1 /* 2 * Copyright (c) 2008-2011 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 <linux/export.h> 19 #include "hw.h" 20 #include "hw-ops.h" 21 22 struct ani_ofdm_level_entry { 23 int spur_immunity_level; 24 int fir_step_level; 25 int ofdm_weak_signal_on; 26 }; 27 28 /* values here are relative to the INI */ 29 30 /* 31 * Legend: 32 * 33 * SI: Spur immunity 34 * FS: FIR Step 35 * WS: OFDM / CCK Weak Signal detection 36 * MRC-CCK: Maximal Ratio Combining for CCK 37 */ 38 39 static const struct ani_ofdm_level_entry ofdm_level_table[] = { 40 /* SI FS WS */ 41 { 0, 0, 1 }, /* lvl 0 */ 42 { 1, 1, 1 }, /* lvl 1 */ 43 { 2, 2, 1 }, /* lvl 2 */ 44 { 3, 2, 1 }, /* lvl 3 (default) */ 45 { 4, 3, 1 }, /* lvl 4 */ 46 { 5, 4, 1 }, /* lvl 5 */ 47 { 6, 5, 1 }, /* lvl 6 */ 48 { 7, 6, 1 }, /* lvl 7 */ 49 { 7, 7, 1 }, /* lvl 8 */ 50 { 7, 8, 0 } /* lvl 9 */ 51 }; 52 #define ATH9K_ANI_OFDM_NUM_LEVEL \ 53 ARRAY_SIZE(ofdm_level_table) 54 #define ATH9K_ANI_OFDM_MAX_LEVEL \ 55 (ATH9K_ANI_OFDM_NUM_LEVEL-1) 56 #define ATH9K_ANI_OFDM_DEF_LEVEL \ 57 3 /* default level - matches the INI settings */ 58 59 /* 60 * MRC (Maximal Ratio Combining) has always been used with multi-antenna ofdm. 61 * With OFDM for single stream you just add up all antenna inputs, you're 62 * only interested in what you get after FFT. Signal alignment is also not 63 * required for OFDM because any phase difference adds up in the frequency 64 * domain. 65 * 66 * MRC requires extra work for use with CCK. You need to align the antenna 67 * signals from the different antenna before you can add the signals together. 68 * You need alignment of signals as CCK is in time domain, so addition can cancel 69 * your signal completely if phase is 180 degrees (think of adding sine waves). 70 * You also need to remove noise before the addition and this is where ANI 71 * MRC CCK comes into play. One of the antenna inputs may be stronger but 72 * lower SNR, so just adding after alignment can be dangerous. 73 * 74 * Regardless of alignment in time, the antenna signals add constructively after 75 * FFT and improve your reception. For more information: 76 * 77 * https://en.wikipedia.org/wiki/Maximal-ratio_combining 78 */ 79 80 struct ani_cck_level_entry { 81 int fir_step_level; 82 int mrc_cck_on; 83 }; 84 85 static const struct ani_cck_level_entry cck_level_table[] = { 86 /* FS MRC-CCK */ 87 { 0, 1 }, /* lvl 0 */ 88 { 1, 1 }, /* lvl 1 */ 89 { 2, 1 }, /* lvl 2 (default) */ 90 { 3, 1 }, /* lvl 3 */ 91 { 4, 0 }, /* lvl 4 */ 92 { 5, 0 }, /* lvl 5 */ 93 { 6, 0 }, /* lvl 6 */ 94 { 7, 0 }, /* lvl 7 (only for high rssi) */ 95 { 8, 0 } /* lvl 8 (only for high rssi) */ 96 }; 97 98 #define ATH9K_ANI_CCK_NUM_LEVEL \ 99 ARRAY_SIZE(cck_level_table) 100 #define ATH9K_ANI_CCK_MAX_LEVEL \ 101 (ATH9K_ANI_CCK_NUM_LEVEL-1) 102 #define ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI \ 103 (ATH9K_ANI_CCK_NUM_LEVEL-3) 104 #define ATH9K_ANI_CCK_DEF_LEVEL \ 105 2 /* default level - matches the INI settings */ 106 107 static void ath9k_hw_update_mibstats(struct ath_hw *ah, 108 struct ath9k_mib_stats *stats) 109 { 110 u32 addr[5] = {AR_RTS_OK, AR_RTS_FAIL, AR_ACK_FAIL, 111 AR_FCS_FAIL, AR_BEACON_CNT}; 112 u32 data[5]; 113 114 REG_READ_MULTI(ah, &addr[0], &data[0], 5); 115 /* AR_RTS_OK */ 116 stats->rts_good += data[0]; 117 /* AR_RTS_FAIL */ 118 stats->rts_bad += data[1]; 119 /* AR_ACK_FAIL */ 120 stats->ackrcv_bad += data[2]; 121 /* AR_FCS_FAIL */ 122 stats->fcs_bad += data[3]; 123 /* AR_BEACON_CNT */ 124 stats->beacons += data[4]; 125 } 126 127 static void ath9k_ani_restart(struct ath_hw *ah) 128 { 129 struct ar5416AniState *aniState = &ah->ani; 130 131 aniState->listenTime = 0; 132 133 ENABLE_REGWRITE_BUFFER(ah); 134 135 REG_WRITE(ah, AR_PHY_ERR_1, 0); 136 REG_WRITE(ah, AR_PHY_ERR_2, 0); 137 REG_WRITE(ah, AR_PHY_ERR_MASK_1, AR_PHY_ERR_OFDM_TIMING); 138 REG_WRITE(ah, AR_PHY_ERR_MASK_2, AR_PHY_ERR_CCK_TIMING); 139 140 REGWRITE_BUFFER_FLUSH(ah); 141 142 ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); 143 144 aniState->ofdmPhyErrCount = 0; 145 aniState->cckPhyErrCount = 0; 146 } 147 148 /* Adjust the OFDM Noise Immunity Level */ 149 static void ath9k_hw_set_ofdm_nil(struct ath_hw *ah, u8 immunityLevel, 150 bool scan) 151 { 152 struct ar5416AniState *aniState = &ah->ani; 153 struct ath_common *common = ath9k_hw_common(ah); 154 const struct ani_ofdm_level_entry *entry_ofdm; 155 const struct ani_cck_level_entry *entry_cck; 156 bool weak_sig; 157 158 ath_dbg(common, ANI, "**** ofdmlevel %d=>%d, rssi=%d[lo=%d hi=%d]\n", 159 aniState->ofdmNoiseImmunityLevel, 160 immunityLevel, BEACON_RSSI(ah), 161 ATH9K_ANI_RSSI_THR_LOW, 162 ATH9K_ANI_RSSI_THR_HIGH); 163 164 if (AR_SREV_9100(ah) && immunityLevel < ATH9K_ANI_OFDM_DEF_LEVEL) 165 immunityLevel = ATH9K_ANI_OFDM_DEF_LEVEL; 166 167 if (!scan) 168 aniState->ofdmNoiseImmunityLevel = immunityLevel; 169 170 entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel]; 171 entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel]; 172 173 if (aniState->spurImmunityLevel != entry_ofdm->spur_immunity_level) 174 ath9k_hw_ani_control(ah, 175 ATH9K_ANI_SPUR_IMMUNITY_LEVEL, 176 entry_ofdm->spur_immunity_level); 177 178 if (aniState->firstepLevel != entry_ofdm->fir_step_level && 179 entry_ofdm->fir_step_level >= entry_cck->fir_step_level) 180 ath9k_hw_ani_control(ah, 181 ATH9K_ANI_FIRSTEP_LEVEL, 182 entry_ofdm->fir_step_level); 183 184 weak_sig = entry_ofdm->ofdm_weak_signal_on; 185 if (ah->opmode == NL80211_IFTYPE_STATION && 186 BEACON_RSSI(ah) <= ATH9K_ANI_RSSI_THR_HIGH) 187 weak_sig = true; 188 /* 189 * Newer chipsets are better at dealing with high PHY error counts - 190 * keep weak signal detection enabled when no RSSI threshold is 191 * available to determine if it is needed (mode != STA) 192 */ 193 else if (AR_SREV_9300_20_OR_LATER(ah) && 194 ah->opmode != NL80211_IFTYPE_STATION) 195 weak_sig = true; 196 197 /* Older chipsets are more sensitive to high PHY error counts */ 198 else if (!AR_SREV_9300_20_OR_LATER(ah) && 199 aniState->ofdmNoiseImmunityLevel >= 8) 200 weak_sig = false; 201 202 if (aniState->ofdmWeakSigDetect != weak_sig) 203 ath9k_hw_ani_control(ah, ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION, 204 weak_sig); 205 206 if (!AR_SREV_9300_20_OR_LATER(ah)) 207 return; 208 209 if (aniState->ofdmNoiseImmunityLevel >= ATH9K_ANI_OFDM_DEF_LEVEL) { 210 ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH; 211 ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_ABOVE_INI; 212 } else { 213 ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_BELOW_INI; 214 ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW; 215 } 216 } 217 218 static void ath9k_hw_ani_ofdm_err_trigger(struct ath_hw *ah) 219 { 220 struct ar5416AniState *aniState = &ah->ani; 221 222 if (aniState->ofdmNoiseImmunityLevel < ATH9K_ANI_OFDM_MAX_LEVEL) 223 ath9k_hw_set_ofdm_nil(ah, aniState->ofdmNoiseImmunityLevel + 1, false); 224 } 225 226 /* 227 * Set the ANI settings to match an CCK level. 