diff options
author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-12 20:52:45 +0300 |
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committer | Jonathan Corbet <corbet@lwn.net> | 2019-06-14 23:21:11 +0300 |
commit | ab42b818954c040fa13639dc031d8541edcecb4b (patch) | |
tree | baf9142b53b039fa58ca66af479156f4886c9cc8 /Documentation/fb/arkfb.rst | |
parent | 10ffebbed5503b1830c7920ef528075785351be6 (diff) | |
download | linux-ab42b818954c040fa13639dc031d8541edcecb4b.tar.xz |
docs: fb: convert docs to ReST and rename to *.rst
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Also, removed the Maintained by, as requested by Geert.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/fb/arkfb.rst')
-rw-r--r-- | Documentation/fb/arkfb.rst | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/fb/arkfb.rst b/Documentation/fb/arkfb.rst new file mode 100644 index 000000000000..aeca8773dd7e --- /dev/null +++ b/Documentation/fb/arkfb.rst @@ -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> |