From: Yu Luming Add output class document Signed-off-by: Luming Yu Cc: "Antonino A. Daplas" Cc: "Brown, Len" Cc: Greg KH Signed-off-by: Andrew Morton --- Documentation/video-output.txt | 34 +++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff -puN /dev/null Documentation/video-output.txt --- /dev/null +++ a/Documentation/video-output.txt @@ -0,0 +1,34 @@ + + 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 + _