ath9k: Fix antenna diversity for CUS198

CUS198/CUS230 need a few tweaks in the antenna diversity
algorithm to accomodate RSSI variation. Add a couple
of knobs to control low RSSI threshold and fast antenna
diversity bias values.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index ed8f8ef..74009f1 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -585,6 +585,8 @@
 #define ATH_ANT_DIV_COMB_MAX_COUNT 100
 #define ATH_ANT_DIV_COMB_ALT_ANT_RATIO 30
 #define ATH_ANT_DIV_COMB_ALT_ANT_RATIO2 20
+#define ATH_ANT_DIV_COMB_ALT_ANT_RATIO_LOW_RSSI 50
+#define ATH_ANT_DIV_COMB_ALT_ANT_RATIO2_LOW_RSSI 50
 
 #define ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA -1
 #define ATH_ANT_DIV_COMB_LNA1_DELTA_HI -4
@@ -607,6 +609,8 @@
 	int rssi_first;
 	int rssi_second;
 	int rssi_third;
+	int ant_ratio;
+	int ant_ratio2;
 	bool alt_good;
 	int quick_scan_cnt;
 	enum ath9k_ant_div_comb_lna_conf main_conf;
@@ -615,6 +619,12 @@
 	bool first_ratio;
 	bool second_ratio;
 	unsigned long scan_start_time;
+
+	/*
+	 * Card-specific config values.
+	 */
+	int low_rssi_thresh;
+	int fast_div_bias;
 };
 
 void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs);