70e66e4df1
ACPI video driver is written according to ACPI spec, appendix B: Video Extensions. So it better be put under the acpi directory instead of the power directory. This patch moves the file there without any other change. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
37 lines
1.5 KiB
Text
37 lines
1.5 KiB
Text
ACPI video extensions
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~~~~~~~~~~~~~~~~~~~~~
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This driver implement the ACPI Extensions For Display Adapters for
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integrated graphics devices on motherboard, as specified in ACPI 2.0
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Specification, Appendix B, allowing to perform some basic control like
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defining the video POST device, retrieving EDID information or to
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setup a video output, etc. Note that this is an ref. implementation
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only. It may or may not work for your integrated video device.
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Interfaces exposed to userland through /proc/acpi/video:
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VGA/info : display the supported video bus device capability like Video ROM, CRT/LCD/TV.
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VGA/ROM : Used to get a copy of the display devices' ROM data (up to 4k).
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VGA/POST_info : Used to determine what options are implemented.
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VGA/POST : Used to get/set POST device.
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VGA/DOS : Used to get/set ownership of output switching:
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Please refer ACPI spec B.4.1 _DOS
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VGA/CRT : CRT output
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VGA/LCD : LCD output
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VGA/TVO : TV output
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VGA/*/brightness : Used to get/set brightness of output device
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Notify event through /proc/acpi/event:
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#define ACPI_VIDEO_NOTIFY_SWITCH 0x80
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#define ACPI_VIDEO_NOTIFY_PROBE 0x81
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#define ACPI_VIDEO_NOTIFY_CYCLE 0x82
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#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
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#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
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#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x82
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#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x83
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#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x84
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#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x85
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#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x86
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