src/control/setup.c

   1 /**
   2  * \file control/setup.c
   3  * \brief Routines to setup control primitives from configuration
   4  * \author Abramo Bagnara <abramo@alsa-project.org>
   5  * \author Jaroslav Kysela <perex@perex.cz>
   6  * \date 2001
   7  *
   8  * Routines to setup control primitives from configuration
   9  */
  10 /*
  11  *  Control Interface - routines for setup from configuration
  12  *  Copyright (c) 2001 by Abramo Bagnara <abramo@alsa-project.org>
  13  *                        Jaroslav Kysela <perex@perex.cz>
  14  *
  15  *
  16  *   This library is free software; you can redistribute it and/or modify
  17  *   it under the terms of the GNU Lesser General Public License as
  18  *   published by the Free Software Foundation; either version 2.1 of
  19  *   the License, or (at your option) any later version.
  20  *
  21  *   This program is distributed in the hope that it will be useful,
  22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   GNU Lesser General Public License for more details.
  25  *
  26  *   You should have received a copy of the GNU Lesser General Public
  27  *   License along with this library; if not, write to the Free Software
  28  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  29  *
  30  */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <stdarg.h>
  35 #include <unistd.h>
  36 #include <string.h>
  37 #include <ctype.h>
  38 #include "local.h"
  39
  40 #ifndef DOC_HIDDEN
  41 typedef struct {
  42         unsigned int lock: 1;
  43         unsigned int preserve: 1;
  44         snd_ctl_elem_id_t *id;
  45         snd_ctl_elem_info_t *info;
  46         snd_ctl_elem_value_t *val;
  47         snd_ctl_elem_value_t *mask;
  48         snd_ctl_elem_value_t *old;
  49         struct list_head list;
  50 } snd_sctl_elem_t;
  51
  52 struct _snd_sctl {
  53         int mode;
  54         snd_ctl_t *ctl;
  55         struct list_head elems;
  56 };
  57 #endif /* DOC_HIDDEN */
  58
  59 static int free_elems(snd_sctl_t *h)
  60 {
  61         int err = 0;
  62         while (!list_empty(&h->elems)) {
  63                 snd_sctl_elem_t *elem = list_entry(h->elems.next, snd_sctl_elem_t, list);
  64                 snd_ctl_elem_id_free(elem->id);
  65                 snd_ctl_elem_info_free(elem->info);
  66                 snd_ctl_elem_value_free(elem->val);
  67                 snd_ctl_elem_value_free(elem->mask);
  68                 snd_ctl_elem_value_free(elem->old);
  69                 list_del(&elem->list);
  70                 free(elem);
  71         }
  72         if ((h->mode & SND_SCTL_NOFREE) == 0)
  73                 err = snd_ctl_close(h->ctl);
  74         free(h);
  75         return err;
  76 }
  77
  78 /**
  79  * \brief Install given values to control elements
  80  * \param h Setup control handle
  81  * \result zero if success, otherwise a negative error code
  82  */
  83 int snd_sctl_install(snd_sctl_t *h)
  84 {
  85         struct list_head *pos;
  86         int err;
  87         unsigned int k;
  88         assert(h);
  89         list_for_each(pos, &h->elems) {
  90                 snd_sctl_elem_t *elem = list_entry(pos, snd_sctl_elem_t, list);
  91                 unsigned int count;
  92                 snd_ctl_elem_type_t type;
  93                 if (elem->lock) {
  94                         err = snd_ctl_elem_lock(h->ctl, elem->id);
  95                         if (err < 0) {
  96                                 SNDERR("Cannot lock ctl elem");
  97                                 return err;
  98                         }
  99                 }
 100                 err = snd_ctl_elem_read(h->ctl, elem->old);
 101                 if (err < 0) {
 102                         SNDERR("Cannot read ctl elem");
 103                         return err;
 104                 }
 105                 count = snd_ctl_elem_info_get_count(elem->info);
 106                 type = snd_ctl_elem_info_get_type(elem->info);
 107                 switch (type) {
 108                 case SND_CTL_ELEM_TYPE_BOOLEAN:
 109                         for (k = 0; k < count; ++k) {
 110                                 int old, val, mask;
 111                                 old = snd_ctl_elem_value_get_boolean(elem->old, k);
 112                                 mask = snd_ctl_elem_value_get_boolean(elem->mask, k);
 113                                 old &= ~mask;
 114                                 if (old) {
 115                                         val = snd_ctl_elem_value_get_boolean(elem->val, k);
 116                                         val |= old;
 117                                         snd_ctl_elem_value_set_boolean(elem->val, k, val);
 118                                 }
 119                         }
 120                         break;
