sound/core/info.c

   1 /*
   2  *  Information interface for ALSA driver
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/time.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/string.h>
  27 #include <sound/core.h>
  28 #include <sound/minors.h>
  29 #include <sound/info.h>
  30 #include <sound/version.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/mutex.h>
  33 #include <stdarg.h>
  34
  35 /*
  36  *
  37  */
  38
  39 #ifdef CONFIG_PROC_FS
  40
  41 int snd_info_check_reserved_words(const char *str)
  42 {
  43         static char *reserved[] =
  44         {
  45                 "version",
  46                 "meminfo",
  47                 "memdebug",
  48                 "detect",
  49                 "devices",
  50                 "oss",
  51                 "cards",
  52                 "timers",
  53                 "synth",
  54                 "pcm",
  55                 "seq",
  56                 NULL
  57         };
  58         char **xstr = reserved;
  59
  60         while (*xstr) {
  61                 if (!strcmp(*xstr, str))
  62                         return 0;
  63                 xstr++;
  64         }
  65         if (!strncmp(str, "card", 4))
  66                 return 0;
  67         return 1;
  68 }
  69
  70 static DEFINE_MUTEX(info_mutex);
  71
  72 struct snd_info_private_data {
  73         struct snd_info_buffer *rbuffer;
  74         struct snd_info_buffer *wbuffer;
  75         struct snd_info_entry *entry;
  76         void *file_private_data;
  77 };
  78
  79 static int snd_info_version_init(void);
  80 static int snd_info_version_done(void);
  81
  82
  83 /* resize the proc r/w buffer */
  84 static int resize_info_buffer(struct snd_info_buffer *buffer,
  85                               unsigned int nsize)
  86 {
  87         char *nbuf;
  88
  89         nsize = PAGE_ALIGN(nsize);
  90         nbuf = kmalloc(nsize, GFP_KERNEL);
  91         if (! nbuf)
  92                 return -ENOMEM;
  93
  94         memcpy(nbuf, buffer->buffer, buffer->len);
  95         kfree(buffer->buffer);
  96         buffer->buffer = nbuf;
  97         buffer->len = nsize;
  98         return 0;
  99 }
 100
 101 /**
 102  * snd_iprintf - printf on the procfs buffer
 103  * @buffer: the procfs buffer
 104  * @fmt: the printf format
 105  *
 106  * Outputs the string on the procfs buffer just like printf().
 107  *
 108  * Returns the size of output string.
 109  */
 110 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
 111 {
 112         va_list args;
 113         int len, res;
 114         int err = 0;
 115
 116         might_sleep();
 117         if (buffer->stop || buffer->error)
 118                 return 0;
 119         len = buffer->len - buffer->size;
 120         va_start(args, fmt);
 121         for (;;) {
 122                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, args);
 123                 if (res < len)
 124                         break;
 125                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
 126                 if (err < 0)
 127                         break;
 128                 len = buffer->len - buffer->size;
 129         }
 130         va_end(args);
 131
 132         if (err < 0)
 133                 return err;
 134         buffer->curr += res;
 135         buffer->size += res;
 136         return res;
 137 }
 138
 139 EXPORT_SYMBOL(snd_iprintf);
 140
 141 /*
 142
 143  */
 144
 145 static struct proc_dir_entry *snd_proc_root;
 146 struct snd_info_entry *snd_seq_root;
 147 EXPORT_SYMBOL(snd_seq_root);
 148
 149 #ifdef CONFIG_SND_OSSEMUL
 150 struct snd_info_entry *snd_oss_root;
 151 #endif
 152
 153 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 154 {
 155         de->owner = THIS_MODULE;
 156 }
 157
 158 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 159                                   struct proc_dir_entry *de)
 160 {
 161         if (de)
 162                 remove_proc_entry(de->name, parent);
 163 }
 164
 165 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 166 {
 167         struct snd_info_private_data *data;
 168         struct snd_info_entry *entry;
 169         loff_t ret;
 170
 171         data = file->private_data;
 172         entry = data->entry;
 173         lock_kernel();
 174         switch (entry->content) {
 175         case SNDRV_INFO_CONTENT_TEXT:
 176                 switch (orig) {
 177                 case 0: /* SEEK_SET */
 178                         file->f_pos = offset;
 179                         ret = file->f_pos;
 180                         goto out;
 181                 case 1: /* SEEK_CUR */
 182                         file->f_pos += offset;
 183                         ret = file->f_pos;
 184                         goto out;
 185                 case 2: /* SEEK_END */
 186                 default:
 187                         ret = -EINVAL;
 188                         goto out;
 189                 }
 190                 break;
 191         case SNDRV_INFO_CONTENT_DATA:
 192                 if (entry->c.ops->llseek) {
 193                         ret = entry->c.ops->llseek(entry,
