When a thermal zone is created that has sub thermal zones via
devicetree or via thermal_zone_add_subtz() expose that relationship in
sysfs.
Cc: Zhang Rui <rui.zh...@intel.com>
Cc: Eduardo Valentin <edubez...@gmail.com>
Signed-off-by: Javi Merino <javi.mer...@arm.com>
---
Documentation/thermal/sysfs-api.txt | 5 +++++
drivers/thermal/thermal_core.c | 22 ++++++++++++++++++++++
include/linux/thermal.h | 3 +++
3 files changed, 30 insertions(+)
diff --git a/Documentation/thermal/sysfs-api.txt
b/Documentation/thermal/sysfs-api.txt
index 5650b7eaaf7e..53972973792a 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -220,6 +220,7 @@ Thermal zone device sys I/F, created once it's registered:
|---trip_point_[0-*]_type: Trip point type
|---trip_point_[0-*]_hyst: Hysteresis value for this trip point
|---emul_temp: Emulated temperature set node
+ |---subtz[0-*] Slave thermal zones of this thermal zone
|---sustainable_power: Sustainable dissipatable power
|---k_po: Proportional term during temperature overshoot
|---k_pu: Proportional term during temperature undershoot
@@ -355,6 +356,10 @@ emul_temp
because userland can easily disable the thermal policy by simply
flooding this sysfs node with low temperature values.
+subtz[0-*]
+ sysfs link to the slave thermal zone device.
+ RO, Optional
+
sustainable_power
An estimate of the sustained power that can be dissipated by
the thermal zone. Used by the power allocator governor. For
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index a2ab482337f3..af72b704af36 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -62,6 +62,8 @@ static DEFINE_MUTEX(thermal_governor_lock);
static struct thermal_governor *def_governor;
struct thermal_zone_link {
+ int id;
+ char name[THERMAL_NAME_LENGTH];
struct thermal_zone_device *slave;
struct list_head node;
};
@@ -2076,6 +2078,23 @@ int thermal_zone_add_subtz(struct thermal_zone_device
*tz,
link->slave = subtz;
list_add_tail(&link->node, &tz->slave_tzs);
+ ret = get_idr(&tz->link_idr, NULL, &link->id);
+ if (ret) {
+ /*
+ * Even if we couldn't create the symlink in sysfs,
+ * we've linked the thermal zones, so return success
+ */
+ ret = 0;
+ goto unlock;
+ }
+
+ snprintf(link->name, ARRAY_SIZE(link->name), "subtz%d", link->id);
+ ret = sysfs_create_link(&tz->device.kobj, &subtz->device.kobj,
+ link->name);
+ if (ret)
+ pr_warn("Failed to create symlink to sub thermal zone: %d\n",
+ ret);
+
ret = 0;
unlock:
@@ -2107,6 +2126,9 @@ int thermal_zone_del_subtz(struct thermal_zone_device *tz,
list_for_each_entry(link, &tz->slave_tzs, node) {
if (link->slave == subtz) {
+ sysfs_remove_link(&tz->device.kobj, link->name);
+ release_idr(&tz->link_idr, NULL, link->id);
+
list_del(&link->node);
kfree(link);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 7996b4e7e61a..c5ca3be8b7ec 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -174,6 +174,8 @@ struct thermal_attr {
* @thermal_instances: list of &struct thermal_instance of this thermal zone
* @idr: &struct idr to generate unique id for this zone's cooling
* devices
+ * @link_idr: &struct idr to generate unique ids for this zone's links to
+ * other thermal zones
* @lock: lock to protect thermal_instances list
* @node: node in thermal_tz_list (in thermal_core.c)
* @poll_queue: delayed work for polling
@@ -202,6 +204,7 @@ struct thermal_zone_device {
void *governor_data;
struct list_head thermal_instances;
struct idr idr;
+ struct idr link_idr;
struct mutex lock;
struct list_head node;
struct delayed_work poll_queue;
--
1.9.1
--
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