 121                 case SND_CTL_ELEM_TYPE_INTEGER:
 122                         for (k = 0; k < count; ++k) {
 123                                 long old, val, mask;
 124                                 old = snd_ctl_elem_value_get_integer(elem->old, k);
 125                                 mask = snd_ctl_elem_value_get_integer(elem->mask, k);
 126                                 old &= ~mask;
 127                                 if (old) {
 128                                         val = snd_ctl_elem_value_get_integer(elem->val, k);
 129                                         val |= old;
 130                                         snd_ctl_elem_value_set_integer(elem->val, k, val);
 131                                 }
 132                         }
 133                         break;
 134                 case SND_CTL_ELEM_TYPE_ENUMERATED:
 135                         for (k = 0; k < count; ++k) {
 136                                 unsigned int old, val, mask;
 137                                 old = snd_ctl_elem_value_get_enumerated(elem->old, k);
 138                                 mask = snd_ctl_elem_value_get_enumerated(elem->mask, k);
 139                                 old &= ~mask;
 140                                 if (old) {
 141                                         val = snd_ctl_elem_value_get_enumerated(elem->val, k);
 142                                         val |= old;
 143                                         snd_ctl_elem_value_set_enumerated(elem->val, k, val);
 144                                 }
 145                         }
 146                         break;
 147                 case SND_CTL_ELEM_TYPE_IEC958:
 148                         count = sizeof(snd_aes_iec958_t);
 149                         /* Fall through */
 150                 case SND_CTL_ELEM_TYPE_BYTES:
 151                         for (k = 0; k < count; ++k) {
 152                                 unsigned char old, val, mask;
 153                                 old = snd_ctl_elem_value_get_byte(elem->old, k);
 154                                 mask = snd_ctl_elem_value_get_byte(elem->mask, k);
 155                                 old &= ~mask;
 156                                 if (old) {
 157                                         val = snd_ctl_elem_value_get_byte(elem->val, k);
 158                                         val |= old;
 159                                         snd_ctl_elem_value_set_byte(elem->val, k, val);
 160                                 }
 161                         }
 162                         break;
 163                 default:
 164                         assert(0);
 165                         break;
 166                 }
 167                 err = snd_ctl_elem_write(h->ctl, elem->val);
 168                 if (err < 0) {
 169                         SNDERR("Cannot write ctl elem");
 170                         return err;
 171                 }
 172         }
 173         return 0;
 174 }
 175
 176 /**
 177  * \brief Remove (restore) previous values from control elements
 178  * \param h Setup control handle
 179  * \result zero if success, otherwise a negative error code
 180  */
 181 int snd_sctl_remove(snd_sctl_t *h)
 182 {
 183         struct list_head *pos;
 184         int err;
 185         assert(h);
 186         list_for_each(pos, &h->elems) {
 187                 snd_sctl_elem_t *elem = list_entry(pos, snd_sctl_elem_t, list);
 188                 if (elem->lock) {
 189                         err = snd_ctl_elem_unlock(h->ctl, elem->id);
 190                         if (err < 0) {
 191                                 SNDERR("Cannot unlock ctl elem");
 192                                 return err;
 193                         }
 194                 }
 195                 if (elem->preserve) {
 196                         err = snd_ctl_elem_write(h->ctl, elem->old);
 197                         if (err < 0) {
 198                                 SNDERR("Cannot restore ctl elem");
 199                                 return err;
 200                         }
 201                 }
 202         }
 203         return 0;
 204 }
 205
 206 static int snd_config_get_ctl_elem_enumerated(snd_config_t *n, snd_ctl_t *ctl,
 207                                               snd_ctl_elem_info_t *info)
 208 {
 209         const char *str;
 210         long val;
 211         unsigned int idx, items;
 212         switch (snd_config_get_type(n)) {
 213         case SND_CONFIG_TYPE_INTEGER:
 214                 snd_config_get_integer(n, &val);
 215                 return val;
 216         case SND_CONFIG_TYPE_STRING:
 217                 snd_config_get_string(n, &str);
 218                 break;
 219         default:
 220                 return -1;
 221         }
 222         items = snd_ctl_elem_info_get_items(info);
