spi-topcliff-pch: Fix issue for transmitting over 4KByte
[zen-stable.git] / Documentation / video-output.txt
blobe517011be4f964db7b452e1e50420eaed83f143d
2                 Video Output Switcher Control
3                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4                 2006 luming.yu@intel.com
6 The output sysfs class driver provides an abstract video output layer that
7 can be used to hook platform specific methods to enable/disable video output
8 device through common sysfs interface. For example, on my IBM ThinkPad T42
9 laptop, The ACPI video driver registered its output devices and read/write
10 method for 'state' with output sysfs class. The user interface under sysfs is:
12 linux:/sys/class/video_output # tree .
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