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| author | Daniel Lezcano <daniel.lezcano@linaro.org> | 2024-09-23 11:59:57 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-10-10 23:33:37 +0200 |
| commit | 445936f9e258eca624c8239056bd8cd6e853b3fd (patch) | |
| tree | 8613f6a964acd230ec6f7b75cad79ec6390be108 /drivers/thermal/thermal_thresholds.h | |
| parent | 827a07525c099f54d3b15110408824541ec66b3c (diff) | |
| download | lwn-445936f9e258eca624c8239056bd8cd6e853b3fd.tar.gz lwn-445936f9e258eca624c8239056bd8cd6e853b3fd.zip | |
thermal: core: Add user thresholds support
The user thresholds mechanism is a way to have the userspace to tell
the thermal framework to send a notification when a temperature limit
is crossed. There is no id, no hysteresis, just the temperature and
the direction of the limit crossing. That means we can be notified
when a threshold is crossed the way up only, or the way down only or
both ways. That allows to create hysteresis values if it is needed.
A threshold can be added, deleted or flushed. The latter means all
thresholds belonging to a thermal zone will be deleted.
When a threshold is added:
- if the same threshold (temperature and direction) exists, an error
is returned
- if a threshold is specified with the same temperature but a
different direction, the specified direction is added
- if there is no threshold with the same temperature then it is
created
When a threshold is deleted:
- if the same threshold (temperature and direction) exists, it is
deleted
- if a threshold is specified with the same temperature but a
different direction, the specified direction is removed
- if there is no threshold with the same temperature, then an error
is returned
When the threshold are flushed:
- All thresholds related to a thermal zone are deleted
When a threshold is crossed:
- the userspace does not need to know which threshold(s) have been
crossed, it will be notified with the current temperature and the
previous temperature
- if multiple thresholds have been crossed between two updates only
one notification will be send to the userspace, it is pointless to
send a notification per thresholds crossed as the userspace can
handle that easily when it has the temperature delta information
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://patch.msgid.link/20240923100005.2532430-2-daniel.lezcano@linaro.org
[ rjw: Subject edit, use BIT(0) and BIT(1) in symbol definitions ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/thermal/thermal_thresholds.h')
| -rw-r--r-- | drivers/thermal/thermal_thresholds.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_thresholds.h b/drivers/thermal/thermal_thresholds.h new file mode 100644 index 000000000000..232f4e8089af --- /dev/null +++ b/drivers/thermal/thermal_thresholds.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __THERMAL_THRESHOLDS_H__ +#define __THERMAL_THRESHOLDS_H__ + +struct user_threshold { + struct list_head list_node; + int temperature; + int direction; +}; + +int thermal_thresholds_init(struct thermal_zone_device *tz); +void thermal_thresholds_exit(struct thermal_zone_device *tz); +void thermal_thresholds_flush(struct thermal_zone_device *tz); +void thermal_thresholds_handle(struct thermal_zone_device *tz, int *low, int *high); +int thermal_thresholds_add(struct thermal_zone_device *tz, int temperature, int direction); +int thermal_thresholds_delete(struct thermal_zone_device *tz, int temperature, int direction); +int thermal_thresholds_for_each(struct thermal_zone_device *tz, + int (*cb)(struct user_threshold *, void *arg), void *arg); +#endif |