1
2		Video Output Switcher Control
3		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4		2006 luming.yu@intel.com
5
6The output sysfs class driver provides an abstract video output layer that
7can be used to hook platform specific methods to enable/disable video output
8device through common sysfs interface. For example, on my IBM ThinkPad T42
9laptop, The ACPI video driver registered its output devices and read/write
10method for 'state' with output sysfs class. The user interface under sysfs is:
11
12linux:/sys/class/video_output # tree .
13.
14|-- CRT0
15|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
16|   |-- state
17|   |-- subsystem -> ../../../class/video_output
18|   `-- uevent
19|-- DVI0
20|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
21|   |-- state
22|   |-- subsystem -> ../../../class/video_output
23|   `-- uevent
24|-- LCD0
25|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
26|   |-- state
27|   |-- subsystem -> ../../../class/video_output
28|   `-- uevent
29`-- TV0
30   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
31   |-- state
32   |-- subsystem -> ../../../class/video_output
33   `-- uevent
34