Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / wireless / ath / ath9k / antenna.c
diff --git a/kernel/drivers/net/wireless/ath/ath9k/antenna.c b/kernel/drivers/net/wireless/ath/ath9k/antenna.c
new file mode 100644 (file)
index 0000000..a366843
--- /dev/null
@@ -0,0 +1,849 @@
+/*
+ * Copyright (c) 2012 Qualcomm Atheros, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ath9k.h"
+
+/*
+ * AR9285
+ * ======
+ *
+ * EEPROM has 2 4-bit fields containing the card configuration.
+ *
+ * antdiv_ctl1:
+ * ------------
+ * bb_enable_ant_div_lnadiv : 1
+ * bb_ant_div_alt_gaintb    : 1
+ * bb_ant_div_main_gaintb   : 1
+ * bb_enable_ant_fast_div   : 1
+ *
+ * antdiv_ctl2:
+ * -----------
+ * bb_ant_div_alt_lnaconf  : 2
+ * bb_ant_div_main_lnaconf : 2
+ *
+ * The EEPROM bits are used as follows:
+ * ------------------------------------
+ *
+ * bb_enable_ant_div_lnadiv      - Enable LNA path rx antenna diversity/combining.
+ *                                 Set in AR_PHY_MULTICHAIN_GAIN_CTL.
+ *
+ * bb_ant_div_[alt/main]_gaintb  - 0 -> Antenna config Alt/Main uses gaintable 0
+ *                                 1 -> Antenna config Alt/Main uses gaintable 1
+ *                                 Set in AR_PHY_MULTICHAIN_GAIN_CTL.
+ *
+ * bb_enable_ant_fast_div        - Enable fast antenna diversity.
+ *                                 Set in AR_PHY_CCK_DETECT.
+ *
+ * bb_ant_div_[alt/main]_lnaconf - Alt/Main LNA diversity/combining input config.
+ *                                 Set in AR_PHY_MULTICHAIN_GAIN_CTL.
+ *                                 10=LNA1
+ *                                 01=LNA2
+ *                                 11=LNA1+LNA2
+ *                                 00=LNA1-LNA2
+ *
+ * AR9485 / AR9565 / AR9331
+ * ========================
+ *
+ * The same bits are present in the EEPROM, but the location in the
+ * EEPROM is different (ant_div_control in ar9300_BaseExtension_1).
+ *
+ * ant_div_alt_lnaconf      ==> bit 0~1
+ * ant_div_main_lnaconf     ==> bit 2~3
+ * ant_div_alt_gaintb       ==> bit 4
+ * ant_div_main_gaintb      ==> bit 5
+ * enable_ant_div_lnadiv    ==> bit 6
+ * enable_ant_fast_div      ==> bit 7
+ */
+
+static inline bool ath_is_alt_ant_ratio_better(struct ath_ant_comb *antcomb,
+                                              int alt_ratio, int maxdelta,
+                                              int mindelta, int main_rssi_avg,
+                                              int alt_rssi_avg, int pkt_count)
+{
+       if (pkt_count <= 50)
+               return false;
+
+       if (alt_rssi_avg > main_rssi_avg + mindelta)
+               return true;
+
+       if (alt_ratio >= antcomb->ant_ratio2 &&
+           alt_rssi_avg >= antcomb->low_rssi_thresh &&
+           (alt_rssi_avg > main_rssi_avg + maxdelta))
+               return true;
+
+       return false;
+}
+
+static inline bool ath_ant_div_comb_alt_check(struct ath_hw_antcomb_conf *conf,
+                                             struct ath_ant_comb *antcomb,
+                                             int alt_ratio, int alt_rssi_avg,
+                                             int main_rssi_avg)
+{
+       bool result, set1, set2;
+
+       result = set1 = set2 = false;
+
+       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2 &&
+           conf->alt_lna_conf == ATH_ANT_DIV_COMB_LNA1)
+               set1 = true;
+
+       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA1 &&
+           conf->alt_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+               set2 = true;
+
+       switch (conf->div_group) {
+       case 0:
+               if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
+                       result = true;
+               break;
+       case 1:
+       case 2:
+               if (alt_rssi_avg < 4 || alt_rssi_avg < antcomb->low_rssi_thresh)
+                       break;
+
+               if ((set1 && (alt_rssi_avg >= (main_rssi_avg - 5))) ||
+                   (set2 && (alt_rssi_avg >= (main_rssi_avg - 2))) ||
+                   (alt_ratio > antcomb->ant_ratio))
+                       result = true;
+
+               break;
+       case 3:
+               if (alt_rssi_avg < 4 || alt_rssi_avg < antcomb->low_rssi_thresh)
+                       break;
+
+               if ((set1 && (alt_rssi_avg >= (main_rssi_avg - 3))) ||
+                   (set2 && (alt_rssi_avg >= (main_rssi_avg + 3))) ||
+                   (alt_ratio > antcomb->ant_ratio))
+                       result = true;
+
+               break;
+       }
+
+       return result;
+}
+
+static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
+                                     struct ath_hw_antcomb_conf ant_conf,
+                                     int main_rssi_avg)
+{
+       antcomb->quick_scan_cnt = 0;
+
+       if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+               antcomb->rssi_lna2 = main_rssi_avg;
+       else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
+               antcomb->rssi_lna1 = main_rssi_avg;
+
+       switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
+       case 0x10: /* LNA2 A-B */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
+               break;
+       case 0x20: /* LNA1 A-B */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
+               break;
