staging: wfx: add support for 'device too hot' indication

Device is able to detect a high temperature. In this case, the traffic
is not allowed to be sent until the temperature decrease.

This patch detects the warnings raised by the device and stop the
traffic accordingly. It also add a delayed task as safeguard in case the
chip would never send the indication that the temperature decrease.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200427134031.323403-7-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/hif_rx.c

@@ -235,12 +235,20 @@ static int hif_suspend_resume_indication(struct wfx_dev *wdev,
 	struct wfx_vif *wvif = wdev_to_wvif(wdev, hif->interface);
 	const struct hif_ind_suspend_resume_tx *body = buf;
 
-	WARN_ON(!wvif);
-	WARN(!body->suspend_resume_flags.bc_mc_only, "unsupported suspend/resume notification");
-	if (body->suspend_resume_flags.resume)
-		wfx_suspend_resume_mc(wvif, STA_NOTIFY_AWAKE);
-	else
-		wfx_suspend_resume_mc(wvif, STA_NOTIFY_SLEEP);
+	if (body->suspend_resume_flags.bc_mc_only) {
+		WARN_ON(!wvif);
+		if (body->suspend_resume_flags.resume)
+			wfx_suspend_resume_mc(wvif, STA_NOTIFY_AWAKE);
+		else
+			wfx_suspend_resume_mc(wvif, STA_NOTIFY_SLEEP);
+	} else {
+		WARN(body->peer_sta_set, "misunderstood indication");
+		WARN(hif->interface != 2, "misunderstood indication");
+		if (body->suspend_resume_flags.resume)
+			wfx_suspend_hot_dev(wdev, STA_NOTIFY_AWAKE);
+		else
+			wfx_suspend_hot_dev(wdev, STA_NOTIFY_SLEEP);
+	}
 
 	return 0;
 }

drivers/staging/wfx/main.c

@@ -341,6 +341,8 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	mutex_init(&wdev->conf_mutex);
 	mutex_init(&wdev->rx_stats_lock);
 	init_completion(&wdev->firmware_ready);
+	INIT_DELAYED_WORK(&wdev->cooling_timeout_work,
+			  wfx_cooling_timeout_work);
 	wfx_init_hif_cmd(&wdev->hif_cmd);
 	wfx_tx_queues_init(wdev);
 

drivers/staging/wfx/sta.c

@@ -38,6 +38,29 @@ u32 wfx_rate_mask_to_hw(struct wfx_dev *wdev, u32 rates)
 	return ret;
 }
 
+void wfx_cooling_timeout_work(struct work_struct *work)
+{
+	struct wfx_dev *wdev = container_of(to_delayed_work(work),
+					    struct wfx_dev,
+					    cooling_timeout_work);
+
+	wdev->chip_frozen = true;
+	wfx_tx_unlock(wdev);
+}
+
+void wfx_suspend_hot_dev(struct wfx_dev *wdev, enum sta_notify_cmd cmd)
+{
+	if (cmd == STA_NOTIFY_AWAKE) {
+		// Device recover normal temperature
+		if (cancel_delayed_work(&wdev->cooling_timeout_work))
+			wfx_tx_unlock(wdev);
+	} else {
+		// Device is too hot
+		schedule_delayed_work(&wdev->cooling_timeout_work, 10 * HZ);
+		wfx_tx_lock(wdev);
+	}
+}
+
 static void wfx_filter_beacon(struct wfx_vif *wvif, bool filter_beacon)
 {
 	const struct hif_ie_table_entry filter_ies[] = {

drivers/staging/wfx/sta.h

@@ -67,6 +67,8 @@ void wfx_unassign_vif_chanctx(struct ieee80211_hw *hw,
 			      struct ieee80211_chanctx_conf *conf);
 
 // WSM Callbacks
+void wfx_cooling_timeout_work(struct work_struct *work);
+void wfx_suspend_hot_dev(struct wfx_dev *wdev, enum sta_notify_cmd cmd);
 void wfx_suspend_resume_mc(struct wfx_vif *wvif, enum sta_notify_cmd cmd);
 void wfx_event_report_rssi(struct wfx_vif *wvif, u8 raw_rcpi_rssi);
 

drivers/staging/wfx/wfx.h

@@ -45,6 +45,7 @@ struct wfx_dev {
 	struct hif_ind_startup	hw_caps;
 	struct wfx_hif		hif;
 	struct sl_context	sl;
+	struct delayed_work	cooling_timeout_work;
 	bool			chip_frozen;
 	struct mutex		conf_mutex;