ep93xx SPI driver v3

[ryan@bluewatersys.com (Ryan Mallon)]

Mika Westerberg wrote:
> On Mon, Apr 19, 2010 at 08:53:28AM +1200, Ryan Mallon wrote:
>> Martin Guy wrote:
>>> If we can get that working, a reasonable second stage would make it
>>> work for ep93xx-SPI transfers, making SD card access even less
>>> CPU-intensive
>> Sine the M2M DMA support for the ep93xx is not in the mainline yet, I
>> would be happy for the SPI driver to be merged without DMA support, and
>> to have it added at a later date.
> 
> Yeah. This discussion actually referred to future improvements. We
> can implement DMA support later on.
> 
> BTW: do you guys think that there is any real use of polling mode
> in the driver or should I drop it out completely? I mean, if we are
> going to add proper timeout / error reporting for polling, it makes
> the driver more complex.

I recall not being able to get interrupt mode working in the driver the
Hartley and I worked on. I can't remember if this was a limitation of
our hardware, or just bugs in the interrupt code. I'll try and find some
time today to test the driver out.

~Ryan