linux/drivers/net/wireless/intel/iwlegacy/4965-calib.c
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   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 - 2011 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.
  18 *
  19 * You should have received a copy of the GNU General Public License
  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
  23 *
  24 * The full GNU General Public License is included in this distribution
  25 * in the file called LICENSE.GPL.
  26 *
  27 * Contact Information:
  28 *  Intel Linux Wireless <ilw@linux.intel.com>
  29 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  30 *
  31 * BSD LICENSE
  32 *
  33 * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.
  34 * All rights reserved.
  35 *
  36 * Redistribution and use in source and binary forms, with or without
  37 * modification, are permitted provided that the following conditions
  38 * are met:
  39 *
  40 *  * Redistributions of source code must retain the above copyright
  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.
  46 *  * Neither the name Intel Corporation nor the names of its
  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/slab.h>
  64#include <net/mac80211.h>
  65
  66#include "common.h"
  67#include "4965.h"
  68
  69/*****************************************************************************
  70 * INIT calibrations framework
  71 *****************************************************************************/
  72
  73struct stats_general_data {
  74        u32 beacon_silence_rssi_a;
  75        u32 beacon_silence_rssi_b;
  76        u32 beacon_silence_rssi_c;
  77        u32 beacon_energy_a;
  78        u32 beacon_energy_b;
  79        u32 beacon_energy_c;
  80};
  81
  82/*****************************************************************************
  83 * RUNTIME calibrations framework
  84 *****************************************************************************/
  85
  86/* "false alarms" are signals that our DSP tries to lock onto,
  87 *   but then determines that they are either noise, or transmissions
  88 *   from a distant wireless network (also "noise", really) that get
  89 *   "stepped on" by stronger transmissions within our own network.
  90 * This algorithm attempts to set a sensitivity level that is high
  91 *   enough to receive all of our own network traffic, but not so
  92 *   high that our DSP gets too busy trying to lock onto non-network
  93 *   activity/noise. */
  94static int
  95il4965_sens_energy_cck(struct il_priv *il, u32 norm_fa, u32 rx_enable_time,
  96                       struct stats_general_data *rx_info)
  97{
  98        u32 max_nrg_cck = 0;
  99        int i = 0;
 100        u8 max_silence_rssi = 0;
 101        u32 silence_ref = 0;
 102        u8 silence_rssi_a = 0;
 103        u8 silence_rssi_b = 0;
 104        u8 silence_rssi_c = 0;
 105        u32 val;
 106
 107        /* "false_alarms" values below are cross-multiplications to assess the
 108         *   numbers of false alarms within the measured period of actual Rx
 109         *   (Rx is off when we're txing), vs the min/max expected false alarms
 110         *   (some should be expected if rx is sensitive enough) in a
 111         *   hypothetical listening period of 200 time units (TU), 204.8 msec:
 112         *
 113         * MIN_FA/fixed-time < false_alarms/actual-rx-time < MAX_FA/beacon-time
 114         *
 115         * */
 116        u32 false_alarms = norm_fa * 200 * 1024;
 117        u32 max_false_alarms = MAX_FA_CCK * rx_enable_time;
 118        u32 min_false_alarms = MIN_FA_CCK * rx_enable_time;
 119        struct il_sensitivity_data *data = NULL;
 120        const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
 121
 122        data = &(il->sensitivity_data);
 123
 124        data->nrg_auto_corr_silence_diff = 0;
 125
 126        /* Find max silence rssi among all 3 receivers.
 127         * This is background noise, which may include transmissions from other
 128         *    networks, measured during silence before our network's beacon */
 129        silence_rssi_a =
 130            (u8) ((rx_info->beacon_silence_rssi_a & ALL_BAND_FILTER) >> 8);
 131        silence_rssi_b =
 132            (u8) ((rx_info->beacon_silence_rssi_b & ALL_BAND_FILTER) >> 8);
 133        silence_rssi_c =
 134            (u8) ((rx_info->beacon_silence_rssi_c & ALL_BAND_FILTER) >> 8);
 135
 136        val = max(silence_rssi_b, silence_rssi_c);
 137        max_silence_rssi = max(silence_rssi_a, (u8) val);
 138
 139        /* Store silence rssi in 20-beacon history table */
 140        data->nrg_silence_rssi[data->nrg_silence_idx] = max_silence_rssi;
 141        data->nrg_silence_idx++;
 142        if (data->nrg_silence_idx >= NRG_NUM_PREV_STAT_L)
 143                data->nrg_silence_idx = 0;
 144
 145        /* Find max silence rssi across 20 beacon history */
 146        for (i = 0; i < NRG_NUM_PREV_STAT_L; i++) {
 147                val = data->nrg_silence_rssi[i];
 148                silence_ref = max(silence_ref, val);
 149        }
 150        D_CALIB("silence a %u, b %u, c %u, 20-bcn max %u\n", silence_rssi_a,
 151                silence_rssi_b, silence_rssi_c, silence_ref);
 152
 153        /* Find max rx energy (min value!) among all 3 receivers,
 154         *   measured during beacon frame.
