1*4f4cfa6cSMauro Carvalho ChehabVideo Output Switcher Control 2*4f4cfa6cSMauro Carvalho Chehab~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3*4f4cfa6cSMauro Carvalho Chehab 4*4f4cfa6cSMauro Carvalho Chehab2006 luming.yu@intel.com 5*4f4cfa6cSMauro Carvalho Chehab 6*4f4cfa6cSMauro Carvalho ChehabThe output sysfs class driver provides an abstract video output layer that 7*4f4cfa6cSMauro Carvalho Chehabcan be used to hook platform specific methods to enable/disable video output 8*4f4cfa6cSMauro Carvalho Chehabdevice through common sysfs interface. For example, on my IBM ThinkPad T42 9*4f4cfa6cSMauro Carvalho Chehablaptop, The ACPI video driver registered its output devices and read/write 10*4f4cfa6cSMauro Carvalho Chehabmethod for 'state' with output sysfs class. The user interface under sysfs is:: 11*4f4cfa6cSMauro Carvalho Chehab 12*4f4cfa6cSMauro Carvalho Chehab linux:/sys/class/video_output # tree . 13*4f4cfa6cSMauro Carvalho Chehab . 14*4f4cfa6cSMauro Carvalho Chehab |-- CRT0 15*4f4cfa6cSMauro Carvalho Chehab | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 16*4f4cfa6cSMauro Carvalho Chehab | |-- state 17*4f4cfa6cSMauro Carvalho Chehab | |-- subsystem -> ../../../class/video_output 18*4f4cfa6cSMauro Carvalho Chehab | `-- uevent 19*4f4cfa6cSMauro Carvalho Chehab |-- DVI0 20*4f4cfa6cSMauro Carvalho Chehab | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 21*4f4cfa6cSMauro Carvalho Chehab | |-- state 22*4f4cfa6cSMauro Carvalho Chehab | |-- subsystem -> ../../../class/video_output 23*4f4cfa6cSMauro Carvalho Chehab | `-- uevent 24*4f4cfa6cSMauro Carvalho Chehab |-- LCD0 25*4f4cfa6cSMauro Carvalho Chehab | |-- device -> ../../../devices/pci0000:00/0000:00:01.0 26*4f4cfa6cSMauro Carvalho Chehab | |-- state 27*4f4cfa6cSMauro Carvalho Chehab | |-- subsystem -> ../../../class/video_output 28*4f4cfa6cSMauro Carvalho Chehab | `-- uevent 29*4f4cfa6cSMauro Carvalho Chehab `-- TV0 30*4f4cfa6cSMauro Carvalho Chehab |-- device -> ../../../devices/pci0000:00/0000:00:01.0 31*4f4cfa6cSMauro Carvalho Chehab |-- state 32*4f4cfa6cSMauro Carvalho Chehab |-- subsystem -> ../../../class/video_output 33*4f4cfa6cSMauro Carvalho Chehab `-- uevent 34*4f4cfa6cSMauro Carvalho Chehab 35