From 5915a3db0c3983f1cd5e046bf70086c7d0c686d2 Mon Sep 17 00:00:00 2001 From: Aaron Lu Date: Fri, 11 Oct 2013 21:27:43 +0800 Subject: backlight: introduce backlight_device_registered Introduce a new API for modules to query if a specific type of backlight device has been registered. This is useful for some backlight device provider module (e.g. ACPI video) to know if a native control interface(e.g. the interface created by i915) is available and then do things accordingly (e.g. avoid registering its own on Win8 systems). Signed-off-by: Aaron Lu Signed-off-by: Rafael J. Wysocki --- include/linux/backlight.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/backlight.h') diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 53b77949c79d..5f9cd963213d 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -100,6 +100,9 @@ struct backlight_device { /* The framebuffer notifier block */ struct notifier_block fb_notif; + /* list entry of all registered backlight devices */ + struct list_head entry; + struct device dev; }; @@ -123,6 +126,7 @@ extern void devm_backlight_device_unregister(struct device *dev, struct backlight_device *bd); extern void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason); +extern bool backlight_device_registered(enum backlight_type type); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) -- cgit v1.2.3-59-g8ed1b