To allow different mitigative actions based on a sensor temperature, it
is desirable to have multiple thermal zones share the same source. The
thermal zones could have different thresholds, mitigative actions and
even different governors.
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---
drivers/thermal/of-thermal.c | 32 ++++++++++++++++++++++++++------
include/linux/thermal.h | 2 ++
2 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index b402edd09ed1..06e581a37c67 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -39,10 +39,14 @@ struct __thermal_bind_params {
* struct thermal_sensor - Holds individual sensor data
* @sensor_data: sensor driver private data passed as input argument
* @ops: sensor driver ops
+ * @tz_list: list of thermal zones for this sensor
+ * @lock: lock sensor during operations
*/
struct thermal_sensor {
void *sensor_data;
const struct thermal_zone_of_device_ops *ops;
+ struct list_head tz_list;
+ struct mutex lock;
};
/**
@@ -430,11 +434,24 @@ thermal_zone_of_add_sensor(struct device_node *zone,
if (sensor->ops->set_emul_temp)
tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
+ mutex_lock(&sensor->lock);
+ list_add_tail(&tzd->sensor_tzd, &sensor->tz_list);
+ mutex_unlock(&sensor->lock);
mutex_unlock(&tzd->lock);
return tzd;
}
+static struct thermal_zone_device *
+thermal_zone_of_get_sensor_tzd(struct thermal_sensor *sensor)
+{
+ if (list_empty(&sensor->tz_list))
+ return ERR_PTR(-ENODEV);
+
+ return list_first_entry(&sensor->tz_list, struct thermal_zone_device,
+ sensor_tzd);
+}
+
/**
* thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
* @dev: a valid struct device pointer of a sensor device. Must contain
@@ -460,12 +477,11 @@ thermal_zone_of_add_sensor(struct device_node *zone,
* 01 - This function must enqueue the new sensor instead of using
* it as the only source of temperature values.
*
- * 02 - There must be a way to match the sensor with all thermal zones
- * that refer to it.
- *
* Return: On success returns a valid struct thermal_zone_device,
* otherwise, it returns a corresponding ERR_PTR(). Caller must
* check the return value with help of IS_ERR() helper.
+ * The returned thermal_zone_device is one of the thermal zones that is
+ * using this sensor as the temeprature source.
*/
struct thermal_zone_device *
thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
@@ -489,6 +505,8 @@ thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
of_node_put(np);
return ERR_PTR(-ENOMEM);
}
+ INIT_LIST_HEAD(&sensor->tz_list);
+ mutex_init(&sensor->lock);
sensor->sensor_data = data;
sensor->ops = ops;
sensor_np = of_node_get(dev->of_node);
@@ -521,14 +539,14 @@ thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
of_node_put(sensor_specs.np);
of_node_put(child);
- goto exit;
}
of_node_put(sensor_specs.np);
}
-exit:
+
of_node_put(sensor_np);
of_node_put(np);
+ tzd = thermal_zone_of_get_sensor_tzd(sensor);
if (tzd == ERR_PTR(-ENODEV))
kfree(sensor);
return tzd;
@@ -569,7 +587,9 @@ void thermal_zone_of_sensor_unregister(struct device *dev,
tzd->ops->get_trend = NULL;
tzd->ops->set_emul_temp = NULL;
- kfree(tz->sensor);
+ list_del(&tzd->sensor_tzd);
+ if (list_empty(&tz->sensor->tz_list))
+ kfree(tz->sensor);
tz->sensor = NULL;
mutex_unlock(&tzd->lock);
}
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 7a133bd6ff86..09e1669a4919 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -188,6 +188,7 @@ struct thermal_attr {
* @node: node in thermal_tz_list (in thermal_core.c)
* @poll_queue: delayed work for polling
* @notify_event: Last notification event
+ * @sensor_tzd: node in sensor's list of thermal zone devices
*/
struct thermal_zone_device {
int id;
@@ -220,6 +221,7 @@ struct thermal_zone_device {
struct list_head node;
struct delayed_work poll_queue;
enum thermal_notify_event notify_event;
+ struct list_head sensor_tzd;
};
/**
--
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