On Thu, Mar 31, 2022 at 06:13:53PM +0200, Martin Povišer wrote: > > > On 31. 3. 2022, at 16:10, Vinod Koul <vkoul@xxxxxxxxxx> wrote: > > > > On 31-03-22, 09:06, Martin Povišer wrote: > >> > >>> On 31. 3. 2022, at 8:50, Martin Povišer <povik@xxxxxxxxxxx> wrote: > >>>> > >>>> On 31. 3. 2022, at 7:23, Vinod Koul <vkoul@xxxxxxxxxx> 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@xxxxxxxxxxx> > >>>>> --- > >>>>> .../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 not 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? > > I am not sure that’s right. Reading the dmaengine docs, DMA requests seem to have > to do with the DMA-controller-to-peripheral connection, but the proposed property > tells us which of four independent IRQ outputs of the DMA controller we actually > have in the interrupts= property. That is, it has to do with the DMA-controller-to-CPU > connection. Why do they have to be different? IRQF_SHARED doesn't work? Why can't you request each IRQ until it succeeds? What happens when there are 5 DMA controllers? If using more than 1 interrupt will never work or be needed, then I'm inclined to say just describe that 1 interrupt. Yes, that goes against 'describe all the h/w', but there's always exceptions. I suppose you need to know which 'interrupts' index (output) you are using. If so, you can do something like this: interrupts = <-1>, <-1>, <3 0>, <-1>; Rob