 155         * Save it in 10-beacon history table. */
 156        i = data->nrg_energy_idx;
 157        val = min(rx_info->beacon_energy_b, rx_info->beacon_energy_c);
 158        data->nrg_value[i] = min(rx_info->beacon_energy_a, val);
 159
 160        data->nrg_energy_idx++;
 161        if (data->nrg_energy_idx >= 10)
 162                data->nrg_energy_idx = 0;
 163
 164        /* Find min rx energy (max value) across 10 beacon history.
 165         * This is the minimum signal level that we want to receive well.
 166         * Add backoff (margin so we don't miss slightly lower energy frames).
 167         * This establishes an upper bound (min value) for energy threshold. */
 168        max_nrg_cck = data->nrg_value[0];
 169        for (i = 1; i < 10; i++)
 170                max_nrg_cck = (u32) max(max_nrg_cck, (data->nrg_value[i]));
 171        max_nrg_cck += 6;
 172
 173        D_CALIB("rx energy a %u, b %u, c %u, 10-bcn max/min %u\n",
 174                rx_info->beacon_energy_a, rx_info->beacon_energy_b,
 175                rx_info->beacon_energy_c, max_nrg_cck - 6);
 176
 177        /* Count number of consecutive beacons with fewer-than-desired
 178         *   false alarms. */
 179        if (false_alarms < min_false_alarms)
 180                data->num_in_cck_no_fa++;
 181        else
 182                data->num_in_cck_no_fa = 0;
 183        D_CALIB("consecutive bcns with few false alarms = %u\n",
 184                data->num_in_cck_no_fa);
 185
 186        /* If we got too many false alarms this time, reduce sensitivity */
 187        if (false_alarms > max_false_alarms &&
 188            data->auto_corr_cck > AUTO_CORR_MAX_TH_CCK) {
 189                D_CALIB("norm FA %u > max FA %u\n", false_alarms,
 190                        max_false_alarms);
 191                D_CALIB("... reducing sensitivity\n");
 192                data->nrg_curr_state = IL_FA_TOO_MANY;
 193                /* Store for "fewer than desired" on later beacon */
 194                data->nrg_silence_ref = silence_ref;
 195
 196                /* increase energy threshold (reduce nrg value)
 197                 *   to decrease sensitivity */
 198                data->nrg_th_cck = data->nrg_th_cck - NRG_STEP_CCK;
 199                /* Else if we got fewer than desired, increase sensitivity */
 200        } else if (false_alarms < min_false_alarms) {
 201                data->nrg_curr_state = IL_FA_TOO_FEW;
 202
 203                /* Compare silence level with silence level for most recent
 204                 *   healthy number or too many false alarms */
 205                data->nrg_auto_corr_silence_diff =
 206                    (s32) data->nrg_silence_ref - (s32) silence_ref;
 207
 208                D_CALIB("norm FA %u < min FA %u, silence diff %d\n",
 209                        false_alarms, min_false_alarms,
 210                        data->nrg_auto_corr_silence_diff);
 211
 212                /* Increase value to increase sensitivity, but only if:
 213                 * 1a) previous beacon did *not* have *too many* false alarms
 214                 * 1b) AND there's a significant difference in Rx levels
 215                 *      from a previous beacon with too many, or healthy # FAs
 216                 * OR 2) We've seen a lot of beacons (100) with too few
 217                 *       false alarms */
 218                if (data->nrg_prev_state != IL_FA_TOO_MANY &&
 219                    (data->nrg_auto_corr_silence_diff > NRG_DIFF ||
 220                     data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA)) {
 221
 222                        D_CALIB("... increasing sensitivity\n");
 223                        /* Increase nrg value to increase sensitivity */
 224                        val = data->nrg_th_cck + NRG_STEP_CCK;
 225                        data->nrg_th_cck = min((u32) ranges->min_nrg_cck, val);
 226                } else {
 227                        D_CALIB("... but not changing sensitivity\n");
 228                }
 229
 230                /* Else we got a healthy number of false alarms, keep status quo */
 231        } else {
 232                D_CALIB(" FA in safe zone\n");
 233                data->nrg_curr_state = IL_FA_GOOD_RANGE;
 234
 235                /* Store for use in "fewer than desired" with later beacon */
 236                data->nrg_silence_ref = silence_ref;
 237
 238                /* If previous beacon had too many false alarms,
 239                 *   give it some extra margin by reducing sensitivity again
 240                 *   (but don't go below measured energy of desired Rx) */
 241                if (IL_FA_TOO_MANY == data->nrg_prev_state) {
 242                        D_CALIB("... increasing margin\n");
 243                        if (data->nrg_th_cck > (max_nrg_cck + NRG_MARGIN))
 244                                data->nrg_th_cck -= NRG_MARGIN;
 245                        else
 246                                data->nrg_th_cck = max_nrg_cck;
 247                }
 248        }
 249
 250        /* Make sure the energy threshold does not go above the measured
 251         * energy of the desired Rx signals (reduced by backoff margin),
 252         * or else we might start missing Rx frames.
 253         * Lower value is higher energy, so we use max()!
