PL-330 DMA driver

[Linus Walleij]

2010/2/17 Guennadi Liakhovetski <g.liakhovetski at gmx.de>:

> Of course, there's also a problem of reusing peripheral drivers with
> different DMA controllers...

That's what I'm facing with MMCI and a host of other peripherals.

We have to either:

(1) Use something, i.e the DMA engine slave

(2) Fork the driver entirely to some ste-mmci.c and delete all generic
  code. (Repeat for each vendor using a primecell!)

(3) Sprinkle mmci.c with #ifdef ARCH_U300 for our DMA engine.
  Or, not so bad, atleast sprinkle the smallish part I have now
  broken out in mmci.c that deals with DMA transfers.

I think the current patch does (1) and it actually works, then if
it gets burdensome to others, using a generic DMA engine can
be a special case of (3) since that works for us so we're on the right
path in two cases and (2) doesn't look good to me.

Yours,
Linus Walleij