2006 [email protected]
The output sysfs class driver provides an abstract video output layer that can be used to hook platform specific methods to enable/disable video output device through common sysfs interface. For example, on my IBM ThinkPad T42 laptop, The ACPI video driver registered its output devices and read/write method for 'state' with output sysfs class. The user interface under sysfs is:
linux:/sys/class/video_output # tree . . |-- CRT0 | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 | |-- state | |-- subsystem -> ../../../class/video_output | `-- uevent |-- DVI0 | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 | |-- state | |-- subsystem -> ../../../class/video_output | `-- uevent |-- LCD0 | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 | |-- state | |-- subsystem -> ../../../class/video_output | `-- uevent `-- TV0 |-- device -> ../../../devices/pci0000:00/0000:00:01.0 |-- state |-- subsystem -> ../../../class/video_output `-- uevent