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authorAaron Lu <aaron.lu@intel.com>2013-10-11 21:27:43 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-10-16 01:16:04 +0200
commit5915a3db0c3983f1cd5e046bf70086c7d0c686d2 (patch)
treed3f56cdf916f71ac50789abf511ee16b6bc55fe6 /include/linux/backlight.h
parent068aab7766cf968a8ddb86a6d7c6bbed9d61e353 (diff)
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 <aaron.lu@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/backlight.h')
-rw-r--r--include/linux/backlight.h4
1 files changed, 4 insertions, 0 deletions
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)