sound/core/info.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
snd_info_check_reserved_words
alloc_info_private
valid_pos
snd_info_entry_llseek
snd_info_entry_read
snd_info_entry_write
snd_info_entry_poll
snd_info_entry_ioctl
snd_info_entry_mmap
snd_info_entry_open
snd_info_entry_release
snd_info_text_entry_write
snd_info_seq_show
snd_info_text_entry_open
snd_info_text_entry_release
create_subdir
snd_info_init
snd_info_done
snd_card_id_read
snd_info_card_create
snd_info_card_register
snd_info_card_id_change
snd_info_card_disconnect
snd_info_card_free
snd_info_get_line
snd_info_get_str
snd_info_create_entry
snd_info_create_module_entry
snd_info_create_card_entry
snd_info_disconnect
snd_info_free_entry
__snd_info_register
snd_info_register
snd_card_rw_proc_new
snd_info_version_read
snd_info_version_init
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Information interface for ALSA driver
   4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5  */
   6 
   7 #include <linux/init.h>
   8 #include <linux/time.h>
   9 #include <linux/mm.h>
  10 #include <linux/slab.h>
  11 #include <linux/string.h>
  12 #include <linux/module.h>
  13 #include <sound/core.h>
  14 #include <sound/minors.h>
  15 #include <sound/info.h>
  16 #include <linux/utsname.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/mutex.h>
  19 #include <stdarg.h>
  20 
  21 int snd_info_check_reserved_words(const char *str)
  22 {
  23         static char *reserved[] =
  24         {
  25                 "version",
  26                 "meminfo",
  27                 "memdebug",
  28                 "detect",
  29                 "devices",
  30                 "oss",
  31                 "cards",
  32                 "timers",
  33                 "synth",
  34                 "pcm",
  35                 "seq",
  36                 NULL
  37         };
  38         char **xstr = reserved;
  39 
  40         while (*xstr) {
  41                 if (!strcmp(*xstr, str))
  42                         return 0;
  43                 xstr++;
  44         }
  45         if (!strncmp(str, "card", 4))
  46                 return 0;
  47         return 1;
  48 }
  49 
  50 static DEFINE_MUTEX(info_mutex);
  51 
  52 struct snd_info_private_data {
  53         struct snd_info_buffer *rbuffer;
  54         struct snd_info_buffer *wbuffer;
  55         struct snd_info_entry *entry;
  56         void *file_private_data;
  57 };
  58 
  59 static int snd_info_version_init(void);
  60 static void snd_info_disconnect(struct snd_info_entry *entry);
  61 
  62 /*
  63 
  64  */
  65 
  66 static struct snd_info_entry *snd_proc_root;
  67 struct snd_info_entry *snd_seq_root;
  68 EXPORT_SYMBOL(snd_seq_root);
  69 
  70 #ifdef CONFIG_SND_OSSEMUL
  71 struct snd_info_entry *snd_oss_root;
  72 #endif
  73 
  74 static int alloc_info_private(struct snd_info_entry *entry,
  75                               struct snd_info_private_data **ret)
  76 {
  77         struct snd_info_private_data *data;
  78 
  79         if (!entry || !entry->p)
  80                 return -ENODEV;
  81         if (!try_module_get(entry->module))
  82                 return -EFAULT;
  83         data = kzalloc(sizeof(*data), GFP_KERNEL);
  84         if (!data) {
  85                 module_put(entry->module);
  86                 return -ENOMEM;
  87         }
  88         data->entry = entry;
  89         *ret = data;
  90         return 0;
  91 }
  92 
  93 static bool valid_pos(loff_t pos, size_t count)
  94 {
  95         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
  96                 return false;
  97         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
  98                 return false;
  99         return true;
 100 }
 101 
 102 /*
 103  * file ops for binary proc files
 104  */
 105 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 106 {
 107         struct snd_info_private_data *data;
 108         struct snd_info_entry *entry;
 109         loff_t ret = -EINVAL, size;
 110 
 111         data = file->private_data;
 112         entry = data->entry;
 113         mutex_lock(&entry->access);
 114         if (entry->c.ops->llseek) {
 115                 offset = entry->c.ops->llseek(entry,
 116                                               data->file_private_data,
 117                                               file, offset, orig);
 118                 goto out;
 119         }
 120 
 121         size = entry->size;
