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
22struct 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
39static 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
80struct ani_cck_level_entry {
81 int fir_step_level;
82 int mrc_cck_on;
83};
84
85static 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
107static 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
127static 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, stats: &ah->ah_mibStats);
143
144 aniState->ofdmPhyErrCount = 0;
145 aniState->cckPhyErrCount = 0;
146}
147
148/* Adjust the OFDM Noise Immunity Level */
149static 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 cmd: ATH9K_ANI_SPUR_IMMUNITY_LEVEL,
176 param: 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 cmd: ATH9K_ANI_FIRSTEP_LEVEL,
182 param: 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, cmd: ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
204 param: 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
218static 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, immunityLevel: aniState->ofdmNoiseImmunityLevel + 1, scan: false);
224}
225
226/*
227 * Set the ANI settings to match an CCK level.
228 */
229static 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 cmd: ATH9K_ANI_FIRSTEP_LEVEL,
260 param: 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 cmd: ATH9K_ANI_MRC_CCK,
270 param: entry_cck->mrc_cck_on);
271}
272
273static 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, immunityLevel: aniState->cckNoiseImmunityLevel + 1,
279 scan: false);
280}
281
282/*
283 * only lower either OFDM or CCK errors per turn
284 * we lower the other one next time
285 */
286static 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, immunityLevel: aniState->ofdmNoiseImmunityLevel - 1,
294 scan: false);
295 return;
296 }
297
298 /* lower CCK noise immunity */
299 if (aniState->cckNoiseImmunityLevel > 0)
300 ath9k_hw_set_cck_nil(ah, immunityLevel: aniState->cckNoiseImmunityLevel - 1,
301 scan: 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 */
309void 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, immunityLevel: ofdm_nil, scan: is_scanning);
364 ath9k_hw_set_cck_nil(ah, immunityLevel: cck_nil, scan: is_scanning);
365
366 ath9k_ani_restart(ah);
367}
368
369static 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, stats: &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
401void 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}
439EXPORT_SYMBOL(ath9k_hw_ani_monitor);
440
441void 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, stats: &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 */
463void 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, stats: &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}
475EXPORT_SYMBOL(ath9k_hw_disable_mib_counters);
476
477void 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

source code of linux/drivers/net/wireless/ath/ath9k/ani.c