Re: [iPAQ] supported hardware?

Thanks Nicholas,

I saw your code and I also studied the code in the audio driver you mentioned.
I have been able to get DMA working using a combination of the existing code and
your code ( specifically the function "sa1100_start_dma" ). My code isn't
generic stuff but at least it's working and I can tidy it up later. I was also
in a steep DMA learning curve.

My understanding is that the "generic" API as presented in
/arch/arm/kernel/dma.c (kernel 2.4.0-test4) needs the architecture specific
functions (arch_xxx() ). These functions are still under development (and are
presently commented out in 2.4.0-test4). If this is true can you give some
indication as to when they will be finished.?

>>Maybe it can be of some help to you as well.
Your help now and in the future would be much appreciated. One question comes to
mind since you offer ;-)
The physical and virtual addresses returned from the call to
"consistent_alloc()" were different (as expected) but when I tried to convert
physical to virtual using the macros "virt_to_phys" and "phys_to_virt".the
addresses were the same. I only got DMA working when I ditched these macros and
stayed with the physical address returned from "consistent_alloc()". Any
comments?

Regards
Charlie

BTW I've cross posted this to the linux@handhelds according to Jim Gettys recent
guidelines.

Nicolas Pitre wrote:

> On Wed, 9 Aug 2000, Charlie Flynn wrote:
>
> > I'm working on a port to enable the iPAQ to have network connectivity (
> > pseudo ethernet driver) using the USB as a data link layer. I've had some
> > success and can transfer data between the PC host and the iPAQ with DMA
> > switched off, however I'm still trying to get DMA working. It shouldn't be
> > long though.
>
> I started to write a generic SA1100 DMA support layer. The UDA1341 audio
> driver is currently using small part of it. Maybe it can be of some help
> to you as well. See linux/arch/arm/kernel/dma-sa1100.c.
>
> Nicolas
Received on Thu Aug 10 19:35:31 2000