diff options
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/ani.c')
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/ani.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/ani.c b/drivers/net/wireless/ath/ath9k/ani.c new file mode 100644 index 0000000..5214dd7 --- /dev/null +++ b/drivers/net/wireless/ath/ath9k/ani.c @@ -0,0 +1,513 @@ +/* + * Copyright (c) 2008-2011 Atheros Communications Inc. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <linux/kernel.h> +#include <linux/export.h> +#include "hw.h" +#include "hw-ops.h" + +struct ani_ofdm_level_entry { + int spur_immunity_level; + int fir_step_level; + int ofdm_weak_signal_on; +}; + +/* values here are relative to the INI */ + +/* + * Legend: + * + * SI: Spur immunity + * FS: FIR Step + * WS: OFDM / CCK Weak Signal detection + * MRC-CCK: Maximal Ratio Combining for CCK + */ + +static const struct ani_ofdm_level_entry ofdm_level_table[] = { + /* SI FS WS */ + { 0, 0, 1 }, /* lvl 0 */ + { 1, 1, 1 }, /* lvl 1 */ + { 2, 2, 1 }, /* lvl 2 */ + { 3, 2, 1 }, /* lvl 3 (default) */ + { 4, 3, 1 }, /* lvl 4 */ + { 5, 4, 1 }, /* lvl 5 */ + { 6, 5, 1 }, /* lvl 6 */ + { 7, 6, 1 }, /* lvl 7 */ + { 7, 7, 1 }, /* lvl 8 */ + { 7, 8, 0 } /* lvl 9 */ +}; +#define ATH9K_ANI_OFDM_NUM_LEVEL \ + ARRAY_SIZE(ofdm_level_table) +#define ATH9K_ANI_OFDM_MAX_LEVEL \ + (ATH9K_ANI_OFDM_NUM_LEVEL-1) +#define ATH9K_ANI_OFDM_DEF_LEVEL \ + 3 /* default level - matches the INI settings */ + +/* + * MRC (Maximal Ratio Combining) has always been used with multi-antenna ofdm. + * With OFDM for single stream you just add up all antenna inputs, you're + * only interested in what you get after FFT. Signal alignment is also not + * required for OFDM because any phase difference adds up in the frequency + * domain. + * + * MRC requires extra work for use with CCK. You need to align the antenna + * signals from the different antenna before you can add the signals together. + * You need alignment of signals as CCK is in time domain, so addition can cancel + * your signal completely if phase is 180 degrees (think of adding sine waves). + * You also need to remove noise before the addition and this is where ANI + * MRC CCK comes into play. One of the antenna inputs may be stronger but + * lower SNR, so just adding after alignment can be dangerous. + * + * Regardless of alignment in time, the antenna signals add constructively after + * FFT and improve your reception. For more information: + * + * http://en.wikipedia.org/wiki/Maximal-ratio_combining + */ + +struct ani_cck_level_entry { + int fir_step_level; + int mrc_cck_on; +}; + +static const struct ani_cck_level_entry cck_level_table[] = { + /* FS MRC-CCK */ + { 0, 1 }, /* lvl 0 */ + { 1, 1 }, /* lvl 1 */ + { 2, 1 }, /* lvl 2 (default) */ + { 3, 1 }, /* lvl 3 */ + { 4, 0 }, /* lvl 4 */ + { 5, 0 }, /* lvl 5 */ + { 6, 0 }, /* lvl 6 */ + { 7, 0 }, /* lvl 7 (only for high rssi) */ + { 8, 0 } /* lvl 8 (only for high rssi) */ +}; + +#define ATH9K_ANI_CCK_NUM_LEVEL \ + ARRAY_SIZE(cck_level_table) +#define ATH9K_ANI_CCK_MAX_LEVEL \ + (ATH9K_ANI_CCK_NUM_LEVEL-1) +#define ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI \ + (ATH9K_ANI_CCK_NUM_LEVEL-3) +#define ATH9K_ANI_CCK_DEF_LEVEL \ + 2 /* default level - matches the INI settings */ + +static void ath9k_hw_update_mibstats(struct ath_hw *ah, + struct ath9k_mib_stats *stats) +{ + u32 addr[5] = {AR_RTS_OK, AR_RTS_FAIL, AR_ACK_FAIL, + AR_FCS_FAIL, AR_BEACON_CNT}; + u32 data[5]; + + REG_READ_MULTI(ah, &addr[0], &data[0], 5); + /* AR_RTS_OK */ + stats->rts_good += data[0]; + /* AR_RTS_FAIL */ + stats->rts_bad += data[1]; + /* AR_ACK_FAIL */ + stats->ackrcv_bad += data[2]; + /* AR_FCS_FAIL */ + stats->fcs_bad += data[3]; + /* AR_BEACON_CNT */ + stats->beacons += data[4]; +} + +static void ath9k_ani_restart(struct ath_hw *ah) +{ + struct ar5416AniState *aniState = &ah->ani; + + aniState->listenTime = 0; + + ENABLE_REGWRITE_BUFFER(ah); + + REG_WRITE(ah, AR_PHY_ERR_1, 0); + REG_WRITE(ah, AR_PHY_ERR_2, 0); + REG_WRITE(ah, AR_PHY_ERR_MASK_1, AR_PHY_ERR_OFDM_TIMING); + REG_WRITE(ah, AR_PHY_ERR_MASK_2, AR_PHY_ERR_CCK_TIMING); + + REGWRITE_BUFFER_FLUSH(ah); + + ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); + + aniState->ofdmPhyErrCount = 0; + aniState->cckPhyErrCount = 0; +} + +/* Adjust the OFDM Noise Immunity Level */ +static void ath9k_hw_set_ofdm_nil(struct ath_hw *ah, u8 immunityLevel, + bool scan) +{ + struct ar5416AniState *aniState = &ah->ani; + struct ath_common *common = ath9k_hw_common(ah); + const struct ani_ofdm_level_entry *entry_ofdm; + const struct ani_cck_level_entry *entry_cck; + bool weak_sig; + + ath_dbg(common, ANI, "**** ofdmlevel %d=>%d, rssi=%d[lo=%d hi=%d]\n", + aniState->ofdmNoiseImmunityLevel, + immunityLevel, BEACON_RSSI(ah), + ATH9K_ANI_RSSI_THR_LOW, + ATH9K_ANI_RSSI_THR_HIGH); + + if (AR_SREV_9100(ah) && immunityLevel < ATH9K_ANI_OFDM_DEF_LEVEL) + immunityLevel = ATH9K_ANI_OFDM_DEF_LEVEL; + + if (!scan) + aniState->ofdmNoiseImmunityLevel = immunityLevel; + + entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel]; + entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel]; + + if (aniState->spurImmunityLevel != entry_ofdm->spur_immunity_level) + ath9k_hw_ani_control(ah, + ATH9K_ANI_SPUR_IMMUNITY_LEVEL, + entry_ofdm->spur_immunity_level); + + if (aniState->firstepLevel != entry_ofdm->fir_step_level && + entry_ofdm->fir_step_level >= entry_cck->fir_step_level) + ath9k_hw_ani_control(ah, + ATH9K_ANI_FIRSTEP_LEVEL, + entry_ofdm->fir_step_level); + + weak_sig = entry_ofdm->ofdm_weak_signal_on; + if (ah->opmode == NL80211_IFTYPE_STATION && + BEACON_RSSI(ah) <= ATH9K_ANI_RSSI_THR_HIGH) + weak_sig = true; + /* + * Newer chipsets are better at dealing with high PHY error counts - + * keep weak signal detection enabled when no RSSI threshold is + * available to determine if it is needed (mode != STA) + */ + else if (AR_SREV_9300_20_OR_LATER(ah) && + ah->opmode != NL80211_IFTYPE_STATION) + weak_sig = true; + + /* Older chipsets are more sensitive to high PHY error counts */ + else if (!AR_SREV_9300_20_OR_LATER(ah) && + aniState->ofdmNoiseImmunityLevel >= 8) + weak_sig = false; + + if (aniState->ofdmWeakSigDetect != weak_sig) + ath9k_hw_ani_control(ah, ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION, + weak_sig); + + if (!AR_SREV_9300_20_OR_LATER(ah)) + return; + + if (aniState->ofdmNoiseImmunityLevel >= ATH9K_ANI_OFDM_DEF_LEVEL) { + ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH; + ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_ABOVE_INI; + } else { + ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_BELOW_INI; + ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW; + } +} + +static void ath9k_hw_ani_ofdm_err_trigger(struct ath_hw *ah) +{ + struct ar5416AniState *aniState = &ah->ani; + + if (aniState->ofdmNoiseImmunityLevel < ATH9K_ANI_OFDM_MAX_LEVEL) + ath9k_hw_set_ofdm_nil(ah, aniState->ofdmNoiseImmunityLevel + 1, false); +} + +/* + * Set the ANI settings to match an CCK level. + */ +static void ath9k_hw_set_cck_nil(struct ath_hw *ah, u_int8_t immunityLevel, + bool scan) +{ + struct ar5416AniState *aniState = &ah->ani; + struct ath_common *common = ath9k_hw_common(ah); + const struct ani_ofdm_level_entry *entry_ofdm; + const struct ani_cck_level_entry *entry_cck; + + ath_dbg(common, ANI, "**** ccklevel %d=>%d, rssi=%d[lo=%d hi=%d]\n", + aniState->cckNoiseImmunityLevel, immunityLevel, + BEACON_RSSI(ah), ATH9K_ANI_RSSI_THR_LOW, + ATH9K_ANI_RSSI_THR_HIGH); + + if (AR_SREV_9100(ah) && immunityLevel < ATH9K_ANI_CCK_DEF_LEVEL) + immunityLevel = ATH9K_ANI_CCK_DEF_LEVEL; + + if (ah->opmode == NL80211_IFTYPE_STATION && + BEACON_RSSI(ah) <= ATH9K_ANI_RSSI_THR_LOW && + immunityLevel > ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI) + immunityLevel = ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI; + + if (!scan) + aniState->cckNoiseImmunityLevel = immunityLevel; + + entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel]; + entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel]; + + if (aniState->firstepLevel != entry_cck->fir_step_level && + entry_cck->fir_step_level >= entry_ofdm->fir_step_level) + ath9k_hw_ani_control(ah, + ATH9K_ANI_FIRSTEP_LEVEL, + entry_cck->fir_step_level); + + /* Skip MRC CCK for pre AR9003 families */ + if (!AR_SREV_9300_20_OR_LATER(ah) || AR_SREV_9485(ah) || + AR_SREV_9565(ah) || AR_SREV_9561(ah)) + return; + + if (aniState->mrcCCK != entry_cck->mrc_cck_on) + ath9k_hw_ani_control(ah, + ATH9K_ANI_MRC_CCK, + entry_cck->mrc_cck_on); +} + +static void ath9k_hw_ani_cck_err_trigger(struct ath_hw *ah) +{ + struct ar5416AniState *aniState = &ah->ani; + + if (aniState->cckNoiseImmunityLevel < ATH9K_ANI_CCK_MAX_LEVEL) + ath9k_hw_set_cck_nil(ah, aniState->cckNoiseImmunityLevel + 1, + false); +} + +/* + * only lower either OFDM or CCK errors per turn + * we lower the other one next time + */ +static void ath9k_hw_ani_lower_immunity(struct ath_hw *ah) +{ + struct ar5416AniState *aniState = &ah->ani; + + /* lower OFDM noise immunity */ + if (aniState->ofdmNoiseImmunityLevel > 0 && + (aniState->ofdmsTurn || aniState->cckNoiseImmunityLevel == 0)) { + ath9k_hw_set_ofdm_nil(ah, aniState->ofdmNoiseImmunityLevel - 1, + false); + return; + } + + /* lower CCK noise immunity */ + if (aniState->cckNoiseImmunityLevel > 0) + ath9k_hw_set_cck_nil(ah, aniState->cckNoiseImmunityLevel - 1, + false); +} + +/* + * Restore the ANI