drivers/net/wireless/ath/regd.c

   1 /*
   2  * Copyright (c) 2008-2009 Atheros Communications Inc.
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <net/cfg80211.h>
  19 #include <net/mac80211.h>
  20 #include "regd.h"
  21 #include "regd_common.h"
  22
  23 /*
  24  * This is a set of common rules used by our world regulatory domains.
  25  * We have 12 world regulatory domains. To save space we consolidate
  26  * the regulatory domains in 5 structures by frequency and change
  27  * the flags on our reg_notifier() on a case by case basis.
  28  */
  29
  30 /* Only these channels all allow active scan on all world regulatory domains */
  31 #define ATH9K_2GHZ_CH01_11      REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)
  32
  33 /* We enable active scan on these a case by case basis by regulatory domain */
  34 #define ATH9K_2GHZ_CH12_13      REG_RULE(2467-10, 2472+10, 40, 0, 20,\
  35                                         NL80211_RRF_PASSIVE_SCAN)
  36 #define ATH9K_2GHZ_CH14         REG_RULE(2484-10, 2484+10, 40, 0, 20,\
  37                                 NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)
  38
  39 /* We allow IBSS on these on a case by case basis by regulatory domain */
  40 #define ATH9K_5GHZ_5150_5350    REG_RULE(5150-10, 5350+10, 40, 0, 30,\
  41                                 NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
  42 #define ATH9K_5GHZ_5470_5850    REG_RULE(5470-10, 5850+10, 40, 0, 30,\
  43                                 NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
  44 #define ATH9K_5GHZ_5725_5850    REG_RULE(5725-10, 5850+10, 40, 0, 30,\
  45                                 NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
  46
  47 #define ATH9K_2GHZ_ALL          ATH9K_2GHZ_CH01_11, \
  48                                 ATH9K_2GHZ_CH12_13, \
  49                                 ATH9K_2GHZ_CH14
  50
  51 #define ATH9K_5GHZ_ALL          ATH9K_5GHZ_5150_5350, \
  52                                 ATH9K_5GHZ_5470_5850
  53
  54 /* This one skips what we call "mid band" */
  55 #define ATH9K_5GHZ_NO_MIDBAND   ATH9K_5GHZ_5150_5350, \
  56                                 ATH9K_5GHZ_5725_5850
  57
  58 /* Can be used for:
  59  * 0x60, 0x61, 0x62 */
  60 static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
  61         .n_reg_rules = 5,
  62         .alpha2 =  "99",
  63         .reg_rules = {
  64                 ATH9K_2GHZ_ALL,
  65                 ATH9K_5GHZ_ALL,
  66         }
  67 };
  68
  69 /* Can be used by 0x63 and 0x65 */
  70 static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
  71         .n_reg_rules = 4,
  72         .alpha2 =  "99",
  73         .reg_rules = {
  74                 ATH9K_2GHZ_CH01_11,
  75                 ATH9K_2GHZ_CH12_13,
  76                 ATH9K_5GHZ_NO_MIDBAND,
  77         }
  78 };
  79
  80 /* Can be used by 0x64 only */
  81 static const struct ieee80211_regdomain ath_world_regdom_64 = {
  82         .n_reg_rules = 3,
  83         .alpha2 =  "99",
  84         .reg_rules = {
  85                 ATH9K_2GHZ_CH01_11,
  86                 ATH9K_5GHZ_NO_MIDBAND,
  87         }
  88 };
  89
  90 /* Can be used by 0x66 and 0x69 */
  91 static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
  92         .n_reg_rules = 3,
  93         .alpha2 =  "99",
  94         .reg_rules = {
  95                 ATH9K_2GHZ_CH01_11,
  96                 ATH9K_5GHZ_ALL,
  97         }
  98 };
  99
 100 /* Can be used by 0x67, 0x68, 0x6A and 0x6C */
 101 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A_6C = {
 102         .n_reg_rules = 4,
 103         .alpha2 =  "99",
 104         .reg_rules = {
 105                 ATH9K_2GHZ_CH01_11,
 106                 ATH9K_2GHZ_CH12_13,
 107                 ATH9K_5GHZ_ALL,
 108         }
 109 };
 110
 111 static inline bool is_wwr_sku(u16 regd)
 112 {
 113         return ((regd & COUNTRY_ERD_FLAG) != COUNTRY_ERD_FLAG) &&
 114                 (((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
 115                 (regd == WORLD));
