wl12xx: Add support for HW channel switch

The wl12xx FW supports HW channel switch.  If we don't use it,
sometimes the firmware gets confused when recalibrating to the new
channel, causing RX problems.  This commit adds HW channel switch
support by implementing the channell_switch op.
Signed-off-by: Shahar Levi <shahar_levi@ti.com>
[added one comment, remove the tx_flush and rephrased the commit message]
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/boot.c

@@ -503,7 +503,8 @@ static int wl1271_boot_run_firmware(struct wl1271 *wl)
 		BA_SESSION_RX_CONSTRAINT_EVENT_ID |
 		REMAIN_ON_CHANNEL_COMPLETE_EVENT_ID |
 		INACTIVE_STA_EVENT_ID |
-		MAX_TX_RETRY_EVENT_ID;
+		MAX_TX_RETRY_EVENT_ID |
+		CHANNEL_SWITCH_COMPLETE_EVENT_ID;
 
 	ret = wl1271_event_unmask(wl);
 	if (ret < 0) {

drivers/net/wireless/wl12xx/cmd.c

@@ -1700,3 +1700,61 @@ int wl12xx_croc(struct wl1271 *wl, u8 role_id)
 out:
 	return ret;
 }
+
+int wl12xx_cmd_channel_switch(struct wl1271 *wl,
+			      struct ieee80211_channel_switch *ch_switch)
+{
+	struct wl12xx_cmd_channel_switch *cmd;
+	int ret;
+
+	wl1271_debug(DEBUG_ACX, "cmd channel switch");
+
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (!cmd) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	cmd->channel = ch_switch->channel->hw_value;
+	cmd->switch_time = ch_switch->count;
+	cmd->tx_suspend = ch_switch->block_tx;
+	cmd->flush = 0; /* this value is ignored by the FW */
+
+	ret = wl1271_cmd_send(wl, CMD_CHANNEL_SWITCH, cmd, sizeof(*cmd), 0);
+	if (ret < 0) {
+		wl1271_error("failed to send channel switch command");
+		goto out_free;
+	}
+
+out_free:
+	kfree(cmd);
+
+out:
+	return ret;
+}
+
+int wl12xx_cmd_stop_channel_switch(struct wl1271 *wl)
+{
+	struct wl12xx_cmd_stop_channel_switch *cmd;
+	int ret;
+
+	wl1271_debug(DEBUG_ACX, "cmd stop channel switch");
+
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (!cmd) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = wl1271_cmd_send(wl, CMD_STOP_CHANNEL_SWICTH, cmd, sizeof(*cmd), 0);
+	if (ret < 0) {
+		wl1271_error("failed to stop channel switch command");
+		goto out_free;
+	}
+
+out_free:
+	kfree(cmd);
+
+out:
+	return ret;
+}

drivers/net/wireless/wl12xx/cmd.h

@@ -79,6 +79,9 @@ int wl12xx_cmd_remove_peer(struct wl1271 *wl, u8 hlid);
 int wl12xx_cmd_config_fwlog(struct wl1271 *wl);
 int wl12xx_cmd_start_fwlog(struct wl1271 *wl);
 int wl12xx_cmd_stop_fwlog(struct wl1271 *wl);
+int wl12xx_cmd_channel_switch(struct wl1271 *wl,
+			      struct ieee80211_channel_switch *ch_switch);
+int wl12xx_cmd_stop_channel_switch(struct wl1271 *wl);
 
 enum wl1271_commands {
 	CMD_INTERROGATE     = 1,    /*use this to read information elements*/
@@ -677,4 +680,21 @@ struct wl12xx_cmd_stop_fwlog {
 	struct wl1271_cmd_header header;
 } __packed;
 
+struct wl12xx_cmd_channel_switch {
+	struct wl1271_cmd_header header;
+
+	/* The new serving channel */
+	u8 channel;
+	/* Relative time of the serving channel switch in TBTT units */
+	u8 switch_time;
+	/* 1: Suspend TX till switch time; 0: Do not suspend TX */
+	u8 tx_suspend;
+	/* 1: Flush TX at switch time; 0: Do not flush */
+	u8 flush;
+} __packed;
+
+struct wl12xx_cmd_stop_channel_switch {
+	struct wl1271_cmd_header header;
+} __packed;
+
 #endif /* __WL1271_CMD_H__ */

drivers/net/wireless/wl12xx/event.c

@@ -300,6 +300,21 @@ static int wl1271_event_process(struct wl1271 *wl, struct event_mailbox *mbox)
 			wl1271_stop_ba_event(wl);
 	}
 
