ACPI: move thermal trip handling to generic thermal layer

The ACPI code currently carries its own thermal trip handling, meaning that
any other thermal implementation will need to reimplement it. Move the code
to the generic thermal layer.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 186 insertions, 2 deletions

diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index bd139adc6d3..6378741882f 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -30,6 +30,7 @@
 #include <linux/idr.h>
 #include <linux/thermal.h>
 #include <linux/spinlock.h>
+#include <linux/reboot.h>
 
 MODULE_AUTHOR("Zhang Rui");
 MODULE_DESCRIPTION("Generic thermal management sysfs support");
@@ -517,6 +518,97 @@ thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
 }
 #endif
 
+static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
+					    int delay)
+{
+	cancel_delayed_work(&(tz->poll_queue));
+
+	if (!delay)
+		return;
+
+	if (delay > 1000)
+		schedule_delayed_work(&(tz->poll_queue),
+				      round_jiffies(msecs_to_jiffies(delay)));
+	else
+		schedule_delayed_work(&(tz->poll_queue),
+				      msecs_to_jiffies(delay));
+}
+
+static void thermal_zone_device_passive(struct thermal_zone_device *tz,
+					int temp, int trip_temp, int trip)
+{
+	int trend = 0;
+	struct thermal_cooling_device_instance *instance;
+	struct thermal_cooling_device *cdev;
+	long state, max_state;
+
+	/*
+	 * Above Trip?
+	 * -----------
+	 * Calculate the thermal trend (using the passive cooling equation)
+	 * and modify the performance limit for all passive cooling devices
+	 * accordingly.  Note that we assume symmetry.
+	 */
+	if (temp >= trip_temp) {
+		tz->passive = true;
+
+		trend = (tz->tc1 * (temp - tz->last_temperature)) +
+			(tz->tc2 * (temp - trip_temp));
+
+		/* Heating up? */
+		if (trend > 0) {
+			list_for_each_entry(instance, &tz->cooling_devices,
+					    node) {
+				if (instance->trip != trip)
+					continue;
+				cdev = instance->cdev;
+				cdev->ops->get_cur_state(cdev, &state);
+				cdev->ops->get_max_state(cdev, &max_state);
+				if (state++ < max_state)
+					cdev->ops->set_cur_state(cdev, state);
+			}
+		} else if (trend < 0) { /* Cooling off? */
+			list_for_each_entry(instance, &tz->cooling_devices,
+					    node) {
+				if (instance->trip != trip)
+					continue;
+				cdev = instance->cdev;
+				cdev->ops->get_cur_state(cdev, &state);
+				cdev->ops->get_max_state(cdev, &max_state);
+				if (state > 0)
+					cdev->ops->set_cur_state(cdev, --state);
+			}
+		}
+		return;
+	}
+
+	/*
+	 * Below Trip?
+	 * -----------
+	 * Implement passive cooling hysteresis to slowly increase performance
+	 * and avoid thrashing around the passive trip point.  Note that we
+	 * assume symmetry.
+	 */
+	list_for_each_entry(instance, &tz->cooling_devices, node) {
+		if (instance->trip != trip)
+			continue;
+		cdev = instance->cdev;
+		cdev->ops->get_cur_state(cdev, &state);
+		cdev->ops->get_max_state(cdev, &max_state);
+		if (state > 0)
+			cdev->ops->set_cur_state(cdev, --state);
+		if (state == 0)
+			tz->passive = false;
+	}
+}
+
+static void thermal_zone_device_check(struct work_struct *work)
+{
+	struct thermal_zone_device *tz = container_of(work, struct
+						      thermal_zone_device,
+						      poll_queue.work);
+	thermal_zone_device_update(tz);
+}
 
 /**
  * thermal_zone_bind_cooling_device - bind a cooling device to a thermal zone
@@ -787,20 +879,101 @@ void thermal_cooling_device_unregister(struct
 EXPORT_SYMBOL(thermal_cooling_device_unregister);
 
