Re: NAND review

[Simon Kallweit <simon dot kallweit at intefo dot ch>]

Rutger Hofman wrote:
> > Jonathan Larmour wrote:
> > > that). But I'm also concerned about possibly having too much layering 
> > > in Rutger's version for small simple implementations.
>
> Well, there is one obvious candidate for being thinned out in my NAND 
> implementation: the ANC layer that hides the presence of multiple 
> controllers and/or chips. Making this optional for the (common) case of 
> one controller and one (or multiple identical) chips will be easy.

I don't really like that idea, as it cuts flexibility a lot. I think we 
will see the need to control 2 or more NAND controllers and/or chips at 
the same time. With Ross's solution this is currently possible and this 
rare case is where his implementation shines IMHO, because you just 
simply implement it in the platform instead of trying to implement it 
generically.

> I dislike the idea of code duplication, and so much is common across 
> controller functionality. Hence the split into common and 
> device-specific code, which enforces an API in-between. I did my best to 
> design this API in a way that is flexible and powerful, but of course I 
> cannot rule out that controllers exist that fit this interface only with 
> a lot of workarounds. Needless to say, I am very much open to 
> suggestions for improvement.

I'm with you on the code duplication matter and I think there should be 
a clear API between chips and the NAND controllers. I can't really judge 
if this is even possible. I have not yet used NAND flash and I don't 
know how diverse the controllers/chips out there are. Is there anyone 
with more insight?

Simon