LPC bus access howto

[Guillaume Knispel]

On Mon, 21 Nov 2011 17:01:29 +0100
Andre Haupt <andre at bitwigglers.org> wrote:

> Hi all,
> 
> We have a FPGA which will be connected to the LPC bus. This FPGA will
> provide some GPIO functionality, a rotary encoder, etc.
> 
> Now i want to write a kernel driver to talk to this FPGA.
> I am unsure how to get access to the LPC bus in the first place.
> What kernel APIs should i use? How to get the memory mapping right, etc?

The LPC is typically automatically mapped by the hardware (southbridge)
for some fixed ranges, various configurable ranges and might also use
PCI substractive decoding. 

LPC is indeed an ISA bus with the physical layer replaced by something
with fewer signals, but from the point of view of the software there is
almost no difference, so look for how to program ISA drivers and you
will probably have your answer.

-- 
Guillaume Knispel
Avencall - 10 bis, rue Lucien Voilin - 92800 Puteaux
Tel. : (+33) 141 389 960