 122         switch (orig) {
 123         case SEEK_SET:
 124                 break;
 125         case SEEK_CUR:
 126                 offset += file->f_pos;
 127                 break;
 128         case SEEK_END:
 129                 if (!size)
 130                         goto out;
 131                 offset += size;
 132                 break;
 133         default:
 134                 goto out;
 135         }
 136         if (offset < 0)
 137                 goto out;
 138         if (size && offset > size)
 139                 offset = size;
 140         file->f_pos = offset;
 141         ret = offset;
 142  out:
 143         mutex_unlock(&entry->access);
 144         return ret;
 145 }
 146 
 147 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 148                                    size_t count, loff_t * offset)
 149 {
 150         struct snd_info_private_data *data = file->private_data;
 151         struct snd_info_entry *entry = data->entry;
 152         size_t size;
 153         loff_t pos;
 154 
 155         pos = *offset;
 156         if (!valid_pos(pos, count))
 157                 return -EIO;
 158         if (pos >= entry->size)
 159                 return 0;
 160         size = entry->size - pos;
 161         size = min(count, size);
 162         size = entry->c.ops->read(entry, data->file_private_data,
 163                                   file, buffer, size, pos);
 164         if ((ssize_t) size > 0)
 165                 *offset = pos + size;
 166         return size;
 167 }
 168 
 169 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 170                                     size_t count, loff_t * offset)
 171 {
 172         struct snd_info_private_data *data = file->private_data;
 173         struct snd_info_entry *entry = data->entry;
 174         ssize_t size = 0;
 175         loff_t pos;
 176 
 177         pos = *offset;
 178         if (!valid_pos(pos, count))
 179                 return -EIO;
 180         if (count > 0) {
 181                 size_t maxsize = entry->size - pos;
 182                 count = min(count, maxsize);
 183                 size = entry->c.ops->write(entry, data->file_private_data,
 184                                            file, buffer, count, pos);
 185         }
 186         if (size > 0)
 187                 *offset = pos + size;
 188         return size;
 189 }
 190 
 191 static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
 192 {
 193         struct snd_info_private_data *data = file->private_data;
 194         struct snd_info_entry *entry = data->entry;
 195         __poll_t mask = 0;
 196 
 197         if (entry->c.ops->poll)
 198                 return entry->c.ops->poll(entry,
 199                                           data->file_private_data,
 200                                           file, wait);
 201         if (entry->c.ops->read)
 202                 mask |= EPOLLIN | EPOLLRDNORM;
 203         if (entry->c.ops->write)
 204                 mask |= EPOLLOUT | EPOLLWRNORM;
 205         return mask;
 206 }
 207 
 208 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 209                                 unsigned long arg)
 210 {
 211         struct snd_info_private_data *data = file->private_data;
 212         struct snd_info_entry *entry = data->entry;
 213 
 214         if (!entry->c.ops->ioctl)
 215                 return -ENOTTY;
 216         return entry->c.ops->ioctl(entry, data->file_private_data,
 217                                    file, cmd, arg);
 218 }
 219 
 220 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 221 {
 222         struct inode *inode = file_inode(file);
 223         struct snd_info_private_data *data;
 224         struct snd_info_entry *entry;
 225 
 226         data = file->private_data;
 227         if (data == NULL)
 228                 return 0;
 229         entry = data->entry;
 230         if (!entry->c.ops->mmap)
 231                 return -ENXIO;
 232         return entry->c.ops->mmap(entry, data->file_private_data,
 233                                   inode, file, vma);
 234 }
 235 
 236 static int snd_info_entry_open(struct inode *inode, struct file *file)
 237 {
 238         struct snd_info_entry *entry = PDE_DATA(inode);
 239         struct snd_info_private_data *data;
 240         int mode, err;
 241 
 242         mutex_lock(&info_mutex);
 243         err = alloc_info_private(entry, &data);
 244         if (err < 0)
