drivers/net/wireless/ath/ath9k/calib.c

   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 "hw.h"
  18 #include "hw-ops.h"
  19 #include <linux/export.h>
  20
  21 /* Common calibration code */
  22
  23
  24 static int16_t ath9k_hw_get_nf_hist_mid(int16_t *nfCalBuffer)
  25 {
  26         int16_t nfval;
  27         int16_t sort[ATH9K_NF_CAL_HIST_MAX];
  28         int i, j;
  29
  30         for (i = 0; i < ATH9K_NF_CAL_HIST_MAX; i++)
  31                 sort[i] = nfCalBuffer[i];
  32
  33         for (i = 0; i < ATH9K_NF_CAL_HIST_MAX - 1; i++) {
  34                 for (j = 1; j < ATH9K_NF_CAL_HIST_MAX - i; j++) {
  35                         if (sort[j] > sort[j - 1]) {
  36                                 nfval = sort[j];
  37                                 sort[j] = sort[j - 1];
  38                                 sort[j - 1] = nfval;
  39                         }
  40                 }
  41         }
  42         nfval = sort[(ATH9K_NF_CAL_HIST_MAX - 1) >> 1];
  43
  44         return nfval;
  45 }
  46
  47 static struct ath_nf_limits *ath9k_hw_get_nf_limits(struct ath_hw *ah,
  48                                                     struct ath9k_channel *chan)
  49 {
  50         struct ath_nf_limits *limit;
  51
  52         if (!chan || IS_CHAN_2GHZ(chan))
  53                 limit = &ah->nf_2g;
  54         else
  55                 limit = &ah->nf_5g;
  56
  57         return limit;
  58 }
  59
  60 static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
  61                                    struct ath9k_channel *chan)
  62 {
  63         return ath9k_hw_get_nf_limits(ah, chan)->nominal;
  64 }
  65
  66 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan)
  67 {
  68         s8 noise = ATH_DEFAULT_NOISE_FLOOR;
  69
  70         if (chan && chan->noisefloor) {
  71                 s8 delta = chan->noisefloor -
  72                            ATH9K_NF_CAL_NOISE_THRESH -
  73                            ath9k_hw_get_default_nf(ah, chan);
  74                 if (delta > 0)
  75                         noise += delta;
  76         }
  77         return noise;
  78 }
  79 EXPORT_SYMBOL(ath9k_hw_getchan_noise);
  80
  81 static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
  82                                               struct ath9k_hw_cal_data *cal,
  83                                               int16_t *nfarray)
  84 {
  85         struct ath_common *common = ath9k_hw_common(ah);
  86         struct ath_nf_limits *limit;
  87         struct ath9k_nfcal_hist *h;
  88         bool high_nf_mid = false;
  89         u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
  90         int i;
  91
  92         h = cal->nfCalHist;
  93         limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
  94
  95         for (i = 0; i < NUM_NF_READINGS; i++) {
  96                 if (!(chainmask & (1 << i)) ||
  97                     ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(ah->curchan)))
  98                         continue;
  99
 100                 h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
 101
 102                 if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
 103                         h[i].currIndex = 0;
 104
 105                 if (h[i].invalidNFcount > 0) {
 106                         h[i].invalidNFcount--;
 107                         h[i].privNF = nfarray[i];
 108                 } else {
 109                         h[i].privNF =
 110                                 ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
 111                 }
 112
 113                 if (!h[i].privNF)
 114                         continue;
 115
 116                 if (h[i].privNF > limit->max) {
 117                         high_nf_mid = true;
 118
 119                         ath_dbg(common, CALIBRATE,
 120                                 "NFmid[%d] (%d) > MAX (%d), %s\n",
 121                                 i, h[i].privNF, limit->max,
 122                                 (cal->nfcal_interference ?
 123                                  "not corrected (due to interference)" :
 124                                  "correcting to MAX"));
 125
 126                         /*
 127                          * Normally we limit the average noise floor by the
 128                          * hardware specific maximum here. However if we have
 129                          * encountered stuck beacons because of interference,
 130                          * we bypass this limit here in order to better deal
 131                          * with our environment.
 132                          */
 133                         if (!cal->nfcal_interference)
 134                                 h[i].privNF = limit->max;
 135                 }
 136         }
 137
 138         /*
 139          * If the noise floor seems normal for all chains, assume that
 140          * there is no significant interference in the environment anymore.
 141          * Re-enable the enforcement of the NF maximum again.
