git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/iwlwifi/iwl-calib.c

   1 /******************************************************************************
   2  *
   3  * This file is provided under a dual BSD/GPLv2 license.  When using or
   4  * redistributing this file, you may do so under either license.
   5  *
   6  * GPL LICENSE SUMMARY
   7  *
   8  * Copyright(c) 2008 Intel Corporation. All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of version 2 of the GNU General Public License as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
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  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  22  * USA
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  25  * in the file called LICENSE.GPL.
  26  *
  27  * Contact Information:
  28  * Tomas Winkler <tomas.winkler@intel.com>
  29  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  30  *
  31  * BSD LICENSE
  32  *
  33  * Copyright(c) 2005 - 2008 Intel Corporation. All rights reserved.
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  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  *
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  41  *    notice, this list of conditions and the following disclaimer.
  42  *  * Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in
  44  *    the documentation and/or other materials provided with the
  45  *    distribution.
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  47  *    contributors may be used to endorse or promote products derived
  48  *    from this software without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  51  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  52  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  53  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  54  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  55  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  56  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  60  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  61  *****************************************************************************/
  62
  63 #include <linux/kernel.h>
  64 #include <net/mac80211.h>
  65
  66 #include "iwl-dev.h"
  67 #include "iwl-core.h"
  68 #include "iwl-calib.h"
  69 #include "iwl-eeprom.h"
  70
  71 /* "false alarms" are signals that our DSP tries to lock onto,
  72  *   but then determines that they are either noise, or transmissions
  73  *   from a distant wireless network (also "noise", really) that get
  74  *   "stepped on" by stronger transmissions within our own network.
  75  * This algorithm attempts to set a sensitivity level that is high
  76  *   enough to receive all of our own network traffic, but not so
  77  *   high that our DSP gets too busy trying to lock onto non-network
  78  *   activity/noise. */
  79 static int iwl_sens_energy_cck(struct iwl_priv *priv,
  80                                    u32 norm_fa,
  81                                    u32 rx_enable_time,
  82                                    struct statistics_general_data *rx_info)
  83 {
  84         u32 max_nrg_cck = 0;
  85         int i = 0;
  86         u8 max_silence_rssi = 0;
  87         u32 silence_ref = 0;
  88         u8 silence_rssi_a = 0;
  89         u8 silence_rssi_b = 0;
  90         u8 silence_rssi_c = 0;
  91         u32 val;
  92
  93         /* "false_alarms" values below are cross-multiplications to assess the
  94          *   numbers of false alarms within the measured period of actual Rx
  95          *   (Rx is off when we're txing), vs the min/max expected false alarms
  96          *   (some should be expected if rx is sensitive enough) in a
  97          *   hypothetical listening period of 200 time units (TU), 204.8 msec:
  98          *
  99          * MIN_FA/fixed-time < false_alarms/actual-rx-time < MAX_FA/beacon-time
 100          *
 101          * */
 102         u32 false_alarms = norm_fa * 200 * 1024;
 103         u32 max_false_alarms = MAX_FA_CCK * rx_enable_time;
 104         u32 min_false_alarms = MIN_FA_CCK * rx_enable_time;
 105         struct iwl_sensitivity_data *data = NULL;
 106         const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;
 107
 108         data = &(priv->sensitivity_data);
 109
 110         data->nrg_auto_corr_silence_diff = 0;
 111
 112         /* Find max silence rssi among all 3 receivers.
 113          * This is background noise, which may include transmissions from other
 114          *    networks, measured during silence before our network's beacon */
 115         silence_rssi_a = (u8)((rx_info->beacon_silence_rssi_a &
 116                             ALL_BAND_FILTER) >> 8);
 117         silence_rssi_b = (u8)((rx_info->beacon_silence_rssi_b &
 118                             ALL_BAND_FILTER) >> 8);
 119         silence_rssi_c = (u8)((rx_info->beacon_silence_rssi_c &
 120                             ALL_BAND_FILTER) >> 8);
 121
 122         val = max(silence_rssi_b, silence_rssi_c);
 123         max_silence_rssi = max(silence_rssi_a, (u8) val);
 124
 125         /* Store silence rssi in 20-beacon history table */
 126         data->nrg_silence_rssi[data->nrg_silence_idx] = max_silence_rssi;
 127         data->nrg_silence_idx++;
 128         if (data->nrg_silence_idx >= NRG_NUM_PREV_STAT_L)
 129                 data->nrg_silence_idx = 0;
 130
 131         /* Find max silence rssi across 20 beacon history */
 132         for (i = 0; i < NRG_NUM_PREV_STAT_L; i++) {
 133                 val = data->nrg_silence_rssi[i];
 134                 silence_ref = max(silence_ref, val);
 135         }
 136         IWL_DEBUG_CALIB("silence a %u, b %u, c %u, 20-bcn max %u\n",
 137                         silence_rssi_a, silence_rssi_b, silence_rssi_c,
 138                         silence_ref);
 139
 140         /* Find max rx energy (min value!) among all 3 receivers,
 141          *   measured during beacon frame.