parameters in the HAL and reset the statistics. + * This routine should be called for every hardware reset and for + * every channel change. + */ +void ath9k_ani_reset(struct ath_hw *ah, bool is_scanning) +{ + struct ar5416AniState *aniState = &ah->ani; + struct ath9k_channel *chan = ah->curchan; + struct ath_common *common = ath9k_hw_common(ah); + int ofdm_nil, cck_nil; + + if (!chan) + return; + + BUG_ON(aniState == NULL); + ah->stats.ast_ani_reset++; + + ofdm_nil = max_t(int, ATH9K_ANI_OFDM_DEF_LEVEL, + aniState->ofdmNoiseImmunityLevel); + cck_nil = max_t(int, ATH9K_ANI_CCK_DEF_LEVEL, + aniState->cckNoiseImmunityLevel); + + if (is_scanning || + (ah->opmode != NL80211_IFTYPE_STATION && + ah->opmode != NL80211_IFTYPE_ADHOC)) { + /* + * If we're scanning or in AP mode, the defaults (ini) + * should be in place. For an AP we assume the historical + * levels for this channel are probably outdated so start + * from defaults instead. + */ + if (aniState->ofdmNoiseImmunityLevel != + ATH9K_ANI_OFDM_DEF_LEVEL || + aniState->cckNoiseImmunityLevel != + ATH9K_ANI_CCK_DEF_LEVEL) { + ath_dbg(common, ANI, + "Restore defaults: opmode %u chan %d Mhz is_scanning=%d ofdm:%d cck:%d\n", + ah->opmode, + chan->channel, + is_scanning, + aniState->ofdmNoiseImmunityLevel, + aniState->cckNoiseImmunityLevel); + + ofdm_nil = ATH9K_ANI_OFDM_DEF_LEVEL; + cck_nil = ATH9K_ANI_CCK_DEF_LEVEL; + } + } else { + /* + * restore historical levels for this channel + */ + ath_dbg(common, ANI, + "Restore history: opmode %u chan %d Mhz is_scanning=%d ofdm:%d cck:%d\n", + ah->opmode, + chan->channel, + is_scanning, + aniState->ofdmNoiseImmunityLevel, + aniState->cckNoiseImmunityLevel); + } + ath9k_hw_set_ofdm_nil(ah, ofdm_nil, is_scanning); + ath9k_hw_set_cck_nil(ah, cck_nil, is_scanning); + + ath9k_ani_restart(ah); +} + +static bool ath9k_hw_ani_read_counters(struct ath_hw *ah) +{ + struct ath_common *common = ath9k_hw_common(ah); + struct ar5416AniState *aniState = &ah->ani; + u32 phyCnt1, phyCnt2; + int32_t listenTime; + + ath_hw_cycle_counters_update(common); + listenTime = ath_hw_get_listen_time(common); + + if (listenTime <= 0) { + ah->stats.ast_ani_lneg_or_lzero++; + ath9k_ani_restart(ah); + return false; + } + + aniState->listenTime += listenTime; + + ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); + + phyCnt1 = REG_READ(ah, AR_PHY_ERR_1); + phyCnt2 = REG_READ(ah, AR_PHY_ERR_2); + + ah->stats.ast_ani_ofdmerrs += phyCnt1 - aniState->ofdmPhyErrCount; + aniState->ofdmPhyErrCount = phyCnt1; + + ah->stats.ast_ani_cckerrs += phyCnt2 - aniState->cckPhyErrCount; + aniState->cckPhyErrCount = phyCnt2; + + return true; +} + +void ath9k_hw_ani_monitor(struct ath_hw *ah, struct ath9k_channel *chan) +{ + struct ar5416AniState *aniState = &ah->ani; + struct ath_common *common = ath9k_hw_common(ah); + u32 ofdmPhyErrRate, cckPhyErrRate; + + if (!ath9k_hw_ani_read_counters(ah)) + return; + + ofdmPhyErrRate = aniState->ofdmPhyErrCount * 1000 / + aniState->listenTime; + cckPhyErrRate = aniState->cckPhyErrCount * 1000 / + aniState->listenTime; + + ath_dbg(common, ANI, + "listenTime=%d OFDM:%d errs=%d/s CCK:%d errs=%d/s