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| author | Ondrej Zajicek <santiago@crfreenet.org> | 2007-05-09 02:35:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:57 -0700 |
| commit | 558b7bd86c32978648cda5deb5c758d77ef0c165 (patch) | |
| tree | 4840567ca9496fe5bf0e9ac564650d613ae6c360 /Documentation/fb/vt8623fb.txt | |
| parent | c3c117f06e95ea993ba4ed3b246fd76f87a4683f (diff) | |
| download | kernel_samsung_smdk4412-558b7bd86c32978648cda5deb5c758d77ef0c165.zip kernel_samsung_smdk4412-558b7bd86c32978648cda5deb5c758d77ef0c165.tar.gz kernel_samsung_smdk4412-558b7bd86c32978648cda5deb5c758d77ef0c165.tar.bz2 | |
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/fb/vt8623fb.txt')
| -rw-r--r-- | Documentation/fb/vt8623fb.txt | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/fb/vt8623fb.txt b/Documentation/fb/vt8623fb.txt new file mode 100644 index 0000000..f654576 --- /dev/null +++ b/Documentation/fb/vt8623fb.txt @@ -0,0 +1,64 @@ + + vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset + =============================================================== + + +Supported Hardware +================== + + VIA VT8623 [CLE266] chipset and its graphics core + (known as CastleRock or Unichrome) + +I tested vt8623fb on VIA EPIA ML-6000 + + +Supported Features +================== + + * 4 bpp pseudocolor modes (with 18bit palette, two variants) + * 8 bpp pseudocolor mode (with 18bit palette) + * 16 bpp truecolor mode (RGB 565) + * 32 bpp truecolor mode (RGB 888) + * text mode (activated by bpp = 0) + * doublescan mode variant (not available in text mode) + * panning in both directions + * suspend/resume support + * DPMS support + +Text mode is supported even in higher resolutions, but there is limitation to +lower pixclocks (maximum about 100 MHz). This limitation is not enforced by +driver. Text mode supports 8bit wide fonts only (hardware limitation) and +16bit tall fonts (driver limitation). + +There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with +packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode +with interleaved planes (1 byte interleave), MSB first. Both modes support +8bit wide fonts only (driver limitation). + +Suspend/resume works on systems that initialize video card during resume and +if device is active (for example used by fbcon). + + +Missing Features +================ +(alias TODO list) + + * secondary (not initialized by BIOS) device support + * MMIO support + * interlaced mode variant + * support for fontwidths != 8 in 4 bpp modes + * support for fontheight != 16 in text mode + * hardware cursor + * video overlay support + * vsync synchronization + * acceleration support (8514-like 2D, busmaster transfers) + + +Known bugs +========== + + * cursor disable in text mode doesn't work + + +-- +Ondrej Zajicek <santiago@crfreenet.org> |