[PATCH] framebuffer: new driver for cyberblade/i1 graphics core

This is a framebuffer driver for the Cyberblade/i1 graphics core.

Currently tridenfb claims to support the cyberblade/i1 graphics core.  This
is of very limited truth.  Even vesafb is faster and provides more working
modes and a much better quality of the video signal.  There is a great
number of bugs in tridentfb ...  but most often it is impossible to decide
if these bugs are real bugs or if fixing them for the cyberblade/i1 core
would break support for one of the other supported chips.

Tridentfb seems to be unmaintained,and documentation for most of the
supported chips is not available.  So "fixing" cyberblade/i1 support inside
of tridentfb was not an option, it would have caused numerous
if(CYBERBLADEi1) else ...  cases and would have rendered the code to be
almost unmaintainable.

A first version of this driver was published on 2005-07-31.  A fix for a
bug reported by Jochen Hein was integrated as well as some changes
requested by Antonino A.  Daplas.

A message has been added to tridentfb to inform current users of tridentfb
to switch to cyblafb if the cyberblade/i1 graphics core is detected.

This patch is one logical change, but because of the included documentation
it is bigger than 70kb.  Therefore it is not sent to lkml and
linux-fbdev-devel,

Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de>
Cc: Muli Ben-Yehuda <mulix@mulix.org>
Acked-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/Documentation/fb/cyblafb/documentation b/Documentation/fb/cyblafb/documentation
new file mode 100644
index 000000000000..bb1aac048425
--- /dev/null
+++ b/Documentation/fb/cyblafb/documentation
@@ -0,0 +1,17 @@
+Available Documentation
+=======================
+
+Apollo PLE 133 Chipset VT8601A North Bridge Datasheet, Rev. 1.82, October 22,
+2001, available from VIA:
+
+        http://www.viavpsd.com/product/6/15/DS8601A182.pdf
+
+The datasheet is incomplete, some registers that need to be programmed are not
+explained at all and important bits are listed as "reserved". But you really
+need the datasheet to understand the code.  "p. xxx" comments refer to page
+numbers of this document.
+
+XFree/XOrg drivers are available and of good quality, looking at the code
+there is a good idea if the datasheet does not provide enough information
+or if the datasheet seems to be wrong.
+