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authorFabio Baltieri <fabio.baltieri@gmail.com>2012-11-04 13:54:34 +0400
committerBryan Wu <cooloney@gmail.com>2012-11-27 02:28:50 +0400
commita8df7b1ab70bfd6f261fa5e96985fca638299acc (patch)
tree92e50e11054d9182757899e9c16070dbffadc83b
parent5cce0105c8d07d3bd5f578c77d273e1a1e09f157 (diff)
downloadlinux-a8df7b1ab70bfd6f261fa5e96985fca638299acc.tar.xz
leds: add led_trigger_rename function
Implements a "led_trigger_rename" function to rename a trigger with proper locking. This assumes that led name was originally allocated in non-constant storage. Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Cc: Kurt Van Dijck <kurt.van.dijck@eia.be> Signed-off-by: Bryan Wu <cooloney@gmail.com>
-rw-r--r--drivers/leds/led-triggers.c13
-rw-r--r--include/linux/leds.h18
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 262eb4193710..a4fa4bf02d53 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -166,6 +166,19 @@ void led_trigger_set_default(struct led_classdev *led_cdev)
}
EXPORT_SYMBOL_GPL(led_trigger_set_default);
+void led_trigger_rename_static(const char *name, struct led_trigger *trig)
+{
+ /* new name must be on a temporary string to prevent races */
+ BUG_ON(name == trig->name);
+
+ down_write(&triggers_list_lock);
+ /* this assumes that trig->name was originaly allocated to
+ * non constant storage */
+ strcpy((char *)trig->name, name);
+ up_write(&triggers_list_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_rename_static);
+
/* LED Trigger Interface */
int led_trigger_register(struct led_trigger *trig)
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 6e53bb31c220..8107592cfc41 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -139,6 +139,24 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
+/**
+ * led_trigger_rename_static - rename a trigger
+ * @name: the new trigger name
+ * @trig: the LED trigger to rename
+ *
+ * Change a LED trigger name by copying the string passed in
+ * name into current trigger name, which MUST be large
+ * enough for the new string.
+ *
+ * Note that name must NOT point to the same string used
+ * during LED registration, as that could lead to races.
+ *
+ * This is meant to be used on triggers with statically
+ * allocated name.
+ */
+extern void led_trigger_rename_static(const char *name,
+ struct led_trigger *trig);
+
/*
* LED Triggers
*/