leds: Introduce devres helper for led_classdev_register

(cooloney@gmail.com: add _unregister function into the document)

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

3 files changed, 65 insertions, 0 deletions

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 6d1e8eeb5990..e1e2bbd7a404 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -289,6 +289,10 @@ IRQ
   devm_request_irq()
   devm_request_threaded_irq()
 
+LED
+  devm_led_classdev_register()
+  devm_led_classdev_unregister()
+
 MDIO
   devm_mdiobus_alloc()
   devm_mdiobus_alloc_size()
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 795ec994c663..768d33a79881 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -288,6 +288,63 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_classdev_unregister);
 
+static void devm_led_classdev_release(struct device *dev, void *res)
+{
+        led_classdev_unregister(*(struct led_classdev **)res);
+}
+
+/**
+ * devm_led_classdev_register - resource managed led_classdev_register()
+ * @parent: The device to register.
+ * @led_cdev: the led_classdev structure for this device.
+ */
+int devm_led_classdev_register(struct device *parent,
+                               struct led_classdev *led_cdev)
+{
+        struct led_classdev **dr;
+        int rc;
+
+        dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
+        if (!dr)
+                return -ENOMEM;
+
+        rc = led_classdev_register(parent, led_cdev);
+        if (rc) {
+                devres_free(dr);
+                return rc;
+        }
+
+        *dr = led_cdev;
+        devres_add(parent, dr);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_register);
+
+static int devm_led_classdev_match(struct device *dev, void *res, void *data)
+{
+        struct led_cdev **p = res;
+
+        if (WARN_ON(!p || !*p))
+                return 0;
+
+        return *p == data;
+}
+
+/**
+ * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
+ * @parent: The device to unregister.
+ * @led_cdev: the led_classdev structure for this device.
+ */
+void devm_led_classdev_unregister(struct device *dev,
+                                  struct led_classdev *led_cdev)
+{
+        WARN_ON(devres_release(dev,
+                               devm_led_classdev_release,
+                               devm_led_classdev_match, led_cdev));
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
+
 static int __init leds_init(void)
 {
         leds_class = class_create(THIS_MODULE, "leds");
diff --git a/include/linux/leds.h b/include/linux/leds.h
index f70f84f35674..ed634279062e 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -105,7 +105,11 @@ struct led_classdev {
 
 extern int led_classdev_register(struct device *parent,
                                  struct led_classdev *led_cdev);
+extern int devm_led_classdev_register(struct device *parent,
+                                      struct led_classdev *led_cdev);
 extern void led_classdev_unregister(struct led_classdev *led_cdev);
+extern void devm_led_classdev_unregister(struct device *parent,
+                                         struct led_classdev *led_cdev);
 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 extern void led_classdev_resume(struct led_classdev *led_cdev);