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authorAaron Lu <aaron.lu@intel.com>2013-06-21 00:15:59 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-21 00:15:59 +0200
commit70e66e4df19167653aba95b4dacbcfd3254a4019 (patch)
tree23b49c176becf710e458aadd91f6cde6a9cc2f68 /Documentation/acpi
parent3afe6dab86b669dd5bcef07b67d3ba7fb12a69a0 (diff)
downloadkernel-70e66e4df19167653aba95b4dacbcfd3254a4019.tar.gz
ACPI / video: move video_extension.txt to Documentation/acpi
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>
Diffstat (limited to 'Documentation/acpi')
-rw-r--r--Documentation/acpi/video_extension.txt37
1 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/acpi/video_extension.txt b/Documentation/acpi/video_extension.txt
new file mode 100644
index 000000000000..b2f9b1598ac2
--- /dev/null
+++ b/Documentation/acpi/video_extension.txt
@@ -0,0 +1,37 @@
+ACPI video extensions
+~~~~~~~~~~~~~~~~~~~~~
+
+This driver implement the ACPI Extensions For Display Adapters for
+integrated graphics devices on motherboard, as specified in ACPI 2.0
+Specification, Appendix B, allowing to perform some basic control like
+defining the video POST device, retrieving EDID information or to
+setup a video output, etc. Note that this is an ref. implementation
+only. It may or may not work for your integrated video device.
+
+Interfaces exposed to userland through /proc/acpi/video:
+
+VGA/info : display the supported video bus device capability like Video ROM, CRT/LCD/TV.
+VGA/ROM : Used to get a copy of the display devices' ROM data (up to 4k).
+VGA/POST_info : Used to determine what options are implemented.
+VGA/POST : Used to get/set POST device.
+VGA/DOS : Used to get/set ownership of output switching:
+ Please refer ACPI spec B.4.1 _DOS
+VGA/CRT : CRT output
+VGA/LCD : LCD output
+VGA/TVO : TV output
+VGA/*/brightness : Used to get/set brightness of output device
+
+Notify event through /proc/acpi/event:
+
+#define ACPI_VIDEO_NOTIFY_SWITCH 0x80
+#define ACPI_VIDEO_NOTIFY_PROBE 0x81
+#define ACPI_VIDEO_NOTIFY_CYCLE 0x82
+#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
+#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
+
+#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x82
+#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x83
+#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x84
+#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x85
+#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x86
+