 223         for (idx = 0; idx < items; idx++) {
 224                 int err;
 225                 snd_ctl_elem_info_set_item(info, idx);
 226                 err = snd_ctl_elem_info(ctl, info);
 227                 if (err < 0) {
 228                         SNDERR("Cannot obtain info for CTL elem");
 229                         return err;
 230                 }
 231                 if (strcmp(str, snd_ctl_elem_info_get_item_name(info)) == 0)
 232                         return idx;
 233         }
 234         return -1;
 235 }
 236
 237 static int snd_config_get_ctl_elem_value(snd_config_t *conf,
 238                                          snd_ctl_t *ctl,
 239                                          snd_ctl_elem_value_t *val,
 240                                          snd_ctl_elem_value_t *mask,
 241                                          snd_ctl_elem_info_t *info)
 242 {
 243         int err;
 244         snd_config_iterator_t i, next;
 245         snd_ctl_elem_id_t *id;
 246         snd_ctl_elem_type_t type;
 247         unsigned int count;
 248         long v;
 249         long idx;
 250         snd_ctl_elem_id_alloca(&id);
 251         snd_ctl_elem_value_get_id(val, id);
 252         count = snd_ctl_elem_info_get_count(info);
 253         type = snd_ctl_elem_info_get_type(info);
 254         if (count == 1) {
 255                 switch (type) {
 256                 case SND_CTL_ELEM_TYPE_BOOLEAN:
 257                         v = snd_config_get_bool(conf);
 258                         if (v >= 0) {
 259                                 snd_ctl_elem_value_set_boolean(val, 0, v);
 260                                 if (mask)
 261                                         snd_ctl_elem_value_set_boolean(mask, 0, 1);
 262                                 return 0;
 263                         }
 264                         break;
 265                 case SND_CTL_ELEM_TYPE_INTEGER:
 266                         err = snd_config_get_integer(conf, &v);
 267                         if (err == 0) {
 268                                 snd_ctl_elem_value_set_integer(val, 0, v);
 269                                 if (mask)
 270                                         snd_ctl_elem_value_set_integer(mask, 0, ~0L);
 271                                 return 0;
 272                         }
 273                         break;
 274                 case SND_CTL_ELEM_TYPE_ENUMERATED:
 275                         v = snd_config_get_ctl_elem_enumerated(conf, ctl, info);
 276                         if (v >= 0) {
 277                                 snd_ctl_elem_value_set_enumerated(val, 0, v);
 278                                 if (mask)
 279                                         snd_ctl_elem_value_set_enumerated(mask, 0, ~0);
 280                                 return 0;
 281                         }
 282                         break;
 283                 case SND_CTL_ELEM_TYPE_BYTES:
 284                 case SND_CTL_ELEM_TYPE_IEC958:
 285                         break;
 286                 default:
 287                         SNDERR("Unknown control type: %d", type);
 288                         return -EINVAL;
 289                 }
 290         }
 291         switch (type) {
 292         case SND_CTL_ELEM_TYPE_IEC958:
 293                 count = sizeof(snd_aes_iec958_t);
 294                 /* Fall through */
 295         case SND_CTL_ELEM_TYPE_BYTES:
 296         {
 297                 const char *buf;
 298                 err = snd_config_get_string(conf, &buf);
 299                 if (err >= 0) {
 300                         int c1 = 0;
 301                         unsigned int len = strlen(buf);
 302                         unsigned int idx = 0;
 303                         if (len % 2 != 0 || len > count * 2) {
 304                         _bad_content:
 305                                 SNDERR("bad value content\n");
 306                                 return -EINVAL;
 307                         }
 308                         while (*buf) {
 309                                 int c = *buf++;
 310                                 if (c >= '0' && c <= '9')
 311                                         c -= '0';
 312                                 else if (c >= 'a' && c <= 'f')
 313                                         c = c - 'a' + 10;
 314                                 else if (c >= 'A' && c <= 'F')
 315                                         c = c - 'A' + 10;
 316                                 else {
 317                                         goto _bad_content;
 318                                 }
 319                                 if (idx % 2 == 1) {
 320                                         snd_ctl_elem_value_set_byte(val, idx / 2, c1 << 4 | c);
 321                                         if (mask)
