Re: FPGA programming driver architecture

[Hugo Villeneuve <hugo@hugovil.com>]

On Thu, 8 Jan 2009 20:14:36 -0200
"Thiago Galesi" <thiagogalesi@gmail.com> wrote:

> > > > Hi,
> > > > I have written some code to program a FPGA in Linux, for two
> > > > different types of boards: one uses a serial interface (SPI) and
> > > > the second a parallel interface. I have been able to sucessfully
> > > > program both boards. I'm now trying to clean my code and make it
> > > > more generic, as well as better in line with the Linux driver
> > > > model.
> 
> Considering the several FPGA models available and ways to program it,
> I guess the important thing to consider is what can be made generic.
> (that is what will become fpgaload)

I have a pretty good idea of what goes into the core and
what goes into the specific interface modules (spi, parallel, etc).

> Also, there may be cases where after FPGA is programmed it "becomes a
> device" (PCI or whatever)

This is exactly the case for my board, but it doesn´t change anything
to the programming side of things, apart for the fact that the FPGA
must be configured before using any in-FPGA PCI bus for example.

> > > - fpgaload-core which contains all the code that can be shared
> > > between the drivers like requesting firmware, providing sysfs
> > > attributes,
> > > - fpgaload-spi would handle the low-level SPI connection
> > > - fpgaload-par would handle the low-level parallel connection
> 
> I think this maybe split into three layers (maybe)
> 
> 1 - low level connection: paralell / spi / i2c / whatever
> 2 - vendor: xylinx, altera, etc
> 3 - generic stuff
> 
> Take a look at the MTD and SPI drivers and how they split things

I think that for the moment, I will focus on implementing the core
module and the parallel/SPI interfaces only. Later we may want to add
more fonctionality (vendors, JTAG, etc).

But for now, my main problem is that I need to have some insight on how
I actually implement the different modules:

Bus driver?
class driver?
platform driver?

Can anybody give some advice on that?

Thank-you, Hugo.

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Hugo Villeneuve
www.hugovil.com
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