summaryrefslogtreecommitdiffstats
path: root/Documentation/fb/vt8623fb.rst
diff options
context:
space:
mode:
authorLinus Torvalds2019-07-09 21:34:26 +0200
committerLinus Torvalds2019-07-09 21:34:26 +0200
commite9a83bd2322035ed9d7dcf35753d3f984d76c6a5 (patch)
tree66dc466ff9aec0f9bb7f39cba50a47eab6585559 /Documentation/fb/vt8623fb.rst
parentMerge tag 'printk-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/p... (diff)
parentdocs: automarkup.py: ignore exceptions when seeking for xrefs (diff)
downloadkernel-qcow2-linux-e9a83bd2322035ed9d7dcf35753d3f984d76c6a5.tar.gz
kernel-qcow2-linux-e9a83bd2322035ed9d7dcf35753d3f984d76c6a5.tar.xz
kernel-qcow2-linux-e9a83bd2322035ed9d7dcf35753d3f984d76c6a5.zip
Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
Diffstat (limited to 'Documentation/fb/vt8623fb.rst')
-rw-r--r--Documentation/fb/vt8623fb.rst64
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/fb/vt8623fb.rst b/Documentation/fb/vt8623fb.rst
new file mode 100644
index 000000000000..ba1730937dd8
--- /dev/null
+++ b/Documentation/fb/vt8623fb.rst
@@ -0,0 +1,64 @@
+===============================================================
+vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset
+===============================================================
+
+
+Supported Hardware
+==================
+
+VIA VT8623 [CLE266] chipset and its graphics core
+(known as CastleRock or Unichrome)
+
+I tested vt8623fb on VIA EPIA ML-6000
+
+
+Supported Features
+==================
+
+ * 4 bpp pseudocolor modes (with 18bit palette, two variants)
+ * 8 bpp pseudocolor mode (with 18bit palette)
+ * 16 bpp truecolor mode (RGB 565)
+ * 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
+ * DPMS support
+
+Text mode is supported even in higher resolutions, but there is limitation to
+lower pixclocks (maximum about 100 MHz). This limitation is not enforced by
+driver. Text mode supports 8bit wide fonts only (hardware limitation) and
+16bit tall fonts (driver limitation).
+
+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
+ * MMIO support
+ * interlaced mode variant
+ * support for fontwidths != 8 in 4 bpp modes
+ * support for fontheight != 16 in text mode
+ * hardware cursor
+ * video overlay support
+ * vsync synchronization
+ * acceleration support (8514-like 2D, busmaster transfers)
+
+
+Known bugs
+==========
+
+ * cursor disable in text mode doesn't work
+
+
+--
+Ondrej Zajicek <santiago@crfreenet.org>