+       case 0x21: /* LNA1 LNA2 */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->second_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               break;
+       case 0x12: /* LNA2 LNA1 */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->second_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               break;
+       case 0x13: /* LNA2 A+B */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
+               break;
+       case 0x23: /* LNA1 A+B */
+               antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               antcomb->first_quick_scan_conf =
+                       ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
+               break;
+       default:
+               break;
+       }
+}
+
+static void ath_ant_set_alt_ratio(struct ath_ant_comb *antcomb,
+                                 struct ath_hw_antcomb_conf *conf)
+{
+       /* set alt to the conf with maximun ratio */
+       if (antcomb->first_ratio && antcomb->second_ratio) {
+               if (antcomb->rssi_second > antcomb->rssi_third) {
+                       /* first alt*/
+                       if ((antcomb->first_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1) ||
+                           (antcomb->first_quick_scan_conf == ATH_ANT_DIV_COMB_LNA2))
+                               /* Set alt LNA1 or LNA2*/
+                               if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+                                       conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                               else
+                                       conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                       else
+                               /* Set alt to A+B or A-B */
+                               conf->alt_lna_conf =
+                                       antcomb->first_quick_scan_conf;
+               } else if ((antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1) ||
+                          (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA2)) {
+                       /* Set alt LNA1 or LNA2 */
+                       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       else
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               } else {
+                       /* Set alt to A+B or A-B */
+                       conf->alt_lna_conf = antcomb->second_quick_scan_conf;
+               }
+       } else if (antcomb->first_ratio) {
+               /* first alt */
+               if ((antcomb->first_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1) ||
+                   (antcomb->first_quick_scan_conf == ATH_ANT_DIV_COMB_LNA2))
+                       /* Set alt LNA1 or LNA2 */
+                       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       else
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               else
+                       /* Set alt to A+B or A-B */
+                       conf->alt_lna_conf = antcomb->first_quick_scan_conf;
+       } else if (antcomb->second_ratio) {
+               /* second alt */
+               if ((antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1) ||
+                   (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA2))
+                       /* Set alt LNA1 or LNA2 */
+                       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       else
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               else
+                       /* Set alt to A+B or A-B */
+                       conf->alt_lna_conf = antcomb->second_quick_scan_conf;
+       } else {
+               /* main is largest */
+               if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
+                   (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
+                       /* Set alt LNA1 or LNA2 */
+                       if (conf->main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       else
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               else
+                       /* Set alt to A+B or A-B */
+                       conf->alt_lna_conf = antcomb->main_conf;
+       }
+}
+
+static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
+                                      struct ath_hw_antcomb_conf *div_ant_conf,
+                                      int main_rssi_avg, int alt_rssi_avg,
+                                      int alt_ratio)
+{
+       /* alt_good */
+       switch (antcomb->quick_scan_cnt) {
+       case 0:
+               /* set alt to main, and alt to first conf */
+               div_ant_conf->main_lna_conf = antcomb->main_conf;
+               div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
+               break;
+       case 1:
+               /* set alt to main, and alt to first conf */
+               div_ant_conf->main_lna_conf = antcomb->main_conf;
+               div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
+               antcomb->rssi_first = main_rssi_avg;
+               antcomb->rssi_second = alt_rssi_avg;
+
+               if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
+                       /* main is LNA1 */
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->first_ratio = true;
+                       else
+                               antcomb->first_ratio = false;
+               } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->first_ratio = true;