 245                 goto unlock;
 246 
 247         mode = file->f_flags & O_ACCMODE;
 248         if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
 249             ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
 250                 err = -ENODEV;
 251                 goto error;
 252         }
 253 
 254         if (entry->c.ops->open) {
 255                 err = entry->c.ops->open(entry, mode, &data->file_private_data);
 256                 if (err < 0)
 257                         goto error;
 258         }
 259 
 260         file->private_data = data;
 261         mutex_unlock(&info_mutex);
 262         return 0;
 263 
 264  error:
 265         kfree(data);
 266         module_put(entry->module);
 267  unlock:
 268         mutex_unlock(&info_mutex);
 269         return err;
 270 }
 271 
 272 static int snd_info_entry_release(struct inode *inode, struct file *file)
 273 {
 274         struct snd_info_private_data *data = file->private_data;
 275         struct snd_info_entry *entry = data->entry;
 276 
 277         if (entry->c.ops->release)
 278                 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
 279                                       data->file_private_data);
 280         module_put(entry->module);
 281         kfree(data);
 282         return 0;
 283 }
 284 
 285 static const struct file_operations snd_info_entry_operations =
 286 {
 287         .owner =                THIS_MODULE,
 288         .llseek =               snd_info_entry_llseek,
 289         .read =                 snd_info_entry_read,
 290         .write =                snd_info_entry_write,
 291         .poll =                 snd_info_entry_poll,
 292         .unlocked_ioctl =       snd_info_entry_ioctl,
 293         .mmap =                 snd_info_entry_mmap,
 294         .open =                 snd_info_entry_open,
 295         .release =              snd_info_entry_release,
 296 };
 297 
 298 /*
 299  * file ops for text proc files
 300  */
 301 static ssize_t snd_info_text_entry_write(struct file *file,
 302                                          const char __user *buffer,
 303                                          size_t count, loff_t *offset)
 304 {
 305         struct seq_file *m = file->private_data;
 306         struct snd_info_private_data *data = m->private;
 307         struct snd_info_entry *entry = data->entry;
 308         struct snd_info_buffer *buf;
 309         loff_t pos;
 310         size_t next;
 311         int err = 0;
 312 
 313         if (!entry->c.text.write)
 314                 return -EIO;
 315         pos = *offset;
 316         if (!valid_pos(pos, count))
 317                 return -EIO;
 318         next = pos + count;
 319         /* don't handle too large text inputs */
 320         if (next > 16 * 1024)
 321                 return -EIO;
 322         mutex_lock(&entry->access);
 323         buf = data->wbuffer;
 324         if (!buf) {
 325                 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 326                 if (!buf) {
 327                         err = -ENOMEM;
 328                         goto error;
 329                 }
 330         }
 331         if (next > buf->len) {
 332                 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
 333                 if (!nbuf) {
 334                         err = -ENOMEM;
 335                         goto error;
 336                 }
 337                 kvfree(buf->buffer);
 338                 buf->buffer = nbuf;
 339                 buf->len = PAGE_ALIGN(next);
 340         }
 341         if (copy_from_user(buf->buffer + pos, buffer, count)) {
 342                 err = -EFAULT;
 343                 goto error;
 344         }
 345         buf->size = next;
 346  error:
 347         mutex_unlock(&entry->access);
 348         if (err < 0)
 349                 return err;
 350         *offset = next;
 351         return count;
 352 }
 353 
 354 static int snd_info_seq_show(struct seq_file *seq, void *p)
 355 {
 356         struct snd_info_private_data *data = seq->private;
 357         struct snd_info_entry *entry = data->entry;
 358 
 359         if (!entry->c.text.read) {
 360                 return -EIO;
 361         } else {
 362                 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
 363                 entry->c.text.read(entry, data->rbuffer);
 364         }
 365         return 0;
 366 }
 367 
 368 static int snd_info_text_entry_open(struct inode *inode, struct file *file)
