Re: [PATCH 3/3] dmaengine: sun6i: Add support for Allwinner A64

[Stefan Bruens <stefan.bruens@rwth-aachen.de>]

On Samstag, 2. September 2017 00:32:50 CEST André Przywara wrote:
> Hi,
> 
> On 01/09/17 02:19, Stefan Bruens wrote:
> > On Freitag, 1. September 2017 02:31:35 CEST Andre Przywara wrote:
> >> Hi,
> >> 
> >> On 31/08/17 00:36, Stefan Brüns wrote:
> >>> The A64 SoC has the same dma engine as the H3 (sun8i), with a
> >>> reduced amount of physical channels. Add the proper config data
> >>> and compatible string to support it.
> >> 
> >> ...
> >> 
> >>> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> >>> index 5f4eee4513e5..6a17c5d63582 100644
> >>> --- a/drivers/dma/sun6i-dma.c
> >>> +++ b/drivers/dma/sun6i-dma.c
> >>> @@ -1068,6 +1068,12 @@ static struct sun6i_dma_config sun8i_h3_dma_cfg =
> >>> {
> >>> 
> >>>  	.nr_max_vchans   = 34,
> >>>  	.dmac_variant    = DMAC_VARIANT_H3,
> >>>  
> >>>  };
> >>> 
> >>> +
> >>> +static struct sun6i_dma_config sun50i_a64_dma_cfg = {
> >>> +	.nr_max_channels = 8,
> >>> +	.nr_max_requests = 27,
> >>> +	.nr_max_vchans   = 38,
> >>> +	.dmac_variant    = DMAC_VARIANT_H3,
> >>> 
> >>>  };
> >>>  
[...]
> > There are also the incompatibilities in the "DMA channel configuration
> > register" (burst length; burst width; burst length field offset).
> > 
> > We can either have 3 different compatible strings, or another property for
> > the register model.
> 
> The latter is usually frowned upon, using separate compatible strings
> for each group of SoCs is the way to go here.

Just for clarification, I was not talking about a property in the devicetree, 
but about a struct member in the config data, i.e. the .dmac_variant above.

Kind regards,

Stefan

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