Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 849 insertions, 0 deletions

diff --git a/kernel/drivers/net/wireless/ath/ath9k/antenna.c b/kernel/drivers/net/wireless/ath/ath9k/antenna.c
new file mode 100644
index 000000000..a3668433d
--- /dev/null
+++ b/kernel/drivers/net/wireless/ath/ath9k/antenna.c
@@ -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;
+}