 142          * Save it in 10-beacon history table. */
 143         i = data->nrg_energy_idx;
 144         val = min(rx_info->beacon_energy_b, rx_info->beacon_energy_c);
 145         data->nrg_value[i] = min(rx_info->beacon_energy_a, val);
 146
 147         data->nrg_energy_idx++;
 148         if (data->nrg_energy_idx >= 10)
 149                 data->nrg_energy_idx = 0;
 150
 151         /* Find min rx energy (max value) across 10 beacon history.
 152          * This is the minimum signal level that we want to receive well.
 153          * Add backoff (margin so we don't miss slightly lower energy frames).
 154          * This establishes an upper bound (min value) for energy threshold. */
 155         max_nrg_cck = data->nrg_value[0];
 156         for (i = 1; i < 10; i++)
 157                 max_nrg_cck = (u32) max(max_nrg_cck, (data->nrg_value[i]));
 158         max_nrg_cck += 6;
 159
 160         IWL_DEBUG_CALIB("rx energy a %u, b %u, c %u, 10-bcn max/min %u\n",
 161                         rx_info->beacon_energy_a, rx_info->beacon_energy_b,
 162                         rx_info->beacon_energy_c, max_nrg_cck - 6);
 163
 164         /* Count number of consecutive beacons with fewer-than-desired
 165          *   false alarms. */
 166         if (false_alarms < min_false_alarms)
 167                 data->num_in_cck_no_fa++;
 168         else
 169                 data->num_in_cck_no_fa = 0;
 170         IWL_DEBUG_CALIB("consecutive bcns with few false alarms = %u\n",
 171                         data->num_in_cck_no_fa);
 172
 173         /* If we got too many false alarms this time, reduce sensitivity */
 174         if ((false_alarms > max_false_alarms) &&
 175                 (data->auto_corr_cck > AUTO_CORR_MAX_TH_CCK)) {
 176                 IWL_DEBUG_CALIB("norm FA %u > max FA %u\n",
 177                      false_alarms, max_false_alarms);
 178                 IWL_DEBUG_CALIB("... reducing sensitivity\n");
 179                 data->nrg_curr_state = IWL_FA_TOO_MANY;
 180                 /* Store for "fewer than desired" on later beacon */
 181                 data->nrg_silence_ref = silence_ref;
 182
 183                 /* increase energy threshold (reduce nrg value)
 184                  *   to decrease sensitivity */
 185                 if (data->nrg_th_cck >
 186                         (ranges->max_nrg_cck + NRG_STEP_CCK))
 187                         data->nrg_th_cck = data->nrg_th_cck
 188                                                  - NRG_STEP_CCK;
 189                 else
 190                         data->nrg_th_cck = ranges->max_nrg_cck;
 191         /* Else if we got fewer than desired, increase sensitivity */
 192         } else if (false_alarms < min_false_alarms) {
 193                 data->nrg_curr_state = IWL_FA_TOO_FEW;
 194
 195                 /* Compare silence level with silence level for most recent
 196                  *   healthy number or too many false alarms */
 197                 data->nrg_auto_corr_silence_diff = (s32)data->nrg_silence_ref -
 198                                                    (s32)silence_ref;
 199
 200                 IWL_DEBUG_CALIB("norm FA %u < min FA %u, silence diff %d\n",
 201                          false_alarms, min_false_alarms,
 202                          data->nrg_auto_corr_silence_diff);
 203
 204                 /* Increase value to increase sensitivity, but only if:
 205                  * 1a) previous beacon did *not* have *too many* false alarms
 206                  * 1b) AND there's a significant difference in Rx levels
 207                  *      from a previous beacon with too many, or healthy # FAs
 208                  * OR 2) We've seen a lot of beacons (100) with too few
 209                  *       false alarms */
 210                 if ((data->nrg_prev_state != IWL_FA_TOO_MANY) &&
 211                         ((data->nrg_auto_corr_silence_diff > NRG_DIFF) ||
 212                         (data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA))) {
 213
 214                         IWL_DEBUG_CALIB("... increasing sensitivity\n");
 215                         /* Increase nrg value to increase sensitivity */
 216                         val = data->nrg_th_cck + NRG_STEP_CCK;
 217                         data->nrg_th_cck = min((u32)ranges->min_nrg_cck, val);
 218                 } else {
 219                         IWL_DEBUG_CALIB("... but not changing sensitivity\n");
 220                 }
 221
 222         /* Else we got a healthy number of false alarms, keep status quo */
 223         } else {
 224                 IWL_DEBUG_CALIB(" FA in safe zone\n");
 225                 data->nrg_curr_state = IWL_FA_GOOD_RANGE;
 226
 227                 /* Store for use in "fewer than desired" with later beacon */
 228                 data->nrg_silence_ref = silence_ref;
 229
 230                 /* If previous beacon had too many false alarms,
 231                  *   give it some extra margin by reducing sensitivity again
 232                  *   (but don't go below measured energy of desired Rx) */
 233                 if (IWL_FA_TOO_MANY == data->nrg_prev_state) {
 234                         IWL_DEBUG_CALIB("... increasing margin\n");
 235                         if (data->nrg_th_cck > (max_nrg_cck + NRG_MARGIN))
 236                                 data->nrg_th_cck -= NRG_MARGIN;
 237                         else
 238                                 data->nrg_th_cck = max_nrg_cck;
 239                 }
 240         }
 241
 242         /* Make sure the energy threshold does not go above the measured
 243          * energy of the desired Rx signals (reduced by backoff margin),
 244          * or else we might start missing Rx frames.
