thermal/core: Add critical and hot ops

BugLink: https://bugs.launchpad.net/bugs/1906168

Currently there is no way to the sensors to directly call an ops in
interrupt mode without calling thermal_zone_device_update assuming all
the trip points are defined.

A sensor may want to do something special if a trip point is hot or
critical.

This patch adds the critical and hot ops to the thermal zone device,
so a sensor can directly invoke them or let the thermal framework to
call the sensor specific ones.

Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20201210121514.25760-2-daniel.lezcano@linaro.org
(cherry picked from commit d7203ee)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>

drivers/thermal/thermal_core.c

@@ -380,6 +380,25 @@ static void thermal_emergency_poweroff(void)
 			      msecs_to_jiffies(poweroff_delay_ms));
 }
 
+void thermal_zone_device_critical(struct thermal_zone_device *tz)
+{
+	dev_emerg(&tz->device, "%s: critical temperature reached, "
+		  "shutting down\n", tz->type);
+
+	mutex_lock(&poweroff_lock);
+	if (!power_off_triggered) {
+		/*
+		 * Queue a backup emergency shutdown in the event of
+		 * orderly_poweroff failure
+		 */
+		thermal_emergency_poweroff();
+		orderly_poweroff(true);
+		power_off_triggered = true;
+	}
+	mutex_unlock(&poweroff_lock);
+}
+EXPORT_SYMBOL(thermal_zone_device_critical);
+
 static void handle_critical_trips(struct thermal_zone_device *tz,
 				  int trip, enum thermal_trip_type trip_type)
 {
@@ -396,22 +415,10 @@ static void handle_critical_trips(struct thermal_zone_device *tz,
 	if (tz->ops->notify)
 		tz->ops->notify(tz, trip, trip_type);
 
-	if (trip_type == THERMAL_TRIP_CRITICAL) {
-		dev_emerg(&tz->device,
-			  "critical temperature reached (%d C), shutting down\n",
-			  tz->temperature / 1000);
-		mutex_lock(&poweroff_lock);
-		if (!power_off_triggered) {
-			/*
-			 * Queue a backup emergency shutdown in the event of
-			 * orderly_poweroff failure
-			 */
-			thermal_emergency_poweroff();
-			orderly_poweroff(true);
-			power_off_triggered = true;
-		}
-		mutex_unlock(&poweroff_lock);
-	}
+	if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
+		tz->ops->hot(tz);
+	else if (trip_type == THERMAL_TRIP_CRITICAL)
+		tz->ops->critical(tz);
 }
 
 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
@@ -1424,6 +1431,10 @@ thermal_zone_device_register(const char *type, int trips, int mask,
 
 	tz->id = id;
 	strlcpy(tz->type, type, sizeof(tz->type));
+
+	if (!ops->critical)
+		ops->critical = thermal_zone_device_critical;
+
 	tz->ops = ops;
 	tz->tzp = tzp;
 	tz->device.class = &thermal_class;

include/linux/thermal.h

@@ -79,6 +79,8 @@ struct thermal_zone_device_ops {
 			  enum thermal_trend *);
 	int (*notify) (struct thermal_zone_device *, int,
 		       enum thermal_trip_type);
+	void (*hot)(struct thermal_zone_device *);
+	void (*critical)(struct thermal_zone_device *);
 };
 
 struct thermal_cooling_device_ops {
@@ -399,6 +401,7 @@ void thermal_cdev_update(struct thermal_cooling_device *);
 void thermal_notify_framework(struct thermal_zone_device *, int);
 int thermal_zone_device_enable(struct thermal_zone_device *tz);
 int thermal_zone_device_disable(struct thermal_zone_device *tz);
+void thermal_zone_device_critical(struct thermal_zone_device *tz);
 #else
 static inline struct thermal_zone_device *thermal_zone_device_register(
 	const char *type, int trips, int mask, void *devdata,