[RFC PATCH 10/11] thermal: create tz->device.groups dynamically

From: Eduardo Valentin
Date: Sat Apr 23 2016 - 19:35:29 EST


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.zhang@xxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
---
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 b1b2945..13a85d7 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1169,7 +1169,7 @@ 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 */
};

/**
@@ -1281,6 +1281,25 @@ 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 = kzalloc(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)
@@ -1913,7 +1932,7 @@ 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);

@@ -2042,7 +2061,7 @@ 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