 116 }
 117
 118 static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
 119 {
 120         return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
 121 }
 122
 123 bool ath_is_world_regd(struct ath_regulatory *reg)
 124 {
 125         return is_wwr_sku(ath_regd_get_eepromRD(reg));
 126 }
 127 EXPORT_SYMBOL(ath_is_world_regd);
 128
 129 static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
 130 {
 131         /* this is the most restrictive */
 132         return &ath_world_regdom_64;
 133 }
 134
 135 static const struct
 136 ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
 137 {
 138         switch (reg->regpair->regDmnEnum) {
 139         case 0x60:
 140         case 0x61:
 141         case 0x62:
 142                 return &ath_world_regdom_60_61_62;
 143         case 0x63:
 144         case 0x65:
 145                 return &ath_world_regdom_63_65;
 146         case 0x64:
 147                 return &ath_world_regdom_64;
 148         case 0x66:
 149         case 0x69:
 150                 return &ath_world_regdom_66_69;
 151         case 0x67:
 152         case 0x68:
 153         case 0x6A:
 154         case 0x6C:
 155                 return &ath_world_regdom_67_68_6A_6C;
 156         default:
 157                 WARN_ON(1);
 158                 return ath_default_world_regdomain();
 159         }
 160 }
 161
 162 bool ath_is_49ghz_allowed(u16 regdomain)
 163 {
 164         /* possibly more */
 165         return regdomain == MKK9_MKKC;
 166 }
 167 EXPORT_SYMBOL(ath_is_49ghz_allowed);
 168
 169 /* Frequency is one where radar detection is required */
 170 static bool ath_is_radar_freq(u16 center_freq)
 171 {
 172         return (center_freq >= 5260 && center_freq <= 5700);
 173 }
 174
 175 /*
 176  * N.B: These exception rules do not apply radar freqs.
 177  *
 178  * - We enable adhoc (or beaconing) if allowed by 11d
 179  * - We enable active scan if the channel is allowed by 11d
 180  * - If no country IE has been processed and a we determine we have
 181  *   received a beacon on a channel we can enable active scan and
 182  *   adhoc (or beaconing).
 183  */
 184 static void
 185 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
 186                               enum nl80211_reg_initiator initiator)
 187 {
 188         enum ieee80211_band band;
 189         struct ieee80211_supported_band *sband;
 190         const struct ieee80211_reg_rule *reg_rule;
 191         struct ieee80211_channel *ch;
 192         unsigned int i;
 193         u32 bandwidth = 0;
 194         int r;
 195
 196         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 197
 198                 if (!wiphy->bands[band])
 199                         continue;
 200
 201                 sband = wiphy->bands[band];
 202
 203                 for (i = 0; i < sband->n_channels; i++) {
 204
 205                         ch = &sband->channels[i];
 206
 207                         if (ath_is_radar_freq(ch->center_freq) ||
 208                             (ch->flags & IEEE80211_CHAN_RADAR))
 209                                 continue;
 210
 211                         if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
 212                                 r = freq_reg_info(wiphy,
 213                                                   ch->center_freq,
 214                                                   bandwidth,
 215                                                   &reg_rule);
 216                                 if (r)
 217                                         continue;
 218                                 /*
 219                                  * If 11d had a rule for this channel ensure
 220                                  * we enable adhoc/beaconing if it allows us to
 221                                  * use it. Note that we would have disabled it
 222                                  * by applying our static world regdomain by
 223                                  * default during init, prior to calling our
 224                                  * regulatory_hint().
