thermal: debug: add debug statement for core and step_wise

To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.

Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671

A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:

[ 355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[ 355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[ 355.147644] get_target_state: thermal cooling_device8: cur_state=0
[ 355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[ 355.147652] get_target_state: thermal cooling_device7: cur_state=0
[ 355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[ 355.147660] get_target_state: thermal cooling_device6: cur_state=0
[ 355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[ 355.147668] get_target_state: thermal cooling_device5: cur_state=0
[ 355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[ 355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[ 355.147776] get_target_state: thermal cooling_device0: cur_state=0
[ 355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[ 355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[ 355.147845] get_target_state: thermal cooling_device1: cur_state=0
[ 355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[ 355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[ 355.147904] get_target_state: thermal cooling_device2: cur_state=0
[ 355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[ 355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[ 355.147963] get_target_state: thermal cooling_device3: cur_state=0
[ 355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[ 355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[ 355.148022] get_target_state: thermal cooling_device4: cur_state=0
[ 355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[ 355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[ 355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1

Signed-off-by: Aaron Lu <[e-mail]>
Acked-by: Eduardo Valentin <[e-mail]>
Signed-off-by: Zhang Rui <[e-mail]>

drivers/thermal/step_wise.c

···
 	 */
 	cdev->ops->get_cur_state(cdev, &cur_state);
 	next_target = instance->target;
+	dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
 
 	switch (trend) {
 	case THERMAL_TREND_RAISING:
···
 	if (tz->temperature >= trip_temp)
 		throttle = true;
 
+	dev_dbg(&tz->device, "Trip%d[type=%d,temp=%ld]:trend=%d,throttle=%d\n",
+				trip, trip_type, trip_temp, trend, throttle);
+
 	mutex_lock(&tz->lock);
 
 	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
···
 
 		old_target = instance->target;
 		instance->target = get_target_state(instance, trend, throttle);
+		dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
+					old_target, (int)instance->target);
 
 		if (old_target == instance->target)
 			continue;

drivers/thermal/thermal_core.c

···
 	tz->last_temperature = tz->temperature;
 	tz->temperature = temp;
 	mutex_unlock(&tz->lock);
+
+	dev_dbg(&tz->device, "last_temperature=%d, current_temperature=%d\n",
+				tz->last_temperature, tz->temperature);
 }
 
 void thermal_zone_device_update(struct thermal_zone_device *tz)
···
 	mutex_lock(&cdev->lock);
 	/* Make sure cdev enters the deepest cooling state */
 	list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
+		dev_dbg(&cdev->device, "zone%d->target=%lu\n",
+				instance->tz->id, instance->target);
 		if (instance->target == THERMAL_NO_TARGET)
 			continue;
 		if (instance->target > target)
···
 	mutex_unlock(&cdev->lock);
 	cdev->ops->set_cur_state(cdev, target);
 	cdev->updated = true;
+	dev_dbg(&cdev->device, "set to state %lu\n", target);
 }
 EXPORT_SYMBOL(thermal_cdev_update);