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