 254         */
 255        data->nrg_th_cck = max(max_nrg_cck, data->nrg_th_cck);
 256        D_CALIB("new nrg_th_cck %u\n", data->nrg_th_cck);
 257
 258        data->nrg_prev_state = data->nrg_curr_state;
 259
 260        /* Auto-correlation CCK algorithm */
 261        if (false_alarms > min_false_alarms) {
 262
 263                /* increase auto_corr values to decrease sensitivity
 264                 * so the DSP won't be disturbed by the noise
 265                 */
 266                if (data->auto_corr_cck < AUTO_CORR_MAX_TH_CCK)
 267                        data->auto_corr_cck = AUTO_CORR_MAX_TH_CCK + 1;
 268                else {
 269                        val = data->auto_corr_cck + AUTO_CORR_STEP_CCK;
 270                        data->auto_corr_cck =
 271                            min((u32) ranges->auto_corr_max_cck, val);
 272                }
 273                val = data->auto_corr_cck_mrc + AUTO_CORR_STEP_CCK;
 274                data->auto_corr_cck_mrc =
 275                    min((u32) ranges->auto_corr_max_cck_mrc, val);
 276        } else if (false_alarms < min_false_alarms &&
 277                   (data->nrg_auto_corr_silence_diff > NRG_DIFF ||
 278                    data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA)) {
 279
 280                /* Decrease auto_corr values to increase sensitivity */
 281                val = data->auto_corr_cck - AUTO_CORR_STEP_CCK;
 282                data->auto_corr_cck = max((u32) ranges->auto_corr_min_cck, val);
 283                val = data->auto_corr_cck_mrc - AUTO_CORR_STEP_CCK;
 284                data->auto_corr_cck_mrc =
 285                    max((u32) ranges->auto_corr_min_cck_mrc, val);
 286        }
 287
 288        return 0;
 289}
 290
 291static int
 292il4965_sens_auto_corr_ofdm(struct il_priv *il, u32 norm_fa, u32 rx_enable_time)
 293{
 294        u32 val;
 295        u32 false_alarms = norm_fa * 200 * 1024;
 296        u32 max_false_alarms = MAX_FA_OFDM * rx_enable_time;
 297        u32 min_false_alarms = MIN_FA_OFDM * rx_enable_time;
 298        struct il_sensitivity_data *data = NULL;
 299        const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
 300
 301        data = &(il->sensitivity_data);
 302
 303        /* If we got too many false alarms this time, reduce sensitivity */
 304        if (false_alarms > max_false_alarms) {
 305
 306                D_CALIB("norm FA %u > max FA %u)\n", false_alarms,
 307                        max_false_alarms);
 308
 309                val = data->auto_corr_ofdm + AUTO_CORR_STEP_OFDM;
 310                data->auto_corr_ofdm =
 311                    min((u32) ranges->auto_corr_max_ofdm, val);
 312
 313                val = data->auto_corr_ofdm_mrc + AUTO_CORR_STEP_OFDM;
 314                data->auto_corr_ofdm_mrc =
 315                    min((u32) ranges->auto_corr_max_ofdm_mrc, val);
 316
 317                val = data->auto_corr_ofdm_x1 + AUTO_CORR_STEP_OFDM;
 318                data->auto_corr_ofdm_x1 =
 319                    min((u32) ranges->auto_corr_max_ofdm_x1, val);
 320
 321                val = data->auto_corr_ofdm_mrc_x1 + AUTO_CORR_STEP_OFDM;
 322                data->auto_corr_ofdm_mrc_x1 =
 323                    min((u32) ranges->auto_corr_max_ofdm_mrc_x1, val);
 324        }
 325
 326        /* Else if we got fewer than desired, increase sensitivity */
 327        else if (false_alarms < min_false_alarms) {
 328
 329                D_CALIB("norm FA %u < min FA %u\n", false_alarms,
 330                        min_false_alarms);
 331
 332                val = data->auto_corr_ofdm - AUTO_CORR_STEP_OFDM;
 333                data->auto_corr_ofdm =
 334                    max((u32) ranges->auto_corr_min_ofdm, val);
 335
 336                val = data->auto_corr_ofdm_mrc - AUTO_CORR_STEP_OFDM;
 337                data->auto_corr_ofdm_mrc =
 338                    max((u32) ranges->auto_corr_min_ofdm_mrc, val);
 339
 340                val = data->auto_corr_ofdm_x1 - AUTO_CORR_STEP_OFDM;
 341                data->auto_corr_ofdm_x1 =
 342                    max((u32) ranges->auto_corr_min_ofdm_x1, val);
 343
 344                val = data->auto_corr_ofdm_mrc_x1 - AUTO_CORR_STEP_OFDM;
 345                data->auto_corr_ofdm_mrc_x1 =
 346                    max((u32) ranges->auto_corr_min_ofdm_mrc_x1, val);
 347        } else {
 348                D_CALIB("min FA %u < norm FA %u < max FA %u OK\n",
 349                        min_false_alarms, false_alarms, max_false_alarms);
 350        }
 351        return 0;
 352}
 353
 354static void
 355il4965_prepare_legacy_sensitivity_tbl(struct il_priv *il,
 356                                      struct il_sensitivity_data *data,
 357                                      __le16 *tbl)
 358{