+                       else
+                               antcomb->first_ratio = false;
+               } else {
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
+                                               0,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->first_ratio = true;
+                       else
+                               antcomb->first_ratio = false;
+               }
+               break;
+       case 2:
+               antcomb->alt_good = false;
+               antcomb->scan_not_start = false;
+               antcomb->scan = false;
+               antcomb->rssi_first = main_rssi_avg;
+               antcomb->rssi_third = alt_rssi_avg;
+
+               switch(antcomb->second_quick_scan_conf) {
+               case ATH_ANT_DIV_COMB_LNA1:
+                       antcomb->rssi_lna1 = alt_rssi_avg;
+                       break;
+               case ATH_ANT_DIV_COMB_LNA2:
+                       antcomb->rssi_lna2 = alt_rssi_avg;
+                       break;
+               case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
+                       if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
+                               antcomb->rssi_lna2 = main_rssi_avg;
+                       else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
+                               antcomb->rssi_lna1 = main_rssi_avg;
+                       break;
+               default:
+                       break;
+               }
+
+               if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
+                   div_ant_conf->lna1_lna2_switch_delta)
+                       div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               else
+                       div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+
+               if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->second_ratio = true;
+                       else
+                               antcomb->second_ratio = false;
+               } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->second_ratio = true;
+                       else
+                               antcomb->second_ratio = false;
+               } else {
+                       if (ath_is_alt_ant_ratio_better(antcomb, alt_ratio,
+                                               ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
+                                               0,
+                                               main_rssi_avg, alt_rssi_avg,
+                                               antcomb->total_pkt_count))
+                               antcomb->second_ratio = true;
+                       else
+                               antcomb->second_ratio = false;
+               }
+
+               ath_ant_set_alt_ratio(antcomb, div_ant_conf);
+
+               break;
+       default:
+               break;
+       }
+}
+
+static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
+                                         struct ath_ant_comb *antcomb,
+                                         int alt_ratio)
+{
+       ant_conf->main_gaintb = 0;
+       ant_conf->alt_gaintb = 0;
+
+       if (ant_conf->div_group == 0) {
+               /* Adjust the fast_div_bias based on main and alt lna conf */
+               switch ((ant_conf->main_lna_conf << 4) |
+                               ant_conf->alt_lna_conf) {
+               case 0x01: /* A-B LNA2 */
+                       ant_conf->fast_div_bias = 0x3b;
+                       break;
+               case 0x02: /* A-B LNA1 */
+                       ant_conf->fast_div_bias = 0x3d;
+                       break;
+               case 0x03: /* A-B A+B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x10: /* LNA2 A-B */
+                       ant_conf->fast_div_bias = 0x7;
+                       break;
+               case 0x12: /* LNA2 LNA1 */
+                       ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x13: /* LNA2 A+B */
+                       ant_conf->fast_div_bias = 0x7;
+                       break;
+               case 0x20: /* LNA1 A-B */
+                       ant_conf->fast_div_bias = 0x6;
+                       break;
+               case 0x21: /* LNA1 LNA2 */
+                       ant_conf->fast_div_bias = 0x0;
+                       break;
+               case 0x23: /* LNA1 A+B */
+                       ant_conf->fast_div_bias = 0x6;
+                       break;
+               case 0x30: /* A+B A-B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x31: /* A+B LNA2 */
+                       ant_conf->fast_div_bias = 0x3b;
+                       break;
+               case 0x32: /* A+B LNA1 */
+                       ant_conf->fast_div_bias = 0x3d;
+                       break;
+               default:
+                       break;
+               }
+       } else if (ant_conf->div_group == 1) {
+               /* Adjust the fast_div_bias based on main and alt_lna_conf */
+               switch ((ant_conf->main_lna_conf << 4) |
+                       ant_conf->alt_lna_conf) {
+               case 0x01: /* A-B LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x02: /* A-B LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x03: /* A-B A+B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x10: /* LNA2 A-B */
+                       if (!(antcomb->scan) &&
