thermal: core: introduce thermal_helpers.c

Here we have a simple code organization. This patch moves
functions that do not need to handle thermal core internal
data structure to thermal_helpers.c file.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c
new file mode 100644
index 000000000000..dfdba5a720cd
--- /dev/null
+++ b/drivers/thermal/thermal_helpers.c
@@ -0,0 +1,196 @@
+/*
+ *  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>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sysfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/string.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;
+}
+EXPORT_SYMBOL(get_tz_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);
+
+/**
+ * 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 = -EINVAL;
+	int count;
+	int crit_temp = INT_MAX;
+	enum thermal_trip_type type;
+
+	if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
+		goto exit;
+
+	mutex_lock(&tz->lock);
+
+	ret = tz->ops->get_temp(tz, temp);
+
+	if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
+		for (count = 0; count < tz->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;
+	}
+
+	mutex_unlock(&tz->lock);
+exit:
+	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;
+
+	mutex_lock(&tz->lock);
+
+	if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
+		goto exit;
+
+	for (i = 0; i < tz->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)
+		goto exit;
+
+	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);
+
+exit:
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_set_trips);
+
+void thermal_cdev_update(struct thermal_cooling_device *cdev)
+{
+	struct thermal_instance *instance;
+	unsigned long target = 0;
+
+	mutex_lock(&cdev->lock);
+	/* cooling device is updated*/
+	if (cdev->updated) {
+		mutex_unlock(&cdev->lock);
+		return;
+	}
+
+	/* 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;
+	}
+	cdev->ops->set_cur_state(cdev, target);
+	cdev->updated = true;
+	mutex_unlock(&cdev->lock);
+	trace_cdev_update(cdev, target);
+	dev_dbg(&cdev->device, "set to state %lu\n", target);
+}
+EXPORT_SYMBOL(thermal_cdev_update);