ANDROID: GKI: drivers: thermal: Add post suspend evaluate flag to thermal zone devicetree

Thermal core framework subscribes for suspend/resume notification.
On resume notification it re-evaluates each thermal zone for
temperature and cooling state update. For some devices,
a large number of thermal zones are enabled for different mitigations.
Re-evaluating each thermal zone during resume leads to multiple issues
including delay in back to back suspend resume scenario, power penalty
for frequent wake up due to re-setting trip threshold especially
during cold temperature usecases.

Add wake-capable-sensor property to thermal zone devicetree node to
denote that these sensors are wakeup capable. If a thermal zone has
this property defined, thermal framework ignores resume re-evaluation
and can service the threshold notification during the suspend/resume
path.

Test: build
Bug: 149945768
Change-Id: I07edf80ad29009378af4c70e750d01bde6f30806
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>
(cherry picked from commit a915ed479e)
[hridya: added some pointer checks]
Signed-off-by: Hridya Valsaraju <hridya@google.com>

Documentation/devicetree/bindings/thermal/thermal.txt

@@ -169,6 +169,9 @@ Optional property:
   Type: bool		thresholds, so the governors may mitigate by ensuring
 			timing closures and other low temperature operating
 			issues.
+- wake-capable-sensor:	Set to true if thermal zone sensor is wake up capable
+  Type: bool		and cooling devices binded to this thermal zone are not
+  Size: none		affected during suspend.
 
 Note: The delay properties are bound to the maximum dT/dt (temperature
 derivative over time) in two situations for a thermal zone:

drivers/thermal/of-thermal.c

@@ -64,6 +64,7 @@ struct __sensor_param {
  * @slope: slope of the temperature adjustment curve
  * @offset: offset of the temperature adjustment curve
  * @default_disable: Keep the thermal zone disabled by default
+ * @is_wakeable: Ignore post suspend thermal zone re-evaluation
  * @tzd: thermal zone device pointer for this sensor
  * @ntrips: number of trip points
  * @trips: an array of trip points (0..ntrips - 1)
@@ -81,6 +82,7 @@ struct __thermal_zone {
 	int offset;
 	struct thermal_zone_device *tzd;
 	bool default_disable;
+	bool is_wakeable;
 
 	/* trip data */
 	int ntrips;
@@ -475,6 +477,13 @@ static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
 	return -EINVAL;
 }
 
+static bool of_thermal_is_wakeable(struct thermal_zone_device *tz)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	return data->is_wakeable;
+}
+
 static struct thermal_zone_device_ops of_thermal_ops = {
 	.get_mode = of_thermal_get_mode,
 	.set_mode = of_thermal_set_mode,
@@ -488,6 +497,8 @@ static struct thermal_zone_device_ops of_thermal_ops = {
 
 	.bind = of_thermal_bind,
 	.unbind = of_thermal_unbind,
+
+	.is_wakeable = of_thermal_is_wakeable,
 };
 
 static struct thermal_zone_of_device_ops of_virt_ops = {
@@ -1085,6 +1096,8 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 	}
 	tz->polling_delay = prop;
 
+	tz->is_wakeable = of_property_read_bool(np,
+					"wake-capable-sensor");
 	/*
 	 * REVIST: for now, the thermal framework supports only
 	 * one sensor per thermal zone. Thus, we are considering

drivers/thermal/thermal_core.c

@@ -470,7 +470,11 @@ void thermal_zone_device_update(struct thermal_zone_device *tz,
 {
 	int count;
 
-	if (atomic_read(&in_suspend))
+	if (!tz || !tz->ops)
+		return;
+
+	if (atomic_read(&in_suspend) && (!tz->ops->is_wakeable ||
+		!(tz->ops->is_wakeable(tz))))
 		return;
 
 	if (!tz->ops->get_temp)
@@ -1506,6 +1510,9 @@ static int thermal_pm_notify(struct notifier_block *nb,
 	case PM_POST_SUSPEND:
 		atomic_set(&in_suspend, 0);
 		list_for_each_entry(tz, &thermal_tz_list, node) {
+			if (tz->ops && tz->ops->is_wakeable &&
+			    tz->ops->is_wakeable(tz))
+				continue;
 			thermal_zone_device_init(tz);
 			thermal_zone_device_update(tz,
 						   THERMAL_EVENT_UNSPECIFIED);

include/linux/thermal.h

@@ -116,6 +116,7 @@ struct thermal_zone_device_ops {
 			  enum thermal_trend *);
 	int (*notify) (struct thermal_zone_device *, int,
 		       enum thermal_trip_type);
+	bool (*is_wakeable)(struct thermal_zone_device *);
 };
 
 struct thermal_cooling_device_ops {