sound/usb/6fire/control.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Linux driver for TerraTec DMX 6Fire USB
   4  *
   5  * Mixer control
   6  *
   7  * Author:      Torsten Schenk <torsten.schenk@zoho.com>
   8  * Created:     Jan 01, 2011
   9  * Copyright:   (C) Torsten Schenk
  10  *
  11  * Thanks to:
  12  * - Holger Ruckdeschel: he found out how to control individual channel
  13  *   volumes and introduced mute switch
  14  */
  15
  16 #include <linux/interrupt.h>
  17 #include <sound/control.h>
  18 #include <sound/tlv.h>
  19
  20 #include "control.h"
  21 #include "comm.h"
  22 #include "chip.h"
  23
  24 static const char * const opt_coax_texts[2] = { "Optical", "Coax" };
  25 static const char * const line_phono_texts[2] = { "Line", "Phono" };
  26
  27 /*
  28  * data that needs to be sent to device. sets up card internal stuff.
  29  * values dumped from windows driver and filtered by trial'n'error.
  30  */
  31 static const struct {
  32         u8 type;
  33         u8 reg;
  34         u8 value;
  35 }
  36 init_data[] = {
  37         { 0x22, 0x00, 0x00 }, { 0x20, 0x00, 0x08 }, { 0x22, 0x01, 0x01 },
  38         { 0x20, 0x01, 0x08 }, { 0x22, 0x02, 0x00 }, { 0x20, 0x02, 0x08 },
  39         { 0x22, 0x03, 0x00 }, { 0x20, 0x03, 0x08 }, { 0x22, 0x04, 0x00 },
  40         { 0x20, 0x04, 0x08 }, { 0x22, 0x05, 0x01 }, { 0x20, 0x05, 0x08 },
  41         { 0x22, 0x04, 0x01 }, { 0x12, 0x04, 0x00 }, { 0x12, 0x05, 0x00 },
  42         { 0x12, 0x0d, 0x38 }, { 0x12, 0x21, 0x82 }, { 0x12, 0x22, 0x80 },
  43         { 0x12, 0x23, 0x00 }, { 0x12, 0x06, 0x02 }, { 0x12, 0x03, 0x00 },
  44         { 0x12, 0x02, 0x00 }, { 0x22, 0x03, 0x01 },
  45         { 0 } /* TERMINATING ENTRY */
  46 };
  47
  48 static const int rates_altsetting[] = { 1, 1, 2, 2, 3, 3 };
  49 /* values to write to soundcard register for all samplerates */
  50 static const u16 rates_6fire_vl[] = {0x00, 0x01, 0x00, 0x01, 0x00, 0x01};
  51 static const u16 rates_6fire_vh[] = {0x11, 0x11, 0x10, 0x10, 0x00, 0x00};
  52
  53 static DECLARE_TLV_DB_MINMAX(tlv_output, -9000, 0);
  54 static DECLARE_TLV_DB_MINMAX(tlv_input, -1500, 1500);
  55
  56 enum {
  57         DIGITAL_THRU_ONLY_SAMPLERATE = 3
  58 };
  59
  60 static void usb6fire_control_output_vol_update(struct control_runtime *rt)
  61 {
  62         struct comm_runtime *comm_rt = rt->chip->comm;
  63         int i;
  64
  65         if (comm_rt)
  66                 for (i = 0; i < 6; i++)
  67                         if (!(rt->ovol_updated & (1 << i))) {
  68                                 comm_rt->write8(comm_rt, 0x12, 0x0f + i,
  69                                         180 - rt->output_vol[i]);
  70                                 rt->ovol_updated |= 1 << i;
  71                         }
  72 }
  73
  74 static void usb6fire_control_output_mute_update(struct control_runtime *rt)
  75 {
  76         struct comm_runtime *comm_rt = rt->chip->comm;
  77
  78         if (comm_rt)
  79                 comm_rt->write8(comm_rt, 0x12, 0x0e, ~rt->output_mute);
  80 }
  81
  82 static void usb6fire_control_input_vol_update(struct control_runtime *rt)
  83 {
  84         struct comm_runtime *comm_rt = rt->chip->comm;
  85         int i;
  86
  87         if (comm_rt)
  88                 for (i = 0; i < 2; i++)
  89                         if (!(rt->ivol_updated & (1 << i))) {
  90                                 comm_rt->write8(comm_rt, 0x12, 0x1c + i,
  91                                         rt->input_vol[i] & 0x3f);
  92                                 rt->ivol_updated |= 1 << i;
  93                         }
  94 }
  95
  96 static void usb6fire_control_line_phono_update(struct control_runtime *rt)
  97 {
  98         struct comm_runtime *comm_rt = rt->chip->comm;
  99         if (comm_rt) {
 100                 comm_rt->write8(comm_rt, 0x22, 0x02, rt->line_phono_switch);
 101                 comm_rt->write8(comm_rt, 0x21, 0x02, rt->line_phono_switch);
 102         }
 103 }
 104
 105 static void usb6fire_control_opt_coax_update(struct control_runtime *rt)
