From 681e14730c73cc2c71af282c001de6bc71c22f00 Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Wed, 9 May 2007 02:35:31 -0700 Subject: arkfb: new framebuffer driver for ARK Logic cards This patch adds fbdev driver for graphics cards with ARK Logic 2000PV graphics chip with ICS 5342 ramdac. [adaplas@gmail.com: build fixes] Signed-off-by: Ondrej Zajicek Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/fb/arkfb.txt | 68 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 Documentation/fb/arkfb.txt (limited to 'Documentation/fb/arkfb.txt') diff --git a/Documentation/fb/arkfb.txt b/Documentation/fb/arkfb.txt new file mode 100644 index 000000000000..e8487a9d6a05 --- /dev/null +++ b/Documentation/fb/arkfb.txt @@ -0,0 +1,68 @@ + + arkfb - fbdev driver for ARK Logic chips + ======================================== + + +Supported Hardware +================== + + ARK 2000PV chip + ICS 5342 ramdac + + - only BIOS initialized VGA devices supported + - probably not working on big endian + + +Supported Features +================== + + * 4 bpp pseudocolor modes (with 18bit palette, two variants) + * 8 bpp pseudocolor mode (with 18bit palette) + * 16 bpp truecolor modes (RGB 555 and RGB 565) + * 24 bpp truecolor mode (RGB 888) + * 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 + +Text mode is supported even in higher resolutions, but there is limitation to +lower pixclocks (i got maximum about 70 MHz, it is dependent on specific +hardware). This limitation is not enforced by driver. Text mode supports 8bit +wide fonts only (hardware limitation) and 16bit tall fonts (driver +limitation). Unfortunately character attributes (like color) in text mode are +broken for unknown reason, so its usefulness is limited. + +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 + * big endian support + * DPMS support + * MMIO support + * interlaced mode variant + * support for fontwidths != 8 in 4 bpp modes + * support for fontheight != 16 in text mode + * hardware cursor + * vsync synchronization + * feature connector support + * acceleration support (8514-like 2D) + + +Known bugs +========== + + * character attributes (and cursor) in text mode are broken + +-- +Ondrej Zajicek -- cgit v1.2.3-58-ga151