linux/sound/core/info.c
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   1/*
   2 *  Information interface for ALSA driver
   3 *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/init.h>
  23#include <linux/time.h>
  24#include <linux/mm.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
  41int 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
  70static DEFINE_MUTEX(info_mutex);
  71
  72struct 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
  79static int snd_info_version_init(void);
  80static int snd_info_version_done(void);
  81static void snd_info_disconnect(struct snd_info_entry *entry);
  82
  83
  84/* resize the proc r/w buffer */
  85static int resize_info_buffer(struct snd_info_buffer *buffer,
  86                              unsigned int nsize)
  87{
  88        char *nbuf;
  89
  90        nsize = PAGE_ALIGN(nsize);
  91        nbuf = kmalloc(nsize, GFP_KERNEL);
  92        if (! nbuf)
  93                return -ENOMEM;
  94
  95        memcpy(nbuf, buffer->buffer, buffer->len);
  96        kfree(buffer->buffer);
  97        buffer->buffer = nbuf;
  98        buffer->len = nsize;
  99        return 0;
 100}
 101
 102/**
 103 * snd_iprintf - printf on the procfs buffer
 104 * @buffer: the procfs buffer
 105 * @fmt: the printf format
 106 *
 107 * Outputs the string on the procfs buffer just like printf().
 108 *
 109 * Returns the size of output string.
 110 */
 111int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
 112{
 113        va_list args;
 114        int len, res;
 115        int err = 0;
 116
 117        might_sleep();
 118        if (buffer->stop || buffer->error)
 119                return 0;
 120        len = buffer->len - buffer->size;
 121        va_start(args, fmt);
 122        for (;;) {
 123                va_list ap;
 124                va_copy(ap, args);
 125                res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
 126                va_end(ap);
 127                if (res < len)
 128                        break;
 129                err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
 130                if (err < 0)
 131                        break;
 132                len = buffer->len - buffer->size;
 133        }
 134        va_end(args);
 135
 136        if (err < 0)
 137                return err;
 138        buffer->curr += res;
 139        buffer->size += res;
 140        return res;
 141}
 142
 143EXPORT_SYMBOL(snd_iprintf);
 144
 145/*
 146
 147 */
 148
 149static struct proc_dir_entry *snd_proc_root;
 150struct snd_info_entry *snd_seq_root;
 151EXPORT_SYMBOL(snd_seq_root);
 152
 153#ifdef CONFIG_SND_OSSEMUL
 154struct snd_info_entry *snd_oss_root;
 155#endif
 156
 157static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
 158{
 159        de->owner = THIS_MODULE;
 160}
 161
 162static void snd_remove_proc_entry(struct proc_dir_entry *parent,
 163                                  struct proc_dir_entry *de)
 164{
 165        if (de)
 166                remove_proc_entry(de->name, parent);
 167}
 168
 169static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 170{
 171        struct snd_info_private_data *data;
 172        struct snd_info_entry *entry;
 173        loff_t ret;
 174
 175        data = file->private_data;
 176        entry = data->entry;
 177        lock_kernel();
 178        switch (entry->content) {
 179        case SNDRV_INFO_CONTENT_TEXT:
 180                switch (orig) {
 181                case SEEK_SET:
 182                        file->f_pos = offset;
 183                        ret = file->f_pos;
 184                        goto out;
 185                case SEEK_CUR:
 186                        file->f_pos += offset;
 187                        ret = file->f_pos;
 188                        goto out;
 189                case SEEK_END:
 190                default:
 191                        ret = -EINVAL;
 192                        goto out;
 193                }
 194                break;
 195        case SNDRV_INFO_CONTENT_DATA:
 196                if (entry->c.ops->llseek) {
 197                        ret = entry->c.ops->llseek(entry,
 198                                                    data->file_private_data,
 199                                                    file, offset, orig);
 200                        goto out;
 201                }
 202                break;
 203        }
 204        ret = -ENXIO;
 205out:
 206        unlock_kernel();
 207        return ret;
 208}
 209
 210static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 211                                   size_t count, loff_t * offset)
 212{
 213        struct snd_info_private_data *data;
 214        struct snd_info_entry *entry;
 215        struct snd_info_buffer *buf;
 216        size_t size = 0;
 217        loff_t pos;
 218
 219        data = file->private_data;
 220        if (snd_BUG_ON(!data))
