Re: [PATCH 1/3] dmaengine: qcom_bam_dma: Generalize BAM register offset calculations

[Kumar Gala <galak@codeaurora.org>]

On Sep 18, 2014, at 3:52 AM, Archit Taneja <architt@codeaurora.org> wrote:

> The BAM DMA IP comes in different versions. The register offset layout varies
> among these versions. The layouts depend on which generation/family of SoCs they
> belong to.
> 
> The current SoCs(like 8084, 8074) have a layout where the Top level registers
> come in the beginning of the address range, followed by pipe and event
> registers. The BAM revision numbers fall above 1.4.0.
> 
> The older SoCs (like 8064, 8960) have a layout where the pipe registers come
> first, and the top level come later. These have BAM revision numbers lesser than
> 1.4.0.
> 
> It isn't suitable to have macros provide the register offsets with the layouts
> changed. Future BAM revisions may have different register layouts too. The
> register addresses are now calculated by referring a table which contains a base
> offset and multipliers for pipe/evnt/ee registers.
> 
> We have a common function bam_addr() which computes addresses for all the
> registers. When computing address of top level/ee registers, we pass 0 to the
> pipe argument in addr() since they don't have any multiple instances.
> 
> Some of the unused register definitions are removed. We can add new registers as
> we need them.
> 
> Signed-off-by: Archit Taneja <architt@codeaurora.org>
> ---
> drivers/dma/qcom_bam_dma.c | 176 +++++++++++++++++++++++++++++----------------
> 1 file changed, 113 insertions(+), 63 deletions(-)

Reviewed-by: Kumar Gala <galak@codeaurora.org>

- k

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