[PATCH 1/4] Add DMA sector to Documentation/powerpc/booting-without-of.txt file.
Wei.Zhang at freescale.com
Thu Jul 12 19:48:56 EST 2007
> -----Original Message-----
> From: Segher Boessenkool [mailto:segher at kernel.crashing.org]
> Sent: Thursday, July 12, 2007 1:54 AM
> To: Wood Scott-B07421
> Cc: Zhang Wei-r63237; linuxppc-dev at ozlabs.org; paulus at samba.org
> Subject: Re: [PATCH 1/4] Add DMA sector to
> Documentation/powerpc/booting-without-of.txt file.
> >>> I'd rather just treat the different DMA channels as independent
> >>> devices,
> >>> rather than children of a dma "bus", and change the compatible
> >>> name if
> >>> they're not general purpose. There's only one register that's
> >>> shared
> >>> among the channels, and it's a superfluous status summary
> >> Your and my ideas are both sides of a coin. :-)
> > I think there's a substantive difference between them.
> Making each
> > channel an independent device makes it easier for other drivers to
> > use them.
> True. If the DMA channels are independent enough, putting them
> in nodes of their own isn't too cumbersome, either.
If you want to use DMA engine driver for the reserved channel, you
should add it to dma-controller node and assign 'reserved'.
If you don't want to use DMA engine driver, just remove it from
dma-controller node and put the channel to special device node.
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