 221                return -ENXIO;
 222        pos = *offset;
 223        if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 224                return -EIO;
 225        if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 226                return -EIO;
 227        entry = data->entry;
 228        switch (entry->content) {
 229        case SNDRV_INFO_CONTENT_TEXT:
 230                buf = data->rbuffer;
 231                if (buf == NULL)
 232                        return -EIO;
 233                if (pos >= buf->size)
 234                        return 0;
 235                size = buf->size - pos;
 236                size = min(count, size);
 237                if (copy_to_user(buffer, buf->buffer + pos, size))
 238                        return -EFAULT;
 239                break;
 240        case SNDRV_INFO_CONTENT_DATA:
 241                if (entry->c.ops->read)
 242                        size = entry->c.ops->read(entry,
 243                                                  data->file_private_data,
 244                                                  file, buffer, count, pos);
 245                break;
 246        }
 247        if ((ssize_t) size > 0)
 248                *offset = pos + size;
 249        return size;
 250}
 251
 252static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
 253                                    size_t count, loff_t * offset)
 254{
 255        struct snd_info_private_data *data;
 256        struct snd_info_entry *entry;
 257        struct snd_info_buffer *buf;
 258        ssize_t size = 0;
 259        loff_t pos;
 260
 261        data = file->private_data;
 262        if (snd_BUG_ON(!data))
 263                return -ENXIO;
 264        entry = data->entry;
 265        pos = *offset;
 266        if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
 267                return -EIO;
 268        if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
 269                return -EIO;
 270        switch (entry->content) {
 271        case SNDRV_INFO_CONTENT_TEXT:
 272                buf = data->wbuffer;
 273                if (buf == NULL)
 274                        return -EIO;
 275                mutex_lock(&entry->access);
 276                if (pos + count >= buf->len) {
 277                        if (resize_info_buffer(buf, pos + count)) {
 278                                mutex_unlock(&entry->access);
 279                                return -ENOMEM;
 280                        }
 281                }
 282                if (copy_from_user(buf->buffer + pos, buffer, count)) {
 283                        mutex_unlock(&entry->access);
 284                        return -EFAULT;
 285                }
 286                buf->size = pos + count;
 287                mutex_unlock(&entry->access);
 288                size = count;
 289                break;
 290        case SNDRV_INFO_CONTENT_DATA:
 291                if (entry->c.ops->write)
 292                        size = entry->c.ops->write(entry,
 293                                                   data->file_private_data,
 294                                                   file, buffer, count, pos);
 295                break;
 296        }
 297        if ((ssize_t) size > 0)
 298                *offset = pos + size;
 299        return size;
 300}
 301
 302static int snd_info_entry_open(struct inode *inode, struct file *file)
 303{
 304        struct snd_info_entry *entry;
 305        struct snd_info_private_data *data;
 306        struct snd_info_buffer *buffer;
 307        struct proc_dir_entry *p;
 308        int mode, err;
 309
 310        mutex_lock(&info_mutex);
 311        p = PDE(inode);
 312        entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
 313        if (entry == NULL || ! entry->p) {
 314                mutex_unlock(&info_mutex);
 315                return -ENODEV;
 316        }
 317        if (!try_module_get(entry->module)) {
 318                err = -EFAULT;
 319                goto __error1;
 320        }
 321        mode = file->f_flags & O_ACCMODE;
 322        if (mode == O_RDONLY || mode == O_RDWR) {
 323                if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 324                     entry->c.ops->read == NULL)) {
 325                        err = -ENODEV;
 326                        goto __error;
 327                }
 328        }
 329        if (mode == O_WRONLY || mode == O_RDWR) {
 330                if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
 331                     entry->c.ops->write == NULL)) {
 332                        err = -ENODEV;
 333                        goto __error;
 334                }
 335        }
 336        data = kzalloc(sizeof(*data), GFP_KERNEL);
 337        if (data == NULL) {
 338                err = -ENOMEM;
 339                goto __error;
 340        }
 341        data->entry = entry;
 342        switch (entry->content) {
