Re: [PATCH 1/2] dt-bindings: dma: Add Apple ADMAC

Vinod Koul
2022-03-31T14:10:13Z

On 31-03-22, 09:06, Martin Povišer wrote:
>
> > On 31. 3. 2022, at 8:50, Martin Povišer <povik@cutebit.org> wrote:
> >
> >>
> >> On 31. 3. 2022, at 7:23, Vinod Koul <vkoul@kernel.org> wrote:
> >>
> >> On 30-03-22, 18:44, Martin Povišer wrote:
> >>> Apple's Audio DMA Controller (ADMAC) is used to fetch and store audio
> >>> samples on Apple SoCs from the "Apple Silicon" family.
> >>>
> >>> Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
> >>> ---
> >>> .../devicetree/bindings/dma/apple,admac.yaml | 73 +++++++++++++++++++
> >>> 1 file changed, 73 insertions(+)
> >>> create mode 100644 Documentation/devicetree/bindings/dma/apple,admac.yaml
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/dma/apple,admac.yaml b/Documentation/devicetree/bindings/dma/apple,admac.yaml
> >>> new file mode 100644
> >>> index 000000000000..34f76a9a2983
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/dma/apple,admac.yaml
> >
> >>> + apple,internal-irq-destination:
> >>> + $ref: /schemas/types.yaml#/definitions/uint32
> >>> + description: Index influencing internal routing of the IRQs
> >>> + within the peripheral.
> >>
> >> do you have more details for this, is this for peripheral and if so
> >> suited to be in dam-cells?
> >
> > By peripheral I meant the DMA controller itself here.

Dmaengine convention is that peripheral is device which we are doing dma
to/from, like audio controller/fifo here

> > Effectively the controller has four independent IRQ outputs and the driver
> > needs to know which one we are using. (It need to be the same output even
> > for different ADMAC instances on one die.)

That smells like a mux to me.. why not use dma-requests for this?

--
~Vinod