Re: [PATCH 4/5] dmaengine: sprd: Add Spreadtrum DMA configuration

[Vinod Koul]

On Thu, Apr 12, 2018 at 07:30:01PM +0800, Baolin Wang wrote:

> >> > what does block and transaction len refer to here
> >>
> >>  Our DMA has 3 transfer mode: transaction transfer, block transfer and
> >> fragment transfer. One transaction transfer can contain several blocks
> >> transfer, and each block can be set proper block step. One block can
> >> contain several fragments transfer with proper fragment step. It can
> >> generate interrupts when one transaction transfer or block transfer or
> >> fragment transfer is completed if user set the interrupt type. So here
> >> we should set the length for transaction transfer, block transfer and
> >> fragment transfer.
> >
> > what are the max size these types support?
> 
> These types max size definition:
> 
> #define SPRD_DMA_FRG_LEN_MASK GENMASK(16, 0)
> 
> #define SPRD_DMA_BLK_LEN_MASK GENMASK(16, 0)
> 
> #define SPRD_DMA_TRSC_LEN_MASK GENMASK(27, 0)

They are register defines. How many items or bytes do each type of txn
support?

-- 
~Vinod