+                           (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
+                               ant_conf->fast_div_bias = 0x3f;
+                       else
+                               ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x12: /* LNA2 LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x13: /* LNA2 A+B */
+                       if (!(antcomb->scan) &&
+                           (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
+                               ant_conf->fast_div_bias = 0x3f;
+                       else
+                               ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x20: /* LNA1 A-B */
+                       if (!(antcomb->scan) &&
+                           (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
+                               ant_conf->fast_div_bias = 0x3f;
+                       else
+                               ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x21: /* LNA1 LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x23: /* LNA1 A+B */
+                       if (!(antcomb->scan) &&
+                           (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
+                               ant_conf->fast_div_bias = 0x3f;
+                       else
+                               ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x30: /* A+B A-B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x31: /* A+B LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x32: /* A+B LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               default:
+                       break;
+               }
+       } else if (ant_conf->div_group == 2) {
+               /* Adjust the fast_div_bias based on main and alt_lna_conf */
+               switch ((ant_conf->main_lna_conf << 4) |
+                               ant_conf->alt_lna_conf) {
+               case 0x01: /* A-B LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x02: /* A-B LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x03: /* A-B A+B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x10: /* LNA2 A-B */
+                       if (!antcomb->scan && (alt_ratio > antcomb->ant_ratio))
+                               ant_conf->fast_div_bias = 0x1;
+                       else
+                               ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x12: /* LNA2 LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x13: /* LNA2 A+B */
+                       if (!antcomb->scan && (alt_ratio > antcomb->ant_ratio))
+                               ant_conf->fast_div_bias = 0x1;
+                       else
+                               ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x20: /* LNA1 A-B */
+                       if (!antcomb->scan && (alt_ratio > antcomb->ant_ratio))
+                               ant_conf->fast_div_bias = 0x1;
+                       else
+                               ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x21: /* LNA1 LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x23: /* LNA1 A+B */
+                       if (!antcomb->scan && (alt_ratio > antcomb->ant_ratio))
+                               ant_conf->fast_div_bias = 0x1;
+                       else
+                               ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x30: /* A+B A-B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x31: /* A+B LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x32: /* A+B LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               default:
+                       break;
+               }
+
+               if (antcomb->fast_div_bias)
+                       ant_conf->fast_div_bias = antcomb->fast_div_bias;
+       } else if (ant_conf->div_group == 3) {
+               switch ((ant_conf->main_lna_conf << 4) |
+                       ant_conf->alt_lna_conf) {
+               case 0x01: /* A-B LNA2 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x02: /* A-B LNA1 */
+                       ant_conf->fast_div_bias = 0x39;
+                       break;
+               case 0x03: /* A-B A+B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x10: /* LNA2 A-B */
+                       ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x12: /* LNA2 LNA1 */
+                       ant_conf->fast_div_bias = 0x3f;
+                       break;
+               case 0x13: /* LNA2 A+B */
+                       ant_conf->fast_div_bias = 0x2;
+                       break;
+               case 0x20: /* LNA1 A-B */
+                       ant_conf->fast_div_bias = 0x3;
+                       break;
+               case 0x21: /* LNA1 LNA2 */
+                       ant_conf->fast_div_bias = 0x3;
+                       break;
+               case 0x23: /* LNA1 A+B */
+                       ant_conf->fast_div_bias = 0x3;
+                       break;
+               case 0x30: /* A+B A-B */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               case 0x31: /* A+B LNA2 */
+                       ant_conf->fast_div_bias = 0x6;
+                       break;
+               case 0x32: /* A+B LNA1 */
+                       ant_conf->fast_div_bias = 0x1;
+                       break;
+               default:
+                       break;
+               }
+       }
+}
+
+static void ath_ant_try_scan(struct ath_ant_comb *antcomb,