 245          * Lower value is higher energy, so we use max()!
 246          */
 247         data->nrg_th_cck = max(max_nrg_cck, data->nrg_th_cck);
 248         IWL_DEBUG_CALIB("new nrg_th_cck %u\n", data->nrg_th_cck);
 249
 250         data->nrg_prev_state = data->nrg_curr_state;
 251
 252         /* Auto-correlation CCK algorithm */
 253         if (false_alarms > min_false_alarms) {
 254
 255                 /* increase auto_corr values to decrease sensitivity
 256                  * so the DSP won't be disturbed by the noise
 257                  */
 258                 if (data->auto_corr_cck < AUTO_CORR_MAX_TH_CCK)
 259                         data->auto_corr_cck = AUTO_CORR_MAX_TH_CCK + 1;
 260                 else {
 261                         val = data->auto_corr_cck + AUTO_CORR_STEP_CCK;
 262                         data->auto_corr_cck =
 263                                 min((u32)ranges->auto_corr_max_cck, val);
 264                 }
 265                 val = data->auto_corr_cck_mrc + AUTO_CORR_STEP_CCK;
 266                 data->auto_corr_cck_mrc =
 267                         min((u32)ranges->auto_corr_max_cck_mrc, val);
 268         } else if ((false_alarms < min_false_alarms) &&
 269            ((data->nrg_auto_corr_silence_diff > NRG_DIFF) ||
 270            (data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA))) {
 271
 272                 /* Decrease auto_corr values to increase sensitivity */
 273                 val = data->auto_corr_cck - AUTO_CORR_STEP_CCK;
 274                 data->auto_corr_cck =
 275                         max((u32)ranges->auto_corr_min_cck, val);
 276                 val = data->auto_corr_cck_mrc - AUTO_CORR_STEP_CCK;
 277                 data->auto_corr_cck_mrc =
 278                         max((u32)ranges->auto_corr_min_cck_mrc, val);
 279         }
 280
 281         return 0;
 282 }
 283
 284
 285 static int iwl_sens_auto_corr_ofdm(struct iwl_priv *priv,
 286                                        u32 norm_fa,
 287                                        u32 rx_enable_time)
 288 {
 289         u32 val;
 290         u32 false_alarms = norm_fa * 200 * 1024;
 291         u32 max_false_alarms = MAX_FA_OFDM * rx_enable_time;
 292         u32 min_false_alarms = MIN_FA_OFDM * rx_enable_time;
 293         struct iwl_sensitivity_data *data = NULL;
 294         const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;
 295
 296         data = &(priv->sensitivity_data);
 297
 298         /* If we got too many false alarms this time, reduce sensitivity */
 299         if (false_alarms > max_false_alarms) {
 300
 301                 IWL_DEBUG_CALIB("norm FA %u > max FA %u)\n",
 302                              false_alarms, max_false_alarms);
 303
 304                 val = data->auto_corr_ofdm + AUTO_CORR_STEP_OFDM;
 305                 data->auto_corr_ofdm =
 306                         min((u32)ranges->auto_corr_max_ofdm, val);
 307
 308                 val = data->auto_corr_ofdm_mrc + AUTO_CORR_STEP_OFDM;
 309                 data->auto_corr_ofdm_mrc =
 310                         min((u32)ranges->auto_corr_max_ofdm_mrc, val);
 311
 312                 val = data->auto_corr_ofdm_x1 + AUTO_CORR_STEP_OFDM;
 313                 data->auto_corr_ofdm_x1 =
 314                         min((u32)ranges->auto_corr_max_ofdm_x1, val);
 315
 316                 val = data->auto_corr_ofdm_mrc_x1 + AUTO_CORR_STEP_OFDM;
 317                 data->auto_corr_ofdm_mrc_x1 =
 318                         min((u32)ranges->auto_corr_max_ofdm_mrc_x1, val);
 319         }
 320
 321         /* Else if we got fewer than desired, increase sensitivity */
 322         else if (false_alarms < min_false_alarms) {
 323
 324                 IWL_DEBUG_CALIB("norm FA %u < min FA %u\n",