 343        case SNDRV_INFO_CONTENT_TEXT:
 344                if (mode == O_RDONLY || mode == O_RDWR) {
 345                        buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 346                        if (buffer == NULL)
 347                                goto __nomem;
 348                        data->rbuffer = buffer;
 349                        buffer->len = PAGE_SIZE;
 350                        buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 351                        if (buffer->buffer == NULL)
 352                                goto __nomem;
 353                }
 354                if (mode == O_WRONLY || mode == O_RDWR) {
 355                        buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 356                        if (buffer == NULL)
 357                                goto __nomem;
 358                        data->wbuffer = buffer;
 359                        buffer->len = PAGE_SIZE;
 360                        buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
 361                        if (buffer->buffer == NULL)
 362                                goto __nomem;
 363                }
 364                break;
 365        case SNDRV_INFO_CONTENT_DATA:   /* data */
 366                if (entry->c.ops->open) {
 367                        if ((err = entry->c.ops->open(entry, mode,
 368                                                      &data->file_private_data)) < 0) {
 369                                kfree(data);
 370                                goto __error;
 371                        }
 372                }
 373                break;
 374        }
 375        file->private_data = data;
 376        mutex_unlock(&info_mutex);
 377        if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
 378            (mode == O_RDONLY || mode == O_RDWR)) {
 379                if (entry->c.text.read) {
 380                        mutex_lock(&entry->access);
 381                        entry->c.text.read(entry, data->rbuffer);
 382                        mutex_unlock(&entry->access);
 383                }
 384        }
 385        return 0;
 386
 387 __nomem:
 388        if (data->rbuffer) {
 389                kfree(data->rbuffer->buffer);
 390                kfree(data->rbuffer);
 391        }
 392        if (data->wbuffer) {
 393                kfree(data->wbuffer->buffer);
 394                kfree(data->wbuffer);
 395        }
 396        kfree(data);
 397        err = -ENOMEM;
 398      __error:
 399        module_put(entry->module);
 400      __error1:
 401        mutex_unlock(&info_mutex);
 402        return err;
 403}
 404
 405static int snd_info_entry_release(struct inode *inode, struct file *file)
 406{
 407        struct snd_info_entry *entry;
 408        struct snd_info_private_data *data;
 409        int mode;
 410
 411        mode = file->f_flags & O_ACCMODE;
 412        data = file->private_data;
 413        entry = data->entry;
 414        switch (entry->content) {
 415        case SNDRV_INFO_CONTENT_TEXT:
 416                if (data->rbuffer) {
 417                        kfree(data->rbuffer->buffer);
 418                        kfree(data->rbuffer);
 419                }
 420                if (data->wbuffer) {
 421                        if (entry->c.text.write) {
 422                                entry->c.text.write(entry, data->wbuffer);
 423                                if (data->wbuffer->error) {
 424                                        snd_printk(KERN_WARNING "data write error to %s (%i)\n",
 425                                                entry->name,
 426                                                data->wbuffer->error);
 427                                }
 428                        }
 429                        kfree(data->wbuffer->buffer);
 430                        kfree(data->wbuffer);
 431                }
 432                break;
 433        case SNDRV_INFO_CONTENT_DATA:
 434                if (entry->c.ops->release)
 435                        entry->c.ops->release(entry, mode,
 436                                              data->file_private_data);
 437                break;
 438        }
 439        module_put(entry->module);
 440        kfree(data);
 441        return 0;
 442}
 443
 444static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
 445{
 446        struct snd_info_private_data *data;
 447        struct snd_info_entry *entry;
 448        unsigned int mask;
 449
 450        data = file->private_data;
 451        if (data == NULL)
 452                return 0;
 453        entry = data->entry;
 454        mask = 0;
 455        switch (entry->content) {
 456        case SNDRV_INFO_CONTENT_DATA:
 457                if (entry->c.ops->poll)
 458                        return entry->c.ops->poll(entry,
 459                                                  data->file_private_data,
