Re: [PATCH 07/13] dmaengine: introduce dma_request_channel and private channels

[Guennadi Liakhovetski]

On Fri, 30 Jan 2009, Dan Williams wrote:

> On Fri, Jan 30, 2009 at 10:03 AM, Atsushi Nemoto <anemo@xxxxxxxxxxxxx> wrote:
> > I'm writing a new dma driver.  My DMAC has multiple channels and only
> > one channel is capable for generic memcpy and other channels have
> > fixed role.
> >
> > Does new framework allow dma driver make only one channel public?
> 
> Yes, if the driver registers a dma_device for each channel.
> 
> > Or should I register two dma_device for DMA_MEMCPY and DMA_SLAVE?
> > Could you give me some advice?
> 
> Register multiple dma_devices, the public one with a DMA_MEMCPY, and
> the fixed role devices with DMA_PRIVATE, DMA_MEMCPY, and DMA_SLAVE
> capabilities.
> 
> DMA_PRIVATE ensures that a channel is never considered for public consumption.

Maybe just two dma-devices would suffice: one with the public memcpy 
channel, and one with the rest private slave channels?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
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