1 files changed, 186 insertions, 2 deletions

diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index bd139adc6d32..6378741882f3 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);