 194                                                     data->file_private_data,
 195                                                     file, offset, orig);
 196                         goto out;
 197                 }
 198                 break;
 199         }
 200         ret = -ENXIO;
 201 out:
 202         unlock_kernel();
 203         return ret;
 204 }
 205
 206 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 207                                    size_t count, loff_t * offset)
 208 {
 209         struct snd_info_private_data *data;
 210         struct snd_info_entry *entry;
 211         struct snd_info_buffer *buf;
 212         size_t size = 0;
 213         loff_t pos;
 214
 215         data = file->private_data;
 216         snd_assert(data != NULL, return -ENXIO);
 217         pos = *offset;
 218         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 219                 return -EIO;
 220         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 221                 return -EIO;
 222         entry = data->entry;
 223         switch (entry->content) {
 224         case SNDRV_INFO_CONTENT_TEXT:
 225                 buf = data->rbuffer;
 226                 if (buf == NULL)
 227                         return -EIO;
 228                 if (pos >= buf->size)
 229                         return 0;
 230                 size = buf->size - pos;
 231                 size = min(count, size);
 232                 if (copy_to_user(buffer, buf->buffer + pos, size))
 233                         return -EFAULT;
 234                 break;
 235         case SNDRV_INFO_CONTENT_DATA:
 236                 if (entry->c.ops->read)
 237                         size = entry->c.ops->read(entry,
 238                                                   data->file_private_data,
 239                                                   file, buffer, count, pos);
 240                 break;
 241         }
 242         if ((ssize_t) size > 0)
 243                 *offset = pos + size;
 244         return size;
 245 }
 246
 247 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 248                                     size_t count, loff_t * offset)
 249 {
 250         struct snd_info_private_data *data;
 251         struct snd_info_entry *entry;
 252         struct snd_info_buffer *buf;
 253         ssize_t size = 0;
 254         loff_t pos;
 255
 256         data = file->private_data;
 257         snd_assert(data != NULL, return -ENXIO);
 258         entry = data->entry;
 259         pos = *offset;
 260         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 261                 return -EIO;
 262         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 263                 return -EIO;
 264         switch (entry->content) {
 265         case SNDRV_INFO_CONTENT_TEXT:
 266                 buf = data->wbuffer;
 267                 if (buf == NULL)
 268                         return -EIO;
 269                 mutex_lock(&entry->access);
 270                 if (pos + count >= buf->len) {
 271                         if (resize_info_buffer(buf, pos + count)) {
 272                                 mutex_unlock(&entry->access);
 273                                 return -ENOMEM;
 274                         }
 275                 }
 276                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
 277                         mutex_unlock(&entry->access);
 278                         return -EFAULT;
 279                 }
 280                 buf->size = pos + count;
 281                 mutex_unlock(&entry->access);
 282                 size = count;
 283                 break;
 284         case SNDRV_INFO_CONTENT_DATA:
 285                 if (entry->c.ops->write)
 286                         size = entry->c.ops->write(entry,
 287                                                    data->file_private_data,
 288                                                    file, buffer, count, pos);
 289                 break;
 290         }
 291         if ((ssize_t) size > 0)
 292                 *offset = pos + size;
 293         return size;
 294 }
 295
 296 static int snd_info_entry_open(struct inode *inode, struct file *file)
 297 {
 298         struct snd_info_entry *entry;
 299         struct snd_info_private_data *data;
 300         struct snd_info_buffer *buffer;
 301         struct proc_dir_entry *p;
 302         int mode, err;
 303
 304         mutex_lock(&info_mutex);
 305         p = PDE(inode);
 306         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 307         if (entry == NULL || entry->disconnected) {
 308                 mutex_unlock(&info_mutex);
 309                 return -ENODEV;
 310         }
 311         if (!try_module_get(entry->module)) {
 312                 err = -EFAULT;
 313                 goto __error1;
 314         }
 315         mode = file->f_flags & O_ACCMODE;
 316         if (mode == O_RDONLY || mode == O_RDWR) {
 317                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 318                      entry->c.ops->read == NULL)) {
 319                         err = -ENODEV;
 320                         goto __error;
 321                 }
 322         }
