1*4882a593SmuzhiyunVideo Output Switcher Control 2*4882a593Smuzhiyun~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3*4882a593Smuzhiyun 4*4882a593Smuzhiyun2006 luming.yu@intel.com 5*4882a593Smuzhiyun 6*4882a593SmuzhiyunThe output sysfs class driver provides an abstract video output layer that 7*4882a593Smuzhiyuncan be used to hook platform specific methods to enable/disable video output 8*4882a593Smuzhiyundevice through common sysfs interface. For example, on my IBM ThinkPad T42 9*4882a593Smuzhiyunlaptop, The ACPI video driver registered its output devices and read/write 10*4882a593Smuzhiyunmethod for 'state' with output sysfs class. The user interface under sysfs is:: 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun linux:/sys/class/video_output # tree . 13*4882a593Smuzhiyun . 14*4882a593Smuzhiyun |-- CRT0 15*4882a593Smuzhiyun | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 16*4882a593Smuzhiyun | |-- state 17*4882a593Smuzhiyun | |-- subsystem -> ../../../class/video_output 18*4882a593Smuzhiyun | `-- uevent 19*4882a593Smuzhiyun |-- DVI0 20*4882a593Smuzhiyun | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 21*4882a593Smuzhiyun | |-- state 22*4882a593Smuzhiyun | |-- subsystem -> ../../../class/video_output 23*4882a593Smuzhiyun | `-- uevent 24*4882a593Smuzhiyun |-- LCD0 25*4882a593Smuzhiyun | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 26*4882a593Smuzhiyun | |-- state 27*4882a593Smuzhiyun | |-- subsystem -> ../../../class/video_output 28*4882a593Smuzhiyun | `-- uevent 29*4882a593Smuzhiyun `-- TV0 30*4882a593Smuzhiyun |-- device -> ../../../devices/pci0000:00/0000:00:01.0 31*4882a593Smuzhiyun |-- state 32*4882a593Smuzhiyun |-- subsystem -> ../../../class/video_output 33*4882a593Smuzhiyun `-- uevent 34*4882a593Smuzhiyun 35