 106 {
 107         struct comm_runtime *comm_rt = rt->chip->comm;
 108         if (comm_rt) {
 109                 comm_rt->write8(comm_rt, 0x22, 0x00, rt->opt_coax_switch);
 110                 comm_rt->write8(comm_rt, 0x21, 0x00, rt->opt_coax_switch);
 111         }
 112 }
 113
 114 static int usb6fire_control_set_rate(struct control_runtime *rt, int rate)
 115 {
 116         int ret;
 117         struct usb_device *device = rt->chip->dev;
 118         struct comm_runtime *comm_rt = rt->chip->comm;
 119
 120         if (rate < 0 || rate >= CONTROL_N_RATES)
 121                 return -EINVAL;
 122
 123         ret = usb_set_interface(device, 1, rates_altsetting[rate]);
 124         if (ret < 0)
 125                 return ret;
 126
 127         /* set soundcard clock */
 128         ret = comm_rt->write16(comm_rt, 0x02, 0x01, rates_6fire_vl[rate],
 129                         rates_6fire_vh[rate]);
 130         if (ret < 0)
 131                 return ret;
 132
 133         return 0;
 134 }
 135
 136 static int usb6fire_control_set_channels(
 137         struct control_runtime *rt, int n_analog_out,
 138         int n_analog_in, bool spdif_out, bool spdif_in)
 139 {
 140         int ret;
 141         struct comm_runtime *comm_rt = rt->chip->comm;
 142
 143         /* enable analog inputs and outputs
 144          * (one bit per stereo-channel) */
 145         ret = comm_rt->write16(comm_rt, 0x02, 0x02,
 146                         (1 << (n_analog_out / 2)) - 1,
 147                         (1 << (n_analog_in / 2)) - 1);
 148         if (ret < 0)
 149                 return ret;
 150
 151         /* disable digital inputs and outputs */
 152         /* TODO: use spdif_x to enable/disable digital channels */
 153         ret = comm_rt->write16(comm_rt, 0x02, 0x03, 0x00, 0x00);
 154         if (ret < 0)
 155                 return ret;
 156
 157         return 0;
 158 }
 159
 160 static int usb6fire_control_streaming_update(struct control_runtime *rt)
 161 {
 162         struct comm_runtime *comm_rt = rt->chip->comm;
 163
 164         if (comm_rt) {
 165                 if (!rt->usb_streaming && rt->digital_thru_switch)
 166                         usb6fire_control_set_rate(rt,
 167                                 DIGITAL_THRU_ONLY_SAMPLERATE);
 168                 return comm_rt->write16(comm_rt, 0x02, 0x00, 0x00,
 169                         (rt->usb_streaming ? 0x01 : 0x00) |
 170                         (rt->digital_thru_switch ? 0x08 : 0x00));
 171         }
 172         return -EINVAL;
 173 }
 174
 175 static int usb6fire_control_output_vol_info(struct snd_kcontrol *kcontrol,
 176                 struct snd_ctl_elem_info *uinfo)
 177 {
 178         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 179         uinfo->count = 2;
 180         uinfo->value.integer.min = 0;
 181         uinfo->value.integer.max = 180;
 182         return 0;
 183 }
 184
 185 static int usb6fire_control_output_vol_put(struct snd_kcontrol *kcontrol,
 186                 struct snd_ctl_elem_value *ucontrol)
 187 {
 188         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 189         unsigned int ch = kcontrol->private_value;
 190         int changed = 0;
 191
 192         if (ch > 4) {
 193                 dev_err(&rt->chip->dev->dev,
 194                         "Invalid channel in volume control.");
 195                 return -EINVAL;
 196         }
 197
 198         if (rt->output_vol[ch] != ucontrol->value.integer.value[0]) {
 199                 rt->output_vol[ch] = ucontrol->value.integer.value[0];
 200                 rt->ovol_updated &= ~(1 << ch);
 201                 changed = 1;
 202         }
 203         if (rt->output_vol[ch + 1] != ucontrol->value.integer.value[1]) {
 204                 rt->output_vol[ch + 1] = ucontrol->value.integer.value[1];
 205                 rt->ovol_updated &= ~(2 << ch);
 206                 changed = 1;
 207         }
 208
 209         if (changed)
 210                 usb6fire_control_output_vol_update(rt);