 323         if (mode == O_WRONLY || mode == O_RDWR) {
 324                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 325                      entry->c.ops->write == NULL)) {
 326                         err = -ENODEV;
 327                         goto __error;
 328                 }
 329         }
 330         data = kzalloc(sizeof(*data), GFP_KERNEL);
 331         if (data == NULL) {
 332                 err = -ENOMEM;
 333                 goto __error;
 334         }
 335         data->entry = entry;
 336         switch (entry->content) {
 337         case SNDRV_INFO_CONTENT_TEXT:
 338                 if (mode == O_RDONLY || mode == O_RDWR) {
 339                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 340                         if (buffer == NULL)
 341                                 goto __nomem;
 342                         data->rbuffer = buffer;
 343                         buffer->len = PAGE_SIZE;
 344                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 345                         if (buffer->buffer == NULL)
 346                                 goto __nomem;
 347                 }
 348                 if (mode == O_WRONLY || mode == O_RDWR) {
 349                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 350                         if (buffer == NULL)
 351                                 goto __nomem;
 352                         data->wbuffer = buffer;
 353                         buffer->len = PAGE_SIZE;
 354                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 355                         if (buffer->buffer == NULL)
 356                                 goto __nomem;
 357                 }
 358                 break;
 359         case SNDRV_INFO_CONTENT_DATA:   /* data */
 360                 if (entry->c.ops->open) {
 361                         if ((err = entry->c.ops->open(entry, mode,
 362                                                       &data->file_private_data)) < 0) {
 363                                 kfree(data);
 364                                 goto __error;
 365                         }
 366                 }
 367                 break;
 368         }
 369         file->private_data = data;
 370         mutex_unlock(&info_mutex);
 371         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 372             (mode == O_RDONLY || mode == O_RDWR)) {
 373                 if (entry->c.text.read) {
 374                         mutex_lock(&entry->access);
 375                         entry->c.text.read(entry, data->rbuffer);
 376                         mutex_unlock(&entry->access);
 377                 }
 378         }
 379         return 0;
 380
 381  __nomem:
 382         if (data->rbuffer) {
 383                 kfree(data->rbuffer->buffer);
 384                 kfree(data->rbuffer);
 385         }
 386         if (data->wbuffer) {
 387                 kfree(data->wbuffer->buffer);
 388                 kfree(data->wbuffer);
 389         }
 390         kfree(data);
 391         err = -ENOMEM;
 392       __error:
 393         module_put(entry->module);
 394       __error1:
 395         mutex_unlock(&info_mutex);
 396         return err;
 397 }
 398
 399 static int snd_info_entry_release(struct inode *inode, struct file *file)
 400 {
 401         struct snd_info_entry *entry;
 402         struct snd_info_private_data *data;
 403         int mode;
 404
 405         mode = file->f_flags & O_ACCMODE;
 406         data = file->private_data;
 407         entry = data->entry;
 408         switch (entry->content) {
 409         case SNDRV_INFO_CONTENT_TEXT:
 410                 if (data->rbuffer) {
 411                         kfree(data->rbuffer->buffer);
 412                         kfree(data->rbuffer);
 413                 }
 414                 if (data->wbuffer) {
 415                         if (entry->c.text.write) {
 416                                 entry->c.text.write(entry, data->wbuffer);
 417                                 if (data->wbuffer->error) {
 418                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 419                                                 entry->name,
 420                                                 data->wbuffer->error);
 421                                 }
 422                         }
 423                         kfree(data->wbuffer->buffer);
 424                         kfree(data->wbuffer);
 425                 }
 426                 break;
 427         case SNDRV_INFO_CONTENT_DATA:
 428                 if (entry->c.ops->release)
 429                         entry->c.ops->release(entry, mode,
 430                                               data->file_private_data);
 431                 break;
 432         }
 433         module_put(entry->module);
 434         kfree(data);
 435         return 0;
 436 }
 437
 438 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 439 {
 440         struct snd_info_private_data *data;
 441         struct snd_info_entry *entry;
 442         unsigned int mask;
 443
 444         data = file->private_data;
 445         if (data == NULL)
 446                 return 0;
 447         entry = data->entry;
