From b03637b8863159a4518cb0a9ab90577460fe3417 Mon Sep 17 00:00:00 2001 From: Yu Luming Date: Tue, 19 Dec 2006 12:56:18 -0800 Subject: [PATCH] output: Add output class document Signed-off-by: Luming Yu Cc: "Antonino A. Daplas" Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- Documentation/video-output.txt | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 Documentation/video-output.txt diff --git a/Documentation/video-output.txt b/Documentation/video-output.txt new file mode 100644 index 00000000000..e517011be4f --- /dev/null +++ b/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 +