 211
 212         return changed;
 213 }
 214
 215 static int usb6fire_control_output_vol_get(struct snd_kcontrol *kcontrol,
 216                 struct snd_ctl_elem_value *ucontrol)
 217 {
 218         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 219         unsigned int ch = kcontrol->private_value;
 220
 221         if (ch > 4) {
 222                 dev_err(&rt->chip->dev->dev,
 223                         "Invalid channel in volume control.");
 224                 return -EINVAL;
 225         }
 226
 227         ucontrol->value.integer.value[0] = rt->output_vol[ch];
 228         ucontrol->value.integer.value[1] = rt->output_vol[ch + 1];
 229         return 0;
 230 }
 231
 232 static int usb6fire_control_output_mute_put(struct snd_kcontrol *kcontrol,
 233         struct snd_ctl_elem_value *ucontrol)
 234 {
 235         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 236         unsigned int ch = kcontrol->private_value;
 237         u8 old = rt->output_mute;
 238         u8 value = 0;
 239
 240         if (ch > 4) {
 241                 dev_err(&rt->chip->dev->dev,
 242                         "Invalid channel in volume control.");
 243                 return -EINVAL;
 244         }
 245
 246         rt->output_mute &= ~(3 << ch);
 247         if (ucontrol->value.integer.value[0])
 248                 value |= 1;
 249         if (ucontrol->value.integer.value[1])
 250                 value |= 2;
 251         rt->output_mute |= value << ch;
 252
 253         if (rt->output_mute != old)
 254                 usb6fire_control_output_mute_update(rt);
 255
 256         return rt->output_mute != old;
 257 }
 258
 259 static int usb6fire_control_output_mute_get(struct snd_kcontrol *kcontrol,
 260         struct snd_ctl_elem_value *ucontrol)
 261 {
 262         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 263         unsigned int ch = kcontrol->private_value;
 264         u8 value = rt->output_mute >> ch;
 265
 266         if (ch > 4) {
 267                 dev_err(&rt->chip->dev->dev,
 268                         "Invalid channel in volume control.");
 269                 return -EINVAL;
 270         }
 271
 272         ucontrol->value.integer.value[0] = 1 & value;
 273         value >>= 1;
 274         ucontrol->value.integer.value[1] = 1 & value;
 275
 276         return 0;
 277 }
 278
 279 static int usb6fire_control_input_vol_info(struct snd_kcontrol *kcontrol,
 280                 struct snd_ctl_elem_info *uinfo)
 281 {
 282         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 283         uinfo->count = 2;
 284         uinfo->value.integer.min = 0;
 285         uinfo->value.integer.max = 30;
 286         return 0;
 287 }
 288
 289 static int usb6fire_control_input_vol_put(struct snd_kcontrol *kcontrol,
 290                 struct snd_ctl_elem_value *ucontrol)
 291 {
 292         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 293         int changed = 0;
 294
 295         if (rt->input_vol[0] != ucontrol->value.integer.value[0]) {
 296                 rt->input_vol[0] = ucontrol->value.integer.value[0] - 15;
 297                 rt->ivol_updated &= ~(1 << 0);
 298                 changed = 1;
 299         }
 300         if (rt->input_vol[1] != ucontrol->value.integer.value[1]) {
 301                 rt->input_vol[1] = ucontrol->value.integer.value[1] - 15;
 302                 rt->ivol_updated &= ~(1 << 1);
 303                 changed = 1;
 304         }
 305
 306         if (changed)
 307                 usb6fire_control_input_vol_update(rt);
 308
 309         return changed;
 310 }
 311
 312 static int usb6fire_control_input_vol_get(struct snd_kcontrol *kcontrol,
 313                 struct snd_ctl_elem_value *ucontrol)
 314 {
 315         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 316
 317         ucontrol->value.integer.value[0] = rt->input_vol[0] + 15;
 318         ucontrol->value.integer.value[1] = rt->input_vol[1] + 15;
 319
 320         return 0;
 321 }
 322