 448         mask = 0;
 449         switch (entry->content) {
 450         case SNDRV_INFO_CONTENT_DATA:
 451                 if (entry->c.ops->poll)
 452                         return entry->c.ops->poll(entry,
 453                                                   data->file_private_data,
 454                                                   file, wait);
 455                 if (entry->c.ops->read)
 456                         mask |= POLLIN | POLLRDNORM;
 457                 if (entry->c.ops->write)
 458                         mask |= POLLOUT | POLLWRNORM;
 459                 break;
 460         }
 461         return mask;
 462 }
 463
 464 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 465                                 unsigned long arg)
 466 {
 467         struct snd_info_private_data *data;
 468         struct snd_info_entry *entry;
 469
 470         data = file->private_data;
 471         if (data == NULL)
 472                 return 0;
 473         entry = data->entry;
 474         switch (entry->content) {
 475         case SNDRV_INFO_CONTENT_DATA:
 476                 if (entry->c.ops->ioctl)
 477                         return entry->c.ops->ioctl(entry,
 478                                                    data->file_private_data,
 479                                                    file, cmd, arg);
 480                 break;
 481         }
 482         return -ENOTTY;
 483 }
 484
 485 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 486 {
 487         struct inode *inode = file->f_dentry->d_inode;
 488         struct snd_info_private_data *data;
 489         struct snd_info_entry *entry;
 490
 491         data = file->private_data;
 492         if (data == NULL)
 493                 return 0;
 494         entry = data->entry;
 495         switch (entry->content) {
 496         case SNDRV_INFO_CONTENT_DATA:
 497                 if (entry->c.ops->mmap)
 498                         return entry->c.ops->mmap(entry,
 499                                                   data->file_private_data,
 500                                                   inode, file, vma);
 501                 break;
 502         }
 503         return -ENXIO;
 504 }
 505
 506 static struct file_operations snd_info_entry_operations =
 507 {
 508         .owner =                THIS_MODULE,
 509         .llseek =               snd_info_entry_llseek,
 510         .read =                 snd_info_entry_read,
 511         .write =                snd_info_entry_write,
 512         .poll =                 snd_info_entry_poll,
 513         .unlocked_ioctl =       snd_info_entry_ioctl,
 514         .mmap =                 snd_info_entry_mmap,
 515         .open =                 snd_info_entry_open,
 516         .release =              snd_info_entry_release,
 517 };
 518
 519 /**
 520  * snd_create_proc_entry - create a procfs entry
 521  * @name: the name of the proc file
 522  * @mode: the file permission bits, S_Ixxx
 523  * @parent: the parent proc-directory entry
 524  *
 525  * Creates a new proc file entry with the given name and permission
 526  * on the given directory.
 527  *
 528  * Returns the pointer of new instance or NULL on failure.
 529  */
 530 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 531                                                     struct proc_dir_entry *parent)
 532 {
 533         struct proc_dir_entry *p;
 534         p = create_proc_entry(name, mode, parent);
 535         if (p)
 536                 snd_info_entry_prepare(p);
 537         return p;
 538 }
 539
 540 int __init snd_info_init(void)
 541 {
 542         struct proc_dir_entry *p;
 543
 544         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
 545         if (p == NULL)
 546                 return -ENOMEM;
 547         snd_proc_root = p;
 548 #ifdef CONFIG_SND_OSSEMUL
 549         {
 550                 struct snd_info_entry *entry;
 551                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 552                         return -ENOMEM;
 553                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 554                 if (snd_info_register(entry) < 0) {
 555                         snd_info_free_entry(entry);
 556                         return -ENOMEM;
 557                 }
 558                 snd_oss_root = entry;
 559         }
 560 #endif
 561 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 562         {
 563                 struct snd_info_entry *entry;
 564                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 565                         return -ENOMEM;
 566                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 567                 if (snd_info_register(entry) < 0) {
 568                         snd_info_free_entry(entry);
 569                         return -ENOMEM;
 570                 }
 571                 snd_seq_root = entry;
 572         }
 573 #endif
 574         snd_info_version_init();
 575         snd_minor_info_init();
 576         snd_minor_info_oss_init();
 577         snd_card_info_init();
 578         return 0;
 579 }
 580
 581 int __exit snd_info_done(void)
 582 {