 359        tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_IDX] =
 360            cpu_to_le16((u16) data->auto_corr_ofdm);
 361        tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_MRC_IDX] =
 362            cpu_to_le16((u16) data->auto_corr_ofdm_mrc);
 363        tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_IDX] =
 364            cpu_to_le16((u16) data->auto_corr_ofdm_x1);
 365        tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_MRC_IDX] =
 366            cpu_to_le16((u16) data->auto_corr_ofdm_mrc_x1);
 367
 368        tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_IDX] =
 369            cpu_to_le16((u16) data->auto_corr_cck);
 370        tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_MRC_IDX] =
 371            cpu_to_le16((u16) data->auto_corr_cck_mrc);
 372
 373        tbl[HD_MIN_ENERGY_CCK_DET_IDX] = cpu_to_le16((u16) data->nrg_th_cck);
 374        tbl[HD_MIN_ENERGY_OFDM_DET_IDX] = cpu_to_le16((u16) data->nrg_th_ofdm);
 375
 376        tbl[HD_BARKER_CORR_TH_ADD_MIN_IDX] =
 377            cpu_to_le16(data->barker_corr_th_min);
 378        tbl[HD_BARKER_CORR_TH_ADD_MIN_MRC_IDX] =
 379            cpu_to_le16(data->barker_corr_th_min_mrc);
 380        tbl[HD_OFDM_ENERGY_TH_IN_IDX] = cpu_to_le16(data->nrg_th_cca);
 381
 382        D_CALIB("ofdm: ac %u mrc %u x1 %u mrc_x1 %u thresh %u\n",
 383                data->auto_corr_ofdm, data->auto_corr_ofdm_mrc,
 384                data->auto_corr_ofdm_x1, data->auto_corr_ofdm_mrc_x1,
 385                data->nrg_th_ofdm);
 386
 387        D_CALIB("cck: ac %u mrc %u thresh %u\n", data->auto_corr_cck,
 388                data->auto_corr_cck_mrc, data->nrg_th_cck);
 389}
 390
 391/* Prepare a C_SENSITIVITY, send to uCode if values have changed */
 392static int
 393il4965_sensitivity_write(struct il_priv *il)
 394{
 395        struct il_sensitivity_cmd cmd;
 396        struct il_sensitivity_data *data = NULL;
 397        struct il_host_cmd cmd_out = {
 398                .id = C_SENSITIVITY,
 399                .len = sizeof(struct il_sensitivity_cmd),
 400                .flags = CMD_ASYNC,
 401                .data = &cmd,
 402        };
 403
 404        data = &(il->sensitivity_data);
 405
 406        memset(&cmd, 0, sizeof(cmd));
 407
 408        il4965_prepare_legacy_sensitivity_tbl(il, data, &cmd.table[0]);
 409
 410        /* Update uCode's "work" table, and copy it to DSP */
 411        cmd.control = C_SENSITIVITY_CONTROL_WORK_TBL;
 412
 413        /* Don't send command to uCode if nothing has changed */
 414        if (!memcmp
 415            (&cmd.table[0], &(il->sensitivity_tbl[0]),
 416             sizeof(u16) * HD_TBL_SIZE)) {
 417                D_CALIB("No change in C_SENSITIVITY\n");
 418                return 0;
 419        }
 420
 421        /* Copy table for comparison next time */
 422        memcpy(&(il->sensitivity_tbl[0]), &(cmd.table[0]),
 423               sizeof(u16) * HD_TBL_SIZE);
 424
 425        return il_send_cmd(il, &cmd_out);
 426}
 427
 428void
 429il4965_init_sensitivity(struct il_priv *il)
 430{
 431        int ret = 0;
 432        int i;
 433        struct il_sensitivity_data *data = NULL;
 434        const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
 435
 436        if (il->disable_sens_cal)
 437                return;
 438
 439        D_CALIB("Start il4965_init_sensitivity\n");
 440
 441        /* Clear driver's sensitivity algo data */
 442        data = &(il->sensitivity_data);
 443
 444        if (ranges == NULL)
 445                return;
 446
 447        memset(data, 0, sizeof(struct il_sensitivity_data));
 448
 449        data->num_in_cck_no_fa = 0;
 450        data->nrg_curr_state = IL_FA_TOO_MANY;
 451        data->nrg_prev_state = IL_FA_TOO_MANY;
 452        data->nrg_silence_ref = 0;
 453        data->nrg_silence_idx = 0;
 454        data->nrg_energy_idx = 0;
 455
 456        for (i = 0; i < 10; i++)
 457                data->nrg_value[i] = 0;
 458
 459        for (i = 0; i < NRG_NUM_PREV_STAT_L; i++)
 460                data->nrg_silence_rssi[i] = 0;
 461
 462        data->auto_corr_ofdm = ranges->auto_corr_min_ofdm;
 463        data->auto_corr_ofdm_mrc = ranges->auto_corr_min_ofdm_mrc;
 464        data->auto_corr_ofdm_x1 = ranges->auto_corr_min_ofdm_x1;
 465        data->auto_corr_ofdm_mrc_x1 = ranges->auto_corr_min_ofdm_mrc_x1;
 466        data->auto_corr_cck = AUTO_CORR_CCK_MIN_VAL_DEF;
 467        data->auto_corr_cck_mrc = ranges->auto_corr_min_cck_mrc;
 468        data->nrg_th_cck = ranges->nrg_th_cck;
 469        data->nrg_th_ofdm = ranges->nrg_th_ofdm;
 470        data->barker_corr_th_min = ranges->barker_corr_th_min;
 471        data->barker_corr_th_min_mrc = ranges->barker_corr_th_min_mrc;
 472        data->nrg_th_cca = ranges->nrg_th_cca;
 473
 474        data->last_bad_plcp_cnt_ofdm = 0;