228 */ 229 static void ath9k_hw_set_cck_nil(struct ath_hw *ah, u_int8_t immunityLevel, 230 bool scan) 231 { 232 struct ar5416AniState *aniState = &ah->ani; 233 struct ath_common *common = ath9k_hw_common(ah); 234 const struct ani_ofdm_level_entry *entry_ofdm; 235 const struct ani_cck_level_entry *entry_cck; 236 237 ath_dbg(common, ANI, "**** ccklevel %d=>%d, rssi=%d[lo=%d hi=%d]\n", 238 aniState->cckNoiseImmunityLevel, immunityLevel, 239 BEACON_RSSI(ah), ATH9K_ANI_RSSI_THR_LOW, 240 ATH9K_ANI_RSSI_THR_HIGH); 241 242 if (AR_SREV_9100(ah) && immunityLevel < ATH9K_ANI_CCK_DEF_LEVEL) 243 immunityLevel = ATH9K_ANI_CCK_DEF_LEVEL; 244 245 if (ah->opmode == NL80211_IFTYPE_STATION && 246 BEACON_RSSI(ah) <= ATH9K_ANI_RSSI_THR_LOW && 247 immunityLevel > ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI) 248 immunityLevel = ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI; 249 250 if (!scan) 251 aniState->cckNoiseImmunityLevel = immunityLevel; 252 253 entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel]; 254 entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel]; 255 256 if (aniState->firstepLevel != entry_cck->fir_step_level && 257 entry_cck->fir_step_level >= entry_ofdm->fir_step_level) 258 ath9k_hw_ani_control(ah, 259 ATH9K_ANI_FIRSTEP_LEVEL, 260 entry_cck->fir_step_level); 261 262 /* Skip MRC CCK for pre AR9003 families */ 263 if (!AR_SREV_9300_20_OR_LATER(ah) || AR_SREV_9485(ah) || 264 AR_SREV_9565(ah) || AR_SREV_9561(ah)) 265 return; 266 267 if (aniState->mrcCCK != entry_cck->mrc_cck_on) 268 ath9k_hw_ani_control(ah, 269 ATH9K_ANI_MRC_CCK, 270 entry_cck->mrc_cck_on); 271 } 272 273 static void ath9k_hw_ani_cck_err_trigger(struct ath_hw *ah) 274 { 275 struct ar5416AniState *aniState = &ah->ani; 276 277 if (aniState->cckNoiseImmunityLevel < ATH9K_ANI_CCK_MAX_LEVEL) 278 ath9k_hw_set_cck_nil(ah, aniState->cckNoiseImmunityLevel + 1, 279 false); 280 } 281 282 /* 283 * only lower either OFDM or CCK errors per turn 284 * we lower the other one next time 285 */ 286 static void ath9k_hw_ani_lower_immunity(struct ath_hw *ah) 287 { 288 struct ar5416AniState *aniState = &ah->ani; 289 290 /* lower OFDM noise immunity */ 291 if (aniState->ofdmNoiseImmunityLevel > 0 && 292 (aniState->ofdmsTurn || aniState->cckNoiseImmunityLevel == 0)) { 293 ath9k_hw_set_ofdm_nil(ah, aniState->ofdmNoiseImmunityLevel - 1, 294 false); 295 return; 296 } 297 298 /* lower CCK noise immunity */ 299 if (aniState->cckNoiseImmunityLevel > 0) 300 ath9k_hw_set_cck_nil(ah, aniState->cckNoiseImmunityLevel - 1, 301 false); 302 } 303 304 /* 305 * Restore the ANI parameters in the HAL and reset the statistics. 306 * This routine should be called for every hardware reset and for 307 * every channel change. 