MPC85xx DMA support for Kernel 2.6?
Kumar Gala
kumar.gala at freescale.com
Fri Jul 1 01:30:41 EST 2005
On Jun 30, 2005, at 10:12 AM, Clemens Koller wrote:
> Hello!
>
> I am planning to use DMA/burst access for copying large chunks of data
> (100MBytes) from the Local Bus (UPM accessed SRAM) to System Memory
> (DDR)
> as fast as possible (200MBytes/s). (As you can guess, that's a
> framegrabber).
>
> As far as I have seen, the DMA engines of the MPC85xx (fsl-dma) are
> not
> supported in the classical way (dma_request(), free_dma()) in the
> kernel 2.6.x.
> The memory allocators in arch/ppc/dma-mapping.c seem to be usable,
> but there is no valuable dma support yet (true?).
>
> I can program the DMA Controllers in my MPC8540 on my own to
> achieve what I want
> but it would be great to get/produce/stick with as much cross-
> platform reusable
> code as possible.
>
> Is there any ongoing work to put DMA support for the mpc85xx and
> similar
> devices into the kernel? Is there any ongoing work in this area
> or is somebody working with the fsl-dma and can publish some code and
> share some ideas?
I'm not aware of anyone work on such a thing. I'd be more than happy
to accept patches for it. I know several of us have written some
APIs on top of the DMA for 85xx. Those however are non-standard APIs.
What APIs exist for general purpose DMA engines? Last time I looked
at this problem nothing really existed.
- kumar
More information about the Linuxppc-embedded
mailing list