drivers/net/wireless/ath/ath9k/ani.c - linux - Git at Google

 /*
  * 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 aligment 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 aligment 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)
 {
 	stats->ackrcv_bad += REG_READ(ah, AR_ACK_FAIL);
 	stats->rts_bad += REG_READ(ah, AR_RTS_FAIL);
 	stats->fcs_bad += REG_READ(ah, AR_FCS_FAIL);
 	stats->rts_good += REG_READ(ah, AR_RTS_OK);
 	stats->beacons += REG_READ(ah, AR_BEACON_CNT);
 }

 static void ath9k_ani_restart(struct ath_hw *ah)
 {
 	struct ar5416AniState *aniState;

 	if (!ah->curchan)
 		return;

 	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 (!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;

 	/*
 	 * OFDM Weak signal detection is always enabled for AP mode.
 	 */
 	if (ah->opmode != NL80211_IFTYPE_AP &&
 	    aniState->ofdmWeakSigDetect != weak_sig) {
 		ath9k_hw_ani_control(ah,
 				     ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
 				     entry_ofdm->ofdm_weak_signal_on);
 	}

 	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;

 	if (!ah->curchan)
 		return;

 	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 (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))
 		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;

 	if (!ah->curchan)
 		return;

 	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;

 	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 (!ah->curchan)
 		return;

 	BUG_ON(aniState == NULL);
 	ah->stats.ast_ani_reset++;

 	/* only allow a subset of functions in AP mode */
 	if (ah->opmode == NL80211_IFTYPE_AP) {
 		if (IS_CHAN_2GHZ(chan)) {
 			ah->ani_function = (ATH9K_ANI_SPUR_IMMUNITY_LEVEL |
 					    ATH9K_ANI_FIRSTEP_LEVEL);
 			if (AR_SREV_9300_20_OR_LATER(ah))
 				ah->ani_function |= ATH9K_ANI_MRC_CCK;
 		} else
 			ah->ani_function = 0;
 	}

 	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;
 	struct ath_common *common = ath9k_hw_common(ah);
 	u32 ofdmPhyErrRate, cckPhyErrRate;

 	if (!ah->curchan)
 		return;

 	aniState = &ah->ani;
 	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;
 		}
 		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");

 	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;

 	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);
 }
	/*
	* 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 aligment 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 aligment 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)
	{
	stats->ackrcv_bad += REG_READ(ah, AR_ACK_FAIL);
	stats->rts_bad += REG_READ(ah, AR_RTS_FAIL);
	stats->fcs_bad += REG_READ(ah, AR_FCS_FAIL);
	stats->rts_good += REG_READ(ah, AR_RTS_OK);
	stats->beacons += REG_READ(ah, AR_BEACON_CNT);
	}

	static void ath9k_ani_restart(struct ath_hw *ah)
	{
	struct ar5416AniState *aniState;

	if (!ah->curchan)
	return;

	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 (!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;

	/*
	* OFDM Weak signal detection is always enabled for AP mode.
	*/
	if (ah->opmode != NL80211_IFTYPE_AP &&
	aniState->ofdmWeakSigDetect != weak_sig) {
	ath9k_hw_ani_control(ah,
	ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
	entry_ofdm->ofdm_weak_signal_on);
	}

	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;

	if (!ah->curchan)
	return;

	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 (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))
	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;

	if (!ah->curchan)
	return;

	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;

	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 (!ah->curchan)
	return;

	BUG_ON(aniState == NULL);
	ah->stats.ast_ani_reset++;

	/* only allow a subset of functions in AP mode */
	if (ah->opmode == NL80211_IFTYPE_AP) {
	if (IS_CHAN_2GHZ(chan)) {
	ah->ani_function = (ATH9K_ANI_SPUR_IMMUNITY_LEVEL \|
	ATH9K_ANI_FIRSTEP_LEVEL);
	if (AR_SREV_9300_20_OR_LATER(ah))
	ah->ani_function \|= ATH9K_ANI_MRC_CCK;
	} else
	ah->ani_function = 0;
	}

	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;
	struct ath_common *common = ath9k_hw_common(ah);
	u32 ofdmPhyErrRate, cckPhyErrRate;

	if (!ah->curchan)
	return;

	aniState = &ah->ani;
	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;
	}
	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");

	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;

	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);
	}