 475        data->last_fa_cnt_ofdm = 0;
 476        data->last_bad_plcp_cnt_cck = 0;
 477        data->last_fa_cnt_cck = 0;
 478
 479        ret |= il4965_sensitivity_write(il);
 480        D_CALIB("<<return 0x%X\n", ret);
 481}
 482
 483void
 484il4965_sensitivity_calibration(struct il_priv *il, void *resp)
 485{
 486        u32 rx_enable_time;
 487        u32 fa_cck;
 488        u32 fa_ofdm;
 489        u32 bad_plcp_cck;
 490        u32 bad_plcp_ofdm;
 491        u32 norm_fa_ofdm;
 492        u32 norm_fa_cck;
 493        struct il_sensitivity_data *data = NULL;
 494        struct stats_rx_non_phy *rx_info;
 495        struct stats_rx_phy *ofdm, *cck;
 496        unsigned long flags;
 497        struct stats_general_data statis;
 498
 499        if (il->disable_sens_cal)
 500                return;
 501
 502        data = &(il->sensitivity_data);
 503
 504        if (!il_is_any_associated(il)) {
 505                D_CALIB("<< - not associated\n");
 506                return;
 507        }
 508
 509        spin_lock_irqsave(&il->lock, flags);
 510
 511        rx_info = &(((struct il_notif_stats *)resp)->rx.general);
 512        ofdm = &(((struct il_notif_stats *)resp)->rx.ofdm);
 513        cck = &(((struct il_notif_stats *)resp)->rx.cck);
 514
 515        if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
 516                D_CALIB("<< invalid data.\n");
 517                spin_unlock_irqrestore(&il->lock, flags);
 518                return;
 519        }
 520
 521        /* Extract Statistics: */
 522        rx_enable_time = le32_to_cpu(rx_info->channel_load);
 523        fa_cck = le32_to_cpu(cck->false_alarm_cnt);
 524        fa_ofdm = le32_to_cpu(ofdm->false_alarm_cnt);
 525        bad_plcp_cck = le32_to_cpu(cck->plcp_err);
 526        bad_plcp_ofdm = le32_to_cpu(ofdm->plcp_err);
 527
 528        statis.beacon_silence_rssi_a =
 529            le32_to_cpu(rx_info->beacon_silence_rssi_a);
 530        statis.beacon_silence_rssi_b =
 531            le32_to_cpu(rx_info->beacon_silence_rssi_b);
 532        statis.beacon_silence_rssi_c =
 533            le32_to_cpu(rx_info->beacon_silence_rssi_c);
 534        statis.beacon_energy_a = le32_to_cpu(rx_info->beacon_energy_a);
 535        statis.beacon_energy_b = le32_to_cpu(rx_info->beacon_energy_b);
 536        statis.beacon_energy_c = le32_to_cpu(rx_info->beacon_energy_c);
 537
 538        spin_unlock_irqrestore(&il->lock, flags);
 539
 540        D_CALIB("rx_enable_time = %u usecs\n", rx_enable_time);
 541
 542        if (!rx_enable_time) {
 543                D_CALIB("<< RX Enable Time == 0!\n");
 544                return;
 545        }
 546
 547        /* These stats increase monotonically, and do not reset
 548         *   at each beacon.  Calculate difference from last value, or just
 549         *   use the new stats value if it has reset or wrapped around. */
 550        if (data->last_bad_plcp_cnt_cck > bad_plcp_cck)
 551                data->last_bad_plcp_cnt_cck = bad_plcp_cck;
 552        else {
 553                bad_plcp_cck -= data->last_bad_plcp_cnt_cck;
 554                data->last_bad_plcp_cnt_cck += bad_plcp_cck;
 555        }
 556
 557        if (data->last_bad_plcp_cnt_ofdm > bad_plcp_ofdm)
 558                data->last_bad_plcp_cnt_ofdm = bad_plcp_ofdm;
 559        else {
 560                bad_plcp_ofdm -= data->last_bad_plcp_cnt_ofdm;
 561                data->last_bad_plcp_cnt_ofdm += bad_plcp_ofdm;
 562        }
 563
 564        if (data->last_fa_cnt_ofdm > fa_ofdm)
 565                data->last_fa_cnt_ofdm = fa_ofdm;
 566        else {
 567                fa_ofdm -= data->last_fa_cnt_ofdm;
 568                data->last_fa_cnt_ofdm += fa_ofdm;
 569        }
 570
 571        if (data->last_fa_cnt_cck > fa_cck)
 572                data->last_fa_cnt_cck = fa_cck;
 573        else {
 574                fa_cck -= data->last_fa_cnt_cck;
 575                data->last_fa_cnt_cck += fa_cck;
 576        }
 577
 578        /* Total aborted signal locks */
 579        norm_fa_ofdm = fa_ofdm + bad_plcp_ofdm;
 580        norm_fa_cck = fa_cck + bad_plcp_cck;
 581
 582        D_CALIB("cck: fa %u badp %u  ofdm: fa %u badp %u\n", fa_cck,
 583                bad_plcp_cck, fa_ofdm, bad_plcp_ofdm);
 584
 585        il4965_sens_auto_corr_ofdm(il, norm_fa_ofdm, rx_enable_time);
 586        il4965_sens_energy_cck(il, norm_fa_cck, rx_enable_time, &statis);
 587
 588        il4965_sensitivity_write(il);
 589}
 590
 591static inline u8
 592il4965_find_first_chain(u8 mask)
 593{
 594        if (mask & ANT_A)
 595                return CHAIN_A;
 596        if (mask & ANT_B)
 597                return CHAIN_B;
 598        return CHAIN_C;
 599}
 600
 601/**
 602 * Run disconnected antenna algorithm to find out which antennas are
 603 * disconnected.
