thermal/core: Add a generic thermal_zone_get_trip() function

The thermal_zone_device_ops structure defines a set of ops family,
get_trip_temp(), get_trip_hyst(), get_trip_type(). Each of them is
returning a property of a trip point.

The result is the code is calling the ops everywhere to get a trip
point which is supposed to be defined in the backend driver. It is a
non-sense as a thermal trip can be generic and used by the backend
driver to declare its trip points.

Part of the thermal framework has been changed and all the OF thermal
drivers are using the same definition for the trip point and use a
thermal zone registration variant to pass those trip points which are
part of the thermal zone device structure.

Consequently, we can use a generic function to get the trip points
when they are stored in the thermal zone device structure.

This approach can be generalized to all the drivers and we can get rid
of the ops->get_trip_*. That will result to a much more simpler code
and make possible to rework how the thermal trip are handled in the
thermal core framework as discussed previously.

This change adds a function thermal_zone_get_trip() where we get the
thermal trip point structure which contains all the properties (type,
temp, hyst) instead of doing multiple calls to ops->get_trip_*.

That opens the door for trip point extension with more attributes. For
instance, replacing the trip points disabled bitmask with a 'disabled'
field in the structure.

Here we replace all the calls to ops->get_trip_* in the thermal core
code with a call to the thermal_zone_get_trip() function.

The thermal zone ops defines a callback to retrieve the critical
temperature. As the trip handling is being reworked, all the trip
points will be the same whatever the driver and consequently finding
the critical trip temperature will be just a loop to search for a
critical trip point type.

Provide such a generic function, so we encapsulate the ops
get_crit_temp() which can be removed when all the backend drivers are
using the generic trip points handling.

While at it, add the thermal_zone_get_num_trips() to encapsulate the
code more and reduce the grip with the thermal framework internals.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-2-daniel.lezcano@linaro.org

drivers/thermal/thermal_core.c

@@ -344,35 +344,31 @@ static void handle_critical_trips(struct thermal_zone_device *tz,
 		tz->ops->critical(tz);
 }
 
-static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
+static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
 {
-	enum thermal_trip_type type;
-	int trip_temp, hyst = 0;
+	struct thermal_trip trip;
 
 	/* Ignore disabled trip points */
-	if (test_bit(trip, &tz->trips_disabled))
+	if (test_bit(trip_id, &tz->trips_disabled))
 		return;
 
-	tz->ops->get_trip_temp(tz, trip, &trip_temp);
-	tz->ops->get_trip_type(tz, trip, &type);
-	if (tz->ops->get_trip_hyst)
-		tz->ops->get_trip_hyst(tz, trip, &hyst);
+	__thermal_zone_get_trip(tz, trip_id, &trip);
 
 	if (tz->last_temperature != THERMAL_TEMP_INVALID) {
-		if (tz->last_temperature < trip_temp &&
-		    tz->temperature >= trip_temp)
-			thermal_notify_tz_trip_up(tz->id, trip,
+		if (tz->last_temperature < trip.temperature &&
+		    tz->temperature >= trip.temperature)
+			thermal_notify_tz_trip_up(tz->id, trip_id,
 						  tz->temperature);
-		if (tz->last_temperature >= trip_temp &&
-		    tz->temperature < (trip_temp - hyst))
-			thermal_notify_tz_trip_down(tz->id, trip,
+		if (tz->last_temperature >= trip.temperature &&
+		    tz->temperature < (trip.temperature - trip.hysteresis))
+			thermal_notify_tz_trip_down(tz->id, trip_id,
 						    tz->temperature);
 	}
 
-	if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
-		handle_critical_trips(tz, trip, trip_temp, type);
+	if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
+		handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
 	else
-		handle_non_critical_trips(tz, trip);
+		handle_non_critical_trips(tz, trip_id);
 }
 
 static void update_temperature(struct thermal_zone_device *tz)
@@ -1159,6 +1155,79 @@ static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms
 		*delay_jiffies = round_jiffies(*delay_jiffies);
 }
 
+int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
+{
+	return tz->num_trips;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_num_trips);
+
+int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
+{
+	int i, ret = -EINVAL;
+
+	if (tz->ops->get_crit_temp)
+		return tz->ops->get_crit_temp(tz, temp);
+
+	if (!tz->trips)
+		return -EINVAL;
+
+	mutex_lock(&tz->lock);
+
+	for (i = 0; i < tz->num_trips; i++) {
+		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = tz->trips[i].temperature;
+			ret = 0;
+			break;
+		}
+	}
+
+	mutex_unlock(&tz->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
+
+int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
+			    struct thermal_trip *trip)
+{
+	int ret;
+
+	if (!tz || trip_id < 0 || trip_id >= tz->num_trips || !trip)
+		return -EINVAL;
+
+	if (tz->trips) {
+		*trip = tz->trips[trip_id];
+		return 0;
+	}
+
+	if (tz->ops->get_trip_hyst) {
+		ret = tz->ops->get_trip_hyst(tz, trip_id, &trip->hysteresis);
+		if (ret)
+			return ret;
+	} else {
+		trip->hysteresis = 0;
+	}
+
+	ret = tz->ops->get_trip_temp(tz, trip_id, &trip->temperature);
+	if (ret)
+		return ret;
+
+	return tz->ops->get_trip_type(tz, trip_id, &trip->type);
+}
+
+int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
+			  struct thermal_trip *trip)
+{
+	int ret;
+
+	mutex_lock(&tz->lock);
+	ret = __thermal_zone_get_trip(tz, trip_id, trip);
+	mutex_unlock(&tz->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
+
 /**
  * thermal_zone_device_register_with_trips() - register a new thermal zone device
  * @type:	the thermal zone device type
@@ -1191,8 +1260,6 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t
 					int polling_delay)
 {
 	struct thermal_zone_device *tz;
-	enum thermal_trip_type trip_type;
-	int trip_temp;
 	int id;
 	int result;
 	int count;
@@ -1232,7 +1299,7 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t
 		return ERR_PTR(-EINVAL);
 	}
 