+                            struct ath_hw_antcomb_conf *conf,
+                            int curr_alt_set, int alt_rssi_avg,
+                            int main_rssi_avg)
+{
+       switch (curr_alt_set) {
+       case ATH_ANT_DIV_COMB_LNA2:
+               antcomb->rssi_lna2 = alt_rssi_avg;
+               antcomb->rssi_lna1 = main_rssi_avg;
+               antcomb->scan = true;
+               /* set to A+B */
+               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               break;
+       case ATH_ANT_DIV_COMB_LNA1:
+               antcomb->rssi_lna1 = alt_rssi_avg;
+               antcomb->rssi_lna2 = main_rssi_avg;
+               antcomb->scan = true;
+               /* set to A+B */
+               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+               break;
+       case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
+               antcomb->rssi_add = alt_rssi_avg;
+               antcomb->scan = true;
+               /* set to A-B */
+               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+               break;
+       case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
+               antcomb->rssi_sub = alt_rssi_avg;
+               antcomb->scan = false;
+               if (antcomb->rssi_lna2 >
+                   (antcomb->rssi_lna1 + conf->lna1_lna2_switch_delta)) {
+                       /* use LNA2 as main LNA */
+                       if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
+                           (antcomb->rssi_add > antcomb->rssi_sub)) {
+                               /* set to A+B */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+                       } else if (antcomb->rssi_sub >
+                                  antcomb->rssi_lna1) {
+                               /* set to A-B */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+                       } else {
+                               /* set to LNA1 */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       }
+               } else {
+                       /* use LNA1 as main LNA */
+                       if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
+                           (antcomb->rssi_add > antcomb->rssi_sub)) {
+                               /* set to A+B */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
+                       } else if (antcomb->rssi_sub >
+                                  antcomb->rssi_lna1) {
+                               /* set to A-B */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
+                       } else {
+                               /* set to LNA2 */
+                               conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                               conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                       }
+               }
+               break;
+       default:
+               break;
+       }
+}
+
+static bool ath_ant_try_switch(struct ath_hw_antcomb_conf *div_ant_conf,
+                              struct ath_ant_comb *antcomb,
+                              int alt_ratio, int alt_rssi_avg,
+                              int main_rssi_avg, int curr_main_set,
+                              int curr_alt_set)
+{
+       bool ret = false;
+
+       if (ath_ant_div_comb_alt_check(div_ant_conf, antcomb, alt_ratio,
+                                      alt_rssi_avg, main_rssi_avg)) {
+               if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
+                       /*
+                        * Switch main and alt LNA.
+                        */
+                       div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+                       div_ant_conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+               } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
+                       div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+                       div_ant_conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+               }
+
+               ret = true;
+       } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
+                  (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
+               /*
+                 Set alt to another LNA.
+               */
+               if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
+                       div_ant_conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA1;
+               else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
+                       div_ant_conf->alt_lna_conf = ATH_ANT_DIV_COMB_LNA2;
+
+               ret = true;
+       }
+
+       return ret;
+}
+
+static bool ath_ant_short_scan_check(struct ath_ant_comb *antcomb)
+{
+       int alt_ratio;
+
+       if (!antcomb->scan || !antcomb->alt_good)
+               return false;
+
+       if (time_after(jiffies, antcomb->scan_start_time +
+                      msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
+               return true;
+
+       if (antcomb->total_pkt_count == ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
+               alt_ratio = ((antcomb->alt_recv_cnt * 100) /
+                            antcomb->total_pkt_count);
+               if (alt_ratio < antcomb->ant_ratio)
+                       return true;
+       }
+
+       return false;
+}
+
+void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