 142          */
 143         if (!high_nf_mid)
 144                 cal->nfcal_interference = false;
 145 }
 146
 147 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
 148                                    enum ieee80211_band band,
 149                                    int16_t *nft)
 150 {
 151         switch (band) {
 152         case IEEE80211_BAND_5GHZ:
 153                 *nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
 154                 break;
 155         case IEEE80211_BAND_2GHZ:
 156                 *nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
 157                 break;
 158         default:
 159                 BUG_ON(1);
 160                 return false;
 161         }
 162
 163         return true;
 164 }
 165
 166 void ath9k_hw_reset_calibration(struct ath_hw *ah,
 167                                 struct ath9k_cal_list *currCal)
 168 {
 169         int i;
 170
 171         ath9k_hw_setup_calibration(ah, currCal);
 172
 173         currCal->calState = CAL_RUNNING;
 174
 175         for (i = 0; i < AR5416_MAX_CHAINS; i++) {
 176                 ah->meas0.sign[i] = 0;
 177                 ah->meas1.sign[i] = 0;
 178                 ah->meas2.sign[i] = 0;
 179                 ah->meas3.sign[i] = 0;
 180         }
 181
 182         ah->cal_samples = 0;
 183 }
 184
 185 /* This is done for the currently configured channel */
 186 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
 187 {
 188         struct ath_common *common = ath9k_hw_common(ah);
 189         struct ieee80211_conf *conf = &common->hw->conf;
 190         struct ath9k_cal_list *currCal = ah->cal_list_curr;
 191
 192         if (!ah->caldata)
 193                 return true;
 194
 195         if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
 196                 return true;
 197
 198         if (currCal == NULL)
 199                 return true;
 200
 201         if (currCal->calState != CAL_DONE) {
 202                 ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
 203                         currCal->calState);
 204                 return true;
 205         }
 206
 207         if (!(ah->supp_cals & currCal->calData->calType))
 208                 return true;
 209
 210         ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
 211                 currCal->calData->calType, conf->chandef.chan->center_freq);
 212
 213         ah->caldata->CalValid &= ~currCal->calData->calType;
 214         currCal->calState = CAL_WAITING;
 215
 216         return false;
 217 }
 218 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
 219
 220 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
 221 {
 222         if (ah->caldata)
 223                 ah->caldata->nfcal_pending = true;
 224
 225         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
 226                     AR_PHY_AGC_CONTROL_ENABLE_NF);
 227
 228         if (update)
 229                 REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 230                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 231         else
 232                 REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
 233                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 234
 235         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
 236 }
 237
 238 void ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
 239 {
 240         struct ath9k_nfcal_hist *h = NULL;
 241         unsigned i, j;
 242         int32_t val;
 243         u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
 244         struct ath_common *common = ath9k_hw_common(ah);
 245         struct ieee80211_conf *conf = &common->hw->conf;
 246         s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
 247
 248         if (ah->caldata)
 249                 h = ah->caldata->nfCalHist;
 250
 251         for (i = 0; i < NUM_NF_READINGS; i++) {
 252                 if (chainmask & (1 << i)) {
 253                         s16 nfval;
 254
 255                         if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
 256                                 continue;
 257
 258                         if (h)
 259                                 nfval = h[i].privNF;
 260                         else
 261                                 nfval = default_nf;
 262
 263                         val = REG_READ(ah, ah->nf_regs[i]);
 264                         val &= 0xFFFFFE00;
 265                         val |= (((u32) nfval << 1) & 0x1ff);
 266                         REG_WRITE(ah, ah->nf_regs[i], val);
 267                 }
 268         }
 269
 270         /*
 271          * Load software filtered NF value into baseband internal minCCApwr
 272          * variable.
 273          */
 274         REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 275                     AR_PHY_AGC_CONTROL_ENABLE_NF);
 276         REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 277                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 278         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
 279
 280         /*
 281          * Wait for load to complete, should be fast, a few 10s of us.
 282          * The max delay was changed from an original 250us to 10000us
 283          * since 250us often results in NF load timeout and causes deaf
 284          * condition during stress testing 12/12/2009
 285          */
 286         for (j = 0; j < 10000; j++) {
 287                 if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
 288                      AR_PHY_AGC_CONTROL_NF) == 0)
 289                         break;
 290                 udelay(10);
 291         }
 292
 293         /*
 294          * We timed out waiting for the noisefloor to load, probably due to an
 295          * in-progress rx. Simply return here and allow the load plenty of time
 296          * to complete before the next calibration interval.  We need to avoid
 297          * trying to load -50 (which happens below) while the previous load is
 298          * still in progress as this can cause rx deafness. Instead by returning
 299          * here, the baseband nf cal will just be capped by our present
 300          * noisefloor until the next calibration timer.
 301          */
 302         if (j == 10000) {
 303                 ath_dbg(common, ANY,
 304                         "Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
 305                         REG_READ(ah, AR_PHY_AGC_CONTROL));
 306                 return;
 307         }
 308
 309         /*
 310          * Restore maxCCAPower register parameter again so that we're not capped
 311          * by the median we just loaded.  This will be initial (and max) value
 312          * of next noise floor calibration the baseband does.
