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authorOndrej Zajicek <santiago@crfreenet.org>2007-05-09 02:35:31 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 12:30:57 -0700
commit681e14730c73cc2c71af282c001de6bc71c22f00 (patch)
tree3dfb470010566c2085524d9ae7d4791a787e4aaf /Documentation/fb/arkfb.txt
parent558b7bd86c32978648cda5deb5c758d77ef0c165 (diff)
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>
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+
+ 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>