-	if (num_trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
+	if (num_trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp) && !trips)
 		return ERR_PTR(-EINVAL);
 
 	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
@@ -1283,9 +1350,10 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t
 		goto release_device;
 
 	for (count = 0; count < num_trips; count++) {
-		if (tz->ops->get_trip_type(tz, count, &trip_type) ||
-		    tz->ops->get_trip_temp(tz, count, &trip_temp) ||
-		    !trip_temp)
+		struct thermal_trip trip;
+
+		result = thermal_zone_get_trip(tz, count, &trip);
+		if (result)
 			set_bit(count, &tz->trips_disabled);
 	}
 

drivers/thermal/thermal_core.h

@@ -114,6 +114,8 @@ void __thermal_zone_device_update(struct thermal_zone_device *tz,
 
 /* Helpers */
 void __thermal_zone_set_trips(struct thermal_zone_device *tz);
+int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
+			    struct thermal_trip *trip);
 int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp);
 
 /* sysfs I/F */

drivers/thermal/thermal_helpers.c

@@ -83,7 +83,7 @@ int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
 	int ret = -EINVAL;
 	int count;
 	int crit_temp = INT_MAX;
-	enum thermal_trip_type type;
+	struct thermal_trip trip;
 
 	lockdep_assert_held(&tz->lock);
 
@@ -91,10 +91,9 @@ int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
 
 	if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
 		for (count = 0; count < tz->num_trips; count++) {
-			ret = tz->ops->get_trip_type(tz, count, &type);
-			if (!ret && type == THERMAL_TRIP_CRITICAL) {
-				ret = tz->ops->get_trip_temp(tz, count,
-						&crit_temp);
+			ret = __thermal_zone_get_trip(tz, count, &trip);
+			if (!ret && trip.type == THERMAL_TRIP_CRITICAL) {
+				crit_temp = trip.temperature;
 				break;
 			}
 		}
@@ -164,29 +163,30 @@ EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
  */
 void __thermal_zone_set_trips(struct thermal_zone_device *tz)
 {
-	int low = -INT_MAX;
-	int high = INT_MAX;
-	int trip_temp, hysteresis;
+	struct thermal_trip trip;
+	int low = -INT_MAX, high = INT_MAX;
 	int i, ret;
 
 	lockdep_assert_held(&tz->lock);
 
-	if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
+	if (!tz->ops->set_trips)
 		return;
 
 	for (i = 0; i < tz->num_trips; i++) {
 		int trip_low;
 
-		tz->ops->get_trip_temp(tz, i, &trip_temp);
-		tz->ops->get_trip_hyst(tz, i, &hysteresis);
+		ret = __thermal_zone_get_trip(tz, i , &trip);
+		if (ret)
+			return;
 
-		trip_low = trip_temp - hysteresis;
+		trip_low = trip.temperature - trip.hysteresis;
 
 		if (trip_low < tz->temperature && trip_low > low)
 			low = trip_low;
 
-		if (trip_temp > tz->temperature && trip_temp < high)
-			high = trip_temp;
+		if (trip.temperature > tz->temperature &&
+		    trip.temperature < high)
+			high = trip.temperature;
 	}
 
 	/* No need to change trip points */

drivers/thermal/thermal_netlink.c

@@ -452,7 +452,8 @@ static int thermal_genl_cmd_tz_get_trip(struct param *p)
 	struct sk_buff *msg = p->msg;
 	struct thermal_zone_device *tz;
 	struct nlattr *start_trip;
-	int i, id;
+	struct thermal_trip trip;
+	int ret, i, id;
 
 	if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
 		return -EINVAL;
@@ -471,18 +472,14 @@ static int thermal_genl_cmd_tz_get_trip(struct param *p)
 
 	for (i = 0; i < tz->num_trips; i++) {
 
-		enum thermal_trip_type type;
-		int temp, hyst = 0;
-
-		tz->ops->get_trip_type(tz, i, &type);
-		tz->ops->get_trip_temp(tz, i, &temp);
-		if (tz->ops->get_trip_hyst)
-			tz->ops->get_trip_hyst(tz, i, &hyst);
+		ret = __thermal_zone_get_trip(tz, i, &trip);
+		if (ret)
+			goto out_cancel_nest;
 
 		if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_ID, i) ||
-		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TYPE, type) ||
-		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TEMP, temp) ||
-		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_HYST, hyst))
+		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TYPE, trip.type) ||
+		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TEMP, trip.temperature) ||
+		    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_HYST, trip.hysteresis))
 			goto out_cancel_nest;
 	}
 

drivers/thermal/thermal_sysfs.c

@@ -83,27 +83,25 @@ trip_point_type_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
 {
 	struct thermal_zone_device *tz = to_thermal_zone(dev);
-	enum thermal_trip_type type;
-	int trip, result;
+	struct thermal_trip trip;
+	int trip_id, result;
 