+{
+       struct ath_hw_antcomb_conf div_ant_conf;
+       struct ath_ant_comb *antcomb = &sc->ant_comb;
+       int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
+       int curr_main_set;
+       int main_rssi = rs->rs_rssi_ctl[0];
+       int alt_rssi = rs->rs_rssi_ctl[1];
+       int rx_ant_conf,  main_ant_conf;
+       bool short_scan = false, ret;
+
+       rx_ant_conf = (rs->rs_rssi_ctl[2] >> ATH_ANT_RX_CURRENT_SHIFT) &
+                      ATH_ANT_RX_MASK;
+       main_ant_conf = (rs->rs_rssi_ctl[2] >> ATH_ANT_RX_MAIN_SHIFT) &
+                        ATH_ANT_RX_MASK;
+
+       if (alt_rssi >= antcomb->low_rssi_thresh) {
+               antcomb->ant_ratio = ATH_ANT_DIV_COMB_ALT_ANT_RATIO;
+               antcomb->ant_ratio2 = ATH_ANT_DIV_COMB_ALT_ANT_RATIO2;
+       } else {
+               antcomb->ant_ratio = ATH_ANT_DIV_COMB_ALT_ANT_RATIO_LOW_RSSI;
+               antcomb->ant_ratio2 = ATH_ANT_DIV_COMB_ALT_ANT_RATIO2_LOW_RSSI;
+       }
+
+       /* Record packet only when both main_rssi and  alt_rssi is positive */
+       if (main_rssi > 0 && alt_rssi > 0) {
+               antcomb->total_pkt_count++;
+               antcomb->main_total_rssi += main_rssi;
+               antcomb->alt_total_rssi  += alt_rssi;
+
+               if (main_ant_conf == rx_ant_conf)
+                       antcomb->main_recv_cnt++;
+               else
+                       antcomb->alt_recv_cnt++;
+       }
+
+       if (main_ant_conf == rx_ant_conf) {
+               ANT_STAT_INC(ANT_MAIN, recv_cnt);
+               ANT_LNA_INC(ANT_MAIN, rx_ant_conf);
+       } else {
+               ANT_STAT_INC(ANT_ALT, recv_cnt);
+               ANT_LNA_INC(ANT_ALT, rx_ant_conf);
+       }
+
+       /* Short scan check */
+       short_scan = ath_ant_short_scan_check(antcomb);
+
+       if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
+            rs->rs_moreaggr) && !short_scan)
+               return;
+
+       if (antcomb->total_pkt_count) {
+               alt_ratio = ((antcomb->alt_recv_cnt * 100) /
+                            antcomb->total_pkt_count);
+               main_rssi_avg = (antcomb->main_total_rssi /
+                                antcomb->total_pkt_count);
+               alt_rssi_avg = (antcomb->alt_total_rssi /
+                                antcomb->total_pkt_count);
+       }
+
+       ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
+       curr_alt_set = div_ant_conf.alt_lna_conf;
+       curr_main_set = div_ant_conf.main_lna_conf;
+       antcomb->count++;
+
+       if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
+               if (alt_ratio > antcomb->ant_ratio) {
+                       ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
+                                                 main_rssi_avg);
+                       antcomb->alt_good = true;
+               } else {
+                       antcomb->alt_good = false;
+               }
+
+               antcomb->count = 0;
+               antcomb->scan = true;
+               antcomb->scan_not_start = true;
+       }
+
+       if (!antcomb->scan) {
+               ret = ath_ant_try_switch(&div_ant_conf, antcomb, alt_ratio,
+                                        alt_rssi_avg, main_rssi_avg,
+                                        curr_main_set, curr_alt_set);
+               if (ret)
+                       goto div_comb_done;
+       }
+
+       if (!antcomb->scan &&
+           (alt_rssi_avg < (main_rssi_avg + div_ant_conf.lna1_lna2_delta)))
+               goto div_comb_done;
+
+       if (!antcomb->scan_not_start) {
+               ath_ant_try_scan(antcomb, &div_ant_conf, curr_alt_set,
+                                alt_rssi_avg, main_rssi_avg);
+       } else {
+               if (!antcomb->alt_good) {
+                       antcomb->scan_not_start = false;
+                       /* Set alt to another LNA */
+                       if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
+                               div_ant_conf.main_lna_conf =
+                                       ATH_ANT_DIV_COMB_LNA2;
+                               div_ant_conf.alt_lna_conf =
+                                       ATH_ANT_DIV_COMB_LNA1;
+                       } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
+                               div_ant_conf.main_lna_conf =
+                                       ATH_ANT_DIV_COMB_LNA1;
+                               div_ant_conf.alt_lna_conf =
+                                       ATH_ANT_DIV_COMB_LNA2;
+                       }
+                       goto div_comb_done;
+               }
+               ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
+                                                  main_rssi_avg, alt_rssi_avg,
+                                                  alt_ratio);
+               antcomb->quick_scan_cnt++;
+       }
+
+div_comb_done:
+       ath_ant_div_conf_fast_divbias(&div_ant_conf, antcomb, alt_ratio);
+       ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
+       ath9k_debug_stat_ant(sc, &div_ant_conf, main_rssi_avg, alt_rssi_avg);
+
+       antcomb->scan_start_time = jiffies;
+       antcomb->total_pkt_count = 0;
+       antcomb->main_total_rssi = 0;
+       antcomb->alt_total_rssi = 0;
+       antcomb->main_recv_cnt = 0;
+       antcomb->alt_recv_cnt = 0;
+}