 325                              false_alarms, min_false_alarms);
 326
 327                 val = data->auto_corr_ofdm - AUTO_CORR_STEP_OFDM;
 328                 data->auto_corr_ofdm =
 329                         max((u32)ranges->auto_corr_min_ofdm, val);
 330
 331                 val = data->auto_corr_ofdm_mrc - AUTO_CORR_STEP_OFDM;
 332                 data->auto_corr_ofdm_mrc =
 333                         max((u32)ranges->auto_corr_min_ofdm_mrc, val);
 334
 335                 val = data->auto_corr_ofdm_x1 - AUTO_CORR_STEP_OFDM;
 336                 data->auto_corr_ofdm_x1 =
 337                         max((u32)ranges->auto_corr_min_ofdm_x1, val);
 338
 339                 val = data->auto_corr_ofdm_mrc_x1 - AUTO_CORR_STEP_OFDM;
 340                 data->auto_corr_ofdm_mrc_x1 =
 341                         max((u32)ranges->auto_corr_min_ofdm_mrc_x1, val);
 342         } else {
 343                 IWL_DEBUG_CALIB("min FA %u < norm FA %u < max FA %u OK\n",
 344                          min_false_alarms, false_alarms, max_false_alarms);
 345         }
 346         return 0;
 347 }
 348
 349 /* Prepare a SENSITIVITY_CMD, send to uCode if values have changed */
 350 static int iwl_sensitivity_write(struct iwl_priv *priv)
 351 {
 352         int ret = 0;
 353         struct iwl_sensitivity_cmd cmd ;
 354         struct iwl_sensitivity_data *data = NULL;
 355         struct iwl_host_cmd cmd_out = {
 356                 .id = SENSITIVITY_CMD,
 357                 .len = sizeof(struct iwl_sensitivity_cmd),
 358                 .meta.flags = CMD_ASYNC,
 359                 .data = &cmd,
 360         };
 361
 362         data = &(priv->sensitivity_data);
 363
 364         memset(&cmd, 0, sizeof(cmd));
 365
 366         cmd.table[HD_AUTO_CORR32_X4_TH_ADD_MIN_INDEX] =
 367                                 cpu_to_le16((u16)data->auto_corr_ofdm);
 368         cmd.table[HD_AUTO_CORR32_X4_TH_ADD_MIN_MRC_INDEX] =
 369                                 cpu_to_le16((u16)data->auto_corr_ofdm_mrc);
 370         cmd.table[HD_AUTO_CORR32_X1_TH_ADD_MIN_INDEX] =
 371                                 cpu_to_le16((u16)data->auto_corr_ofdm_x1);
 372         cmd.table[HD_AUTO_CORR32_X1_TH_ADD_MIN_MRC_INDEX] =
 373                                 cpu_to_le16((u16)data->auto_corr_ofdm_mrc_x1);
 374
 375         cmd.table[HD_AUTO_CORR40_X4_TH_ADD_MIN_INDEX] =
 376                                 cpu_to_le16((u16)data->auto_corr_cck);
 377         cmd.table[HD_AUTO_CORR40_X4_TH_ADD_MIN_MRC_INDEX] =
 378                                 cpu_to_le16((u16)data->auto_corr_cck_mrc);
 379
 380         cmd.table[HD_MIN_ENERGY_CCK_DET_INDEX] =
 381                                 cpu_to_le16((u16)data->nrg_th_cck);
 382         cmd.table[HD_MIN_ENERGY_OFDM_DET_INDEX] =
 383                                 cpu_to_le16((u16)data->nrg_th_ofdm);
 384
 385         cmd.table[HD_BARKER_CORR_TH_ADD_MIN_INDEX] =
 386                                 __constant_cpu_to_le16(190);
 387         cmd.table[HD_BARKER_CORR_TH_ADD_MIN_MRC_INDEX] =
 388                                 __constant_cpu_to_le16(390);
 389         cmd.table[HD_OFDM_ENERGY_TH_IN_INDEX] =
 390                                 __constant_cpu_to_le16(62);
 391
 392         IWL_DEBUG_CALIB("ofdm: ac %u mrc %u x1 %u mrc_x1 %u thresh %u\n",
 393                         data->auto_corr_ofdm, data->auto_corr_ofdm_mrc,
 394                         data->auto_corr_ofdm_x1, data->auto_corr_ofdm_mrc_x1,
 395                         data->nrg_th_ofdm);
 396
 397         IWL_DEBUG_CALIB("cck: ac %u mrc %u thresh %u\n",
 398                         data->auto_corr_cck, data->auto_corr_cck_mrc,
 399                         data->nrg_th_cck);
 400
 401         /* Update uCode's "work" table, and copy it to DSP */
 402         cmd.control = SENSITIVITY_CMD_CONTROL_WORK_TABLE;