 583         snd_card_info_done();
 584         snd_minor_info_oss_done();
 585         snd_minor_info_done();
 586         snd_info_version_done();
 587         if (snd_proc_root) {
 588 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 589                 snd_info_unregister(snd_seq_root);
 590 #endif
 591 #ifdef CONFIG_SND_OSSEMUL
 592                 snd_info_unregister(snd_oss_root);
 593 #endif
 594                 snd_remove_proc_entry(&proc_root, snd_proc_root);
 595         }
 596         return 0;
 597 }
 598
 599 /*
 600
 601  */
 602
 603
 604 /*
 605  * create a card proc file
 606  * called from init.c
 607  */
 608 int snd_info_card_create(struct snd_card *card)
 609 {
 610         char str[8];
 611         struct snd_info_entry *entry;
 612
 613         snd_assert(card != NULL, return -ENXIO);
 614
 615         sprintf(str, "card%i", card->number);
 616         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 617                 return -ENOMEM;
 618         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 619         if (snd_info_register(entry) < 0) {
 620                 snd_info_free_entry(entry);
 621                 return -ENOMEM;
 622         }
 623         card->proc_root = entry;
 624         return 0;
 625 }
 626
 627 /*
 628  * register the card proc file
 629  * called from init.c
 630  */
 631 int snd_info_card_register(struct snd_card *card)
 632 {
 633         struct proc_dir_entry *p;
 634
 635         snd_assert(card != NULL, return -ENXIO);
 636
 637         if (!strcmp(card->id, card->proc_root->name))
 638                 return 0;
 639
 640         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 641         if (p == NULL)
 642                 return -ENOMEM;
 643         card->proc_root_link = p;
 644         return 0;
 645 }
 646
 647 /*
 648  * de-register the card proc file
 649  * called from init.c
 650  */
 651 int snd_info_card_free(struct snd_card *card)
 652 {
 653         snd_assert(card != NULL, return -ENXIO);
 654         if (card->proc_root_link) {
 655                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 656                 card->proc_root_link = NULL;
 657         }
 658         if (card->proc_root) {
 659                 snd_info_unregister(card->proc_root);
 660                 card->proc_root = NULL;
 661         }
 662         return 0;
 663 }
 664
 665
 666 /**
 667  * snd_info_get_line - read one line from the procfs buffer
 668  * @buffer: the procfs buffer
 669  * @line: the buffer to store
 670  * @len: the max. buffer size - 1
 671  *
 672  * Reads one line from the buffer and stores the string.
 673  *
 674  * Returns zero if successful, or 1 if error or EOF.
 675  */
 676 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 677 {
 678         int c = -1;
 679
 680         if (len <= 0 || buffer->stop || buffer->error)
 681                 return 1;
 682         while (--len > 0) {
 683                 c = buffer->buffer[buffer->curr++];
 684                 if (c == '\n') {
 685                         if (buffer->curr >= buffer->size)
 686                                 buffer->stop = 1;
 687                         break;
 688                 }
 689                 *line++ = c;
 690                 if (buffer->curr >= buffer->size) {
 691                         buffer->stop = 1;
 692                         break;
 693                 }
 694         }
 695         while (c != '\n' && !buffer->stop) {
 696                 c = buffer->buffer[buffer->curr++];
 697                 if (buffer->curr >= buffer->size)
 698                         buffer->stop = 1;
 699         }
 700         *line = '\0';
 701         return 0;
 702 }
 703
 704 EXPORT_SYMBOL(snd_info_get_line);
 705
 706 /**
 707  * snd_info_get_str - parse a string token
 708  * @dest: the buffer to store the string token
 709  * @src: the original string
 710  * @len: the max. length of token - 1
 711  *
 712  * Parses the original string and copy a token to the given
 713  * string buffer.
 714  *
 715  * Returns the updated pointer of the original string so that
 716  * it can be used for the next call.
 717  */
 718 char *snd_info_get_str(char *dest, char *src, int len)
 719 {
 720         int c;
 721
 722         while (*src == ' ' || *src == '\t')
 723                 src++;
 724         if (*src == '"' || *src == '\'') {
 725                 c = *src++;
 726                 while (--len > 0 && *src && *src != c) {
 727                         *dest++ = *src++;
 728                 }
 729                 if (*src == c)
 730                         src++;
 731         } else {
 732                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 733                         *dest++ = *src++;
 734                 }
 735         }
 736         *dest = 0;
 737         while (*src == ' ' || *src == '\t')
 738                 src++;
 739         return src;
 740 }
 741
 742 EXPORT_SYMBOL(snd_info_get_str);
 743
 744 /**
 745  * snd_info_create_entry - create an info entry
 746  * @name: the proc file name
 747  *
 748  * Creates an info entry with the given file name and initializes as
 749  * the default state.