 313          */
 314         ENABLE_REGWRITE_BUFFER(ah);
 315         for (i = 0; i < NUM_NF_READINGS; i++) {
 316                 if (chainmask & (1 << i)) {
 317                         if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
 318                                 continue;
 319
 320                         val = REG_READ(ah, ah->nf_regs[i]);
 321                         val &= 0xFFFFFE00;
 322                         val |= (((u32) (-50) << 1) & 0x1ff);
 323                         REG_WRITE(ah, ah->nf_regs[i], val);
 324                 }
 325         }
 326         REGWRITE_BUFFER_FLUSH(ah);
 327 }
 328
 329
 330 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
 331 {
 332         struct ath_common *common = ath9k_hw_common(ah);
 333         struct ath_nf_limits *limit;
 334         int i;
 335
 336         if (IS_CHAN_2GHZ(ah->curchan))
 337                 limit = &ah->nf_2g;
 338         else
 339                 limit = &ah->nf_5g;
 340
 341         for (i = 0; i < NUM_NF_READINGS; i++) {
 342                 if (!nf[i])
 343                         continue;
 344
 345                 ath_dbg(common, CALIBRATE,
 346                         "NF calibrated [%s] [chain %d] is %d\n",
 347                         (i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
 348
 349                 if (nf[i] > limit->max) {
 350                         ath_dbg(common, CALIBRATE,
 351                                 "NF[%d] (%d) > MAX (%d), correcting to MAX\n",
 352                                 i, nf[i], limit->max);
 353                         nf[i] = limit->max;
 354                 } else if (nf[i] < limit->min) {
 355                         ath_dbg(common, CALIBRATE,
 356                                 "NF[%d] (%d) < MIN (%d), correcting to NOM\n",
 357                                 i, nf[i], limit->min);
 358                         nf[i] = limit->nominal;
 359                 }
 360         }
 361 }
 362
 363 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
 364 {
 365         struct ath_common *common = ath9k_hw_common(ah);
 366         int16_t nf, nfThresh;
 367         int16_t nfarray[NUM_NF_READINGS] = { 0 };
 368         struct ath9k_nfcal_hist *h;
 369         struct ieee80211_channel *c = chan->chan;
 370         struct ath9k_hw_cal_data *caldata = ah->caldata;
 371
 372         if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
 373                 ath_dbg(common, CALIBRATE,
 374                         "NF did not complete in calibration window\n");
 375                 return false;
 376         }
 377
 378         ath9k_hw_do_getnf(ah, nfarray);
 379         ath9k_hw_nf_sanitize(ah, nfarray);
 380         nf = nfarray[0];
 381         if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
 382             && nf > nfThresh) {
 383                 ath_dbg(common, CALIBRATE,
 384                         "noise floor failed detected; detected %d, threshold %d\n",
 385                         nf, nfThresh);
 386         }
 387
 388         if (!caldata) {
 389                 chan->noisefloor = nf;
 390                 return false;
 391         }
 392
 393         h = caldata->nfCalHist;
 394         caldata->nfcal_pending = false;
 395         ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
 396         chan->noisefloor = h[0].privNF;
 397         ah->noise = ath9k_hw_getchan_noise(ah, chan);
 398         return true;
 399 }
 400 EXPORT_SYMBOL(ath9k_hw_getnf);
 401
 402 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
 403                                   struct ath9k_channel *chan)
 404 {
 405         struct ath9k_nfcal_hist *h;
 406         s16 default_nf;
 407         int i, j;
 408
 409         ah->caldata->channel = chan->channel;
 410         ah->caldata->channelFlags = chan->channelFlags;
 411         ah->caldata->chanmode = chan->chanmode;
 412         h = ah->caldata->nfCalHist;
 413         default_nf = ath9k_hw_get_default_nf(ah, chan);
 414         for (i = 0; i < NUM_NF_READINGS; i++) {
 415                 h[i].currIndex = 0;
 416                 h[i].privNF = default_nf;
 417                 h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
 418                 for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++) {
 419                         h[i].nfCalBuffer[j] = default_nf;
 420                 }
 421         }
 422 }
 423
 424
 425 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
 426 {
 427         struct ath9k_hw_cal_data *caldata = ah->caldata;
 428
 429         if (unlikely(!caldata))
 430                 return;
 431
 432         /*
 433          * If beacons are stuck, the most likely cause is interference.
 434          * Triggering a noise floor calibration at this point helps the
 435          * hardware adapt to a noisy environment much faster.
 436          * To ensure that we recover from stuck beacons quickly, let
 437          * the baseband update the internal NF value itself, similar to
 438          * what is being done after a full reset.
 439          */
 440         if (!caldata->nfcal_pending)
 441                 ath9k_hw_start_nfcal(ah, true);
 442         else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF))
 443                 ath9k_hw_getnf(ah, ah->curchan);
 444
 445         caldata->nfcal_interference = true;
 446 }
 447 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
 448