 403
 404         /* Don't send command to uCode if nothing has changed */
 405         if (!memcmp(&cmd.table[0], &(priv->sensitivity_tbl[0]),
 406                     sizeof(u16)*HD_TABLE_SIZE)) {
 407                 IWL_DEBUG_CALIB("No change in SENSITIVITY_CMD\n");
 408                 return 0;
 409         }
 410
 411         /* Copy table for comparison next time */
 412         memcpy(&(priv->sensitivity_tbl[0]), &(cmd.table[0]),
 413                sizeof(u16)*HD_TABLE_SIZE);
 414
 415         ret = iwl_send_cmd(priv, &cmd_out);
 416         if (ret)
 417                 IWL_ERROR("SENSITIVITY_CMD failed\n");
 418
 419         return ret;
 420 }
 421
 422 void iwl_init_sensitivity(struct iwl_priv *priv)
 423 {
 424         int ret = 0;
 425         int i;
 426         struct iwl_sensitivity_data *data = NULL;
 427         const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;
 428
 429         if (priv->disable_sens_cal)
 430                 return;
 431
 432         IWL_DEBUG_CALIB("Start iwl_init_sensitivity\n");
 433
 434         /* Clear driver's sensitivity algo data */
 435         data = &(priv->sensitivity_data);
 436
 437         if (ranges == NULL)
 438                 /* can happen if IWLWIFI_RUN_TIME_CALIB is selected
 439                  * but no IWLXXXX_RUN_TIME_CALIB for specific is selected */
 440                 return;
 441
 442         memset(data, 0, sizeof(struct iwl_sensitivity_data));
 443
 444         data->num_in_cck_no_fa = 0;
 445         data->nrg_curr_state = IWL_FA_TOO_MANY;
 446         data->nrg_prev_state = IWL_FA_TOO_MANY;
 447         data->nrg_silence_ref = 0;
 448         data->nrg_silence_idx = 0;
 449         data->nrg_energy_idx = 0;
 450
 451         for (i = 0; i < 10; i++)
 452                 data->nrg_value[i] = 0;
 453
 454         for (i = 0; i < NRG_NUM_PREV_STAT_L; i++)
 455                 data->nrg_silence_rssi[i] = 0;
 456
 457         data->auto_corr_ofdm = 90;
 458         data->auto_corr_ofdm_mrc = ranges->auto_corr_min_ofdm_mrc;
 459         data->auto_corr_ofdm_x1  = ranges->auto_corr_min_ofdm_x1;
 460         data->auto_corr_ofdm_mrc_x1 = ranges->auto_corr_min_ofdm_mrc_x1;
 461         data->auto_corr_cck = AUTO_CORR_CCK_MIN_VAL_DEF;
 462         data->auto_corr_cck_mrc = ranges->auto_corr_min_cck_mrc;
 463         data->nrg_th_cck = ranges->nrg_th_cck;
 464         data->nrg_th_ofdm = ranges->nrg_th_ofdm;
 465
 466         data->last_bad_plcp_cnt_ofdm = 0;
 467         data->last_fa_cnt_ofdm = 0;
 468         data->last_bad_plcp_cnt_cck = 0;
 469         data->last_fa_cnt_cck = 0;
 470
 471         ret |= iwl_sensitivity_write(priv);
 472         IWL_DEBUG_CALIB("<<return 0x%X\n", ret);
 473 }
 474 EXPORT_SYMBOL(iwl_init_sensitivity);
 475
 476 void iwl_sensitivity_calibration(struct iwl_priv *priv,
 477                                     struct iwl4965_notif_statistics *resp)
 478 {
 479         u32 rx_enable_time;
 480         u32 fa_cck;
 481         u32 fa_ofdm;
 482         u32 bad_plcp_cck;
 483         u32 bad_plcp_ofdm;
 484         u32 norm_fa_ofdm;
 485         u32 norm_fa_cck;
 486         struct iwl_sensitivity_data *data = NULL;
 487         struct statistics_rx_non_phy *rx_info = &(resp->rx.general);
 488         struct statistics_rx *statistics = &(resp->rx);
 489         unsigned long flags;
 490         struct statistics_general_data statis;
 491
 492         if (priv->disable_sens_cal)
 493                 return;
 494
 495         data = &(priv->sensitivity_data);
 496
 497         if (!iwl_is_associated(priv)) {
 498                 IWL_DEBUG_CALIB("<< - not associated\n");
 499                 return;
 500         }
 501
 502         spin_lock_irqsave(&priv->lock, flags);
 503         if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
