[PATCH 1/3] dmaengine: mmp-pdma support

[Vinod Koul]

On Thu, 2012-07-26 at 15:02 +0800, zhangfei gao wrote:
> On Thu, Jul 26, 2012 at 2:51 PM, Vinod Koul <vinod.koul at linux.intel.com> wrote:
> > On Fri, 2012-07-20 at 13:46 +0800, Zhangfei Gao wrote:
> >> +struct mmp_dma_platdata {
> >> +       int chancnt;
> >> +};
> >> +
> >> +struct mmp_dma_slave_config {
> >> +       struct dma_slave_config slave_config;
> >> +       u32 drcmr;
> >> +};
> > Why do you need these definitions?
> >
> > What is drcmr used for?
> 
> Hi, Vinod
> 
> "drcmr" is request_line, we used to select which channel map to
> specific peripheral.
> Is it possible adding request_line to slave_config?
Can you use the slave_id.

> 
> Refer mail with Arnd before.
> > For peripheral dma, one special requirement of DMA_RCMRx
> > The register is used select which channel is mapped to the peripheral.
> > The channel can be alloc dynamically, but the register is constant to
> > specific peripheral.
> > For example, nand_dma, pxa910 use DRCMR97 (0x1184), what's worse,
> > pxa688 use DRCMR28 (0x170).
> >
> > There is no connection between channel number and drcmr, since channel
> > is dynamically allocated.
> > So we encapsulating the slave config parsing drcmr to dma-engine driver.
> 
> [Arnd]
> Ah, so it is the request line. Now the current plan for this is to go
> into the "dmas" property of the child device using the dma engine binding.
> 
> >
> >
> > --
> > ~Vinod
> >
> >
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-- 
~Vinod