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authorOndrej Zajicek <santiago@crfreenet.org>2007-05-09 05:35:31 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 15:30:57 -0400
commit558b7bd86c32978648cda5deb5c758d77ef0c165 (patch)
tree4840567ca9496fe5bf0e9ac564650d613ae6c360 /Documentation
parentc3c117f06e95ea993ba4ed3b246fd76f87a4683f (diff)
vt8623fb: new framebuffer driver for VIA VT8623
This patch adds fbdev driver for graphics core in VIA VT8623 [adaplas@gmail.com: build fixes] Signed-off-by: Ondrej Zajicek <santiago@crfreenet.org> Signed-off-by: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/fb/vt8623fb.txt64
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diff --git a/Documentation/fb/vt8623fb.txt b/Documentation/fb/vt8623fb.txt
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1
2 vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset
3 ===============================================================
4
5
6Supported Hardware
7==================
8
9 VIA VT8623 [CLE266] chipset and its graphics core
10 (known as CastleRock or Unichrome)
11
12I tested vt8623fb on VIA EPIA ML-6000
13
14
15Supported Features
16==================
17
18 * 4 bpp pseudocolor modes (with 18bit palette, two variants)
19 * 8 bpp pseudocolor mode (with 18bit palette)
20 * 16 bpp truecolor mode (RGB 565)
21 * 32 bpp truecolor mode (RGB 888)
22 * text mode (activated by bpp = 0)
23 * doublescan mode variant (not available in text mode)
24 * panning in both directions
25 * suspend/resume support
26 * DPMS support
27
28Text mode is supported even in higher resolutions, but there is limitation to
29lower pixclocks (maximum about 100 MHz). This limitation is not enforced by
30driver. Text mode supports 8bit wide fonts only (hardware limitation) and
3116bit tall fonts (driver limitation).
32
33There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with
34packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode
35with interleaved planes (1 byte interleave), MSB first. Both modes support
368bit wide fonts only (driver limitation).
37
38Suspend/resume works on systems that initialize video card during resume and
39if device is active (for example used by fbcon).
40
41
42Missing Features
43================
44(alias TODO list)
45
46 * secondary (not initialized by BIOS) device support
47 * MMIO support
48 * interlaced mode variant
49 * support for fontwidths != 8 in 4 bpp modes
50 * support for fontheight != 16 in text mode
51 * hardware cursor
52 * video overlay support
53 * vsync synchronization
54 * acceleration support (8514-like 2D, busmaster transfers)
55
56
57Known bugs
58==========
59
60 * cursor disable in text mode doesn't work
61
62
63--
64Ondrej Zajicek <santiago@crfreenet.org>