ofdm_turn=%d\n", + aniState->listenTime, + aniState->ofdmNoiseImmunityLevel, + ofdmPhyErrRate, aniState->cckNoiseImmunityLevel, + cckPhyErrRate, aniState->ofdmsTurn); + + if (aniState->listenTime > ah->aniperiod) { + if (cckPhyErrRate < ah->config.cck_trig_low && + ofdmPhyErrRate < ah->config.ofdm_trig_low) { + ath9k_hw_ani_lower_immunity(ah); + aniState->ofdmsTurn = !aniState->ofdmsTurn; + } else if (ofdmPhyErrRate > ah->config.ofdm_trig_high) { + ath9k_hw_ani_ofdm_err_trigger(ah); + aniState->ofdmsTurn = false; + } else if (cckPhyErrRate > ah->config.cck_trig_high) { + ath9k_hw_ani_cck_err_trigger(ah); + aniState->ofdmsTurn = true; + } else + return; + + ath9k_ani_restart(ah); + } +} +EXPORT_SYMBOL(ath9k_hw_ani_monitor); + +void ath9k_enable_mib_counters(struct ath_hw *ah) +{ + struct ath_common *common = ath9k_hw_common(ah); + + ath_dbg(common, ANI, "Enable MIB counters\n"); + + ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); + + ENABLE_REGWRITE_BUFFER(ah); + + REG_WRITE(ah, AR_FILT_OFDM, 0); + REG_WRITE(ah, AR_FILT_CCK, 0); + REG_WRITE(ah, AR_MIBC, + ~(AR_MIBC_COW | AR_MIBC_FMC | AR_MIBC_CMC | AR_MIBC_MCS) + & 0x0f); + REG_WRITE(ah, AR_PHY_ERR_MASK_1, AR_PHY_ERR_OFDM_TIMING); + REG_WRITE(ah, AR_PHY_ERR_MASK_2, AR_PHY_ERR_CCK_TIMING); + + REGWRITE_BUFFER_FLUSH(ah); +} + +/* Freeze the MIB counters, get the stats and then clear them */ +void ath9k_hw_disable_mib_counters(struct ath_hw *ah) +{ + struct ath_common *common = ath9k_hw_common(ah); + + ath_dbg(common, ANI, "Disable MIB counters\n"); + + REG_WRITE(ah, AR_MIBC, AR_MIBC_FMC); + ath9k_hw_update_mibstats(ah, &ah->ah_mibStats); + REG_WRITE(ah, AR_MIBC, AR_MIBC_CMC); + REG_WRITE(ah, AR_FILT_OFDM, 0); + REG_WRITE(ah, AR_FILT_CCK, 0); +} +EXPORT_SYMBOL(ath9k_hw_disable_mib_counters); + +void ath9k_hw_ani_init(struct ath_hw *ah) +{ + struct ath_common *common = ath9k_hw_common(ah); + struct ar5416AniState *ani = &ah->ani; + + ath_dbg(common, ANI, "Initialize ANI\n"); + + if (AR_SREV_9300_20_OR_LATER(ah)) { + ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH; + ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW; + ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH; + ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW; + } else { + ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_OLD; + ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_OLD; + ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH_OLD; + ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW_OLD; + } + + ani->spurImmunityLevel = ATH9K_ANI_SPUR_IMMUNE_LVL; + ani->firstepLevel = ATH9K_ANI_FIRSTEP_LVL; + ani->mrcCCK = AR_SREV_9300_20_OR_LATER(ah) ? true : false; + ani->ofdmsTurn = true; + ani->ofdmWeakSigDetect = true; + ani->cckNoiseImmunityLevel = ATH9K_ANI_CCK_DEF_LEVEL; + ani->ofdmNoiseImmunityLevel = ATH9K_ANI_OFDM_DEF_LEVEL; + + /* + * since we expect some ongoing maintenance on the tables, let's sanity + * check here default level should not modify INI setting. + */ + ah->aniperiod = ATH9K_ANI_PERIOD; + ah->config.ani_poll_interval = ATH9K_ANI_POLLINTERVAL; + + ath9k_ani_restart(ah); + ath9k_enable_mib_counters(ah); +} |