 /**
+ * thermal_zone_device_update - force an update of a thermal zone's state
+ * @ttz:	the thermal zone to update
+ */
+
+void thermal_zone_device_update(struct thermal_zone_device *tz)
+{
+	int count, ret = 0;
+	long temp, trip_temp;
+	enum thermal_trip_type trip_type;
+	struct thermal_cooling_device_instance *instance;
+	struct thermal_cooling_device *cdev;
+
+	mutex_lock(&tz->lock);
+
+	tz->ops->get_temp(tz, &temp);
+
+	for (count = 0; count < tz->trips; count++) {
+		tz->ops->get_trip_type(tz, count, &trip_type);
+		tz->ops->get_trip_temp(tz, count, &trip_temp);
+
+		switch (trip_type) {
+		case THERMAL_TRIP_CRITICAL:
+			if (temp > trip_temp) {
+				if (tz->ops->notify)
+					ret = tz->ops->notify(tz, count,
+							      trip_type);
+				if (!ret) {
+					printk(KERN_EMERG
+					       "Critical temperature reached (%ld C), shutting down.\n",
+					       temp/1000);
+					orderly_poweroff(true);
+				}
+			}
+			break;
+		case THERMAL_TRIP_HOT:
+			if (temp > trip_temp)
+				if (tz->ops->notify)
+					tz->ops->notify(tz, count, trip_type);
+			break;
+		case THERMAL_TRIP_ACTIVE:
+			list_for_each_entry(instance, &tz->cooling_devices,
+					    node) {
+				if (instance->trip != count)
+					continue;
+
+				cdev = instance->cdev;
+
+				if (temp > trip_temp)
+					cdev->ops->set_cur_state(cdev, 1);
+				else
+					cdev->ops->set_cur_state(cdev, 0);
+			}
+			break;
+		case THERMAL_TRIP_PASSIVE:
+			if (temp > trip_temp || tz->passive)
+				thermal_zone_device_passive(tz, temp,
+							    trip_temp, count);
+			break;
+		}
+	}
+	tz->last_temperature = temp;
+	if (tz->passive)
+		thermal_zone_device_set_polling(tz, tz->passive_delay);
+	else if (tz->polling_delay)
+		thermal_zone_device_set_polling(tz, tz->polling_delay);
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL(thermal_zone_device_update);
+
+/**
  * thermal_zone_device_register - register a new thermal zone device
  * @type:	the thermal zone device type
  * @trips:	the number of trip points the thermal zone support
  * @devdata:	private device data
  * @ops:	standard thermal zone device callbacks
+ * @tc1:	thermal coefficient 1 for passive calculations
+ * @tc2:	thermal coefficient 2 for passive calculations
+ * @passive_delay: number of milliseconds to wait between polls when
+ *		   performing passive cooling
+ * @polling_delay: number of milliseconds to wait between polls when checking
+ *		   whether trip points have been crossed (0 for interrupt
+ *		   driven systems)
  *
  * thermal_zone_device_unregister() must be called when the device is no
- * longer needed.
+ * longer needed. The passive cooling formula uses tc1 and tc2 as described in
+ * section 11.1.5.1 of the ACPI specification 3.0.
  */
 struct thermal_zone_device *thermal_zone_device_register(char *type,
 							 int trips,
 							 void *devdata, struct
 							 thermal_zone_device_ops
-							 *ops)
+							 *ops, int tc1, int
+							 tc2,
+							 int passive_delay,
+							 int polling_delay)
 {
 	struct thermal_zone_device *tz;
 	struct thermal_cooling_device *pos;
@@ -834,6 +1007,11 @@ struct thermal_zone_device *thermal_zone_device_register(char *type,
 	tz->device.class = &thermal_class;
 	tz->devdata = devdata;
 	tz->trips = trips;
+	tz->tc1 = tc1;
+	tz->tc2 = tc2;
+	tz->passive_delay = passive_delay;
+	tz->polling_delay = polling_delay;
+
 	dev_set_name(&tz->device, "thermal_zone%d", tz->id);
 	result = device_register(&tz->device);
 	if (result) {
@@ -879,6 +1057,10 @@ struct thermal_zone_device *thermal_zone_device_register(char *type,
 		}
 	mutex_unlock(&thermal_list_lock);
 
+	INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);
+
+	thermal_zone_device_update(tz);
+
 	if (!result)
 		return tz;
 
@@ -918,6 +1100,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 		    tz->ops->unbind(tz, cdev);
 	mutex_unlock(&thermal_list_lock);
 
+	thermal_zone_device_set_polling(tz, 0);
+
 	if (tz->type[0])
 		device_remove_file(&tz->device, &dev_attr_type);
 	device_remove_file(&tz->device, &dev_attr_temp);