 322                                                 snd_ctl_elem_value_set_byte(mask, idx / 2, 0xff);
 323                                 } else
 324                                         c1 = c;
 325                                 idx++;
 326                         }
 327                         return 0;
 328                 }
 329         }
 330         default:
 331                 break;
 332         }
 333         if (snd_config_get_type(conf) != SND_CONFIG_TYPE_COMPOUND) {
 334                 SNDERR("bad value type");
 335                 return -EINVAL;
 336         }
 337
 338         snd_config_for_each(i, next, conf) {
 339                 snd_config_t *n = snd_config_iterator_entry(i);
 340                 const char *id;
 341                 if (snd_config_get_id(n, &id) < 0)
 342                         continue;
 343                 err = safe_strtol(id, &idx);
 344                 if (err < 0 || idx < 0 || (unsigned int) idx >= count) {
 345                         SNDERR("bad value index");
 346                         return -EINVAL;
 347                 }
 348                 switch (type) {
 349                 case SND_CTL_ELEM_TYPE_BOOLEAN:
 350                         v = snd_config_get_bool(n);
 351                         if (v < 0)
 352                                 goto _bad_content;
 353                         snd_ctl_elem_value_set_boolean(val, idx, v);
 354                         if (mask)
 355                                 snd_ctl_elem_value_set_boolean(mask, idx, 1);
 356                         break;
 357                 case SND_CTL_ELEM_TYPE_INTEGER:
 358                         err = snd_config_get_integer(n, &v);
 359                         if (err < 0)
 360                                 goto _bad_content;
 361                         snd_ctl_elem_value_set_integer(val, idx, v);
 362                         if (mask)
 363                                 snd_ctl_elem_value_set_integer(mask, idx, ~0L);
 364                         break;
 365                 case SND_CTL_ELEM_TYPE_ENUMERATED:
 366                         v = snd_config_get_ctl_elem_enumerated(n, ctl, info);
 367                         if (v < 0)
 368                                 goto _bad_content;
 369                         snd_ctl_elem_value_set_enumerated(val, idx, v);
 370                         if (mask)
 371                                 snd_ctl_elem_value_set_enumerated(mask, idx, ~0);
 372                         break;
 373                 case SND_CTL_ELEM_TYPE_BYTES:
 374                 case SND_CTL_ELEM_TYPE_IEC958:
 375                         err = snd_config_get_integer(n, &v);
 376                         if (err < 0 || v < 0 || v > 255)
 377                                 goto _bad_content;
 378                         snd_ctl_elem_value_set_byte(val, idx, v);
 379                         if (mask)
 380                                 snd_ctl_elem_value_set_byte(mask, idx, 0xff);
 381                         break;
 382                 default:
 383                         break;
 384                 }
 385         }
 386         return 0;
 387 }
 388
 389 static int add_elem(snd_sctl_t *h, snd_config_t *_conf, snd_config_t *private_data)
 390 {
 391         snd_config_t *conf;
 392         snd_config_iterator_t i, next;
 393         char *tmp;
 394         int iface = SND_CTL_ELEM_IFACE_MIXER;
 395         const char *name = NULL;
 396         long index = 0;
 397         long device = -1;
 398         long subdevice = -1;
 399         int lock = 0;
 400         int preserve = 0;
 401         int optional = 0;
 402         snd_config_t *value = NULL, *mask = NULL;
 403         snd_sctl_elem_t *elem = NULL;
 404         int err;
 405         err = snd_config_expand(_conf, _conf, NULL, private_data, &conf);
 406         if (err < 0)
 407                 return err;
 408         snd_config_for_each(i, next, conf) {
 409                 snd_config_t *n = snd_config_iterator_entry(i);
 410                 const char *id;
 411                 if (snd_config_get_id(n, &id) < 0)
 412                         continue;
 413                 if (strcmp(id, "comment") == 0)
 414                         continue;
 415                 if (strcmp(id, "iface") == 0 || strcmp(id, "interface") == 0) {
 416                         const char *ptr;
 417                         if ((err = snd_config_get_string(n, &ptr)) < 0) {
 418                                 SNDERR("field %s is not a string", id);
 419                                 goto _err;
 420                         }
 421                         if ((err = snd_config_get_ctl_iface_ascii(ptr)) < 0) {
 422                                 SNDERR("Invalid value for '%s'", id);
 423                                 goto _err;
 424                         }
 425                         iface = err;
