diff options
Diffstat (limited to 'drivers/thermal')
| -rw-r--r-- | drivers/thermal/thermal_sys.c | 188 |
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); |