 504                 IWL_DEBUG_CALIB("<< invalid data.\n");
 505                 spin_unlock_irqrestore(&priv->lock, flags);
 506                 return;
 507         }
 508
 509         /* Extract Statistics: */
 510         rx_enable_time = le32_to_cpu(rx_info->channel_load);
 511         fa_cck = le32_to_cpu(statistics->cck.false_alarm_cnt);
 512         fa_ofdm = le32_to_cpu(statistics->ofdm.false_alarm_cnt);
 513         bad_plcp_cck = le32_to_cpu(statistics->cck.plcp_err);
 514         bad_plcp_ofdm = le32_to_cpu(statistics->ofdm.plcp_err);
 515
 516         statis.beacon_silence_rssi_a =
 517                         le32_to_cpu(statistics->general.beacon_silence_rssi_a);
 518         statis.beacon_silence_rssi_b =
 519                         le32_to_cpu(statistics->general.beacon_silence_rssi_b);
 520         statis.beacon_silence_rssi_c =
 521                         le32_to_cpu(statistics->general.beacon_silence_rssi_c);
 522         statis.beacon_energy_a =
 523                         le32_to_cpu(statistics->general.beacon_energy_a);
 524         statis.beacon_energy_b =
 525                         le32_to_cpu(statistics->general.beacon_energy_b);
 526         statis.beacon_energy_c =
 527                         le32_to_cpu(statistics->general.beacon_energy_c);
 528
 529         spin_unlock_irqrestore(&priv->lock, flags);
 530
 531         IWL_DEBUG_CALIB("rx_enable_time = %u usecs\n", rx_enable_time);
 532
 533         if (!rx_enable_time) {
 534                 IWL_DEBUG_CALIB("<< RX Enable Time == 0! \n");
 535                 return;
 536         }
 537
 538         /* These statistics increase monotonically, and do not reset
 539          *   at each beacon.  Calculate difference from last value, or just
 540          *   use the new statistics value if it has reset or wrapped around. */
 541         if (data->last_bad_plcp_cnt_cck > bad_plcp_cck)
 542                 data->last_bad_plcp_cnt_cck = bad_plcp_cck;
 543         else {
 544                 bad_plcp_cck -= data->last_bad_plcp_cnt_cck;
 545                 data->last_bad_plcp_cnt_cck += bad_plcp_cck;
 546         }
 547
 548         if (data->last_bad_plcp_cnt_ofdm > bad_plcp_ofdm)
 549                 data->last_bad_plcp_cnt_ofdm = bad_plcp_ofdm;
 550         else {
 551                 bad_plcp_ofdm -= data->last_bad_plcp_cnt_ofdm;
 552                 data->last_bad_plcp_cnt_ofdm += bad_plcp_ofdm;
 553         }
 554
 555         if (data->last_fa_cnt_ofdm > fa_ofdm)
 556                 data->last_fa_cnt_ofdm = fa_ofdm;
 557         else {
 558                 fa_ofdm -= data->last_fa_cnt_ofdm;
 559                 data->last_fa_cnt_ofdm += fa_ofdm;
 560         }
 561
 562         if (data->last_fa_cnt_cck > fa_cck)
 563                 data->last_fa_cnt_cck = fa_cck;
 564         else {
 565                 fa_cck -= data->last_fa_cnt_cck;
 566                 data->last_fa_cnt_cck += fa_cck;
 567         }
 568
 569         /* Total aborted signal locks */
 570         norm_fa_ofdm = fa_ofdm + bad_plcp_ofdm;
 571         norm_fa_cck = fa_cck + bad_plcp_cck;
 572
 573         IWL_DEBUG_CALIB("cck: fa %u badp %u  ofdm: fa %u badp %u\n", fa_cck,
 574                         bad_plcp_cck, fa_ofdm, bad_plcp_ofdm);
 575
 576         iwl_sens_auto_corr_ofdm(priv, norm_fa_ofdm, rx_enable_time);
 577         iwl_sens_energy_cck(priv, norm_fa_cck, rx_enable_time, &statis);
 578         iwl_sensitivity_write(priv);
 579
 580         return;
 581 }
 582 EXPORT_SYMBOL(iwl_sensitivity_calibration);
 583
 584 /*
 585  * Accumulate 20 beacons of signal and noise statistics for each of
 586  *   3 receivers/antennas/rx-chains, then figure out:
 587  * 1)  Which antennas are connected.
 588  * 2)  Differential rx gain settings to balance the 3 receivers.
