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                            s16 nf)
  68 {
  69         s8 noise = ATH_DEFAULT_NOISE_FLOOR;
  70
  71         if (nf) {
  72                 s8 delta = nf - 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                                 (test_bit(NFCAL_INTF, &cal->cal_flags) ?
 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 (!test_bit(NFCAL_INTF, &cal->cal_flags))
 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                 clear_bit(NFCAL_INTF, &cal->cal_flags);
 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 ath9k_cal_list *currCal = ah->cal_list_curr;
 190
 191         if (!ah->caldata)
 192                 return true;
 193
 194         if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
 195                 return true;
 196
 197         if (currCal == NULL)
 198                 return true;
 199
 200         if (currCal->calState != CAL_DONE) {
 201                 ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
 202                         currCal->calState);
 203                 return true;
 204         }
 205
 206         if (!(ah->supp_cals & currCal->calData->calType))
 207                 return true;
 208
 209         ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
 210                 currCal->calData->calType, ah->curchan->chan->center_freq);
 211
 212         ah->caldata->CalValid &= ~currCal->calData->calType;
 213         currCal->calState = CAL_WAITING;
 214
 215         return false;
 216 }
 217 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
 218
 219 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
 220 {
 221         if (ah->caldata)
 222                 set_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
 223
 224         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
 225                     AR_PHY_AGC_CONTROL_ENABLE_NF);
 226
 227         if (update)
 228                 REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 229                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 230         else
 231                 REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
 232                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 233
 234         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
 235 }
 236
 237 void ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
 238 {
 239         struct ath9k_nfcal_hist *h = NULL;
 240         unsigned i, j;
 241         int32_t val;
 242         u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
 243         struct ath_common *common = ath9k_hw_common(ah);
 244         s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
 245
 246         if (ah->caldata)
 247                 h = ah->caldata->nfCalHist;
 248
 249         for (i = 0; i < NUM_NF_READINGS; i++) {
 250                 if (chainmask & (1 << i)) {
 251                         s16 nfval;
 252
 253                         if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
 254                                 continue;
 255
 256                         if (h)
 257                                 nfval = h[i].privNF;
 258                         else
 259                                 nfval = default_nf;
 260
 261                         val = REG_READ(ah, ah->nf_regs[i]);
 262                         val &= 0xFFFFFE00;
 263                         val |= (((u32) nfval << 1) & 0x1ff);
 264                         REG_WRITE(ah, ah->nf_regs[i], val);
 265                 }
 266         }
 267
 268         /*
 269          * Load software filtered NF value into baseband internal minCCApwr
 270          * variable.
 271          */
 272         REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 273                     AR_PHY_AGC_CONTROL_ENABLE_NF);
 274         REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
 275                     AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
 276         REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
 277
 278         /*
 279          * Wait for load to complete, should be fast, a few 10s of us.
 280          * The max delay was changed from an original 250us to 10000us
 281          * since 250us often results in NF load timeout and causes deaf
 282          * condition during stress testing 12/12/2009
 283          */
 284         for (j = 0; j < 10000; j++) {
 285                 if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
 286                      AR_PHY_AGC_CONTROL_NF) == 0)
 287                         break;
 288                 udelay(10);
 289         }
 290
 291         /*
 292          * We timed out waiting for the noisefloor to load, probably due to an
 293          * in-progress rx. Simply return here and allow the load plenty of time
 294          * to complete before the next calibration interval.  We need to avoid
 295          * trying to load -50 (which happens below) while the previous load is
 296          * still in progress as this can cause rx deafness. Instead by returning
 297          * here, the baseband nf cal will just be capped by our present
 298          * noisefloor until the next calibration timer.
 299          */
 300         if (j == 10000) {
 301                 ath_dbg(common, ANY,
 302                         "Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
 303                         REG_READ(ah, AR_PHY_AGC_CONTROL));
 304                 return;
 305         }
 306
 307         /*
 308          * Restore maxCCAPower register parameter again so that we're not capped
 309          * by the median we just loaded.  This will be initial (and max) value
 310          * of next noise floor calibration the baseband does.
