$ tree   /sys/class/backlight/
/sys/class/backlight/
├── acpi_video0 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video0
└── intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

2 directories, 0 files