ppc85xx DMA

[Liu Dave-r63238]

> Dear sirs,
> 
> I am trying to add a DMA transfer component to my driver on 
> linux 2.6 on a ppc 8541.  Following the steps listed in the 
> reference manual, I write the SAR, SATR, DAR, DATR and BCR 
> registers before cycling the bit in the MR register to start 
> the transfer.
> 
What is the DMA transfer mode? Is direct or chaining mode?

> The SR register though indicates a transfer error as soon as 
> I write the DAR register.  Clearly I've gotten the mapping 
> wrong. I know what the address I am trying to write to in 
> kernel space is, what is unclear is what address the DAR 
> register is expecting.
> 

Did you ioremap the DMA register space?
The DAR register need the physical address

Dave