Hi Vinod
> > > > When we set simple settings to DMAC, then, it works automatically as cyclic transfer.
> > > > The usage of this DMA is very limited, so it is super simple.
> > > > In addition, this is 2nd DMA which is needed on sound.
> > > > 1st DMA is controled by rcar-dmac.c
> > > > 2nd DMA is this
> > > > almost all settings are set by 1st DMA, 2nd DMA is just relay.
> > > okay that needs to be called out explicitly. While reading driver it wasn't
> > > very clear
> > > So which one is the 1st DMA, how will the client configure these two DMAs?
> >
> > 1st DMA is rcar-dma which was created by Laurent.
> > And it has been sent to you now.
> >
> > ${LINUX}/sound/soc/sh/rcar/core.c
> > is the user of these 2 dmac.
> > 1st DMAC gets "from mem address", and "to reg address".
> > 2nd DMAC gets "from reg address", and "to reg address".
> > DMAC's ID are came from DT.
> So how is the user expectations, will they configure both the engines?
This rcar-audmapp driver is very limited usage, and user is only sound device/driver.
Sound driver configures both 1st/2nd DMAC if needed (it depends on platform).
Sound driver knows all reg address / mem address which are needed for 1st/2nd DMAC settings.
1st/2nd DMAC needs general DMAEngine settings method, not special.
Now, sound driver + 1st/2nd DMAC works well on my local environment.
Best regards
---
Kuninori Morimoto
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