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    SubjectRe: [PATCH 5/7 v2] dma: sh: use an integer slave ID to improve API compatibility
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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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