308 */ 309 void ath9k_ani_reset(struct ath_hw *ah, bool is_scanning) 310 { 311 struct ar5416AniState *aniState = &ah->ani; 312 struct ath9k_channel *chan = ah->curchan; 313 struct ath_common *common = ath9k_hw_common(ah); 314 int ofdm_nil, cck_nil; 315 316 if (!chan) 317 return; 318 319 BUG_ON(aniState == NULL); 320 ah->stats.ast_ani_reset++; 321 322 ofdm_nil = max_t(int, ATH9K_ANI_OFDM_DEF_LEVEL, 323 aniState->ofdmNoiseImmunityLevel); 324 cck_nil = max_t(int, ATH9K_ANI_CCK_DEF_LEVEL, 325 aniState->cckNoiseImmunityLevel); 326 327 if (is_scanning || 328 (ah->opmode != NL80211_IFTYPE_STATION && 329 ah->opmode != NL80211_IFTYPE_ADHOC)) { 330 /* 331 * If we're scanning or in AP mode, the defaults (ini) 332 * should be in place. For an AP we assume the historical 333 * levels for this channel are probably outdated so start 334 * from defaults instead. 335 */ 336 if (aniState->ofdmNoiseImmunityLevel != 337 ATH9K_ANI_OFDM_DEF_LEVEL || 338 aniState->cckNoiseImmunityLevel != 339 ATH9K_ANI_CCK_DEF_LEVEL) { 340 ath_dbg(common, ANI, 341 "Restore defaults: opmode %u chan %d Mhz is_scanning=%d ofdm:%d cck:%d\n", 342 ah->opmode, 343 chan->channel, 344 is_scanning, 345 aniState->ofdmNoiseImmunityLevel, 346 aniState->cckNoiseImmunityLevel); 347 348 ofdm_nil = ATH9K_ANI_OFDM_DEF_LEVEL; 349 cck_nil = ATH9K_ANI_CCK_DEF_LEVEL; 350 } 351 } else { 352 /* 353 * restore historical levels for this channel 354 */ 355 ath_dbg(common, ANI, 356 "Restore history: opmode %u chan %d Mhz is_scanning=%d ofdm:%d cck:%d\n", 357 ah->opmode, 358 chan->channel, 359 is_scanning, 360 aniState->ofdmNoiseImmunityLevel, 361 aniState->cckNoiseImmunityLevel); 362 } 363 ath9k_hw_set_ofdm_nil(ah, ofdm_nil, is_scanning); 364 ath9k_hw_set_cck_nil(ah, cck_nil, is_scanning); 365 366 ath9k_ani_restart(ah); 367 } 368 369 static bool ath9k_hw_ani_read_counters(struct ath_hw *ah) 370 { 371 struct ath_common *common = ath9k_hw_common(ah); 372 struct ar5416AniState *aniState = &ah->ani; 373 u32 phyCnt1, phyCnt2; 374 int32_t listenTime; 375 376 ath_hw_cycle_counters_update(common); 377 listenTime = ath_hw_get_listen_time(common); 378 379 if (listenTime <= 0) { 380 ah->stats.ast_ani_lneg_or_lzero++; 381 ath9k_ani_restart(ah); 382 return false; 383 } 384 385 aniState->listenTime += listenTime; 386 387 ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); 388 389 phyCnt1 = REG_READ(ah, AR_PHY_ERR_1); 390 phyCnt2 = REG_READ(ah, AR_PHY_ERR_2); 391 392 ah->stats.ast_ani_ofdmerrs += phyCnt1 - aniState->ofdmPhyErrCount; 393 aniState->ofdmPhyErrCount = phyCnt1; 394 395 ah->stats.ast_ani_cckerrs += phyCnt2 - aniState->cckPhyErrCount; 396 aniState->cckPhyErrCount = phyCnt2; 397 398 return true; 399 } 400 401 void ath9k_hw_ani_monitor(struct ath_hw *ah, struct ath9k_channel *chan) 402 { 403 struct ar5416AniState *aniState = &ah->ani; 404 struct ath_common *common = ath9k_hw_common(ah); 405 u32 ofdmPhyErrRate, cckPhyErrRate; 406 407 if (!ath9k_hw_ani_read_counters(ah)) 408 return; 409 410 ofdmPhyErrRate = aniState->ofdmPhyErrCount * 1000 / 411 aniState->listenTime; 412 cckPhyErrRate = aniState->cckPhyErrCount * 1000 / 413 aniState->listenTime; 414 415 ath_dbg(common, ANI, 416 "listenTime=%d OFDM:%d errs=%d/s CCK:%d errs=%d/s ofdm_turn=%d\n", 417 aniState->listenTime, 418 aniState->ofdmNoiseImmunityLevel, 419 