 589  */
 590 void iwl_chain_noise_calibration(struct iwl_priv *priv,
 591                               struct iwl4965_notif_statistics *stat_resp)
 592 {
 593         struct iwl_chain_noise_data *data = NULL;
 594
 595         u32 chain_noise_a;
 596         u32 chain_noise_b;
 597         u32 chain_noise_c;
 598         u32 chain_sig_a;
 599         u32 chain_sig_b;
 600         u32 chain_sig_c;
 601         u32 average_sig[NUM_RX_CHAINS] = {INITIALIZATION_VALUE};
 602         u32 average_noise[NUM_RX_CHAINS] = {INITIALIZATION_VALUE};
 603         u32 max_average_sig;
 604         u16 max_average_sig_antenna_i;
 605         u32 min_average_noise = MIN_AVERAGE_NOISE_MAX_VALUE;
 606         u16 min_average_noise_antenna_i = INITIALIZATION_VALUE;
 607         u16 i = 0;
 608         u16 rxon_chnum = INITIALIZATION_VALUE;
 609         u16 stat_chnum = INITIALIZATION_VALUE;
 610         u8 rxon_band24;
 611         u8 stat_band24;
 612         u32 active_chains = 0;
 613         u8 num_tx_chains;
 614         unsigned long flags;
 615         struct statistics_rx_non_phy *rx_info = &(stat_resp->rx.general);
 616
 617         if (priv->disable_chain_noise_cal)
 618                 return;
 619
 620         data = &(priv->chain_noise_data);
 621
 622         /* Accumulate just the first 20 beacons after the first association,
 623          *   then we're done forever. */
 624         if (data->state != IWL_CHAIN_NOISE_ACCUMULATE) {
 625                 if (data->state == IWL_CHAIN_NOISE_ALIVE)
 626                         IWL_DEBUG_CALIB("Wait for noise calib reset\n");
 627                 return;
 628         }
 629
 630         spin_lock_irqsave(&priv->lock, flags);
 631         if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
 632                 IWL_DEBUG_CALIB(" << Interference data unavailable\n");
 633                 spin_unlock_irqrestore(&priv->lock, flags);
 634                 return;
 635         }
 636
 637         rxon_band24 = !!(priv->staging_rxon.flags & RXON_FLG_BAND_24G_MSK);
 638         rxon_chnum = le16_to_cpu(priv->staging_rxon.channel);
 639         stat_band24 = !!(stat_resp->flag & STATISTICS_REPLY_FLG_BAND_24G_MSK);
 640         stat_chnum = le32_to_cpu(stat_resp->flag) >> 16;
 641
 642         /* Make sure we accumulate data for just the associated channel
 643          *   (even if scanning). */
 644         if ((rxon_chnum != stat_chnum) || (rxon_band24 != stat_band24)) {
 645                 IWL_DEBUG_CALIB("Stats not from chan=%d, band24=%d\n",
 646                                 rxon_chnum, rxon_band24);
 647                 spin_unlock_irqrestore(&priv->lock, flags);
 648                 return;
 649         }
 650
 651         /* Accumulate beacon statistics values across 20 beacons */
 652         chain_noise_a = le32_to_cpu(rx_info->beacon_silence_rssi_a) &
 653                                 IN_BAND_FILTER;
 654         chain_noise_b = le32_to_cpu(rx_info->beacon_silence_rssi_b) &
 655                                 IN_BAND_FILTER;
 656         chain_noise_c = le32_to_cpu(rx_info->beacon_silence_rssi_c) &
 657                                 IN_BAND_FILTER;
 658
 659         chain_sig_a = le32_to_cpu(rx_info->beacon_rssi_a) & IN_BAND_FILTER;
 660         chain_sig_b = le32_to_cpu(rx_info->beacon_rssi_b) & IN_BAND_FILTER;
 661         chain_sig_c = le32_to_cpu(rx_info->beacon_rssi_c) & IN_BAND_FILTER;
 662
 663         spin_unlock_irqrestore(&priv->lock, flags);
 664
 665         data->beacon_count++;
 666
 667         data->chain_noise_a = (chain_noise_a + data->chain_noise_a);
 668         data->chain_noise_b = (chain_noise_b + data->chain_noise_b);
 669         data->chain_noise_c = (chain_noise_c + data->chain_noise_c);
 670
 671         data->chain_signal_a = (chain_sig_a + data->chain_signal_a);
 672         data->chain_signal_b = (chain_sig_b + data->chain_signal_b);
 673         data->chain_signal_c = (chain_sig_c + data->chain_signal_c);
 674
 675         IWL_DEBUG_CALIB("chan=%d, band24=%d, beacon=%d\n",
 676                         rxon_chnum, rxon_band24, data->beacon_count);
 677         IWL_DEBUG_CALIB("chain_sig: a %d b %d c %d\n",
 678                         chain_sig_a, chain_sig_b, chain_sig_c);
 679         IWL_DEBUG_CALIB("chain_noise: a %d b %d c %d\n",
 680                         chain_noise_a, chain_noise_b, chain_noise_c);
 681
 682         /* If this is the 20th beacon, determine:
 683          * 1)  Disconnected antennas (using signal strengths)
 684          * 2)  Differential gain (using silence noise) to balance receivers */
 685         if (data->beacon_count != CAL_NUM_OF_BEACONS)
 686                 return;
 687
 688         /* Analyze signal for disconnected antenna */
 689         average_sig[0] = (data->chain_signal_a) / CAL_NUM_OF_BEACONS;