 460                                                  file, wait);
 461                if (entry->c.ops->read)
 462                        mask |= POLLIN | POLLRDNORM;
 463                if (entry->c.ops->write)
 464                        mask |= POLLOUT | POLLWRNORM;
 465                break;
 466        }
 467        return mask;
 468}
 469
 470static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
 471                                unsigned long arg)
 472{
 473        struct snd_info_private_data *data;
 474        struct snd_info_entry *entry;
 475
 476        data = file->private_data;
 477        if (data == NULL)
 478                return 0;
 479        entry = data->entry;
 480        switch (entry->content) {
 481        case SNDRV_INFO_CONTENT_DATA:
 482                if (entry->c.ops->ioctl)
 483                        return entry->c.ops->ioctl(entry,
 484                                                   data->file_private_data,
 485                                                   file, cmd, arg);
 486                break;
 487        }
 488        return -ENOTTY;
 489}
 490
 491static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 492{
 493        struct inode *inode = file->f_path.dentry->d_inode;
 494        struct snd_info_private_data *data;
 495        struct snd_info_entry *entry;
 496
 497        data = file->private_data;
 498        if (data == NULL)
 499                return 0;
 500        entry = data->entry;
 501        switch (entry->content) {
 502        case SNDRV_INFO_CONTENT_DATA:
 503                if (entry->c.ops->mmap)
 504                        return entry->c.ops->mmap(entry,
 505                                                  data->file_private_data,
 506                                                  inode, file, vma);
 507                break;
 508        }
 509        return -ENXIO;
 510}
 511
 512static const struct file_operations snd_info_entry_operations =
 513{
 514        .owner =                THIS_MODULE,
 515        .llseek =               snd_info_entry_llseek,
 516        .read =                 snd_info_entry_read,
 517        .write =                snd_info_entry_write,
 518        .poll =                 snd_info_entry_poll,
 519        .unlocked_ioctl =       snd_info_entry_ioctl,
 520        .mmap =                 snd_info_entry_mmap,
 521        .open =                 snd_info_entry_open,
 522        .release =              snd_info_entry_release,
 523};
 524
 525/**
 526 * snd_create_proc_entry - create a procfs entry
 527 * @name: the name of the proc file
 528 * @mode: the file permission bits, S_Ixxx
 529 * @parent: the parent proc-directory entry
 530 *
 531 * Creates a new proc file entry with the given name and permission
 532 * on the given directory.
 533 *
 534 * Returns the pointer of new instance or NULL on failure.
 535 */
 536static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
 537                                                    struct proc_dir_entry *parent)
 538{
 539        struct proc_dir_entry *p;
 540        p = create_proc_entry(name, mode, parent);
 541        if (p)
 542                snd_info_entry_prepare(p);
 543        return p;
 544}
 545
 546int __init snd_info_init(void)
 547{
 548        struct proc_dir_entry *p;
 549
 550        p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
 551        if (p == NULL)
 552                return -ENOMEM;
 553        snd_proc_root = p;
 554#ifdef CONFIG_SND_OSSEMUL
 555        {
 556                struct snd_info_entry *entry;
 557                if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
 558                        return -ENOMEM;
 559                entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 560                if (snd_info_register(entry) < 0) {
 561                        snd_info_free_entry(entry);
 562                        return -ENOMEM;
 563                }
 564                snd_oss_root = entry;
 565        }
 566#endif
 567#if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 568        {
 569                struct snd_info_entry *entry;
 570                if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
 571                        return -ENOMEM;
 572                entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 573                if (snd_info_register(entry) < 0) {
 574                        snd_info_free_entry(entry);
 575                        return -ENOMEM;
 576                }
 577                snd_seq_root = entry;
 578        }
 579#endif
 580        snd_info_version_init();
 581        snd_minor_info_init();
 582        snd_minor_info_oss_init();
 583        snd_card_info_init();
 584        return 0;
 585}
 586
 587int __exit snd_info_done(void)
 588{
 589        snd_card_info_done();
 590        snd_minor_info_oss_done();
 591        snd_minor_info_done();
 592        snd_info_version_done();