 369 {
 370         struct snd_info_entry *entry = PDE_DATA(inode);
 371         struct snd_info_private_data *data;
 372         int err;
 373 
 374         mutex_lock(&info_mutex);
 375         err = alloc_info_private(entry, &data);
 376         if (err < 0)
 377                 goto unlock;
 378 
 379         data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
 380         if (!data->rbuffer) {
 381                 err = -ENOMEM;
 382                 goto error;
 383         }
 384         if (entry->size)
 385                 err = single_open_size(file, snd_info_seq_show, data,
 386                                        entry->size);
 387         else
 388                 err = single_open(file, snd_info_seq_show, data);
 389         if (err < 0)
 390                 goto error;
 391         mutex_unlock(&info_mutex);
 392         return 0;
 393 
 394  error:
 395         kfree(data->rbuffer);
 396         kfree(data);
 397         module_put(entry->module);
 398  unlock:
 399         mutex_unlock(&info_mutex);
 400         return err;
 401 }
 402 
 403 static int snd_info_text_entry_release(struct inode *inode, struct file *file)
 404 {
 405         struct seq_file *m = file->private_data;
 406         struct snd_info_private_data *data = m->private;
 407         struct snd_info_entry *entry = data->entry;
 408 
 409         if (data->wbuffer && entry->c.text.write)
 410                 entry->c.text.write(entry, data->wbuffer);
 411 
 412         single_release(inode, file);
 413         kfree(data->rbuffer);
 414         if (data->wbuffer) {
 415                 kvfree(data->wbuffer->buffer);
 416                 kfree(data->wbuffer);
 417         }
 418 
 419         module_put(entry->module);
 420         kfree(data);
 421         return 0;
 422 }
 423 
 424 static const struct file_operations snd_info_text_entry_ops =
 425 {
 426         .owner =                THIS_MODULE,
 427         .open =                 snd_info_text_entry_open,
 428         .release =              snd_info_text_entry_release,
 429         .write =                snd_info_text_entry_write,
 430         .llseek =               seq_lseek,
 431         .read =                 seq_read,
 432 };
 433 
 434 static struct snd_info_entry *create_subdir(struct module *mod,
 435                                             const char *name)
 436 {
 437         struct snd_info_entry *entry;
 438 
 439         entry = snd_info_create_module_entry(mod, name, NULL);
 440         if (!entry)
 441                 return NULL;
 442         entry->mode = S_IFDIR | 0555;
 443         if (snd_info_register(entry) < 0) {
 444                 snd_info_free_entry(entry);
 445                 return NULL;
 446         }
 447         return entry;
 448 }
 449 
 450 static struct snd_info_entry *
 451 snd_info_create_entry(const char *name, struct snd_info_entry *parent,
 452                       struct module *module);
 453 
 454 int __init snd_info_init(void)
 455 {
 456         snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
 457         if (!snd_proc_root)
 458                 return -ENOMEM;
 459         snd_proc_root->mode = S_IFDIR | 0555;
 460         snd_proc_root->p = proc_mkdir("asound", NULL);
 461         if (!snd_proc_root->p)
 462                 goto error;
 463 #ifdef CONFIG_SND_OSSEMUL
 464         snd_oss_root = create_subdir(THIS_MODULE, "oss");
 465         if (!snd_oss_root)
 466                 goto error;
 467 #endif
 468 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
 469         snd_seq_root = create_subdir(THIS_MODULE, "seq");
 470         if (!snd_seq_root)
 471                 goto error;
 472 #endif
 473         if (snd_info_version_init() < 0 ||
 474             snd_minor_info_init() < 0 ||
 475             snd_minor_info_oss_init() < 0 ||
 476             snd_card_info_init() < 0 ||
 477             snd_info_minor_register() < 0)
 478                 goto error;
 479         return 0;
 480 
 481  error:
 482         snd_info_free_entry(snd_proc_root);
 483         return -ENOMEM;
 484 }
 485 
 486 int __exit snd_info_done(void)
 487 {
 488         snd_info_free_entry(snd_proc_root);
 489         return 0;
 490 }
 491 
 492 static void snd_card_id_read(struct snd_info_entry *entry,
 493                              struct snd_info_buffer *buffer)
 494 {
 495         struct snd_card *card = entry->private_data;
 496 
 497         snd_iprintf(buffer, "%s\n", card->id);
 498 }
 499 
 500 /*
 501  * create a card proc file
 502  * called from init.c
 503  */
 504 int snd_info_card_create(struct snd_card *card)
 505 {
 506         char str[8];
 507         struct snd_info_entry *entry;
 508 
 509         if (snd_BUG_ON(!card))
 510                 return -ENXIO;
 511 
 512         sprintf(str, "card%i", card->number);
 513         entry = create_subdir(card->module, str);
 514         if (!entry)
 515                 return -ENOMEM;
 516         card->proc_root = entry;
 517 
 518         return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
 519 }
 520 
 521 /*
 522  * register the card proc file
 523  * called from init.c
 524  * can be called multiple times for reinitialization
 525  */
 526 int snd_info_card_register(struct snd_card *card)
 527 {
 528         struct proc_dir_entry *p;
 529         int err;
 530 
 531         if (snd_BUG_ON(!card))
 532                 return -ENXIO;
 533 
 534         err = snd_info_register(card->proc_root);
 535         if (err < 0)
 536                 return err;
 537 
 538         if (!strcmp(card->id, card->proc_root->name))
 539                 return 0;
 540 
 541         if (card->proc_root_link)
 542                 return 0;
 543         p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
 544         if (!p)
 545                 return -ENOMEM;
 546         card->proc_root_link = p;
 547         return 0;
 548 }
 549 
 550 /*
 551  * called on card->id change
 552  */
 553 void snd_info_card_id_change(struct snd_card *card)
 554 {
 555         mutex_lock(&info_mutex);
 556         if (card->proc_root_link) {
 557                 proc_remove(card->proc_root_link);
 558                 card->proc_root_link = NULL;
 559         }
 560         if (strcmp(card->id, card->proc_root->name))
 561                 card->proc_root_link = proc_symlink(card->id,
 562                                                     snd_proc_root->p,
 563                                                     card->proc_root->name);
 564         mutex_unlock(&info_mutex);
 565 }
 566 
 567 /*
 568  * de-register the card proc file
 569  * called from init.c
 570  */
 571 void snd_info_card_disconnect(struct snd_card *card)
 572 {
 573         if (!card)
 574                 return;
 575         mutex_lock(&info_mutex);
 576         proc_remove(card->proc_root_link);
 577         card->proc_root_link = NULL;
 578         if (card->proc_root)
 579                 snd_info_disconnect(card->proc_root);
 580         mutex_unlock(&info_mutex);
 581 }
 582 
 583 /*
 584  * release the card proc file resources
 585  * called from init.c
 586  */
 587 int snd_info_card_free(struct snd_card *card)
 588 {
 589         if (!card)
 590                 return 0;
 591         snd_info_free_entry(card->proc_root);
 592         card->proc_root = NULL;
 593         return 0;
 594 }
 595 
 596 
 597 /**
 598  * snd_info_get_line - read one line from the procfs buffer
 599  * @buffer: the procfs buffer
 600  * @line: the buffer to store
 601  * @len: the max. buffer size
 602  *
 603  * Reads one line from the buffer and stores the string.
 604  *
 605  * Return: Zero if successful, or 1 if error or EOF.
 606  */
 607 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 608 {
 609         int c = -1;
 610 
 611         if (snd_BUG_ON(!buffer || !buffer->buffer))
 612                 return 1;
 613         if (len <= 0 || buffer->stop || buffer->error)
 614                 return 1;
 615         while (!buffer->stop) {
 616                 c = buffer->buffer[buffer->curr++];
 617                 if (buffer->curr >= buffer->size)
 618                         buffer->stop = 1;
 619                 if (c == '\n')
 620                         break;
 621                 if (len > 1) {
 622                         len--;
 623                         *line++ = c;
 624                 }
 625         }
 626         *line = '\0';
 627         return 0;
 628 }
 629 EXPORT_SYMBOL(snd_info_get_line);
 630 
 631 /**
 632  * snd_info_get_str - parse a string token
 633  * @dest: the buffer to store the string token
 634  * @src: the original string
 635  * @len: the max. length of token - 1
 636  *
 637  * Parses the original string and copy a token to the given
 638  * string buffer.
 639  *
 640  * Return: The updated pointer of the original string so that
 641  * it can be used for the next call.
