android_kernel_xiaomi_sm8350/Documentation/fb/cyblafb/documentation

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[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>
2005-09-09 16:04:56 -04:00
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.