ath10k: implement AP CSA

Most channel switching logic has been implemented
already so this patch is pretty small. The patch
makes use of mac80211's vif->csa_active for AP CSA
handling.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/mac.c

@@ -3818,6 +3818,14 @@ static int ath10k_set_bitrate_mask(struct ieee80211_hw *hw,
 	return ath10k_set_fixed_rate_param(arvif, fixed_rate, fixed_nss);
 }
 
+static void ath10k_channel_switch_beacon(struct ieee80211_hw *hw,
+					 struct ieee80211_vif *vif,
+					 struct cfg80211_chan_def *chandef)
+{
+	/* there's no need to do anything here. vif->csa_active is enough */
+	return;
+}
+
 static const struct ieee80211_ops ath10k_ops = {
 	.tx				= ath10k_tx,
 	.start				= ath10k_start,
@@ -3841,6 +3849,7 @@ static const struct ieee80211_ops ath10k_ops = {
 	.restart_complete		= ath10k_restart_complete,
 	.get_survey			= ath10k_get_survey,
 	.set_bitrate_mask		= ath10k_set_bitrate_mask,
+	.channel_switch_beacon		= ath10k_channel_switch_beacon,
 #ifdef CONFIG_PM
 	.suspend			= ath10k_suspend,
 	.resume				= ath10k_resume,
@@ -4220,6 +4229,7 @@ int ath10k_mac_register(struct ath10k *ar)
 	ar->hw->max_listen_interval = ATH10K_MAX_HW_LISTEN_INTERVAL;
 
 	ar->hw->wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
+	ar->hw->wiphy->flags |= WIPHY_FLAG_HAS_CHANNEL_SWITCH;
 	ar->hw->wiphy->max_remain_on_channel_duration = 5000;
 
 	ar->hw->wiphy->flags |= WIPHY_FLAG_AP_UAPSD;

drivers/net/wireless/ath/ath10k/wmi.c

@@ -1405,6 +1405,17 @@ static void ath10k_wmi_event_host_swba(struct ath10k *ar, struct sk_buff *skb)
 			continue;
 		}
 
+		/* There are no completions for beacons so wait for next SWBA
+		 * before telling mac80211 to decrement CSA counter
+		 *
+		 * Once CSA counter is completed stop sending beacons until
+		 * actual channel switch is done */
+		if (arvif->vif->csa_active &&
+		    ieee80211_csa_is_complete(arvif->vif)) {
+			ieee80211_csa_finish(arvif->vif);
+			continue;
+		}
+
 		bcn = ieee80211_beacon_get(ar->hw, arvif->vif);
 		if (!bcn) {
 			ath10k_warn("could not get mac80211 beacon\n");