 642  */
 643 const char *snd_info_get_str(char *dest, const char *src, int len)
 644 {
 645         int c;
 646 
 647         while (*src == ' ' || *src == '\t')
 648                 src++;
 649         if (*src == '"' || *src == '\'') {
 650                 c = *src++;
 651                 while (--len > 0 && *src && *src != c) {
 652                         *dest++ = *src++;
 653                 }
 654                 if (*src == c)
 655                         src++;
 656         } else {
 657                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 658                         *dest++ = *src++;
 659                 }
 660         }
 661         *dest = 0;
 662         while (*src == ' ' || *src == '\t')
 663                 src++;
 664         return src;
 665 }
 666 EXPORT_SYMBOL(snd_info_get_str);
 667 
 668 /*
 669  * snd_info_create_entry - create an info entry
 670  * @name: the proc file name
 671  * @parent: the parent directory
 672  *
 673  * Creates an info entry with the given file name and initializes as
 674  * the default state.
 675  *
 676  * Usually called from other functions such as
 677  * snd_info_create_card_entry().
 678  *
 679  * Return: The pointer of the new instance, or %NULL on failure.
 680  */
 681 static struct snd_info_entry *
 682 snd_info_create_entry(const char *name, struct snd_info_entry *parent,
 683                       struct module *module)
 684 {
 685         struct snd_info_entry *entry;
 686         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 687         if (entry == NULL)
 688                 return NULL;
 689         entry->name = kstrdup(name, GFP_KERNEL);
 690         if (entry->name == NULL) {
 691                 kfree(entry);
 692                 return NULL;
 693         }
 694         entry->mode = S_IFREG | 0444;
 695         entry->content = SNDRV_INFO_CONTENT_TEXT;
 696         mutex_init(&entry->access);
 697         INIT_LIST_HEAD(&entry->children);
 698         INIT_LIST_HEAD(&entry->list);
 699         entry->parent = parent;
 700         entry->module = module;
 701         if (parent) {
 702                 mutex_lock(&parent->access);
 703                 list_add_tail(&entry->list, &parent->children);
 704                 mutex_unlock(&parent->access);
 705         }
 706         return entry;
 707 }
 708 
 709 /**
 710  * snd_info_create_module_entry - create an info entry for the given module
 711  * @module: the module pointer
 712  * @name: the file name
 713  * @parent: the parent directory
 714  *
 715  * Creates a new info entry and assigns it to the given module.
 716  *
 717  * Return: The pointer of the new instance, or %NULL on failure.
 718  */
 719 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 720                                                const char *name,
 721                                                struct snd_info_entry *parent)
 722 {
 723         if (!parent)
 724                 parent = snd_proc_root;
 725         return snd_info_create_entry(name, parent, module);
 726 }
 727 EXPORT_SYMBOL(snd_info_create_module_entry);
 728 
 729 /**
 730  * snd_info_create_card_entry - create an info entry for the given card
 731  * @card: the card instance
 732  * @name: the file name
 733  * @parent: the parent directory
 734  *
 735  * Creates a new info entry and assigns it to the given card.
 736  *
 737  * Return: The pointer of the new instance, or %NULL on failure.
 738  */
 739 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 740                                              const char *name,
 741                                              struct snd_info_entry * parent)
 742 {
 743         if (!parent)
 744                 parent = card->proc_root;
 745         return snd_info_create_entry(name, parent, card->module);
 746 }
 747 EXPORT_SYMBOL(snd_info_create_card_entry);
 748 
 749 static void snd_info_disconnect(struct snd_info_entry *entry)
 750 {
 751         struct snd_info_entry *p;
 752 
 753         if (!entry->p)
 754                 return;
 755         list_for_each_entry(p, &entry->children, list)
 756                 snd_info_disconnect(p);
 757         proc_remove(entry->p);
 758         entry->p = NULL;
 759 }
 760 
 761 /**
 762  * snd_info_free_entry - release the info entry
 763  * @entry: the info entry
 764  *
 765  * Releases the info entry.
