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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/power/video_extension.txt
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+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/TV : 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
+