static int acpi_video_get_next_level(struct acpi_video_device *device,
u32 level_current, u32 event);
static void acpi_video_switch_brightness(struct acpi_video_device *device,
int event);
static int acpi_video_device_get_state(struct acpi_video_device *device,
static int acpi_video_get_next_level(struct acpi_video_device *device,
u32 level_current, u32 event);
static void acpi_video_switch_brightness(struct acpi_video_device *device,
int event);
static int acpi_video_device_get_state(struct acpi_video_device *device,