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+
+		Video Output Switcher Control
+		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+		2006 luming.yu@gmail.com
+
+The output sysfs class driver is to provide video output abstract 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 
+aptop, 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
+