 593        if (snd_proc_root) {
 594#if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
 595                snd_info_free_entry(snd_seq_root);
 596#endif
 597#ifdef CONFIG_SND_OSSEMUL
 598                snd_info_free_entry(snd_oss_root);
 599#endif
 600                snd_remove_proc_entry(NULL, snd_proc_root);
 601        }
 602        return 0;
 603}
 604
 605/*
 606
 607 */
 608
 609
 610/*
 611 * create a card proc file
 612 * called from init.c
 613 */
 614int snd_info_card_create(struct snd_card *card)
 615{
 616        char str[8];
 617        struct snd_info_entry *entry;
 618
 619        if (snd_BUG_ON(!card))
 620                return -ENXIO;
 621
 622        sprintf(str, "card%i", card->number);
 623        if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
 624                return -ENOMEM;
 625        entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 626        if (snd_info_register(entry) < 0) {
 627                snd_info_free_entry(entry);
 628                return -ENOMEM;
 629        }
 630        card->proc_root = entry;
 631        return 0;
 632}
 633
 634/*
 635 * register the card proc file
 636 * called from init.c
 637 */
 638int snd_info_card_register(struct snd_card *card)
 639{
 640        struct proc_dir_entry *p;
 641
 642        if (snd_BUG_ON(!card))
 643                return -ENXIO;
 644
 645        if (!strcmp(card->id, card->proc_root->name))
 646                return 0;
 647
 648        p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
 649        if (p == NULL)
 650                return -ENOMEM;
 651        card->proc_root_link = p;
 652        return 0;
 653}
 654
 655/*
 656 * called on card->id change
 657 */
 658void snd_info_card_id_change(struct snd_card *card)
 659{
 660        mutex_lock(&info_mutex);
 661        if (card->proc_root_link) {
 662                snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 663                card->proc_root_link = NULL;
 664        }
 665        if (strcmp(card->id, card->proc_root->name))
 666                card->proc_root_link = proc_symlink(card->id,
 667                                                    snd_proc_root,
 668                                                    card->proc_root->name);
 669        mutex_unlock(&info_mutex);
 670}
 671
 672/*
 673 * de-register the card proc file
 674 * called from init.c
 675 */
 676void snd_info_card_disconnect(struct snd_card *card)
 677{
 678        if (!card)
 679                return;
 680        mutex_lock(&info_mutex);
 681        if (card->proc_root_link) {
 682                snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
 683                card->proc_root_link = NULL;
 684        }
 685        if (card->proc_root)
 686                snd_info_disconnect(card->proc_root);
 687        mutex_unlock(&info_mutex);
 688}
 689
 690/*
 691 * release the card proc file resources
 692 * called from init.c
 693 */
 694int snd_info_card_free(struct snd_card *card)
 695{
 696        if (!card)
 697                return 0;
 698        snd_info_free_entry(card->proc_root);
 699        card->proc_root = NULL;
 700        return 0;
 701}
 702
 703
 704/**
 705 * snd_info_get_line - read one line from the procfs buffer
 706 * @buffer: the procfs buffer
 707 * @line: the buffer to store
 708 * @len: the max. buffer size - 1
 709 *
 710 * Reads one line from the buffer and stores the string.
 711 *
 712 * Returns zero if successful, or 1 if error or EOF.
 713 */
 714int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 715{
 716        int c = -1;
 717
 718        if (len <= 0 || buffer->stop || buffer->error)
 719                return 1;
 720        while (--len > 0) {
 721                c = buffer->buffer[buffer->curr++];
 722                if (c == '\n') {
 723                        if (buffer->curr >= buffer->size)
 724                                buffer->stop = 1;
 725                        break;
 726                }
 727                *line++ = c;
 728                if (buffer->curr >= buffer->size) {
 729                        buffer->stop = 1;
 730                        break;
 731                }
 732        }
 733        while (c != '\n' && !buffer->stop) {
 734                c = buffer->buffer[buffer->curr++];
 735                if (buffer->curr >= buffer->size)
 736                        buffer->stop = 1;
 737        }
 738        *line = '\0';
 739        return 0;
 740}
 741
 742EXPORT_SYMBOL(snd_info_get_line);
 743
 744/**
 745 * snd_info_get_str - parse a string token
 746 * @dest: the buffer to store the string token
 747 * @src: the original string
 748 * @len: the max. length of token - 1
 749 *
 750 * Parses the original string and copy a token to the given
 751 * string buffer.
 752 *
 753 * Returns the updated pointer of the original string so that
 754 * it can be used for the next call.
