Messages in this thread | | | Date | Thu, 6 Jul 2006 20:48:21 +0200 | From | Haavard Skinnemoen <> | Subject | Re: AVR32 architecture patch against Linux 2.6.18-rc1 available |
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On Thu, 06 Jul 2006 15:34:52 +0100 David Woodhouse <dwmw2@infradead.org> wrote:
> On Thu, 2006-07-06 at 16:13 +0200, Haavard Skinnemoen wrote:
> > As I understand it, though, drivers/dma is mostly for > > memory-to-memory to transfers, while what I really need is > > memory-to-hardware and hardware-to-memory transfers. > > With MMIO those are just a not-so-special case of memory-memory, > surely? If the new framework doesn't support that, it probably > _should_.
Yes, but there are at least two important differences:
* Hanshaking. The DMA controller must know when the peripheral has new data available/is able to accept more data. Thus, you need to specify which set of handshaking signals to use as well as which direction the data is moved. * One of the pointers often stays the same during the whole transfer.
I'm willing to give the drivers/dma framework a try, though, when the time comes to forward-port the drivers that need such infrastructure.
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