 225                                  */
 226                                 if (!(reg_rule->flags &
 227                                     NL80211_RRF_NO_IBSS))
 228                                         ch->flags &=
 229                                           ~IEEE80211_CHAN_NO_IBSS;
 230                                 if (!(reg_rule->flags &
 231                                     NL80211_RRF_PASSIVE_SCAN))
 232                                         ch->flags &=
 233                                           ~IEEE80211_CHAN_PASSIVE_SCAN;
 234                         } else {
 235                                 if (ch->beacon_found)
 236                                         ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
 237                                           IEEE80211_CHAN_PASSIVE_SCAN);
 238                         }
 239                 }
 240         }
 241
 242 }
 243
 244 /* Allows active scan scan on Ch 12 and 13 */
 245 static void
 246 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
 247                                 enum nl80211_reg_initiator initiator)
 248 {
 249         struct ieee80211_supported_band *sband;
 250         struct ieee80211_channel *ch;
 251         const struct ieee80211_reg_rule *reg_rule;
 252         u32 bandwidth = 0;
 253         int r;
 254
 255         sband = wiphy->bands[IEEE80211_BAND_2GHZ];
 256
 257         /*
 258          * If no country IE has been received always enable active scan
 259          * on these channels. This is only done for specific regulatory SKUs
 260          */
 261         if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
 262                 ch = &sband->channels[11]; /* CH 12 */
 263                 if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 264                         ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 265                 ch = &sband->channels[12]; /* CH 13 */
 266                 if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 267                         ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 268                 return;
 269         }
 270
 271         /*
 272          * If a country IE has been received check its rule for this
 273          * channel first before enabling active scan. The passive scan
 274          * would have been enforced by the initial processing of our
 275          * custom regulatory domain.
 276          */
 277
 278         ch = &sband->channels[11]; /* CH 12 */
 279         r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
 280         if (!r) {
 281                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
 282                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 283                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 284         }
 285
 286         ch = &sband->channels[12]; /* CH 13 */
 287         r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
 288         if (!r) {
 289                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
 290                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 291                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 292         }
 293 }
 294
 295 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
 296 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
 297 {
 298         struct ieee80211_supported_band *sband;
 299         struct ieee80211_channel *ch;
 300         unsigned int i;
 301
 302         if (!wiphy->bands[IEEE80211_BAND_5GHZ])
 303                 return;
 304
 305         sband = wiphy->bands[IEEE80211_BAND_5GHZ];
 306
 307         for (i = 0; i < sband->n_channels; i++) {
 308                 ch = &sband->channels[i];
 309                 if (!ath_is_radar_freq(ch->center_freq))
 310                         continue;
 311                 /* We always enable radar detection/DFS on this
 312                  * frequency range. Additionally we also apply on
 313                  * this frequency range:
 314                  * - If STA mode does not yet have DFS supports disable
 315                  *   active scanning
 316                  * - If adhoc mode does not support DFS yet then
 317                  *   disable adhoc in the frequency.
 318                  * - If AP mode does not yet support radar detection/DFS
 319                  *   do not allow AP mode
 320                  */
 321                 if (!(ch->flags & IEEE80211_CHAN_DISABLED))
 322                         ch->flags |= IEEE80211_CHAN_RADAR |
 323                                      IEEE80211_CHAN_NO_IBSS |
 324                                      IEEE80211_CHAN_PASSIVE_SCAN;
 325         }
 326 }
 327
 328 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
 329                                       enum nl80211_reg_initiator initiator,
 330                                       struct ath_regulatory *reg)
 331 {
 332         switch (reg->regpair->regDmnEnum) {
 333         case 0x60:
 334         case 0x63:
 335         case 0x66:
 336         case 0x67:
 337         case 0x6C:
 338                 ath_reg_apply_beaconing_flags(wiphy, initiator);
 339                 break;
 340         case 0x68:
 341                 ath_reg_apply_beaconing_flags(wiphy, initiator);
 342                 ath_reg_apply_active_scan_flags(wiphy, initiator);
 343                 break;
 344         }
 345 }
 346
 347 int ath_reg_notifier_apply(struct wiphy *wiphy,
 348                            struct regulatory_request *request,
 349                            struct ath_regulatory *reg)
 350 {
 351         /* We always apply this */
 352         ath_reg_apply_radar_flags(wiphy);
 353
 354         /*
 355          * This would happen when we have sent a custom regulatory request
 356          * a world regulatory domain and the scheduler hasn't yet processed
 357          * any pending requests in the queue.