 755 */
 756char *snd_info_get_str(char *dest, char *src, int len)
 757{
 758        int c;
 759
 760        while (*src == ' ' || *src == '\t')
 761                src++;
 762        if (*src == '"' || *src == '\'') {
 763                c = *src++;
 764                while (--len > 0 && *src && *src != c) {
 765                        *dest++ = *src++;
 766                }
 767                if (*src == c)
 768                        src++;
 769        } else {
 770                while (--len > 0 && *src && *src != ' ' && *src != '\t') {
 771                        *dest++ = *src++;
 772                }
 773        }
 774        *dest = 0;
 775        while (*src == ' ' || *src == '\t')
 776                src++;
 777        return src;
 778}
 779
 780EXPORT_SYMBOL(snd_info_get_str);
 781
 782/**
 783 * snd_info_create_entry - create an info entry
 784 * @name: the proc file name
 785 *
 786 * Creates an info entry with the given file name and initializes as
 787 * the default state.
 788 *
 789 * Usually called from other functions such as
 790 * snd_info_create_card_entry().
 791 *
 792 * Returns the pointer of the new instance, or NULL on failure.
 793 */
 794static struct snd_info_entry *snd_info_create_entry(const char *name)
 795{
 796        struct snd_info_entry *entry;
 797        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 798        if (entry == NULL)
 799                return NULL;
 800        entry->name = kstrdup(name, GFP_KERNEL);
 801        if (entry->name == NULL) {
 802                kfree(entry);
 803                return NULL;
 804        }
 805        entry->mode = S_IFREG | S_IRUGO;
 806        entry->content = SNDRV_INFO_CONTENT_TEXT;
 807        mutex_init(&entry->access);
 808        INIT_LIST_HEAD(&entry->children);
 809        INIT_LIST_HEAD(&entry->list);
 810        return entry;
 811}
 812
 813/**
 814 * snd_info_create_module_entry - create an info entry for the given module
 815 * @module: the module pointer
 816 * @name: the file name
 817 * @parent: the parent directory
 818 *
 819 * Creates a new info entry and assigns it to the given module.
 820 *
 821 * Returns the pointer of the new instance, or NULL on failure.
 822 */
 823struct snd_info_entry *snd_info_create_module_entry(struct module * module,
 824                                               const char *name,
 825                                               struct snd_info_entry *parent)
 826{
 827        struct snd_info_entry *entry = snd_info_create_entry(name);
 828        if (entry) {
 829                entry->module = module;
 830                entry->parent = parent;
 831        }
 832        return entry;
 833}
 834
 835EXPORT_SYMBOL(snd_info_create_module_entry);
 836
 837/**
 838 * snd_info_create_card_entry - create an info entry for the given card
 839 * @card: the card instance
 840 * @name: the file name
 841 * @parent: the parent directory
 842 *
 843 * Creates a new info entry and assigns it to the given card.
 844 *
 845 * Returns the pointer of the new instance, or NULL on failure.
 846 */
 847struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
 848                                             const char *name,
 849                                             struct snd_info_entry * parent)
 850{
 851        struct snd_info_entry *entry = snd_info_create_entry(name);
 852        if (entry) {
 853                entry->module = card->module;
 854                entry->card = card;
 855                entry->parent = parent;
 856        }
 857        return entry;
 858}
 859
 860EXPORT_SYMBOL(snd_info_create_card_entry);
 861
 862static void snd_info_disconnect(struct snd_info_entry *entry)
 863{
 864        struct list_head *p, *n;
 865        struct proc_dir_entry *root;
 866
 867        list_for_each_safe(p, n, &entry->children) {
 868                snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
 869        }
 870
 871        if (! entry->p)
 872                return;
 873        list_del_init(&entry->list);
 874        root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 875        snd_BUG_ON(!root);
 876        snd_remove_proc_entry(root, entry->p);
 877        entry->p = NULL;
 878}
 879
 880static int snd_info_dev_free_entry(struct snd_device *device)
 881{
 882        struct snd_info_entry *entry = device->device_data;
 883        snd_info_free_entry(entry);
 884        return 0;
 885}
 886
 887static int snd_info_dev_register_entry(struct snd_device *device)
 888{
 889        struct snd_info_entry *entry = device->device_data;
 890        return snd_info_register(entry);
 891}
 892
 893/**
 894 * snd_card_proc_new - create an info entry for the given card
 895 * @card: the card instance
 896 * @name: the file name
 897 * @entryp: the pointer to store the new info entry
 898 *
 899 * Creates a new info entry and assigns it to the given card.