 604 */
 605static void
 606il4965_find_disconn_antenna(struct il_priv *il, u32 * average_sig,
 607                            struct il_chain_noise_data *data)
 608{
 609        u32 active_chains = 0;
 610        u32 max_average_sig;
 611        u16 max_average_sig_antenna_i;
 612        u8 num_tx_chains;
 613        u8 first_chain;
 614        u16 i = 0;
 615
 616        average_sig[0] =
 617            data->chain_signal_a /
 618            il->cfg->chain_noise_num_beacons;
 619        average_sig[1] =
 620            data->chain_signal_b /
 621            il->cfg->chain_noise_num_beacons;
 622        average_sig[2] =
 623            data->chain_signal_c /
 624            il->cfg->chain_noise_num_beacons;
 625
 626        if (average_sig[0] >= average_sig[1]) {
 627                max_average_sig = average_sig[0];
 628                max_average_sig_antenna_i = 0;
 629                active_chains = (1 << max_average_sig_antenna_i);
 630        } else {
 631                max_average_sig = average_sig[1];
 632                max_average_sig_antenna_i = 1;
 633                active_chains = (1 << max_average_sig_antenna_i);
 634        }
 635
 636        if (average_sig[2] >= max_average_sig) {
 637                max_average_sig = average_sig[2];
 638                max_average_sig_antenna_i = 2;
 639                active_chains = (1 << max_average_sig_antenna_i);
 640        }
 641
 642        D_CALIB("average_sig: a %d b %d c %d\n", average_sig[0], average_sig[1],
 643                average_sig[2]);
 644        D_CALIB("max_average_sig = %d, antenna %d\n", max_average_sig,
 645                max_average_sig_antenna_i);
 646
 647        /* Compare signal strengths for all 3 receivers. */
 648        for (i = 0; i < NUM_RX_CHAINS; i++) {
 649                if (i != max_average_sig_antenna_i) {
 650                        s32 rssi_delta = (max_average_sig - average_sig[i]);
 651
 652                        /* If signal is very weak, compared with
 653                         * strongest, mark it as disconnected. */
 654                        if (rssi_delta > MAXIMUM_ALLOWED_PATHLOSS)
 655                                data->disconn_array[i] = 1;
 656                        else
 657                                active_chains |= (1 << i);
 658                        D_CALIB("i = %d  rssiDelta = %d  "
 659                                "disconn_array[i] = %d\n", i, rssi_delta,
 660                                data->disconn_array[i]);
 661                }
 662        }
 663
 664        /*
 665         * The above algorithm sometimes fails when the ucode
 666         * reports 0 for all chains. It's not clear why that
 667         * happens to start with, but it is then causing trouble
 668         * because this can make us enable more chains than the
 669         * hardware really has.
 670         *
 671         * To be safe, simply mask out any chains that we know
 672         * are not on the device.
