thermal: export weight to sysfs

It's useful to have access to the weights for the cooling devices for
thermal zones and change them if needed.  Export them to sysfs.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 7ec632e..3625453 100644 (file)
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -194,6 +194,8 @@ thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
 /sys/class/thermal/thermal_zone[0-*]:
     |---cdev[0-*]:             [0-*]th cooling device in current thermal zone
     |---cdev[0-*]_trip_point:  Trip point that cdev[0-*] is associated with
 /sys/class/thermal/thermal_zone[0-*]:
     |---cdev[0-*]:             [0-*]th cooling device in current thermal zone
     |---cdev[0-*]_trip_point:  Trip point that cdev[0-*] is associated with

+    |---cdev[0-*]_weight:       Influence of the cooling device in
+                                this thermal zone

 
 Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
 the generic thermal driver also creates a hwmon sysfs I/F for each _type_
 
 Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
 the generic thermal driver also creates a hwmon sysfs I/F for each _type_


@@ -267,6 +269,14 @@ cdev[0-*]_trip_point
        point.
        RO, Optional
 
        point.
        RO, Optional
 

+cdev[0-*]_weight
+        The influence of cdev[0-*] in this thermal zone. This value
+        is relative to the rest of cooling devices in the thermal
+        zone. For example, if a cooling device has a weight double
+        than that of other, it's twice as effective in cooling the
+        thermal zone.
+        RW, Optional
+

 passive
        Attribute is only present for zones in which the passive cooling
        policy is not supported by native thermal driver. Default is zero
 passive
        Attribute is only present for zones in which the passive cooling
        policy is not supported by native thermal driver. Default is zero


@@ -320,7 +330,8 @@ passive, active. If an ACPI thermal zone supports critical, passive,
 active[0] and active[1] at the same time, it may register itself as a
 thermal_zone_device (thermal_zone1) with 4 trip points in all.
 It has one processor and one fan, which are both registered as
 active[0] and active[1] at the same time, it may register itself as a
 thermal_zone_device (thermal_zone1) with 4 trip points in all.
 It has one processor and one fan, which are both registered as

-thermal_cooling_device.
+thermal_cooling_device. Both are considered to have the same
+effectiveness in cooling the thermal zone.

 
 If the processor is listed in _PSL method, and the fan is listed in _AL0
 method, the sys I/F structure will be built like this:
 
 If the processor is listed in _PSL method, and the fan is listed in _AL0
 method, the sys I/F structure will be built like this:


@@ -342,8 +353,10 @@ method, the sys I/F structure will be built like this:
     |---trip_point_3_type:     active1
     |---cdev0:                 --->/sys/class/thermal/cooling_device0
     |---cdev0_trip_point:      1       /* cdev0 can be used for passive */
     |---trip_point_3_type:     active1
     |---cdev0:                 --->/sys/class/thermal/cooling_device0
     |---cdev0_trip_point:      1       /* cdev0 can be used for passive */

+    |---cdev0_weight:           1024

     |---cdev1:                 --->/sys/class/thermal/cooling_device3
     |---cdev1_trip_point:      2       /* cdev1 can be used for active[0]*/
     |---cdev1:                 --->/sys/class/thermal/cooling_device3
     |---cdev1_trip_point:      2       /* cdev1 can be used for active[0]*/

+    |---cdev1_weight:           1024

 
 |cooling_device0:
     |---type:                  Processor
 
 |cooling_device0:
     |---type:                  Processor

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index a6cb9b7..605d691 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -922,6 +922,34 @@ static const struct attribute_group *cooling_device_attr_groups[] = {
        NULL,
 };
 
        NULL,
 };
 

+static ssize_t
+thermal_cooling_device_weight_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+       struct thermal_instance *instance;
+
+       instance = container_of(attr, struct thermal_instance, weight_attr);
+
+       return sprintf(buf, "%d\n", instance->weight);
+}
+
+static ssize_t
+thermal_cooling_device_weight_store(struct device *dev,
+                                   struct device_attribute *attr,
+                                   const char *buf, size_t count)
+{
+       struct thermal_instance *instance;
+       int ret, weight;
+
+       ret = kstrtoint(buf, 0, &weight);
+       if (ret)
+               return ret;
+
+       instance = container_of(attr, struct thermal_instance, weight_attr);
+       instance->weight = weight;
+
+       return count;
+}

 /* Device management */
 
 /**
 /* Device management */
 
 /**


@@ -1016,6 +1044,16 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
        if (result)
                goto remove_symbol_link;
 
        if (result)
                goto remove_symbol_link;
 

+       sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
+       sysfs_attr_init(&dev->weight_attr.attr);
+       dev->weight_attr.attr.name = dev->weight_attr_name;
+       dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
+       dev->weight_attr.show = thermal_cooling_device_weight_show;
+       dev->weight_attr.store = thermal_cooling_device_weight_store;
+       result = device_create_file(&tz->device, &dev->weight_attr);
+       if (result)
+               goto remove_trip_file;
+

        mutex_lock(&tz->lock);
        mutex_lock(&cdev->lock);
        list_for_each_entry(pos, &tz->thermal_instances, tz_node)
        mutex_lock(&tz->lock);
        mutex_lock(&cdev->lock);
        list_for_each_entry(pos, &tz->thermal_instances, tz_node)


@@ -1033,6 +1071,8 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
        if (!result)
                return 0;
 
        if (!result)
                return 0;
 

+       device_remove_file(&tz->device, &dev->weight_attr);
+remove_trip_file:

        device_remove_file(&tz->device, &dev->attr);
 remove_symbol_link:
        sysfs_remove_link(&tz->device.kobj, dev->name);
        device_remove_file(&tz->device, &dev->attr);
 remove_symbol_link:
        sysfs_remove_link(&tz->device.kobj, dev->name);

diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 7a465e9..faebe88 100644 (file)
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -46,6 +46,8 @@ struct thermal_instance {
        unsigned long target;   /* expected cooling state */
        char attr_name[THERMAL_NAME_LENGTH];
        struct device_attribute attr;
        unsigned long target;   /* expected cooling state */
        char attr_name[THERMAL_NAME_LENGTH];
        struct device_attribute attr;

+       char weight_attr_name[THERMAL_NAME_LENGTH];
+       struct device_attribute weight_attr;

        struct list_head tz_node; /* node in tz->thermal_instances */
        struct list_head cdev_node; /* node in cdev->thermal_instances */
        unsigned int weight; /* The weight of the cooling device */
        struct list_head tz_node; /* node in tz->thermal_instances */
        struct list_head cdev_node; /* node in cdev->thermal_instances */
        unsigned int weight; /* The weight of the cooling device */