 690         average_sig[1] = (data->chain_signal_b) / CAL_NUM_OF_BEACONS;
 691         average_sig[2] = (data->chain_signal_c) / CAL_NUM_OF_BEACONS;
 692
 693         if (average_sig[0] >= average_sig[1]) {
 694                 max_average_sig = average_sig[0];
 695                 max_average_sig_antenna_i = 0;
 696                 active_chains = (1 << max_average_sig_antenna_i);
 697         } else {
 698                 max_average_sig = average_sig[1];
 699                 max_average_sig_antenna_i = 1;
 700                 active_chains = (1 << max_average_sig_antenna_i);
 701         }
 702
 703         if (average_sig[2] >= max_average_sig) {
 704                 max_average_sig = average_sig[2];
 705                 max_average_sig_antenna_i = 2;
 706                 active_chains = (1 << max_average_sig_antenna_i);
 707         }
 708
 709         IWL_DEBUG_CALIB("average_sig: a %d b %d c %d\n",
 710                      average_sig[0], average_sig[1], average_sig[2]);
 711         IWL_DEBUG_CALIB("max_average_sig = %d, antenna %d\n",
 712                      max_average_sig, max_average_sig_antenna_i);
 713
 714         /* Compare signal strengths for all 3 receivers. */
 715         for (i = 0; i < NUM_RX_CHAINS; i++) {
 716                 if (i != max_average_sig_antenna_i) {
 717                         s32 rssi_delta = (max_average_sig - average_sig[i]);
 718
 719                         /* If signal is very weak, compared with
 720                          * strongest, mark it as disconnected. */
 721                         if (rssi_delta > MAXIMUM_ALLOWED_PATHLOSS)
 722                                 data->disconn_array[i] = 1;
 723                         else
 724                                 active_chains |= (1 << i);
 725                         IWL_DEBUG_CALIB("i = %d  rssiDelta = %d  "
 726                              "disconn_array[i] = %d\n",
 727                              i, rssi_delta, data->disconn_array[i]);
 728                 }
 729         }
 730
 731         num_tx_chains = 0;
 732         for (i = 0; i < NUM_RX_CHAINS; i++) {
 733                 /* loops on all the bits of
 734                  * priv->hw_setting.valid_tx_ant */
 735                 u8 ant_msk = (1 << i);
 736                 if (!(priv->hw_params.valid_tx_ant & ant_msk))
 737                         continue;
 738
 739                 num_tx_chains++;
 740                 if (data->disconn_array[i] == 0)
 741                         /* there is a Tx antenna connected */
 742                         break;
 743                 if (num_tx_chains == priv->hw_params.tx_chains_num &&
 744                 data->disconn_array[i]) {
 745                         /* This is the last TX antenna and is also
 746                          * disconnected connect it anyway */
 747                         data->disconn_array[i] = 0;
 748                         active_chains |= ant_msk;
 749                         IWL_DEBUG_CALIB("All Tx chains are disconnected W/A - "
 750                                 "declare %d as connected\n", i);
 751                         break;
 752                 }
 753         }
 754
 755         IWL_DEBUG_CALIB("active_chains (bitwise) = 0x%x\n",
 756                         active_chains);
 757
 758         /* Save for use within RXON, TX, SCAN commands, etc. */
 759         /*priv->valid_antenna = active_chains;*/
 760         /*FIXME: should be reflected in RX chains in RXON */
 761
 762         /* Analyze noise for rx balance */
 763         average_noise[0] = ((data->chain_noise_a)/CAL_NUM_OF_BEACONS);
 764         average_noise[1] = ((data->chain_noise_b)/CAL_NUM_OF_BEACONS);
 765         average_noise[2] = ((data->chain_noise_c)/CAL_NUM_OF_BEACONS);
 766
 767         for (i = 0; i < NUM_RX_CHAINS; i++) {
 768                 if (!(data->disconn_array[i]) &&
 769                    (average_noise[i] <= min_average_noise)) {
 770                         /* This means that chain i is active and has
 771                          * lower noise values so far: */
 772                         min_average_noise = average_noise[i];
 773                         min_average_noise_antenna_i = i;
 774                 }
 775         }
 776
 777         IWL_DEBUG_CALIB("average_noise: a %d b %d c %d\n",
 778                         average_noise[0], average_noise[1],
 779                         average_noise[2]);
 780
 781         IWL_DEBUG_CALIB("min_average_noise = %d, antenna %d\n",
 782                         min_average_noise, min_average_noise_antenna_i);
 783
 784         priv->cfg->ops->utils->gain_computation(priv, average_noise,
 785                 min_average_noise_antenna_i, min_average_noise);
 786 }
 787 EXPORT_SYMBOL(iwl_chain_noise_calibration);
 788