 311          */
 312         ENABLE_REGWRITE_BUFFER(ah);
 313         for (i = 0; i < NUM_NF_READINGS; i++) {
 314                 if (chainmask & (1 << i)) {
 315                         if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
 316                                 continue;
 317
 318                         val = REG_READ(ah, ah->nf_regs[i]);
 319                         val &= 0xFFFFFE00;
 320                         val |= (((u32) (-50) << 1) & 0x1ff);
 321                         REG_WRITE(ah, ah->nf_regs[i], val);
 322                 }
 323         }
 324         REGWRITE_BUFFER_FLUSH(ah);
 325 }
 326
 327
 328 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
 329 {
 330         struct ath_common *common = ath9k_hw_common(ah);
 331         struct ath_nf_limits *limit;
 332         int i;
 333
 334         if (IS_CHAN_2GHZ(ah->curchan))
 335                 limit = &ah->nf_2g;
 336         else
 337                 limit = &ah->nf_5g;
 338
 339         for (i = 0; i < NUM_NF_READINGS; i++) {
 340                 if (!nf[i])
 341                         continue;
 342
 343                 ath_dbg(common, CALIBRATE,
 344                         "NF calibrated [%s] [chain %d] is %d\n",
 345                         (i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
 346
 347                 if (nf[i] > limit->max) {
 348                         ath_dbg(common, CALIBRATE,
 349                                 "NF[%d] (%d) > MAX (%d), correcting to MAX\n",
 350                                 i, nf[i], limit->max);
 351                         nf[i] = limit->max;
 352                 } else if (nf[i] < limit->min) {
 353                         ath_dbg(common, CALIBRATE,
 354                                 "NF[%d] (%d) < MIN (%d), correcting to NOM\n",
 355                                 i, nf[i], limit->min);
 356                         nf[i] = limit->nominal;
 357                 }
 358         }
 359 }
 360
 361 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
 362 {
 363         struct ath_common *common = ath9k_hw_common(ah);
 364         int16_t nf, nfThresh;
 365         int16_t nfarray[NUM_NF_READINGS] = { 0 };
 366         struct ath9k_nfcal_hist *h;
 367         struct ieee80211_channel *c = chan->chan;
 368         struct ath9k_hw_cal_data *caldata = ah->caldata;
 369
 370         if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
 371                 ath_dbg(common, CALIBRATE,
 372                         "NF did not complete in calibration window\n");
 373                 return false;
 374         }
 375
 376         ath9k_hw_do_getnf(ah, nfarray);
 377         ath9k_hw_nf_sanitize(ah, nfarray);
 378         nf = nfarray[0];
 379         if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
 380             && nf > nfThresh) {
 381                 ath_dbg(common, CALIBRATE,
 382                         "noise floor failed detected; detected %d, threshold %d\n",
 383                         nf, nfThresh);
 384         }
 385
 386         if (!caldata) {
 387                 chan->noisefloor = nf;
 388                 return false;
 389         }
 390
 391         h = caldata->nfCalHist;
 392         clear_bit(NFCAL_PENDING, &caldata->cal_flags);
 393         ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
 394         chan->noisefloor = h[0].privNF;
 395         ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
 396         return true;
 397 }
 398 EXPORT_SYMBOL(ath9k_hw_getnf);
 399
 400 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
 401                                   struct ath9k_channel *chan)
 402 {
 403         struct ath9k_nfcal_hist *h;
 404         s16 default_nf;
 405         int i, j;
 406
 407         ah->caldata->channel = chan->channel;
 408         ah->caldata->channelFlags = chan->channelFlags;
 409         h = ah->caldata->nfCalHist;
 410         default_nf = ath9k_hw_get_default_nf(ah, chan);
 411         for (i = 0; i < NUM_NF_READINGS; i++) {
 412                 h[i].currIndex = 0;
 413                 h[i].privNF = default_nf;
 414                 h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
 415                 for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++) {
 416                         h[i].nfCalBuffer[j] = default_nf;
 417                 }
 418         }
 419 }
 420
 421
 422 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
 423 {
 424         struct ath9k_hw_cal_data *caldata = ah->caldata;
 425
 426         if (unlikely(!caldata))
 427                 return;
 428
 429         /*
 430          * If beacons are stuck, the most likely cause is interference.
 431          * Triggering a noise floor calibration at this point helps the
 432          * hardware adapt to a noisy environment much faster.
 433          * To ensure that we recover from stuck beacons quickly, let
 434          * the baseband update the internal NF value itself, similar to
 435          * what is being done after a full reset.
 436          */
 437         if (!test_bit(NFCAL_PENDING, &caldata->cal_flags))
 438                 ath9k_hw_start_nfcal(ah, true);
 439         else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF))
 440                 ath9k_hw_getnf(ah, ah->curchan);
 441
 442         set_bit(NFCAL_INTF, &caldata->cal_flags);
 443 }
 444 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
 445