+	if ((vector & CHANNEL_SWITCH_COMPLETE_EVENT_ID) && !is_ap) {
+		wl1271_debug(DEBUG_EVENT, "CHANNEL_SWITCH_COMPLETE_EVENT_ID. "
+					  "status = 0x%x",
+					  mbox->channel_switch_status);
+		/*
+		 * That event uses for two cases:
+		 * 1) channel switch complete with status=0
+		 * 2) channel switch failed status=1
+		 */
+		if (test_and_clear_bit(WL1271_FLAG_CS_PROGRESS, &wl->flags) &&
+		    (wl->vif))
+			ieee80211_chswitch_done(wl->vif,
+				mbox->channel_switch_status ? false : true);
+	}
+
 	if ((vector & DUMMY_PACKET_EVENT_ID)) {
 		wl1271_debug(DEBUG_EVENT, "DUMMY_PACKET_ID_EVENT_ID");
 		if (wl->vif)

drivers/net/wireless/wl12xx/main.c

@@ -2222,6 +2222,11 @@ static int wl1271_unjoin(struct wl1271 *wl)
 {
 	int ret;
 
+	if (test_and_clear_bit(WL1271_FLAG_CS_PROGRESS, &wl->flags)) {
+		wl12xx_cmd_stop_channel_switch(wl);
+		ieee80211_chswitch_done(wl->vif, false);
+	}
+
 	/* to stop listening to a channel, we disconnect */
 	ret = wl12xx_cmd_role_stop_sta(wl);
 	if (ret < 0)
@@ -4130,6 +4135,37 @@ static int wl12xx_set_bitrate_mask(struct ieee80211_hw *hw,
 	return 0;
 }
 
+static void wl12xx_op_channel_switch(struct ieee80211_hw *hw,
+				     struct ieee80211_channel_switch *ch_switch)
+{
+	struct wl1271 *wl = hw->priv;
+	int ret;
+
+	wl1271_debug(DEBUG_MAC80211, "mac80211 channel switch");
+
+	mutex_lock(&wl->mutex);
+
+	if (unlikely(wl->state == WL1271_STATE_OFF)) {
+		mutex_unlock(&wl->mutex);
+		ieee80211_chswitch_done(wl->vif, false);
+		return;
+	}
+
+	ret = wl1271_ps_elp_wakeup(wl);
+	if (ret < 0)
+		goto out;
+
+	ret = wl12xx_cmd_channel_switch(wl, ch_switch);
+
+	if (!ret)
+		set_bit(WL1271_FLAG_CS_PROGRESS, &wl->flags);
+
+	wl1271_ps_elp_sleep(wl);
+
+out:
+	mutex_unlock(&wl->mutex);
+}
+
 static bool wl1271_tx_frames_pending(struct ieee80211_hw *hw)
 {
 	struct wl1271 *wl = hw->priv;
@@ -4406,6 +4442,7 @@ static const struct ieee80211_ops wl1271_ops = {
 	.ampdu_action = wl1271_op_ampdu_action,
 	.tx_frames_pending = wl1271_tx_frames_pending,
 	.set_bitrate_mask = wl12xx_set_bitrate_mask,
+	.channel_switch = wl12xx_op_channel_switch,
 	CFG80211_TESTMODE_CMD(wl1271_tm_cmd)
 };
 

drivers/net/wireless/wl12xx/wl12xx.h

@@ -348,6 +348,7 @@ enum wl12xx_flags {
 	WL1271_FLAG_SOFT_GEMINI,
 	WL1271_FLAG_RX_STREAMING_STARTED,
 	WL1271_FLAG_RECOVERY_IN_PROGRESS,
+	WL1271_FLAG_CS_PROGRESS,
 };
 
 struct wl1271_link {