 323 static int usb6fire_control_line_phono_info(struct snd_kcontrol *kcontrol,
 324                 struct snd_ctl_elem_info *uinfo)
 325 {
 326         return snd_ctl_enum_info(uinfo, 1, 2, line_phono_texts);
 327 }
 328
 329 static int usb6fire_control_line_phono_put(struct snd_kcontrol *kcontrol,
 330                 struct snd_ctl_elem_value *ucontrol)
 331 {
 332         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 333         int changed = 0;
 334         if (rt->line_phono_switch != ucontrol->value.integer.value[0]) {
 335                 rt->line_phono_switch = ucontrol->value.integer.value[0];
 336                 usb6fire_control_line_phono_update(rt);
 337                 changed = 1;
 338         }
 339         return changed;
 340 }
 341
 342 static int usb6fire_control_line_phono_get(struct snd_kcontrol *kcontrol,
 343                 struct snd_ctl_elem_value *ucontrol)
 344 {
 345         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 346         ucontrol->value.integer.value[0] = rt->line_phono_switch;
 347         return 0;
 348 }
 349
 350 static int usb6fire_control_opt_coax_info(struct snd_kcontrol *kcontrol,
 351                 struct snd_ctl_elem_info *uinfo)
 352 {
 353         return snd_ctl_enum_info(uinfo, 1, 2, opt_coax_texts);
 354 }
 355
 356 static int usb6fire_control_opt_coax_put(struct snd_kcontrol *kcontrol,
 357                 struct snd_ctl_elem_value *ucontrol)
 358 {
 359         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 360         int changed = 0;
 361
 362         if (rt->opt_coax_switch != ucontrol->value.enumerated.item[0]) {
 363                 rt->opt_coax_switch = ucontrol->value.enumerated.item[0];
 364                 usb6fire_control_opt_coax_update(rt);
 365                 changed = 1;
 366         }
 367         return changed;
 368 }
 369
 370 static int usb6fire_control_opt_coax_get(struct snd_kcontrol *kcontrol,
 371                 struct snd_ctl_elem_value *ucontrol)
 372 {
 373         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 374         ucontrol->value.enumerated.item[0] = rt->opt_coax_switch;
 375         return 0;
 376 }
 377
 378 static int usb6fire_control_digital_thru_put(struct snd_kcontrol *kcontrol,
 379                 struct snd_ctl_elem_value *ucontrol)
 380 {
 381         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 382         int changed = 0;
 383
 384         if (rt->digital_thru_switch != ucontrol->value.integer.value[0]) {
 385                 rt->digital_thru_switch = ucontrol->value.integer.value[0];
 386                 usb6fire_control_streaming_update(rt);
 387                 changed = 1;
 388         }
 389         return changed;
 390 }
 391
 392 static int usb6fire_control_digital_thru_get(struct snd_kcontrol *kcontrol,
 393                 struct snd_ctl_elem_value *ucontrol)
 394 {
 395         struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
 396         ucontrol->value.integer.value[0] = rt->digital_thru_switch;
 397         return 0;
 398 }
 399
 400 static const struct snd_kcontrol_new vol_elements[] = {
 401         {
 402                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 403                 .name = "Analog Playback Volume",
 404                 .index = 0,
 405                 .private_value = 0,
 406                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 407                         SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 408                 .info = usb6fire_control_output_vol_info,
 409                 .get = usb6fire_control_output_vol_get,
 410                 .put = usb6fire_control_output_vol_put,
 411                 .tlv = { .p = tlv_output }
 412         },
 413         {
 414                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 415                 .name = "Analog Playback Volume",
 416                 .index = 1,
 417                 .private_value = 2,
 418                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 419                         SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 420                 .info = usb6fire_control_output_vol_info,
