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>

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 6d1e8eeb5990363c4441238ef305da3082b94b89..e1e2bbd7a40404344adb1c46697cfb47dd47f9ee 100644 (file)
--- 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 795ec994c66341beb3529c6273c753d2b8653c8d..768d33a79881824be66c6a90190820077f0a8dc8 100644 (file)
--- 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 f70f84f35674f38efc1275cf10a460ff025ec16d..ed634279062eb6de41edca0e43bdbb0e8991538f 100644 (file)
--- 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);