 358          */
 359         if (!request)
 360                 return 0;
 361
 362         switch (request->initiator) {
 363         case NL80211_REGDOM_SET_BY_DRIVER:
 364         case NL80211_REGDOM_SET_BY_CORE:
 365         case NL80211_REGDOM_SET_BY_USER:
 366                 break;
 367         case NL80211_REGDOM_SET_BY_COUNTRY_IE:
 368                 if (ath_is_world_regd(reg))
 369                         ath_reg_apply_world_flags(wiphy, request->initiator,
 370                                                   reg);
 371                 break;
 372         }
 373
 374         return 0;
 375 }
 376 EXPORT_SYMBOL(ath_reg_notifier_apply);
 377
 378 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
 379 {
 380         u16 rd = ath_regd_get_eepromRD(reg);
 381         int i;
 382
 383         if (rd & COUNTRY_ERD_FLAG) {
 384                 /* EEPROM value is a country code */
 385                 u16 cc = rd & ~COUNTRY_ERD_FLAG;
 386                 printk(KERN_DEBUG
 387                        "ath: EEPROM indicates we should expect "
 388                         "a country code\n");
 389                 for (i = 0; i < ARRAY_SIZE(allCountries); i++)
 390                         if (allCountries[i].countryCode == cc)
 391                                 return true;
 392         } else {
 393                 /* EEPROM value is a regpair value */
 394                 if (rd != CTRY_DEFAULT)
 395                         printk(KERN_DEBUG "ath: EEPROM indicates we "
 396                                "should expect a direct regpair map\n");
 397                 for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
 398                         if (regDomainPairs[i].regDmnEnum == rd)
 399                                 return true;
 400         }
 401         printk(KERN_DEBUG
 402                  "ath: invalid regulatory domain/country code 0x%x\n", rd);
 403         return false;
 404 }
 405
 406 /* EEPROM country code to regpair mapping */
 407 static struct country_code_to_enum_rd*
 408 ath_regd_find_country(u16 countryCode)
 409 {
 410         int i;
 411
 412         for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
 413                 if (allCountries[i].countryCode == countryCode)
 414                         return &allCountries[i];
 415         }
 416         return NULL;
 417 }
 418
 419 /* EEPROM rd code to regpair mapping */
 420 static struct country_code_to_enum_rd*
 421 ath_regd_find_country_by_rd(int regdmn)
 422 {
 423         int i;
 424
 425         for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
 426                 if (allCountries[i].regDmnEnum == regdmn)
 427                         return &allCountries[i];
 428         }
 429         return NULL;
 430 }
 431
 432 /* Returns the map of the EEPROM set RD to a country code */
 433 static u16 ath_regd_get_default_country(u16 rd)
 434 {
 435         if (rd & COUNTRY_ERD_FLAG) {
 436                 struct country_code_to_enum_rd *country = NULL;
 437                 u16 cc = rd & ~COUNTRY_ERD_FLAG;
 438
 439                 country = ath_regd_find_country(cc);
 440                 if (country != NULL)
 441                         return cc;
 442         }
 443
 444         return CTRY_DEFAULT;
 445 }
 446
 447 static struct reg_dmn_pair_mapping*
 448 ath_get_regpair(int regdmn)
 449 {
 450         int i;
 451
 452         if (regdmn == NO_ENUMRD)
 453                 return NULL;
 454         for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
 455                 if (regDomainPairs[i].regDmnEnum == regdmn)
 456                         return &regDomainPairs[i];
 457         }
 458         return NULL;
 459 }
 460
 461 static int
 462 ath_regd_init_wiphy(struct ath_regulatory *reg,
 463                     struct wiphy *wiphy,
 464                     int (*reg_notifier)(struct wiphy *wiphy,
 465                                         struct regulatory_request *request))
 466 {
 467         const struct ieee80211_regdomain *regd;
 468
 469         wiphy->reg_notifier = reg_notifier;
 470         wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;
 471
 472         if (ath_is_world_regd(reg)) {
 473                 /*
 474                  * Anything applied here (prior to wiphy registration) gets
 475                  * saved on the wiphy orig_* parameters
 476                  */
 477                 regd = ath_world_regdomain(reg);
 478                 wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
 479         } else {
 480                 /*
 481                  * This gets applied in the case of the absence of CRDA,
 482                  * it's our own custom world regulatory domain, similar to
 483                  * cfg80211's but we enable passive scanning.