 426                         continue;
 427                 }
 428                 if (strcmp(id, "name") == 0) {
 429                         if ((err = snd_config_get_string(n, &name)) < 0) {
 430                                 SNDERR("field %s is not a string", id);
 431                                 goto _err;
 432                         }
 433                         continue;
 434                 }
 435                 if (strcmp(id, "index") == 0) {
 436                         if ((err = snd_config_get_integer(n, &index)) < 0) {
 437                                 SNDERR("field %s is not an integer", id);
 438                                 goto _err;
 439                         }
 440                         continue;
 441                 }
 442                 if (strcmp(id, "device") == 0) {
 443                         if ((err = snd_config_get_integer(n, &device)) < 0) {
 444                                 SNDERR("field %s is not an integer", id);
 445                                 goto _err;
 446                         }
 447                         continue;
 448                 }
 449                 if (strcmp(id, "subdevice") == 0) {
 450                         if ((err = snd_config_get_integer(n, &subdevice)) < 0) {
 451                                 SNDERR("field %s is not an integer", id);
 452                                 goto _err;
 453                         }
 454                         continue;
 455                 }
 456                 if (strcmp(id, "lock") == 0) {
 457                         if ((err = snd_config_get_ascii(n, &tmp)) < 0) {
 458                                 SNDERR("field %s has an invalid type", id);
 459                                 goto _err;
 460                         }
 461                         err = snd_config_get_bool_ascii(tmp);
 462                         if (err < 0) {
 463                                 SNDERR("field %s is not a boolean", id);
 464                                 free(tmp);
 465                                 goto _err;
 466                         }
 467                         lock = err;
 468                         free(tmp);
 469                         continue;
 470                 }
 471                 if (strcmp(id, "preserve") == 0) {
 472                         if ((err = snd_config_get_ascii(n, &tmp)) < 0) {
 473                                 SNDERR("field %s has an invalid type", id);
 474                                 goto _err;
 475                         }
 476                         err = snd_config_get_bool_ascii(tmp);
 477                         if (err < 0) {
 478                                 SNDERR("field %s is not a boolean", id);
 479                                 free(tmp);
 480                                 goto _err;
 481                         }
 482                         preserve = err;
 483                         free(tmp);
 484                         continue;
 485                 }
 486                 if (strcmp(id, "value") == 0) {
 487                         value = n;
 488                         continue;
 489                 }
 490                 if (strcmp(id, "mask") == 0) {
 491                         mask = n;
 492                         continue;
 493                 }
 494                 if (strcmp(id, "optional") == 0) {
 495                         if ((err = snd_config_get_ascii(n, &tmp)) < 0) {
 496                                 SNDERR("field %s has an invalid type", id);
 497                                 goto _err;
 498                         }
 499                         err = snd_config_get_bool_ascii(tmp);
 500                         if (err < 0) {
 501                                 SNDERR("field %s is not a boolean", id);
 502                                 free(tmp);
 503                                 goto _err;
 504                         }
 505                         optional = err;
 506                         free(tmp);
 507                         continue;
 508                 }
 509                 SNDERR("Unknown field %s", id);
 510                 return -EINVAL;
 511         }
 512         if (name == NULL) {
 513                 SNDERR("Missing control name");
 514                 err = -EINVAL;
 515                 goto _err;
 516         }
 517         if (value == NULL) {
 518                 SNDERR("Missing control value");
 519                 err = -EINVAL;
 520                 goto _err;
 521         }
 522         if (device < 0)
 523                 device = 0;
 524         if (subdevice < 0)
 525                 subdevice = 0;
 526         elem = calloc(1, sizeof(*elem));
 527         if (!elem)
 528                 return -ENOMEM;
 529         err = snd_ctl_elem_id_malloc(&elem->id);
 530         if (err < 0)
 531                 goto _err;
