Messages in this thread | | | Subject | Re: [PATCH 5/7 v2] dma: sh: use an integer slave ID to improve API compatibility | From | Vinod Koul <> | Date | Mon, 16 Jul 2012 15:07:32 +0530 |
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On Mon, 2012-07-16 at 10:47 +0200, Guennadi Liakhovetski wrote: > > I want to know what does ccr and mid_rid mean to dmac here? > > CHCR contains a few fields, some enable various interrupt sources, some > specify repeat- and renew-modes, others yet specify transfer size, source > and destination address-modes (incrementing, constant, decrementing), > others yet select a DMA client category (slave / memcpy / ...), and a > transfer flag. Some of these fields could be calculated, others are > pre-defined for various slaves, the exact layout of those fields can also > vary between SoCs. I do not understand how clients would provide these values. For pre-defined values, they should be dmac property why should client like spi or mmc have clue about it?
For others like you mentioned, i guess they could be easily calculated, right?
> MID_RID is actually a slave-selector, it contains a magic value, that > cannot be calculated. and again, how does client know this?
-- ~Vinod
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