 421                 .get = usb6fire_control_output_vol_get,
 422                 .put = usb6fire_control_output_vol_put,
 423                 .tlv = { .p = tlv_output }
 424         },
 425         {
 426                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 427                 .name = "Analog Playback Volume",
 428                 .index = 2,
 429                 .private_value = 4,
 430                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 431                         SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 432                 .info = usb6fire_control_output_vol_info,
 433                 .get = usb6fire_control_output_vol_get,
 434                 .put = usb6fire_control_output_vol_put,
 435                 .tlv = { .p = tlv_output }
 436         },
 437         {}
 438 };
 439
 440 static const struct snd_kcontrol_new mute_elements[] = {
 441         {
 442                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 443                 .name = "Analog Playback Switch",
 444                 .index = 0,
 445                 .private_value = 0,
 446                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 447                 .info = snd_ctl_boolean_stereo_info,
 448                 .get = usb6fire_control_output_mute_get,
 449                 .put = usb6fire_control_output_mute_put,
 450         },
 451         {
 452                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 453                 .name = "Analog Playback Switch",
 454                 .index = 1,
 455                 .private_value = 2,
 456                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 457                 .info = snd_ctl_boolean_stereo_info,
 458                 .get = usb6fire_control_output_mute_get,
 459                 .put = usb6fire_control_output_mute_put,
 460         },
 461         {
 462                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 463                 .name = "Analog Playback Switch",
 464                 .index = 2,
 465                 .private_value = 4,
 466                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 467                 .info = snd_ctl_boolean_stereo_info,
 468                 .get = usb6fire_control_output_mute_get,
 469                 .put = usb6fire_control_output_mute_put,
 470         },
 471         {}
 472 };
 473
 474 static const struct snd_kcontrol_new elements[] = {
 475         {
 476                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 477                 .name = "Line/Phono Capture Route",
 478                 .index = 0,
 479                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 480                 .info = usb6fire_control_line_phono_info,
 481                 .get = usb6fire_control_line_phono_get,
 482                 .put = usb6fire_control_line_phono_put
 483         },
 484         {
 485                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 486                 .name = "Opt/Coax Capture Route",
 487                 .index = 0,
 488                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 489                 .info = usb6fire_control_opt_coax_info,
 490                 .get = usb6fire_control_opt_coax_get,
 491                 .put = usb6fire_control_opt_coax_put
 492         },
 493         {
 494                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 495                 .name = "Digital Thru Playback Route",
 496                 .index = 0,
 497                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
 498                 .info = snd_ctl_boolean_mono_info,
 499                 .get = usb6fire_control_digital_thru_get,
 500                 .put = usb6fire_control_digital_thru_put
 501         },
 502         {
 503                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 504                 .name = "Analog Capture Volume",
