1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c
new file mode 100644
index 000000000..1cfeac16e
--- /dev/null
+++ b/drivers/thermal/gov_fair_share.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  fair_share.c - A simple weight based Thermal governor
+ *
+ *  Copyright (C) 2012 Intel Corp
+ *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/thermal.h>
+#include <trace/events/thermal.h>
+
+#include "thermal_core.h"
+
+/**
+ * get_trip_level: - obtains the current trip level for a zone
+ * @tz:		thermal zone device
+ */
+static int get_trip_level(struct thermal_zone_device *tz)
+{
+	int count = 0;
+	int trip_temp;
+	enum thermal_trip_type trip_type;
+
+	if (tz->num_trips == 0 || !tz->ops->get_trip_temp)
+		return 0;
+
+	for (count = 0; count < tz->num_trips; count++) {
+		tz->ops->get_trip_temp(tz, count, &trip_temp);
+		if (tz->temperature < trip_temp)
+			break;
+	}
+
+	/*
+	 * count > 0 only if temperature is greater than first trip
+	 * point, in which case, trip_point = count - 1
+	 */
+	if (count > 0) {
+		tz->ops->get_trip_type(tz, count - 1, &trip_type);
+		trace_thermal_zone_trip(tz, count - 1, trip_type);
+	}
+
+	return count;
+}
+
+static long get_target_state(struct thermal_zone_device *tz,
+		struct thermal_cooling_device *cdev, int percentage, int level)
+{
+	return (long)(percentage * level * cdev->max_state) / (100 * tz->num_trips);
+}
+
+/**
+ * fair_share_throttle - throttles devices associated with the given zone
+ * @tz: thermal_zone_device
+ * @trip: trip point index
+ *
+ * Throttling Logic: This uses three parameters to calculate the new
+ * throttle state of the cooling devices associated with the given zone.
+ *
+ * Parameters used for Throttling:
+ * P1. max_state: Maximum throttle state exposed by the cooling device.
+ * P2. percentage[i]/100:
+ *	How 'effective' the 'i'th device is, in cooling the given zone.
+ * P3. cur_trip_level/max_no_of_trips:
+ *	This describes the extent to which the devices should be throttled.
+ *	We do not want to throttle too much when we trip a lower temperature,
+ *	whereas the throttling is at full swing if we trip critical levels.
+ *	(Heavily assumes the trip points are in ascending order)
+ * new_state of cooling device = P3 * P2 * P1
+ */
+static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
+{
+	struct thermal_instance *instance;
+	int total_weight = 0;
+	int total_instance = 0;
+	int cur_trip_level = get_trip_level(tz);
+
+	lockdep_assert_held(&tz->lock);
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		if (instance->trip != trip)
+			continue;
+
+		total_weight += instance->weight;
+		total_instance++;
+	}
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		int percentage;
+		struct thermal_cooling_device *cdev = instance->cdev;
+
+		if (instance->trip != trip)
+			continue;
+
+		if (!total_weight)
+			percentage = 100 / total_instance;
+		else
+			percentage = (instance->weight * 100) / total_weight;
+
+		instance->target = get_target_state(tz, cdev, percentage,
+						    cur_trip_level);
+
+		mutex_lock(&cdev->lock);
+		__thermal_cdev_update(cdev);
+		mutex_unlock(&cdev->lock);
+	}
+
+	return 0;
+}
+
+static struct thermal_governor thermal_gov_fair_share = {
+	.name		= "fair_share",
+	.throttle	= fair_share_throttle,
+};
+THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share);