 750  *
 751  * Usually called from other functions such as
 752  * snd_info_create_card_entry().
 753  *
 754  * Returns the pointer of the new instance, or NULL on failure.
 755  */
 756 static struct snd_info_entry *snd_info_create_entry(const char *name)
 757 {
 758         struct snd_info_entry *entry;
 759         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 760         if (entry == NULL)
 761                 return NULL;
 762         entry->name = kstrdup(name, GFP_KERNEL);
 763         if (entry->name == NULL) {
 764                 kfree(entry);
 765                 return NULL;
 766         }
 767         entry->mode = S_IFREG | S_IRUGO;
 768         entry->content = SNDRV_INFO_CONTENT_TEXT;
 769         mutex_init(&entry->access);
 770         return entry;
 771 }
 772
 773 /**
 774  * snd_info_create_module_entry - create an info entry for the given module
 775  * @module: the module pointer
 776  * @name: the file name
 777  * @parent: the parent directory
 778  *
 779  * Creates a new info entry and assigns it to the given module.
 780  *
 781  * Returns the pointer of the new instance, or NULL on failure.
 782  */
 783 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 784                                                const char *name,
 785                                                struct snd_info_entry *parent)
 786 {
 787         struct snd_info_entry *entry = snd_info_create_entry(name);
 788         if (entry) {
 789                 entry->module = module;
 790                 entry->parent = parent;
 791         }
 792         return entry;
 793 }
 794
 795 EXPORT_SYMBOL(snd_info_create_module_entry);
 796
 797 /**
 798  * snd_info_create_card_entry - create an info entry for the given card
 799  * @card: the card instance
 800  * @name: the file name
 801  * @parent: the parent directory
 802  *
 803  * Creates a new info entry and assigns it to the given card.
 804  *
 805  * Returns the pointer of the new instance, or NULL on failure.
 806  */
 807 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 808                                              const char *name,
 809                                              struct snd_info_entry * parent)
 810 {
 811         struct snd_info_entry *entry = snd_info_create_entry(name);
 812         if (entry) {
 813                 entry->module = card->module;
 814                 entry->card = card;
 815                 entry->parent = parent;
 816         }
 817         return entry;
 818 }
 819
 820 EXPORT_SYMBOL(snd_info_create_card_entry);
 821
 822 static int snd_info_dev_free_entry(struct snd_device *device)
 823 {
 824         struct snd_info_entry *entry = device->device_data;
 825         snd_info_free_entry(entry);
 826         return 0;
 827 }
 828
 829 static int snd_info_dev_register_entry(struct snd_device *device)
 830 {
 831         struct snd_info_entry *entry = device->device_data;
 832         return snd_info_register(entry);
 833 }
 834
 835 static int snd_info_dev_disconnect_entry(struct snd_device *device)
 836 {
 837         struct snd_info_entry *entry = device->device_data;
 838         entry->disconnected = 1;
 839         return 0;
 840 }
 841
 842 static int snd_info_dev_unregister_entry(struct snd_device *device)
 843 {
 844         struct snd_info_entry *entry = device->device_data;
 845         return snd_info_unregister(entry);
 846 }
 847
 848 /**
 849  * snd_card_proc_new - create an info entry for the given card
 850  * @card: the card instance
 851  * @name: the file name
 852  * @entryp: the pointer to store the new info entry
 853  *
 854  * Creates a new info entry and assigns it to the given card.
 855  * Unlike snd_info_create_card_entry(), this function registers the
 856  * info entry as an ALSA device component, so that it can be
 857  * unregistered/released without explicit call.
 858  * Also, you don't have to register this entry via snd_info_register(),
 859  * since this will be registered by snd_card_register() automatically.
 860  *
 861  * The parent is assumed as card->proc_root.
 862  *
 863  * For releasing this entry, use snd_device_free() instead of
 864  * snd_info_free_entry().
 865  *
 866  * Returns zero if successful, or a negative error code on failure.
