Re: [PATCH v1 3/5] dt-bindings: Add DT bindings for NVIDIA Tegra AHB DMA controller

From: Dmitry Osipenko
Date: Tue Sep 26 2017 - 21:57:51 EST


On 26.09.2017 17:50, Jon Hunter wrote:
>
> On 26/09/17 00:22, Dmitry Osipenko wrote:
>> Document DT bindings for NVIDIA Tegra AHB DMA controller that presents
>> on Tegra20/30 SoC's.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>> ---
>> .../bindings/dma/nvidia,tegra20-ahbdma.txt | 23 ++++++++++++++++++++++
>> 1 file changed, 23 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/dma/nvidia,tegra20-ahbdma.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/nvidia,tegra20-ahbdma.txt b/Documentation/devicetree/bindings/dma/nvidia,tegra20-ahbdma.txt
>> new file mode 100644
>> index 000000000000..2af9aa76ae11
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/nvidia,tegra20-ahbdma.txt
>> @@ -0,0 +1,23 @@
>> +* NVIDIA Tegra AHB DMA controller
>> +
>> +Required properties:
>> +- compatible: Must be "nvidia,tegra20-ahbdma"
>> +- reg: Should contain registers base address and length.
>> +- interrupts: Should contain one entry, DMA controller interrupt.
>> +- clocks: Should contain one entry, DMA controller clock.
>> +- resets : Should contain one entry, DMA controller reset.
>> +- #dma-cells: Should be <1>. The cell represents DMA request select value
>> + for the peripheral. For more details consult the Tegra TRM's
>> + documentation, in particular AHB DMA channel control register
>> + REQ_SEL field.
>
> What about the TRIG_SEL field? Do we need to handle this here as well?
>

Actually, DMA transfer trigger isn't related a hardware description. It's up to
software to decide what trigger to select. So it shouldn't be in the binding.

And I think the same applies to requester... any objections?

--
Dmitry