[PATCH v4 03/30] thermal/core: Add a generic thermal_zone_set_trip() function

[Daniel Lezcano]

The thermal zone ops defines a set_trip callback where we can invoke
the backend driver to set an interrupt for the next trip point
temperature being crossed the way up or down, or setting the low level
with the hysteresis.

The ops is only called from the thermal sysfs code where the userspace
has the ability to modify a trip point characteristic.

With the effort of encapsulating the thermal framework core code,
let's create a thermal_zone_set_trip() which is the writable side of
the thermal_zone_get_trip() and put there all the ops encapsulation.

Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
 drivers/thermal/thermal_core.c  | 44 ++++++++++++++++++++++++++++++
 drivers/thermal/thermal_sysfs.c | 48 +++++++++++----------------------
 include/linux/thermal.h         |  3 +++
 3 files changed, 63 insertions(+), 32 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 381d85ec74a0..fa0f89a24b68 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1183,6 +1183,50 @@ int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 }
 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
 
+int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
+			  const struct thermal_trip *trip)
+{
+	struct thermal_trip t;
+	int ret = -EINVAL;
+
+	mutex_lock(&tz->lock);
+
+	if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips)
+		goto out;
+
+	ret = __thermal_zone_get_trip(tz, trip_id, &t);
+	if (ret)
+		goto out;
+
+	if ((t.temperature != trip->temperature) && tz->ops->set_trip_temp) {
+
+		ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
+		if (ret)
+			goto out;
+	}
+
+	if ((t.hysteresis != trip->hysteresis) && tz->ops->set_trip_hyst) {
+
+		ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
+		if (ret)
+			goto out;
+	}
+
+	if (((t.temperature != trip->temperature) ||
+	     (t.hysteresis != trip->hysteresis)) && tz->trips)
+		tz->trips[trip_id] = *trip;
+
+out:
+	mutex_unlock(&tz->lock);
+
+	if (!ret) {
+		thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
+					      trip->temperature, trip->hysteresis);
+		thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
+	}
+	
+	return ret;
+}
 
 /**
  * thermal_zone_device_register_with_trips() - register a new thermal zone device
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 18cdd7cd0008..8d7b25ab67c2 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -115,31 +115,20 @@ trip_point_temp_store(struct device *dev, struct device_attribute *attr,
 	struct thermal_trip trip;
 	int trip_id, ret;
 
-	if (!tz->ops->set_trip_temp && !tz->trips)
-		return -EPERM;
-
 	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
 		return -EINVAL;
 
-	if (kstrtoint(buf, 10, &trip.temperature))
-		return -EINVAL;
-
-	ret = tz->ops->set_trip_temp(tz, trip_id, trip.temperature);
+	ret = thermal_zone_get_trip(tz, trip_id, &trip);
 	if (ret)
 		return ret;
 
-	if (tz->trips)
-		tz->trips[trip_id].temperature = trip.temperature;
+	if (kstrtoint(buf, 10, &trip.temperature))
+		return -EINVAL;
 
-	ret = thermal_zone_get_trip(tz, trip_id, &trip);
+	ret = thermal_zone_set_trip(tz, trip_id, &trip);
 	if (ret)
 		return ret;
 
-	thermal_notify_tz_trip_change(tz->id, trip_id, trip.type,
-				      trip.temperature, trip.hysteresis);
-
-	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
-
 	return count;
 }
 
@@ -166,29 +155,24 @@ trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
 		      const char *buf, size_t count)
 {
 	struct thermal_zone_device *tz = to_thermal_zone(dev);
-	int trip, ret;
-	int temperature;
-
-	if (!tz->ops->set_trip_hyst)
-		return -EPERM;
+	struct thermal_trip trip;
+	int trip_id, ret;
 
-	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
+	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
 		return -EINVAL;
 
-	if (kstrtoint(buf, 10, &temperature))
-		return -EINVAL;
+	ret = thermal_zone_get_trip(tz, trip_id, &trip);
+	if (ret)
+		return ret;
 
-	/*
-	 * We are not doing any check on the 'temperature' value
-	 * here. The driver implementing 'set_trip_hyst' has to
-	 * take care of this.
-	 */
-	ret = tz->ops->set_trip_hyst(tz, trip, temperature);
+	if (kstrtoint(buf, 10, &trip.hysteresis))
+		return -EINVAL;
 
-	if (!ret)
-		thermal_zone_set_trips(tz);
+	ret = thermal_zone_set_trip(tz, trip_id, &trip);
+	if (ret)
+		return ret;
 
-	return ret ? ret : count;
+	return count;
 }
 
 static ssize_t
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 09dc09228717..5350a437f245 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -338,6 +338,9 @@ static inline void devm_thermal_of_zone_unregister(struct device *dev,
 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 			  struct thermal_trip *trip);
 
+int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
+			  const struct thermal_trip *trip);
+
 int thermal_zone_get_num_trips(struct thermal_zone_device *tz);
 
 #ifdef CONFIG_THERMAL
-- 
2.34.1