 867  */
 868 int snd_card_proc_new(struct snd_card *card, const char *name,
 869                       struct snd_info_entry **entryp)
 870 {
 871         static struct snd_device_ops ops = {
 872                 .dev_free = snd_info_dev_free_entry,
 873                 .dev_register = snd_info_dev_register_entry,
 874                 .dev_disconnect = snd_info_dev_disconnect_entry,
 875                 .dev_unregister = snd_info_dev_unregister_entry
 876         };
 877         struct snd_info_entry *entry;
 878         int err;
 879
 880         entry = snd_info_create_card_entry(card, name, card->proc_root);
 881         if (! entry)
 882                 return -ENOMEM;
 883         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 884                 snd_info_free_entry(entry);
 885                 return err;
 886         }
 887         if (entryp)
 888                 *entryp = entry;
 889         return 0;
 890 }
 891
 892 EXPORT_SYMBOL(snd_card_proc_new);
 893
 894 /**
 895  * snd_info_free_entry - release the info entry
 896  * @entry: the info entry
 897  *
 898  * Releases the info entry.  Don't call this after registered.
 899  */
 900 void snd_info_free_entry(struct snd_info_entry * entry)
 901 {
 902         if (entry == NULL)
 903                 return;
 904         kfree(entry->name);
 905         if (entry->private_free)
 906                 entry->private_free(entry);
 907         kfree(entry);
 908 }
 909
 910 EXPORT_SYMBOL(snd_info_free_entry);
 911
 912 /**
 913  * snd_info_register - register the info entry
 914  * @entry: the info entry
 915  *
 916  * Registers the proc info entry.
 917  *
 918  * Returns zero if successful, or a negative error code on failure.
 919  */
 920 int snd_info_register(struct snd_info_entry * entry)
 921 {
 922         struct proc_dir_entry *root, *p = NULL;
 923
 924         snd_assert(entry != NULL, return -ENXIO);
 925         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 926         mutex_lock(&info_mutex);
 927         p = snd_create_proc_entry(entry->name, entry->mode, root);
 928         if (!p) {
 929                 mutex_unlock(&info_mutex);
 930                 return -ENOMEM;
 931         }
 932         p->owner = entry->module;
 933         if (!S_ISDIR(entry->mode))
 934                 p->proc_fops = &snd_info_entry_operations;
 935         p->size = entry->size;
 936         p->data = entry;
 937         entry->p = p;
 938         mutex_unlock(&info_mutex);
 939         return 0;
 940 }
 941
 942 EXPORT_SYMBOL(snd_info_register);
 943
 944 /**
 945  * snd_info_unregister - de-register the info entry
 946  * @entry: the info entry
 947  *
 948  * De-registers the info entry and releases the instance.
 949  *
 950  * Returns zero if successful, or a negative error code on failure.
 951  */
 952 int snd_info_unregister(struct snd_info_entry * entry)
 953 {
 954         struct proc_dir_entry *root;
 955
 956         if (! entry)
 957                 return 0;
 958         snd_assert(entry->p != NULL, return -ENXIO);
 959         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 960         snd_assert(root, return -ENXIO);
 961         mutex_lock(&info_mutex);
 962         snd_remove_proc_entry(root, entry->p);
 963         mutex_unlock(&info_mutex);
 964         snd_info_free_entry(entry);
 965         return 0;
 966 }
 967
 968 EXPORT_SYMBOL(snd_info_unregister);
 969
 970 /*
 971
 972  */
 973
 974 static struct snd_info_entry *snd_info_version_entry;
 975
 976 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 977 {
 978         snd_iprintf(buffer,
 979                     "Advanced Linux Sound Architecture Driver Version "
 980                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
 981                    );
 982 }
 983
 984 static int __init snd_info_version_init(void)
 985 {
 986         struct snd_info_entry *entry;
 987
 988         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 989         if (entry == NULL)
 990                 return -ENOMEM;
 991         entry->c.text.read = snd_info_version_read;
 992         if (snd_info_register(entry) < 0) {
 993                 snd_info_free_entry(entry);
 994                 return -ENOMEM;
 995         }
 996         snd_info_version_entry = entry;
 997         return 0;
 998 }
 999
1000 static int __exit snd_info_version_done(void)
1001 {
1002         if (snd_info_version_entry)
1003                 snd_info_unregister(snd_info_version_entry);
1004         return 0;
1005 }
1006
1007 #endif /* CONFIG_PROC_FS */