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 <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>

1 files changed, 68 insertions, 0 deletions

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 <santiago@crfreenet.org>