1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c
new file mode 100644
index 000000000..b1152ad7a
--- /dev/null
+++ b/drivers/thermal/thermal_helpers.c
@@ -0,0 +1,240 @@
+// 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 "thermal_core.h"
+#include "thermal_trace.h"
+
+int get_tz_trend(struct thermal_zone_device *tz, const struct thermal_trip *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;
+}
+
+static bool thermal_instance_present(struct thermal_zone_device *tz,
+				     struct thermal_cooling_device *cdev,
+				     const struct thermal_trip *trip)
+{
+	const struct thermal_trip_desc *td = trip_to_trip_desc(trip);
+	struct thermal_instance *ti;
+
+	list_for_each_entry(ti, &td->thermal_instances, trip_node) {
+		if (ti->cdev == cdev)
+			return true;
+	}
+
+	return false;
+}
+
+bool thermal_trip_is_bound_to_cdev(struct thermal_zone_device *tz,
+				   const struct thermal_trip *trip,
+				   struct thermal_cooling_device *cdev)
+{
+	guard(thermal_zone)(tz);
+	guard(cooling_dev)(cdev);
+
+	return thermal_instance_present(tz, cdev, trip);
+}
+EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev);
+
+/**
+ * __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.
+ *
+ * Both tz and tz->ops must be valid pointers when calling this function,
+ * and the tz->ops.get_temp callback must be provided.
+ * The function must be called under tz->lock.
+ *
+ * Return: On success returns 0, an error code otherwise
+ */
+int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	const struct thermal_trip_desc *td;
+	int crit_temp = INT_MAX;
+	int ret = -EINVAL;
+
+	lockdep_assert_held(&tz->lock);
+
+	ret = tz->ops.get_temp(tz, temp);
+
+	if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
+		for_each_trip_desc(tz, td) {
+			const struct thermal_trip *trip = &td->trip;
+
+			if (trip->type == THERMAL_TRIP_CRITICAL) {
+				crit_temp = trip->temperature;
+				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;
+	}
+
+	if (ret)
+		dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret);
+
+	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;
+
+	if (IS_ERR_OR_NULL(tz))
+		return -EINVAL;
+
+	guard(thermal_zone)(tz);
+
+	if (!tz->ops.get_temp)
+		return -EINVAL;
+
+	ret = __thermal_zone_get_temp(tz, temp);
+	if (!ret && *temp <= THERMAL_TEMP_INVALID)
+		return -ENODATA;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
+
+static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state)
+{
+	int ret;
+
+	/*
+	 * No check is needed for the ops->set_cur_state as the
+	 * registering function checked the ops are correctly set
+	 */
+	ret = cdev->ops->set_cur_state(cdev, state);
+	if (ret)
+		return ret;
+
+	thermal_notify_cdev_state_update(cdev, state);
+	thermal_cooling_device_stats_update(cdev, state);
+	thermal_debug_cdev_state_update(cdev, state);
+
+	return 0;
+}
+
+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) {
+		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)
+{
+	guard(cooling_dev)(cdev);
+
+	if (!cdev->updated) {
+		__thermal_cdev_update(cdev);
+		cdev->updated = true;
+	}
+}
+
+/**
+ * thermal_cdev_update_nocheck() - Unconditionally update cooling device state
+ * @cdev: Target cooling device.
+ */
+void thermal_cdev_update_nocheck(struct thermal_cooling_device *cdev)
+{
+	guard(cooling_dev)(cdev);
+
+	__thermal_cdev_update(cdev);
+}
+
+/**
+ * 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);