Some hardware can react autonomously at a programmed temperature.
For example, an SoC might implement a last ditch throttle or a
hardware thermal shutdown. The driver for such a device can
register itself as a cooling_device with the thermal framework.
With this change, the thermal framework notifies such a driver
when userspace alters the relevant trip temperature so that
the driver can reprogram its hardware
Signed-off-by: Matt Longnecker <mlongnec...@nvidia.com>
---
drivers/thermal/thermal_core.c | 30 ++++++++++++++++++++++++++++++
include/linux/thermal.h | 2 ++
2 files changed, 32 insertions(+)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 71b0ec0..f25272e 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -597,6 +597,7 @@ trip_point_temp_store(struct device *dev, struct
device_attribute *attr,
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
unsigned long temperature;
+ struct thermal_instance *pos = NULL;
if (!tz->ops->set_trip_temp)
return -EPERM;
@@ -609,6 +610,20 @@ trip_point_temp_store(struct device *dev, struct
device_attribute *attr,
ret = tz->ops->set_trip_temp(tz, trip, temperature);
+ /*
+ * Notify bound cooling devices that this trip point changed.
+ * This is useful for cooling devices which represent a behavior
+ * which trips in hardware (e.g. catastrophic shutdown)
+ */
+ list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
+ if (pos->tz == tz && pos->trip == trip && pos->cdev) {
+ if (pos->cdev->ops->trip_point_changed)
+ pos->cdev->ops->trip_point_changed(pos->cdev,
+ pos->tz,
+ trip);
+ }
+ }
+
return ret ? ret : count;
}
@@ -641,6 +656,7 @@ trip_point_hyst_store(struct device *dev, struct
device_attribute *attr,
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
unsigned long temperature;
+ struct thermal_instance *pos = NULL;
if (!tz->ops->set_trip_hyst)
return -EPERM;
@@ -658,6 +674,20 @@ trip_point_hyst_store(struct device *dev, struct
device_attribute *attr,
*/
ret = tz->ops->set_trip_hyst(tz, trip, temperature);
+ /*
+ * Notify bound cooling devices that this trip point changed.
+ * This is useful for cooling devices which represent a behavior
+ * which trips in hardware (e.g. catastrophic shutdown)
+ */
+ list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
+ if (pos->tz == tz && pos->trip == trip && pos->cdev) {
+ if (pos->cdev->ops->trip_point_changed)
+ pos->cdev->ops->trip_point_changed(pos->cdev,
+ pos->tz,
+ trip);
+ }
+ }
+
return ret ? ret : count;
}
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index f7e11c7..7da7fc5 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -138,6 +138,8 @@ struct thermal_cooling_device_ops {
int (*get_max_state) (struct thermal_cooling_device *, unsigned long *);
int (*get_cur_state) (struct thermal_cooling_device *, unsigned long *);
int (*set_cur_state) (struct thermal_cooling_device *, unsigned long);
+ void (*trip_point_changed) (struct thermal_cooling_device *,
+ struct thermal_zone_device *, int);
};
struct thermal_cooling_device {
--
1.7.9.5
--
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