 532         err = snd_ctl_elem_info_malloc(&elem->info);
 533         if (err < 0)
 534                 goto _err;
 535         err = snd_ctl_elem_value_malloc(&elem->val);
 536         if (err < 0)
 537                 goto _err;
 538         err = snd_ctl_elem_value_malloc(&elem->mask);
 539         if (err < 0)
 540                 goto _err;
 541         err = snd_ctl_elem_value_malloc(&elem->old);
 542         if (err < 0)
 543                 goto _err;
 544         elem->lock = lock;
 545         elem->preserve = preserve;
 546         snd_ctl_elem_id_set_interface(elem->id, iface);
 547         snd_ctl_elem_id_set_name(elem->id, name);
 548         snd_ctl_elem_id_set_index(elem->id, index);
 549         snd_ctl_elem_id_set_device(elem->id, device);
 550         snd_ctl_elem_id_set_subdevice(elem->id, subdevice);
 551         snd_ctl_elem_info_set_id(elem->info, elem->id);
 552         err = snd_ctl_elem_info(h->ctl, elem->info);
 553         if (err < 0) {
 554                 if (! optional)
 555                         SNDERR("Cannot obtain info for CTL elem (%s,'%s',%li,%li,%li): %s", snd_ctl_elem_iface_name(iface), name, index, device, subdevice, snd_strerror(err));
 556                 goto _err;
 557         }
 558         snd_ctl_elem_value_set_id(elem->val, elem->id);
 559         snd_ctl_elem_value_set_id(elem->old, elem->id);
 560         if (mask) {
 561                 err = snd_config_get_ctl_elem_value(value, h->ctl, elem->val, NULL, elem->info);
 562                 if (err < 0)
 563                         goto _err;
 564                 err = snd_config_get_ctl_elem_value(mask, h->ctl, elem->mask, NULL, elem->info);
 565                 if (err < 0)
 566                         goto _err;
 567         } else {
 568                 err = snd_config_get_ctl_elem_value(value, h->ctl, elem->val, elem->mask, elem->info);
 569                 if (err < 0)
 570                         goto _err;
 571         }
 572
 573         err = snd_config_get_ctl_elem_value(value, h->ctl, elem->val, elem->mask, elem->info);
 574         if (err < 0)
 575                 goto _err;
 576         list_add_tail(&elem->list, &h->elems);
 577
 578  _err:
 579         if (err < 0 && elem) {
 580                 if (elem->id)
 581                         snd_ctl_elem_id_free(elem->id);
 582                 if (elem->info)
 583                         snd_ctl_elem_info_free(elem->info);
 584                 if (elem->val)
 585                         snd_ctl_elem_value_free(elem->val);
 586                 if (elem->mask)
 587                         snd_ctl_elem_value_free(elem->mask);
 588                 if (elem->old)
 589                         snd_ctl_elem_value_free(elem->old);
 590                 free(elem);
 591                 if (err != -ENOMEM && optional)
 592                         err = 0; /* ignore the error */
 593         }
 594         if (conf)
 595                 snd_config_delete(conf);
 596         return err;
 597 }
 598
 599 /**
 600  * \brief Build setup control handle
 601  * \param sctl Result - setup control handle
 602  * \param handle Master control handle
 603  * \param conf Setup configuration
 604  * \param private_data Private data for runtime evaluation
 605  * \param mode Build mode - SND_SCTL_xxxx
 606  * \result zero if success, otherwise a negative error code
 607  */
 608 int snd_sctl_build(snd_sctl_t **sctl, snd_ctl_t *handle, snd_config_t *conf, snd_config_t *private_data, int mode)
 609 {
 610         snd_sctl_t *h;
 611         snd_config_iterator_t i, next;
 612         int err;
 613
 614         assert(sctl);
 615         assert(handle);
 616         assert(conf);
 617         *sctl = NULL;
 618         if (snd_config_get_type(conf) != SND_CONFIG_TYPE_COMPOUND)
 619                 return -EINVAL;
 620         h = calloc(1, sizeof(*h));
 621         if (!h) {
 622                 if (mode & SND_SCTL_NOFREE)
 623                         return -ENOMEM;
 624                 snd_ctl_close(handle);
 625                 return -ENOMEM;
 626         }
 627         h->mode = mode;
 628         h->ctl = handle;
 629         INIT_LIST_HEAD(&h->elems);
 630         snd_config_for_each(i, next, conf) {
 631                 snd_config_t *n = snd_config_iterator_entry(i);
 632                 err = add_elem(h, n, private_data);
 633                 if (err < 0) {
 634                         free_elems(h);
 635                         return err;
 636                 }
 637         }
 638         *sctl = h;
 639         return 0;
 640 }
 641
 642 /**
 643  * \brief Free setup control handle
 644  * \param sctl Setup control handle
 645  * \result zero if success, otherwise a negative error code
 646  */
 647 int snd_sctl_free(snd_sctl_t *sctl)
 648 {
 649         assert(sctl);
 650         return free_elems(sctl);
 651 }