[PATCHv2 13/49] thermal: core: create tz->device.groups dynamically

[Eduardo Valentin]

This is a patch to allow adding groups created dynamically. For now we
create only the existing group. However, this is a preparation to allow
creating trip groups, which are determined only when the number of trips
are known at runtime.

Cc: Zhang Rui <rui.zh...@intel.com>
Cc: linux...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubez...@gmail.com>
---
 drivers/thermal/thermal_core.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index e399ae6..971f033 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1236,7 +1236,7 @@ static const struct attribute_group 
*thermal_zone_attribute_groups[] = {
        &thermal_zone_attribute_group,
        &thermal_zone_mode_attribute_group,
        &thermal_zone_passive_attribute_group,
-       NULL
+       /* This is not NULL terminated as we create the group dynamically */
 };
 
 /**
@@ -1347,6 +1347,25 @@ static void remove_trip_attrs(struct thermal_zone_device 
*tz)
        kfree(tz->trip_hyst_attrs);
 }
 
+static int thermal_zone_create_device_groups(struct thermal_zone_device *tz)
+{
+       const struct attribute_group **groups;
+       int i, size;
+
+       size = ARRAY_SIZE(thermal_zone_attribute_groups) + 1;
+       /* This also takes care of API requirement to be NULL terminated */
+       groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
+       if (!groups)
+               return -ENOMEM;
+
+       for (i = 0; i < size - 1; i++)
+               groups[i] = thermal_zone_attribute_groups[i];
+
+       tz->device.groups = groups;
+
+       return 0;
+}
+
 /* sys I/F for cooling device */
 #define to_cooling_device(_dev)        \
        container_of(_dev, struct thermal_cooling_device, device)
@@ -1982,7 +2001,7 @@ struct thermal_zone_device 
*thermal_zone_device_register(const char *type,
        tz->polling_delay = polling_delay;
 
        /* Add nodes that are always present via .groups */
-       tz->device.groups = thermal_zone_attribute_groups;
+       thermal_zone_create_device_groups(tz);
        /* A new thermal zone needs to be updated anyway. */
        atomic_set(&tz->need_update, 1);
 
@@ -2111,7 +2130,7 @@ void thermal_zone_device_unregister(struct 
thermal_zone_device *tz)
        idr_destroy(&tz->idr);
        mutex_destroy(&tz->lock);
        device_unregister(&tz->device);
-       return;
+       kfree(tz->device.groups);
 }
 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
 
-- 
2.1.4