[PATCH] leds: core: add managed version of led_trigger_register

[Heiner Kallweit <hkallweit1@gmail.com>]

Complementing devm_led_classdev_register add a managed version of
led_trigger_register.

I omit a managed version of led_classdev_unregister as the equivalent
devm_led_classdev_unregister isn't used in the kernel as of today.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/leds/led-triggers.c | 28 ++++++++++++++++++++++++++++
 include/linux/leds.h        |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index e8b1120..e1e9334 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -249,6 +249,34 @@ void led_trigger_unregister(struct led_trigger *trig)
 }
 EXPORT_SYMBOL_GPL(led_trigger_unregister);
 
+static void devm_led_trigger_release(struct device *dev, void *res)
+{
+	led_trigger_unregister(*(struct led_trigger **)res);
+}
+
+int devm_led_trigger_register(struct device *dev,
+			      struct led_trigger *trig)
+{
+	struct led_trigger **dr;
+	int rc;
+
+	dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
+			  GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	*dr = trig;
+
+	rc = led_trigger_register(trig);
+	if (rc)
+		devres_free(dr);
+	else
+		devres_add(dev, dr);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(devm_led_trigger_register);
+
 /* Simple LED Tigger Interface */
 
 void led_trigger_event(struct led_trigger *trig,
diff --git a/include/linux/leds.h b/include/linux/leds.h
index fa359c7..3db0654 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -231,6 +231,8 @@ ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 /* Registration functions for complex triggers */
 extern int led_trigger_register(struct led_trigger *trigger);
 extern void led_trigger_unregister(struct led_trigger *trigger);
+extern int devm_led_trigger_register(struct device *dev,
+				     struct led_trigger *trigger);
 
 extern void led_trigger_register_simple(const char *name,
 				struct led_trigger **trigger);
-- 
2.6.4