int err;
 872
 873         entry = snd_info_create_card_entry(card, name, card->proc_root);
 874         if (! entry)
 875                 return -ENOMEM;
 876         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 877                 snd_info_free_entry(entry);
 878                 return err;
 879         }
 880         if (entryp)
 881                 *entryp = entry;
 882         return 0;
 883 }
 884
 885 /**
 886  * snd_info_free_entry - release the info entry
 887  * @entry: the info entry
 888  *
 889  * Releases the info entry.  Don't call this after registered.
 890  */
 891 void snd_info_free_entry(snd_info_entry_t * entry)
 892 {
 893         if (entry == NULL)
 894                 return;
 895         if (entry->name)
 896                 kfree((char *)entry->name);
 897         if (entry->private_free)
 898                 entry->private_free(entry);
 899         kfree(entry);
 900 }
 901
 902 /**
 903  * snd_info_register - register the info entry
 904  * @entry: the info entry
 905  *
 906  * Registers the proc info entry.
 907  *
 908  * Returns zero if successful, or a negative error code on failure.
 909  */
 910 int snd_info_register(snd_info_entry_t * entry)
 911 {
 912         struct proc_dir_entry *root, *p = NULL;
 913
 914         snd_assert(entry != NULL, return -ENXIO);
 915         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 916         down(&info_mutex);
 917         p = snd_create_proc_entry(entry->name, entry->mode, root);
 918         if (!p) {
 919                 up(&info_mutex);
 920                 return -ENOMEM;
 921         }
 922         p->owner = entry->module;
 923         if (!S_ISDIR(entry->mode))
 924                 p->proc_fops = &snd_info_entry_operations;
 925         p->size = entry->size;
 926         p->data = entry;
 927         entry->p = p;
 928         up(&info_mutex);
 929         return 0;
 930 }
 931
 932 /**
 933  * snd_info_unregister - de-register the info entry
 934  * @entry: the info entry
 935  *
 936  * De-registers the info entry and releases the instance.
 937  *
 938  * Returns zero if successful, or a negative error code on failure.
 939  */
 940 int snd_info_unregister(snd_info_entry_t * entry)
 941 {
 942         struct proc_dir_entry *root;
 943
 944         snd_assert(entry != NULL && entry->p != NULL, return -ENXIO);
 945         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 946         snd_assert(root, return -ENXIO);
 947         down(&info_mutex);
 948         snd_remove_proc_entry(root, entry->p);
 949         up(&info_mutex);
 950         snd_info_free_entry(entry);
 951         return 0;
 952 }
 953
 954 /*
 955
 956  */
 957
 958 static snd_info_entry_t *snd_info_version_entry = NULL;
 959
 960 static void snd_info_version_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 961 {
 962         static char *kernel_version = UTS_RELEASE;
 963
 964         snd_iprintf(buffer,
 965                     "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 966                     "Compiled on " __DATE__ " for kernel %s"
 967 #ifdef CONFIG_SMP
 968                     " (SMP)"
 969 #endif
 970 #ifdef MODVERSIONS
 971                     " with versioned symbols"
 972 #endif
 973                     ".\n", kernel_version);
 974 }
 975
 976 static int __init snd_info_version_init(void)
 977 {
 978         snd_info_entry_t *entry;
 979
 980         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 981         if (entry == NULL)
 982                 return -ENOMEM;
 983         entry->c.text.read_size = 256;
 984         entry->c.text.read = snd_info_version_read;
 985         if (snd_info_register(entry) < 0) {
 986                 snd_info_free_entry(entry);
 987                 return -ENOMEM;
 988         }
 989         snd_info_version_entry = entry;
 990         return 0;
 991 }
 992
 993 static int __exit snd_info_version_done(void)
 994 {
 995         if (snd_info_version_entry)
 996                 snd_info_unregister(snd_info_version_entry);
 997         return 0;
 998 }
 999
1000 #endif /* CONFIG_PROC_FS */