1 files changed, 270 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c
new file mode 100644
index 000000000..fca0b2357
--- /dev/null
+++ b/drivers/thermal/thermal_helpers.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  thermal_helpers.c - helper functions to handle thermal devices
+ *
+ *  Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
+ *
+ *  Highly based on original thermal_core.c
+ *  Copyright (C) 2008 Intel Corp
+ *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
+ *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+
+#include <trace/events/thermal.h>
+
+#include "thermal_core.h"
+
+int get_tz_trend(struct thermal_zone_device *tz, int trip)
+{
+	enum thermal_trend trend;
+
+	if (tz->emul_temperature || !tz->ops->get_trend ||
+	    tz->ops->get_trend(tz, trip, &trend)) {
+		if (tz->temperature > tz->last_temperature)
+			trend = THERMAL_TREND_RAISING;
+		else if (tz->temperature < tz->last_temperature)
+			trend = THERMAL_TREND_DROPPING;
+		else
+			trend = THERMAL_TREND_STABLE;
+	}
+
+	return trend;
+}
+
+struct thermal_instance *
+get_thermal_instance(struct thermal_zone_device *tz,
+		     struct thermal_cooling_device *cdev, int trip)
+{
+	struct thermal_instance *pos = NULL;
+	struct thermal_instance *target_instance = NULL;
+
+	mutex_lock(&tz->lock);
+	mutex_lock(&cdev->lock);
+
+	list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
+		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
+			target_instance = pos;
+			break;
+		}
+	}
+
+	mutex_unlock(&cdev->lock);
+	mutex_unlock(&tz->lock);
+
+	return target_instance;
+}
+EXPORT_SYMBOL(get_thermal_instance);
+
+int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	int ret = -EINVAL;
+	int count;
+	int crit_temp = INT_MAX;
+	enum thermal_trip_type type;
+
+	lockdep_assert_held(&tz->lock);
+
+	if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
+		return -EINVAL;
+
+	ret = tz->ops->get_temp(tz, temp);
+
+	if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
+		for (count = 0; count < tz->num_trips; count++) {
+			ret = tz->ops->get_trip_type(tz, count, &type);
+			if (!ret && type == THERMAL_TRIP_CRITICAL) {
+				ret = tz->ops->get_trip_temp(tz, count,
+						&crit_temp);
+				break;
+			}
+		}
+
+		/*
+		 * Only allow emulating a temperature when the real temperature
+		 * is below the critical temperature so that the emulation code
+		 * cannot hide critical conditions.
+		 */
+		if (!ret && *temp < crit_temp)
+			*temp = tz->emul_temperature;
+	}
+
+	return ret;
+}
+
+/**
+ * thermal_zone_get_temp() - returns the temperature of a thermal zone
+ * @tz: a valid pointer to a struct thermal_zone_device
+ * @temp: a valid pointer to where to store the resulting temperature.
+ *
+ * When a valid thermal zone reference is passed, it will fetch its
+ * temperature and fill @temp.
+ *
+ * Return: On success returns 0, an error code otherwise
+ */
+int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	int ret;
+
+	mutex_lock(&tz->lock);
+
+	if (device_is_registered(&tz->device))
+		ret = __thermal_zone_get_temp(tz, temp);
+	else
+		ret = -ENODEV;
+
+	mutex_unlock(&tz->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
+
+void __thermal_zone_set_trips(struct thermal_zone_device *tz)
+{
+	int low = -INT_MAX;
+	int high = INT_MAX;
+	int trip_temp, hysteresis;
+	int i, ret;
+
+	lockdep_assert_held(&tz->lock);
+
+	if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
+		return;
+
+	for (i = 0; i < tz->num_trips; i++) {
+		int trip_low;
+
+		tz->ops->get_trip_temp(tz, i, &trip_temp);
+		tz->ops->get_trip_hyst(tz, i, &hysteresis);
+
+		trip_low = trip_temp - hysteresis;
+
+		if (trip_low < tz->temperature && trip_low > low)
+			low = trip_low;
+
+		if (trip_temp > tz->temperature && trip_temp < high)
+			high = trip_temp;
+	}
+
+	/* No need to change trip points */
+	if (tz->prev_low_trip == low && tz->prev_high_trip == high)
+		return;
+
+	tz->prev_low_trip = low;
+	tz->prev_high_trip = high;
+
+	dev_dbg(&tz->device,
+		"new temperature boundaries: %d < x < %d\n", low, high);
+
+	/*
+	 * Set a temperature window. When this window is left the driver
+	 * must inform the thermal core via thermal_zone_device_update.
+	 */
+	ret = tz->ops->set_trips(tz, low, high);
+	if (ret)
+		dev_err(&tz->device, "Failed to set trips: %d\n", ret);
+}
+
+/**
+ * thermal_zone_set_trips - Computes the next trip points for the driver
+ * @tz: a pointer to a thermal zone device structure
+ *
+ * The function computes the next temperature boundaries by browsing
+ * the trip points. The result is the closer low and high trip points
+ * to the current temperature. These values are passed to the backend
+ * driver to let it set its own notification mechanism (usually an
+ * interrupt).
+ *
+ * It does not return a value
+ */
+void thermal_zone_set_trips(struct thermal_zone_device *tz)
+{
+	mutex_lock(&tz->lock);
+	__thermal_zone_set_trips(tz);
+	mutex_unlock(&tz->lock);
+}
+
+static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev,
+				       int target)
+{
+	if (cdev->ops->set_cur_state(cdev, target))
+		return;
+
+	thermal_notify_cdev_state_update(cdev->id, target);
+	thermal_cooling_device_stats_update(cdev, target);
+}
+
+void __thermal_cdev_update(struct thermal_cooling_device *cdev)
+{
+	struct thermal_instance *instance;
+	unsigned long target = 0;
+
+	/* 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)
+			target = instance->target;
+	}
+
+	thermal_cdev_set_cur_state(cdev, target);
+
+	trace_cdev_update(cdev, target);
+	dev_dbg(&cdev->device, "set to state %lu\n", target);
+}
+
+/**
+ * thermal_cdev_update - update cooling device state if needed
+ * @cdev:	pointer to struct thermal_cooling_device
+ *
+ * Update the cooling device state if there is a need.
+ */
+void thermal_cdev_update(struct thermal_cooling_device *cdev)
+{
+	mutex_lock(&cdev->lock);
+	if (!cdev->updated) {
+		__thermal_cdev_update(cdev);
+		cdev->updated = true;
+	}
+	mutex_unlock(&cdev->lock);
+}
+
+/**
+ * thermal_zone_get_slope - return the slope attribute of the thermal zone
+ * @tz: thermal zone device with the slope attribute
+ *
+ * Return: If the thermal zone device has a slope attribute, return it, else
+ * return 1.
+ */
+int thermal_zone_get_slope(struct thermal_zone_device *tz)
+{
+	if (tz && tz->tzp)
+		return tz->tzp->slope;
+	return 1;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_slope);
+
+/**
+ * thermal_zone_get_offset - return the offset attribute of the thermal zone
+ * @tz: thermal zone device with the offset attribute
+ *
+ * Return: If the thermal zone device has a offset attribute, return it, else
+ * return 0.
+ */
+int thermal_zone_get_offset(struct thermal_zone_device *tz)
+{
+	if (tz && tz->tzp)
+		return tz->tzp->offset;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_offset);