[ELDK] PPC 44x DMA controller

Stefan Roese sr at denx.de
Wed Jul 1 09:09:57 CEST 2009

Hi Dave,

On Tuesday 30 June 2009 18:41:52 Dave Cogley wrote:
> The old "ppc" architecture in Linux used to support several useful
> libraries that do not appear to have the functionality supported in the
> newer "powerpc" branch.
> I am looking for equivalent built in support of the PPC4xx DMA libraries
> that used to be supported under "ppc/syslib"; ppc4xx_dma.c and
> ppc_sgdma.c.

Ah, you're talking about those functions.

> The ELDK is currently using these libraries to support the
> OTG USB controller on the Canyonlands board. These libraries however are
> currently not built into the mainstream kernel as the should be.

Correct. Please note that this 4xx DMA support is not a real solution (one of 
the reasons that this USB driver was not pushed into kernel.org).

> I have already made the jump to mainstream Linux in my design and am
> running with 2.6.30. I was offering to port said libraries into a
> standard Linux format supporting the PPC4xx arch. In the interim I was
> able to compile the support directly into my device driver and
> everything appears to work with the exception of dma_alloc_coherant
> which is causing a kernel oops.

I'm not sure where the correct place for this 4xx DMA support would be. 
Perhaps drivers/dma or arch/powerpc/syslib? I suggest that you ask on 


Best regards,

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