-	if (!tz->ops->get_trip_type)
-		return -EPERM;
-
-	if (sscanf(attr->attr.name, "trip_point_%d_type", &trip) != 1)
+	if (sscanf(attr->attr.name, "trip_point_%d_type", &trip_id) != 1)
 		return -EINVAL;
 
 	mutex_lock(&tz->lock);
 
 	if (device_is_registered(dev))
-		result = tz->ops->get_trip_type(tz, trip, &type);
+		result = __thermal_zone_get_trip(tz, trip_id, &trip);
 	else
 		result = -ENODEV;
 
 	mutex_unlock(&tz->lock);
+
 	if (result)
 		return result;
 
-	switch (type) {
+	switch (trip.type) {
 	case THERMAL_TRIP_CRITICAL:
 		return sprintf(buf, "critical\n");
 	case THERMAL_TRIP_HOT:
@@ -122,17 +120,16 @@ trip_point_temp_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, hyst = 0;
-	enum thermal_trip_type type;
+	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) != 1)
+	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
 		return -EINVAL;
 
-	if (kstrtoint(buf, 10, &temperature))
+	if (kstrtoint(buf, 10, &trip.temperature))
 		return -EINVAL;
 
 	mutex_lock(&tz->lock);
@@ -143,25 +140,20 @@ trip_point_temp_store(struct device *dev, struct device_attribute *attr,
 	}
 
 	if (tz->ops->set_trip_temp) {
-		ret = tz->ops->set_trip_temp(tz, trip, temperature);
+		ret = tz->ops->set_trip_temp(tz, trip_id, trip.temperature);
 		if (ret)
 			goto unlock;
 	}
 
 	if (tz->trips)
-		tz->trips[trip].temperature = temperature;
-
-	if (tz->ops->get_trip_hyst) {
-		ret = tz->ops->get_trip_hyst(tz, trip, &hyst);
-		if (ret)
-			goto unlock;
-	}
+		tz->trips[trip_id].temperature = trip.temperature;
 
-	ret = tz->ops->get_trip_type(tz, trip, &type);
+	ret = __thermal_zone_get_trip(tz, trip_id, &trip);
 	if (ret)
 		goto unlock;
 
-	thermal_notify_tz_trip_change(tz->id, trip, type, temperature, hyst);
+	thermal_notify_tz_trip_change(tz->id, trip_id, trip.type,
+				      trip.temperature, trip.hysteresis);
 
 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 
@@ -179,19 +171,16 @@ trip_point_temp_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
 {
 	struct thermal_zone_device *tz = to_thermal_zone(dev);
-	int trip, ret;
-	int temperature;
+	struct thermal_trip trip;
+	int trip_id, ret;
 
-	if (!tz->ops->get_trip_temp)
-		return -EPERM;
-
-	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
+	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
 		return -EINVAL;
 
 	mutex_lock(&tz->lock);
 
 	if (device_is_registered(dev))
-		ret = tz->ops->get_trip_temp(tz, trip, &temperature);
+		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
 	else
 		ret = -ENODEV;
 
@@ -200,7 +189,7 @@ trip_point_temp_show(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	return sprintf(buf, "%d\n", temperature);
+	return sprintf(buf, "%d\n", trip.temperature);
 }
 
 static ssize_t
@@ -248,25 +237,22 @@ trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
 {
 	struct thermal_zone_device *tz = to_thermal_zone(dev);
-	int trip, ret;
-	int temperature;
+	struct thermal_trip trip;
+	int trip_id, ret;
 
-	if (!tz->ops->get_trip_hyst)
-		return -EPERM;
-
-	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;
 
 	mutex_lock(&tz->lock);
 
 	if (device_is_registered(dev))
-		ret = tz->ops->get_trip_hyst(tz, trip, &temperature);
+		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
 	else
 		ret = -ENODEV;
 
 	mutex_unlock(&tz->lock);
 
-	return ret ? ret : sprintf(buf, "%d\n", temperature);
+	return ret ? ret : sprintf(buf, "%d\n", trip.hysteresis);
 }
 
 static ssize_t

include/linux/thermal.h

@@ -334,6 +334,13 @@ static inline void devm_thermal_of_zone_unregister(struct device *dev,
 }
 #endif
 
+int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
+			  struct thermal_trip *trip);
+
+int thermal_zone_get_num_trips(struct thermal_zone_device *tz);
+
+int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp);
+
 #ifdef CONFIG_THERMAL
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
 		void *, struct thermal_zone_device_ops *,