 673         */
 674        active_chains &= il->hw_params.valid_rx_ant;
 675
 676        num_tx_chains = 0;
 677        for (i = 0; i < NUM_RX_CHAINS; i++) {
 678                /* loops on all the bits of
 679                 * il->hw_setting.valid_tx_ant */
 680                u8 ant_msk = (1 << i);
 681                if (!(il->hw_params.valid_tx_ant & ant_msk))
 682                        continue;
 683
 684                num_tx_chains++;
 685                if (data->disconn_array[i] == 0)
 686                        /* there is a Tx antenna connected */
 687                        break;
 688                if (num_tx_chains == il->hw_params.tx_chains_num &&
 689                    data->disconn_array[i]) {
 690                        /*
 691                         * If all chains are disconnected
 692                         * connect the first valid tx chain
 693                         */
 694                        first_chain =
 695                            il4965_find_first_chain(il->cfg->valid_tx_ant);
 696                        data->disconn_array[first_chain] = 0;
 697                        active_chains |= BIT(first_chain);
 698                        D_CALIB("All Tx chains are disconnected"
 699                                "- declare %d as connected\n", first_chain);
 700                        break;
 701                }
 702        }
 703
 704        if (active_chains != il->hw_params.valid_rx_ant &&
 705            active_chains != il->chain_noise_data.active_chains)
 706                D_CALIB("Detected that not all antennas are connected! "
 707                        "Connected: %#x, valid: %#x.\n", active_chains,
 708                        il->hw_params.valid_rx_ant);
 709
 710        /* Save for use within RXON, TX, SCAN commands, etc. */
 711        data->active_chains = active_chains;
 712        D_CALIB("active_chains (bitwise) = 0x%x\n", active_chains);
 713}
 714
 715static void
 716il4965_gain_computation(struct il_priv *il, u32 * average_noise,
 717                        u16 min_average_noise_antenna_i, u32 min_average_noise,
 718                        u8 default_chain)
 719{
 720        int i, ret;
 721        struct il_chain_noise_data *data = &il->chain_noise_data;
 722
 723        data->delta_gain_code[min_average_noise_antenna_i] = 0;
 724
 725        for (i = default_chain; i < NUM_RX_CHAINS; i++) {
 726                s32 delta_g = 0;
 727
 728                if (!data->disconn_array[i] &&
 729                    data->delta_gain_code[i] ==
 730                    CHAIN_NOISE_DELTA_GAIN_INIT_VAL) {
 731                        delta_g = average_noise[i] - min_average_noise;
 732                        data->delta_gain_code[i] = (u8) ((delta_g * 10) / 15);
 733                        data->delta_gain_code[i] =
 734                            min(data->delta_gain_code[i],
 735                                (u8) CHAIN_NOISE_MAX_DELTA_GAIN_CODE);
 736
 737                        data->delta_gain_code[i] =
 738                            (data->delta_gain_code[i] | (1 << 2));
 739                } else {
 740                        data->delta_gain_code[i] = 0;
 741                }
 742        }
 743        D_CALIB("delta_gain_codes: a %d b %d c %d\n", data->delta_gain_code[0],
 744                data->delta_gain_code[1], data->delta_gain_code[2]);
 745
 746        /* Differential gain gets sent to uCode only once */
 747        if (!data->radio_write) {
 748                struct il_calib_diff_gain_cmd cmd;
 749                data->radio_write = 1;
 750
 751                memset(&cmd, 0, sizeof(cmd));
 752                cmd.hdr.op_code = IL_PHY_CALIBRATE_DIFF_GAIN_CMD;
 753                cmd.diff_gain_a = data->delta_gain_code[0];
 754                cmd.diff_gain_b = data->delta_gain_code[1];
 755                cmd.diff_gain_c = data->delta_gain_code[2];
 756                ret = il_send_cmd_pdu(il, C_PHY_CALIBRATION, sizeof(cmd), &cmd);
 757                if (ret)
 758                        D_CALIB("fail sending cmd " "C_PHY_CALIBRATION\n");
 759
 760                /* TODO we might want recalculate
 761                 * rx_chain in rxon cmd */
 762
 763                /* Mark so we run this algo only once! */
 764                data->state = IL_CHAIN_NOISE_CALIBRATED;
 765        }
 766}
 767
 768/*
 769 * Accumulate 16 beacons of signal and noise stats for each of
 770 *   3 receivers/antennas/rx-chains, then figure out:
 771 * 1)  Which antennas are connected.
 772 * 2)  Differential rx gain settings to balance the 3 receivers.
 773 */
 774void
 775il4965_chain_noise_calibration(struct il_priv *il, void *stat_resp)
 776{
 777        struct il_chain_noise_data *data = NULL;
 778
 779        u32 chain_noise_a;
 780        u32 chain_noise_b;
 781        u32 chain_noise_c;
 782        u32 chain_sig_a;
 783        u32 chain_sig_b;
 784        u32 chain_sig_c;
 785        u32 average_sig[NUM_RX_CHAINS] = { INITIALIZATION_VALUE };
 786        u32 average_noise[NUM_RX_CHAINS] = { INITIALIZATION_VALUE };
 787        u32 min_average_noise = MIN_AVERAGE_NOISE_MAX_VALUE;
 788        u16 min_average_noise_antenna_i = INITIALIZATION_VALUE;
 789        u16 i = 0;
 790        u16 rxon_chnum = INITIALIZATION_VALUE;
 791        u16 stat_chnum = INITIALIZATION_VALUE;
 792        u8 rxon_band24;
 793        u8 stat_band24;
 794        unsigned long flags;
 795        struct stats_rx_non_phy *rx_info;
 796
 797        if (il->disable_chain_noise_cal)
 798                return;
 799
 800        data = &(il->chain_noise_data);
 801
 802        /*
 803         * Accumulate just the first "chain_noise_num_beacons" after
 804         * the first association, then we're done forever.