 766  */
 767 void snd_info_free_entry(struct snd_info_entry * entry)
 768 {
 769         struct snd_info_entry *p, *n;
 770 
 771         if (!entry)
 772                 return;
 773         if (entry->p) {
 774                 mutex_lock(&info_mutex);
 775                 snd_info_disconnect(entry);
 776                 mutex_unlock(&info_mutex);
 777         }
 778 
 779         /* free all children at first */
 780         list_for_each_entry_safe(p, n, &entry->children, list)
 781                 snd_info_free_entry(p);
 782 
 783         p = entry->parent;
 784         if (p) {
 785                 mutex_lock(&p->access);
 786                 list_del(&entry->list);
 787                 mutex_unlock(&p->access);
 788         }
 789         kfree(entry->name);
 790         if (entry->private_free)
 791                 entry->private_free(entry);
 792         kfree(entry);
 793 }
 794 EXPORT_SYMBOL(snd_info_free_entry);
 795 
 796 static int __snd_info_register(struct snd_info_entry *entry)
 797 {
 798         struct proc_dir_entry *root, *p = NULL;
 799 
 800         if (snd_BUG_ON(!entry))
 801                 return -ENXIO;
 802         root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
 803         mutex_lock(&info_mutex);
 804         if (entry->p || !root)
 805                 goto unlock;
 806         if (S_ISDIR(entry->mode)) {
 807                 p = proc_mkdir_mode(entry->name, entry->mode, root);
 808                 if (!p) {
 809                         mutex_unlock(&info_mutex);
 810                         return -ENOMEM;
 811                 }
 812         } else {
 813                 const struct file_operations *ops;
 814                 if (entry->content == SNDRV_INFO_CONTENT_DATA)
 815                         ops = &snd_info_entry_operations;
 816                 else
 817                         ops = &snd_info_text_entry_ops;
 818                 p = proc_create_data(entry->name, entry->mode, root,
 819                                      ops, entry);
 820                 if (!p) {
 821                         mutex_unlock(&info_mutex);
 822                         return -ENOMEM;
 823                 }
 824                 proc_set_size(p, entry->size);
 825         }
 826         entry->p = p;
 827  unlock:
 828         mutex_unlock(&info_mutex);
 829         return 0;
 830 }
 831 
 832 /**
 833  * snd_info_register - register the info entry
 834  * @entry: the info entry
 835  *
 836  * Registers the proc info entry.
 837  * The all children entries are registered recursively.
 838  *
 839  * Return: Zero if successful, or a negative error code on failure.
 840  */
 841 int snd_info_register(struct snd_info_entry *entry)
 842 {
 843         struct snd_info_entry *p;
 844         int err;
 845 
 846         if (!entry->p) {
 847                 err = __snd_info_register(entry);
 848                 if (err < 0)
 849                         return err;
 850         }
 851 
 852         list_for_each_entry(p, &entry->children, list) {
 853                 err = snd_info_register(p);
 854                 if (err < 0)
 855                         return err;
 856         }
 857 
 858         return 0;
 859 }
 860 EXPORT_SYMBOL(snd_info_register);
 861 
 862 /**
 863  * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
 864  * @card: the card instance
 865  * @name: the file name
 866  * @private_data: the arbitrary private data
 867  * @read: the read callback
 868  * @write: the write callback, NULL for read-only
 869  *
 870  * This proc file entry will be registered via snd_card_register() call, and
 871  * it will be removed automatically at the card removal, too.
 872  */
 873 int snd_card_rw_proc_new(struct snd_card *card, const char *name,
 874                          void *private_data,
 875                          void (*read)(struct snd_info_entry *,
 876                                       struct snd_info_buffer *),
 877                          void (*write)(struct snd_info_entry *entry,
 878                                        struct snd_info_buffer *buffer))
 879 {
 880         struct snd_info_entry *entry;
 881 
 882         entry = snd_info_create_card_entry(card, name, card->proc_root);
 883         if (!entry)
 884                 return -ENOMEM;
 885         snd_info_set_text_ops(entry, private_data, read);
 886         if (write) {
 887                 entry->mode |= 0200;
 888                 entry->c.text.write = write;
 889         }
 890         return 0;
 891 }
 892 EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
 893 
 894 /*
 895 
 896  */
 897 
 898 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 899 {
 900         snd_iprintf(buffer,
 901                     "Advanced Linux Sound Architecture Driver Version k%s.\n",
 902                     init_utsname()->release);
 903 }
 904 
 905 static int __init snd_info_version_init(void)
 906 {
 907         struct snd_info_entry *entry;
 908 
 909         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
 910         if (entry == NULL)
 911                 return -ENOMEM;
 912         entry->c.text.read = snd_info_version_read;
 913         return snd_info_register(entry); /* freed in error path */
 914 }
/* [<][>][^][v][top][bottom][index][help] */
root/sound/core/info.c

DEFINITIONS