 484                  */
 485                 regd = ath_default_world_regdomain();
 486         }
 487         wiphy_apply_custom_regulatory(wiphy, regd);
 488         ath_reg_apply_radar_flags(wiphy);
 489         ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
 490         return 0;
 491 }
 492
 493 /*
 494  * Some users have reported their EEPROM programmed with
 495  * 0x8000 set, this is not a supported regulatory domain
 496  * but since we have more than one user with it we need
 497  * a solution for them. We default to 0x64, which is the
 498  * default Atheros world regulatory domain.
 499  */
 500 static void ath_regd_sanitize(struct ath_regulatory *reg)
 501 {
 502         if (reg->current_rd != COUNTRY_ERD_FLAG)
 503                 return;
 504         printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
 505         reg->current_rd = 0x64;
 506 }
 507
 508 int
 509 ath_regd_init(struct ath_regulatory *reg,
 510               struct wiphy *wiphy,
 511               int (*reg_notifier)(struct wiphy *wiphy,
 512                                   struct regulatory_request *request))
 513 {
 514         struct country_code_to_enum_rd *country = NULL;
 515         u16 regdmn;
 516
 517         if (!reg)
 518                 return -EINVAL;
 519
 520         ath_regd_sanitize(reg);
 521
 522         printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
 523
 524         if (!ath_regd_is_eeprom_valid(reg)) {
 525                 printk(KERN_ERR "ath: Invalid EEPROM contents\n");
 526                 return -EINVAL;
 527         }
 528
 529         regdmn = ath_regd_get_eepromRD(reg);
 530         reg->country_code = ath_regd_get_default_country(regdmn);
 531
 532         if (reg->country_code == CTRY_DEFAULT &&
 533             regdmn == CTRY_DEFAULT) {
 534                 printk(KERN_DEBUG "ath: EEPROM indicates default "
 535                        "country code should be used\n");
 536                 reg->country_code = CTRY_UNITED_STATES;
 537         }
 538
 539         if (reg->country_code == CTRY_DEFAULT) {
 540                 country = NULL;
 541         } else {
 542                 printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
 543                        "map search\n");
 544                 country = ath_regd_find_country(reg->country_code);
 545                 if (country == NULL) {
 546                         printk(KERN_DEBUG
 547                                 "ath: no valid country maps found for "
 548                                 "country code: 0x%0x\n",
 549                                 reg->country_code);
 550                         return -EINVAL;
 551                 } else {
 552                         regdmn = country->regDmnEnum;
 553                         printk(KERN_DEBUG "ath: country maps to "
 554                                "regdmn code: 0x%0x\n",
 555                                regdmn);
 556                 }
 557         }
 558
 559         reg->regpair = ath_get_regpair(regdmn);
 560
 561         if (!reg->regpair) {
 562                 printk(KERN_DEBUG "ath: "
 563                         "No regulatory domain pair found, cannot continue\n");
 564                 return -EINVAL;
 565         }
 566
 567         if (!country)
 568                 country = ath_regd_find_country_by_rd(regdmn);
 569
 570         if (country) {
 571                 reg->alpha2[0] = country->isoName[0];
 572                 reg->alpha2[1] = country->isoName[1];
 573         } else {
 574                 reg->alpha2[0] = '0';
 575                 reg->alpha2[1] = '0';
 576         }
 577
 578         printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
 579                 reg->alpha2[0], reg->alpha2[1]);
 580         printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
 581                 reg->regpair->regDmnEnum);
 582
 583         ath_regd_init_wiphy(reg, wiphy, reg_notifier);
 584         return 0;
 585 }
 586 EXPORT_SYMBOL(ath_regd_init);
 587
 588 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
 589                           enum ieee80211_band band)
 590 {
 591         if (!reg->regpair ||
 592             (reg->country_code == CTRY_DEFAULT &&
 593              is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
 594                 return SD_NO_CTL;
 595         }
 596
 597         switch (band) {
 598         case IEEE80211_BAND_2GHZ:
 599                 return reg->regpair->reg_2ghz_ctl;
 600         case IEEE80211_BAND_5GHZ:
 601                 return reg->regpair->reg_5ghz_ctl;
 602         default:
 603                 return NO_CTL;
 604         }
 605 }
 606 EXPORT_SYMBOL(ath_regd_get_band_ctl);