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| author |   Hans de Goede <hdegoede@redhat.com> | 2014-05-21 15:39:54 +0200 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-05-27 01:29:01 +0200 |
| commit | 3cc6919bd61315ea60baf95f3f9868aacfd1ace4 (patch) | |
| tree | e50ebe95421333e2c18a146fc449ead2b84cd0f4 /include/linux/backlight.h | |
| parent | nouveau: Don't check acpi_video_backlight_support() before registering backlight (diff) | |
| download | linux-dev-3cc6919bd61315ea60baf95f3f9868aacfd1ace4.tar.xz linux-dev-3cc6919bd61315ea60baf95f3f9868aacfd1ace4.zip | |
backlight: Add backlight device (un)registration notification
Some firmware drivers, ie acpi-video want to get themselves out of the
way (in some cases) when their also is a raw backlight device available.
Due to module loading ordering being unknown, acpi-video cannot be certain
that the backlight_device_registered(BACKLIGHT_RAW) it does for this is
the final verdict wrt there being a BACKLIGHT_RAW device.
By adding notification acpi-video can listen for backlight devices showing
up after it has loaded, and unregister its backlight device if desired.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jingoo Han <jg1.han@samsung.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.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 72647429adf6..adb14a8616df 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -40,6 +40,11 @@ enum backlight_type { BACKLIGHT_TYPE_MAX, }; +enum backlight_notification { + BACKLIGHT_REGISTERED, + BACKLIGHT_UNREGISTERED, +}; + struct backlight_device; struct fb_info; @@ -133,6 +138,8 @@ extern void devm_backlight_device_unregister(struct device *dev, extern void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason); extern bool backlight_device_registered(enum backlight_type type); +extern int backlight_register_notifier(struct notifier_block *nb); +extern int backlight_unregister_notifier(struct notifier_block *nb); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) |