ath9k_htc: Add a modparam to enable BTCOEX rather than default

Enable BTCOEX for WB193(which seems to be the only supported
ath9k_htc BTCOEX chipset)only when it is enabled via modparam,
rather than enabling it by default.

Cc: Vivek Natarajan <nataraja@qualcomm.com>
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/htc_drv_gpio.c

@@ -182,8 +182,17 @@ void ath9k_htc_stop_btcoex(struct ath9k_htc_priv *priv)
 void ath9k_htc_init_btcoex(struct ath9k_htc_priv *priv, char *product)
 {
 	struct ath_hw *ah = priv->ah;
+	struct ath_common *common = ath9k_hw_common(ah);
 	int qnum;
 
+	/*
+	 * Check if BTCOEX is globally disabled.
+	 */
+	if (!common->btcoex_enabled) {
+		ah->btcoex_hw.scheme = ATH_BTCOEX_CFG_NONE;
+		return;
+	}
+
 	if (product && strncmp(product, ATH_HTC_BTCOEX_PRODUCT_ID, 5) == 0) {
 		ah->btcoex_hw.scheme = ATH_BTCOEX_CFG_3WIRE;
 	}

drivers/net/wireless/ath/ath9k/htc_drv_init.c

@@ -30,6 +30,10 @@ int htc_modparam_nohwcrypt;
 module_param_named(nohwcrypt, htc_modparam_nohwcrypt, int, 0444);
 MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption");
 
+static int ath9k_htc_btcoex_enable;
+module_param_named(btcoex_enable, ath9k_htc_btcoex_enable, int, 0444);
+MODULE_PARM_DESC(btcoex_enable, "Enable wifi-BT coexistence");
+
 #define CHAN2G(_freq, _idx)  { \
 	.center_freq = (_freq), \
 	.hw_value = (_idx), \
@@ -635,6 +639,7 @@ static int ath9k_init_priv(struct ath9k_htc_priv *priv,
 	common->hw = priv->hw;
 	common->priv = priv;
 	common->debug_mask = ath9k_debug;
+	common->btcoex_enabled = ath9k_htc_btcoex_enable == 1;
 
 	spin_lock_init(&priv->beacon_lock);
 	spin_lock_init(&priv->tx.tx_lock);