ath9k: Add information about antenna diversity
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / net / wireless / ath / ath9k / antenna.c
index 664844c..4cd2bce 100644 (file)
 
 #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(int alt_ratio, int maxdelta,
                                               int mindelta, int main_rssi_avg,
                                               int alt_rssi_avg, int pkt_count)
@@ -25,28 +77,45 @@ static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,
                (alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);
 }
 
-static inline bool ath_ant_div_comb_alt_check(u8 div_group, int alt_ratio,
-                                             int curr_main_set, int curr_alt_set,
-                                             int alt_rssi_avg, int main_rssi_avg)
+static inline bool ath_ant_div_comb_alt_check(struct ath_hw_antcomb_conf *conf,
+                                             int alt_ratio, int alt_rssi_avg,
+                                             int main_rssi_avg)
 {
-       bool result = false;
-       switch (div_group) {
+       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 ((((curr_main_set == ATH_ANT_DIV_COMB_LNA2) &&
-                     (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) &&
-                     (alt_rssi_avg >= (main_rssi_avg - 5))) ||
-                    ((curr_main_set == ATH_ANT_DIV_COMB_LNA1) &&
-                     (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) &&
-                     (alt_rssi_avg >= (main_rssi_avg - 2)))) &&
-                   (alt_rssi_avg >= 4))
+               if (alt_rssi_avg < 4)
+                       break;
+
+               if ((set1 && (alt_rssi_avg >= (main_rssi_avg - 5))) ||
+                   (set2 && (alt_rssi_avg >= (main_rssi_avg - 2))))
                        result = true;
-               else
-                       result = false;
+
+               break;
+       case 3:
+               if (alt_rssi_avg < 4)
+                       break;
+
+               if ((set1 && (alt_rssi_avg >= (main_rssi_avg - 3))) ||
+                   (set2 && (alt_rssi_avg >= (main_rssi_avg + 3))))
+                       result = true;
+
                break;
        }
 
@@ -108,6 +177,74 @@ static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
        }
 }
 
+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,
@@ -147,11 +284,11 @@ static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
                        else
                                antcomb->first_ratio = false;
                } else {
-                       if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
-                             (alt_rssi_avg > main_rssi_avg +
-                              ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
-                            (alt_rssi_avg > main_rssi_avg)) &&
-                           (antcomb->total_pkt_count > 50))
+                       if (ath_is_alt_ant_ratio_better(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;
@@ -164,17 +301,21 @@ static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
                antcomb->rssi_first = main_rssi_avg;
                antcomb->rssi_third = alt_rssi_avg;
 
-               if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
+               switch(antcomb->second_quick_scan_conf) {
+               case ATH_ANT_DIV_COMB_LNA1:
                        antcomb->rssi_lna1 = alt_rssi_avg;
-               else if (antcomb->second_quick_scan_conf ==
-                        ATH_ANT_DIV_COMB_LNA2)
+                       break;
+               case ATH_ANT_DIV_COMB_LNA2:
                        antcomb->rssi_lna2 = alt_rssi_avg;
-               else if (antcomb->second_quick_scan_conf ==
-                        ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
+                       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 +
@@ -202,105 +343,18 @@ static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
                        else
                                antcomb->second_ratio = false;
                } else {
-                       if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
-                             (alt_rssi_avg > main_rssi_avg +
-                              ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
-                            (alt_rssi_avg > main_rssi_avg)) &&
-                           (antcomb->total_pkt_count > 50))
+                       if (ath_is_alt_ant_ratio_better(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;
                }
 
-               /* 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 (div_ant_conf->main_lna_conf ==
-                                           ATH_ANT_DIV_COMB_LNA2)
-                                               div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA1;
-                                       else
-                                               div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA2;
-                               else
-                                       /* Set alt to A+B or A-B */
-                                       div_ant_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 (div_ant_conf->main_lna_conf ==
-                                   ATH_ANT_DIV_COMB_LNA2)
-                                       div_ant_conf->alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
-                               else
-                                       div_ant_conf->alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                       } else {
-                               /* Set alt to A+B or A-B */
-                               div_ant_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 (div_ant_conf->main_lna_conf ==
-                                   ATH_ANT_DIV_COMB_LNA2)
-                                       div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA1;
-                               else
-                                       div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA2;
-                       else
-                               /* Set alt to A+B or A-B */
-                               div_ant_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 (div_ant_conf->main_lna_conf ==
-                                   ATH_ANT_DIV_COMB_LNA2)
-                                       div_ant_conf->alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
-                               else
-                                       div_ant_conf->alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                       else
-                               /* Set alt to A+B or A-B */
-                               div_ant_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 (div_ant_conf->main_lna_conf ==
-                                   ATH_ANT_DIV_COMB_LNA2)
-                                       div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA1;
-                               else
-                                       div_ant_conf->alt_lna_conf =
-                                                       ATH_ANT_DIV_COMB_LNA2;
-                       else
-                               /* Set alt to A+B or A-B */
-                               div_ant_conf->alt_lna_conf = antcomb->main_conf;
-               }
+               ath_ant_set_alt_ratio(antcomb, div_ant_conf);
+
                break;
        default:
                break;
@@ -540,6 +594,137 @@ static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
        }
 }
 
+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 + ATH_ANT_DIV_COMB_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,
+                              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, 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 < ATH_ANT_DIV_COMB_ALT_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;
@@ -549,7 +734,7 @@ void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
        int main_rssi = rs->rs_rssi_ctl0;
        int alt_rssi = rs->rs_rssi_ctl1;
        int rx_ant_conf,  main_ant_conf;
-       bool short_scan = false;
+       bool short_scan = false, ret;
 
        rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
                       ATH_ANT_RX_MASK;
@@ -561,29 +746,26 @@ void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
                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++;
        }
 
-       /* Short scan check */
-       if (antcomb->scan && antcomb->alt_good) {
-               if (time_after(jiffies, antcomb->scan_start_time +
-                   msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
-                       short_scan = true;
-               else
-                       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 < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
-                                       short_scan = true;
-                       }
+       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)
+            rs->rs_moreaggr) && !short_scan)
                return;
 
        if (antcomb->total_pkt_count) {
@@ -595,11 +777,9 @@ void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
                                 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) {
@@ -617,153 +797,47 @@ void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
        }
 
        if (!antcomb->scan) {
-               if (ath_ant_div_comb_alt_check(div_ant_conf.div_group,
-                                       alt_ratio, curr_main_set, curr_alt_set,
-                                       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;
-                       }
-
-                       goto div_comb_done;
-               } 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;
-
-                       goto div_comb_done;
-               }
-
-               if ((alt_rssi_avg < (main_rssi_avg +
-                                    div_ant_conf.lna1_lna2_delta)))
+               ret = ath_ant_try_switch(&div_ant_conf, 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) {
-               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 */
-                       div_ant_conf.main_lna_conf =
-                               ATH_ANT_DIV_COMB_LNA1;
-                       div_ant_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 */
-                       div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
-                       div_ant_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 */
-                       div_ant_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 +
-                           ATH_ANT_DIV_COMB_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 */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                                       div_ant_conf.alt_lna_conf  =
-                                               ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
-                               } else if (antcomb->rssi_sub >
-                                          antcomb->rssi_lna1) {
-                                       /* set to A-B */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                                       div_ant_conf.alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
-                               } else {
-                                       /* set to LNA1 */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                                       div_ant_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 */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
-                                       div_ant_conf.alt_lna_conf  =
-                                               ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
-                               } else if (antcomb->rssi_sub >
-                                          antcomb->rssi_lna1) {
-                                       /* set to A-B */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
-                                       div_ant_conf.alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
-                               } else {
-                                       /* set to LNA2 */
-                                       div_ant_conf.main_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
-                                       div_ant_conf.alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
-                               }
-                       }
-                       break;
-               default:
-                       break;
-               }
+               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;
+                                       ATH_ANT_DIV_COMB_LNA2;
                                div_ant_conf.alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA1;
+                                       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;
+                                       ATH_ANT_DIV_COMB_LNA1;
                                div_ant_conf.alt_lna_conf =
-                                               ATH_ANT_DIV_COMB_LNA2;
+                                       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++;
        }
 
-       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;