 900 * Unlike snd_info_create_card_entry(), this function registers the
 901 * info entry as an ALSA device component, so that it can be
 902 * unregistered/released without explicit call.
 903 * Also, you don't have to register this entry via snd_info_register(),
 904 * since this will be registered by snd_card_register() automatically.
 905 *
 906 * The parent is assumed as card->proc_root.
 907 *
 908 * For releasing this entry, use snd_device_free() instead of
 909 * snd_info_free_entry(). 
 910 *
 911 * Returns zero if successful, or a negative error code on failure.
 912 */
 913int snd_card_proc_new(struct snd_card *card, const char *name,
 914                      struct snd_info_entry **entryp)
 915{
 916        static struct snd_device_ops ops = {
 917                .dev_free = snd_info_dev_free_entry,
 918                .dev_register = snd_info_dev_register_entry,
 919                /* disconnect is done via snd_info_card_disconnect() */
 920        };
 921        struct snd_info_entry *entry;
 922        int err;
 923
 924        entry = snd_info_create_card_entry(card, name, card->proc_root);
 925        if (! entry)
 926                return -ENOMEM;
 927        if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
 928                snd_info_free_entry(entry);
 929                return err;
 930        }
 931        if (entryp)
 932                *entryp = entry;
 933        return 0;
 934}
 935
 936EXPORT_SYMBOL(snd_card_proc_new);
 937
 938/**
 939 * snd_info_free_entry - release the info entry
 940 * @entry: the info entry
 941 *
 942 * Releases the info entry.  Don't call this after registered.
 943 */
 944void snd_info_free_entry(struct snd_info_entry * entry)
 945{
 946        if (entry == NULL)
 947                return;
 948        if (entry->p) {
 949                mutex_lock(&info_mutex);
 950                snd_info_disconnect(entry);
 951                mutex_unlock(&info_mutex);
 952        }
 953        kfree(entry->name);
 954        if (entry->private_free)
 955                entry->private_free(entry);
 956        kfree(entry);
 957}
 958
 959EXPORT_SYMBOL(snd_info_free_entry);
 960
 961/**
 962 * snd_info_register - register the info entry
 963 * @entry: the info entry
 964 *
 965 * Registers the proc info entry.
 966 *
 967 * Returns zero if successful, or a negative error code on failure.
 968 */
 969int snd_info_register(struct snd_info_entry * entry)
 970{
 971        struct proc_dir_entry *root, *p = NULL;
 972
 973        if (snd_BUG_ON(!entry))
 974                return -ENXIO;
 975        root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
 976        mutex_lock(&info_mutex);
 977        p = snd_create_proc_entry(entry->name, entry->mode, root);
 978        if (!p) {
 979                mutex_unlock(&info_mutex);
 980                return -ENOMEM;
 981        }
 982        p->owner = entry->module;
 983        if (!S_ISDIR(entry->mode))
 984                p->proc_fops = &snd_info_entry_operations;
 985        p->size = entry->size;
 986        p->data = entry;
 987        entry->p = p;
 988        if (entry->parent)
 989                list_add_tail(&entry->list, &entry->parent->children);
 990        mutex_unlock(&info_mutex);
 991        return 0;
 992}
 993
 994EXPORT_SYMBOL(snd_info_register);
 995
 996/*
 997
 998 */
 999
1000static struct snd_info_entry *snd_info_version_entry;
1001
1002static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
1003{
1004        snd_iprintf(buffer,
1005                    "Advanced Linux Sound Architecture Driver Version "
1006                    CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
1007                   );
1008}
1009
1010static int __init snd_info_version_init(void)
1011{
1012        struct snd_info_entry *entry;
1013
1014        entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
1015        if (entry == NULL)
1016                return -ENOMEM;
1017        entry->c.text.read = snd_info_version_read;
1018        if (snd_info_register(entry) < 0) {
1019                snd_info_free_entry(entry);
1020                return -ENOMEM;
1021        }
1022        snd_info_version_entry = entry;
1023        return 0;
1024}
1025
1026static int __exit snd_info_version_done(void)
1027{
1028        snd_info_free_entry(snd_info_version_entry);
1029        return 0;
1030}
1031
1032#endif /* CONFIG_PROC_FS */
1033