ofdmPhyErrRate, aniState->cckNoiseImmunityLevel, 420 cckPhyErrRate, aniState->ofdmsTurn); 421 422 if (aniState->listenTime > ah->aniperiod) { 423 if (cckPhyErrRate < ah->config.cck_trig_low && 424 ofdmPhyErrRate < ah->config.ofdm_trig_low) { 425 ath9k_hw_ani_lower_immunity(ah); 426 aniState->ofdmsTurn = !aniState->ofdmsTurn; 427 } else if (ofdmPhyErrRate > ah->config.ofdm_trig_high) { 428 ath9k_hw_ani_ofdm_err_trigger(ah); 429 aniState->ofdmsTurn = false; 430 } else if (cckPhyErrRate > ah->config.cck_trig_high) { 431 ath9k_hw_ani_cck_err_trigger(ah); 432 aniState->ofdmsTurn = true; 433 } else 434 return; 435 436 ath9k_ani_restart(ah); 437 } 438 } 439 EXPORT_SYMBOL(ath9k_hw_ani_monitor); 440 441 void ath9k_enable_mib_counters(struct ath_hw *ah) 442 { 443 struct ath_common *common = ath9k_hw_common(ah); 444 445 ath_dbg(common, ANI, "Enable MIB counters\n"); 446 447 ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); 448 449 ENABLE_REGWRITE_BUFFER(ah); 450 451 REG_WRITE(ah, AR_FILT_OFDM, 0); 452 REG_WRITE(ah, AR_FILT_CCK, 0); 453 REG_WRITE(ah, AR_MIBC, 454 ~(AR_MIBC_COW | AR_MIBC_FMC | AR_MIBC_CMC | AR_MIBC_MCS) 455 & 0x0f); 456 REG_WRITE(ah, AR_PHY_ERR_MASK_1, AR_PHY_ERR_OFDM_TIMING); 457 REG_WRITE(ah, AR_PHY_ERR_MASK_2, AR_PHY_ERR_CCK_TIMING); 458 459 REGWRITE_BUFFER_FLUSH(ah); 460 } 461 462 /* Freeze the MIB counters, get the stats and then clear them */ 463 void ath9k_hw_disable_mib_counters(struct ath_hw *ah) 464 { 465 struct ath_common *common = ath9k_hw_common(ah); 466 467 ath_dbg(common, ANI, "Disable MIB counters\n"); 468 469 REG_WRITE(ah, AR_MIBC, AR_MIBC_FMC); 470 ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); 471 REG_WRITE(ah, AR_MIBC, AR_MIBC_CMC); 472 REG_WRITE(ah, AR_FILT_OFDM, 0); 473 REG_WRITE(ah, AR_FILT_CCK, 0); 474 } 475 EXPORT_SYMBOL(ath9k_hw_disable_mib_counters); 476 477 void ath9k_hw_ani_init(struct ath_hw *ah) 478 { 479 struct ath_common *common = ath9k_hw_common(ah); 480 struct ar5416AniState *ani = &ah->ani; 481 482 ath_dbg(common, ANI, "Initialize ANI\n"); 483 484 if (AR_SREV_9300_20_OR_LATER(ah)) { 485 ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH; 486 ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW; 487 ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH; 488 ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW; 489 } else { 490 ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_OLD; 491 ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_OLD; 492 ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH_OLD; 493 ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW_OLD; 494 } 495 496 ani->spurImmunityLevel = ATH9K_ANI_SPUR_IMMUNE_LVL; 497 ani->firstepLevel = ATH9K_ANI_FIRSTEP_LVL; 498 ani->mrcCCK = AR_SREV_9300_20_OR_LATER(ah) ? true : false; 499 ani->ofdmsTurn = true; 500 ani->ofdmWeakSigDetect = true; 501 ani->cckNoiseImmunityLevel = ATH9K_ANI_CCK_DEF_LEVEL; 502 ani->ofdmNoiseImmunityLevel = ATH9K_ANI_OFDM_DEF_LEVEL; 503 504 /* 505 * since we expect some ongoing maintenance on the tables, let's sanity 506 * check here default level should not modify INI setting. 507 */ 508 ah->aniperiod = ATH9K_ANI_PERIOD; 509 ah->config.ani_poll_interval = ATH9K_ANI_POLLINTERVAL; 510 511 ath9k_ani_restart(ah); 512 ath9k_enable_mib_counters(ah); 513 } 514