Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / fb / arkfb.txt

diff --git a/kernel/Documentation/fb/arkfb.txt b/kernel/Documentation/fb/arkfb.txt
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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>