Video Output Switcher Control
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2006 luming.yu@intel.com
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
