BACKLIGHT(9)           FreeBSD Kernel Developer's Manual          BACKLIGHT(9)

NAME
     backlight, backlight_register, backlight_destroy, BACKLIGHT_GET_STATUS,
     BACKLIGHT_SET_STATUS, - BACKLIGHT methods

SYNOPSIS
     device backlight
     #include <backlight_if.h>
     #include <sys/sys/backlight.h>

     int
     BACKLIGHT_GET_STATUS(device_t bus, struct backlight_props *props);

     int
     BACKLIGHT_SET_STATUS(device_t bus, struct backlight_props *props);

     struct cdev *
     backlight_register(const char *name, device_t dev);

     int
     backlight_destroy(struct cdev *cdev);

DESCRIPTION
     The backlight driver provides a generic way for handling a panel
     backlight.

     Drivers for backlight system register themselves globally using the
     backlight_register() function.  They must define two methods,
     BACKLIGHT_GET_STATUS() which is used to query the current brightness
     level and BACKLIGHT_SET_STATUS() which is used to update it.

INTERFACE
     BACKLIGHT_GET_STATUS(device_t bus, struct backlight_props *props)
             Driver fills the current brightless level and the optional
             supported levels.

     BACKLIGHT_SET_STATUS(device_t bus, struct backlight_props *props)
             Driver update the backlight level based on the brightness member
             of the props struct.

FILES
     /dev/backlight/*

HISTORY
     The backlight interface first appear in FreeBSD 13.0.  The backlight
     driver and manual page was written by Emmanuel Vadot <manu@FreeBSD.org>.

FreeBSD 13.1-RELEASE-p6         October 2, 2020        FreeBSD 13.1-RELEASE-p6