 805         */
 806        if (data->state != IL_CHAIN_NOISE_ACCUMULATE) {
 807                if (data->state == IL_CHAIN_NOISE_ALIVE)
 808                        D_CALIB("Wait for noise calib reset\n");
 809                return;
 810        }
 811
 812        spin_lock_irqsave(&il->lock, flags);
 813
 814        rx_info = &(((struct il_notif_stats *)stat_resp)->rx.general);
 815
 816        if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
 817                D_CALIB(" << Interference data unavailable\n");
 818                spin_unlock_irqrestore(&il->lock, flags);
 819                return;
 820        }
 821
 822        rxon_band24 = !!(il->staging.flags & RXON_FLG_BAND_24G_MSK);
 823        rxon_chnum = le16_to_cpu(il->staging.channel);
 824
 825        stat_band24 =
 826            !!(((struct il_notif_stats *)stat_resp)->
 827               flag & STATS_REPLY_FLG_BAND_24G_MSK);
 828        stat_chnum =
 829            le32_to_cpu(((struct il_notif_stats *)stat_resp)->flag) >> 16;
 830
 831        /* Make sure we accumulate data for just the associated channel
 832         *   (even if scanning). */
 833        if (rxon_chnum != stat_chnum || rxon_band24 != stat_band24) {
 834                D_CALIB("Stats not from chan=%d, band24=%d\n", rxon_chnum,
 835                        rxon_band24);
 836                spin_unlock_irqrestore(&il->lock, flags);
 837                return;
 838        }
 839
 840        /*
 841         *  Accumulate beacon stats values across
 842         * "chain_noise_num_beacons"
 843         */
 844        chain_noise_a =
 845            le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
 846        chain_noise_b =
 847            le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
 848        chain_noise_c =
 849            le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
 850
 851        chain_sig_a = le32_to_cpu(rx_info->beacon_rssi_a) & IN_BAND_FILTER;
 852        chain_sig_b = le32_to_cpu(rx_info->beacon_rssi_b) & IN_BAND_FILTER;
 853        chain_sig_c = le32_to_cpu(rx_info->beacon_rssi_c) & IN_BAND_FILTER;
 854
 855        spin_unlock_irqrestore(&il->lock, flags);
 856
 857        data->beacon_count++;
 858
 859        data->chain_noise_a = (chain_noise_a + data->chain_noise_a);
 860        data->chain_noise_b = (chain_noise_b + data->chain_noise_b);
 861        data->chain_noise_c = (chain_noise_c + data->chain_noise_c);
 862
 863        data->chain_signal_a = (chain_sig_a + data->chain_signal_a);
 864        data->chain_signal_b = (chain_sig_b + data->chain_signal_b);
 865        data->chain_signal_c = (chain_sig_c + data->chain_signal_c);
 866
 867        D_CALIB("chan=%d, band24=%d, beacon=%d\n", rxon_chnum, rxon_band24,
 868                data->beacon_count);
 869        D_CALIB("chain_sig: a %d b %d c %d\n", chain_sig_a, chain_sig_b,
 870                chain_sig_c);
 871        D_CALIB("chain_noise: a %d b %d c %d\n", chain_noise_a, chain_noise_b,
 872                chain_noise_c);
 873
 874        /* If this is the "chain_noise_num_beacons", determine:
 875         * 1)  Disconnected antennas (using signal strengths)
 876         * 2)  Differential gain (using silence noise) to balance receivers */
 877        if (data->beacon_count != il->cfg->chain_noise_num_beacons)
 878                return;
 879
 880        /* Analyze signal for disconnected antenna */
 881        il4965_find_disconn_antenna(il, average_sig, data);
 882
 883        /* Analyze noise for rx balance */
 884        average_noise[0] =
 885            data->chain_noise_a / il->cfg->chain_noise_num_beacons;
 886        average_noise[1] =
 887            data->chain_noise_b / il->cfg->chain_noise_num_beacons;
 888        average_noise[2] =
 889            data->chain_noise_c / il->cfg->chain_noise_num_beacons;
 890
 891        for (i = 0; i < NUM_RX_CHAINS; i++) {
 892                if (!data->disconn_array[i] &&
 893                    average_noise[i] <= min_average_noise) {
 894                        /* This means that chain i is active and has
 895                         * lower noise values so far: */
 896                        min_average_noise = average_noise[i];
 897                        min_average_noise_antenna_i = i;
 898                }
 899        }
 900
 901        D_CALIB("average_noise: a %d b %d c %d\n", average_noise[0],
 902                average_noise[1], average_noise[2]);
 903
 904        D_CALIB("min_average_noise = %d, antenna %d\n", min_average_noise,
 905                min_average_noise_antenna_i);
 906
 907        il4965_gain_computation(il, average_noise, min_average_noise_antenna_i,
 908                                min_average_noise,
 909                                il4965_find_first_chain(il->cfg->valid_rx_ant));
 910
 911        /* Some power changes may have been made during the calibration.
 912         * Update and commit the RXON
 913         */
 914        if (il->ops->update_chain_flags)
 915                il->ops->update_chain_flags(il);
 916
 917        data->state = IL_CHAIN_NOISE_DONE;
 918        il_power_update_mode(il, false);
 919}
 920
 921void
 922il4965_reset_run_time_calib(struct il_priv *il)
 923{
 924        int i;
 925        memset(&(il->sensitivity_data), 0, sizeof(struct il_sensitivity_data));
 926        memset(&(il->chain_noise_data), 0, sizeof(struct il_chain_noise_data));
 927        for (i = 0; i < NUM_RX_CHAINS; i++)
 928                il->chain_noise_data.delta_gain_code[i] =
 929                    CHAIN_NOISE_DELTA_GAIN_INIT_VAL;
 930
 931        /* Ask for stats now, the uCode will send notification
 932         * periodically after association */
 933        il_send_stats_request(il, CMD_ASYNC, true);
 934}
 935