 505                 .index = 0,
 506                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 507                         SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 508                 .info = usb6fire_control_input_vol_info,
 509                 .get = usb6fire_control_input_vol_get,
 510                 .put = usb6fire_control_input_vol_put,
 511                 .tlv = { .p = tlv_input }
 512         },
 513         {}
 514 };
 515
 516 static int usb6fire_control_add_virtual(
 517         struct control_runtime *rt,
 518         struct snd_card *card,
 519         char *name,
 520         const struct snd_kcontrol_new *elems)
 521 {
 522         int ret;
 523         int i;
 524         struct snd_kcontrol *vmaster =
 525                 snd_ctl_make_virtual_master(name, tlv_output);
 526         struct snd_kcontrol *control;
 527
 528         if (!vmaster)
 529                 return -ENOMEM;
 530         ret = snd_ctl_add(card, vmaster);
 531         if (ret < 0)
 532                 return ret;
 533
 534         i = 0;
 535         while (elems[i].name) {
 536                 control = snd_ctl_new1(&elems[i], rt);
 537                 if (!control)
 538                         return -ENOMEM;
 539                 ret = snd_ctl_add(card, control);
 540                 if (ret < 0)
 541                         return ret;
 542                 ret = snd_ctl_add_follower(vmaster, control);
 543                 if (ret < 0)
 544                         return ret;
 545                 i++;
 546         }
 547         return 0;
 548 }
 549
 550 int usb6fire_control_init(struct sfire_chip *chip)
 551 {
 552         int i;
 553         int ret;
 554         struct control_runtime *rt = kzalloc(sizeof(struct control_runtime),
 555                         GFP_KERNEL);
 556         struct comm_runtime *comm_rt = chip->comm;
 557
 558         if (!rt)
 559                 return -ENOMEM;
 560
 561         rt->chip = chip;
 562         rt->update_streaming = usb6fire_control_streaming_update;
 563         rt->set_rate = usb6fire_control_set_rate;
 564         rt->set_channels = usb6fire_control_set_channels;
 565
 566         i = 0;
 567         while (init_data[i].type) {
 568                 comm_rt->write8(comm_rt, init_data[i].type, init_data[i].reg,
 569                                 init_data[i].value);
 570                 i++;
 571         }
 572
 573         usb6fire_control_opt_coax_update(rt);
 574         usb6fire_control_line_phono_update(rt);
 575         usb6fire_control_output_vol_update(rt);
 576         usb6fire_control_output_mute_update(rt);
 577         usb6fire_control_input_vol_update(rt);
 578         usb6fire_control_streaming_update(rt);
 579
 580         ret = usb6fire_control_add_virtual(rt, chip->card,
 581                 "Master Playback Volume", vol_elements);
 582         if (ret) {
 583                 dev_err(&chip->dev->dev, "cannot add control.\n");
 584                 kfree(rt);
 585                 return ret;
 586         }
 587         ret = usb6fire_control_add_virtual(rt, chip->card,
 588                 "Master Playback Switch", mute_elements);
 589         if (ret) {
 590                 dev_err(&chip->dev->dev, "cannot add control.\n");
 591                 kfree(rt);
 592                 return ret;
 593         }
 594
 595         i = 0;
 596         while (elements[i].name) {
 597                 ret = snd_ctl_add(chip->card, snd_ctl_new1(&elements[i], rt));
 598                 if (ret < 0) {
 599                         kfree(rt);
 600                         dev_err(&chip->dev->dev, "cannot add control.\n");
 601                         return ret;
 602                 }
 603                 i++;
 604         }
 605
 606         chip->control = rt;
 607         return 0;
 608 }
 609
 610 void usb6fire_control_abort(struct sfire_chip *chip)
 611 {}
 612
 613 void usb6fire_control_destroy(struct sfire_chip *chip)
 614 {
 615         kfree(chip->control);
 616         chip->control = NULL;
 617 }