Re: [PATCH v2 05/16] dt-bindings: dma: add Canaan k210 to Synopsys DesignWare DMA

[Conor.Dooley]

On 27/06/2022 22:34, Serge Semin wrote:
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> 
> On Mon, Jun 27, 2022 at 08:39:53PM +0100, Conor Dooley wrote:
>> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>
>> The Canaan k210 apparently has a Sysnopsys Designware AXI DMA
>> controller, but according to the documentation & devicetree it has 6
>> interrupts rather than the standard one. Add a custom compatible that
>> supports the 6 interrupt configuration which falls back to the standard
>> binding which is currently the one in use in the devicetree entry.
>>
>> Link: https://canaan-creative.com/wp-content/uploads/2020/03/kendryte_standalone_programming_guide_20190311144158_en.pdf #Page 58
> 
> I believe what you've got here is the per-channel IRQs, which is
> activated for the DW AXI DMAC by setting IP-core synthesize parameter
> DMAX_INTR_IO_TYPE=1 (CHANNEL AND COMMONREG). That's why there are six
> IRQ signals and six DMA-channels available.
> 
> Seeing such setting isn't the Canaan k210 specific, but is the DW AXI
> DMA controller common property, what would be right in this case is to
> unconditionally extend the number of IRQs in the DT-bindings schema.

Cool, willdo.
Thanks for all the great feedback.
Conor.

> 
> Please note the DW AXI DMAC driver currently doesn't support the
> per-channel IRQs. So most likely the DMA will only work with using the
> channel 0 only.
> 
> -Sergey
> 
>> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>> ---
>>  .../bindings/dma/snps,dw-axi-dmac.yaml        | 35 ++++++++++++++-----
>>  1 file changed, 26 insertions(+), 9 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> index 4324a94b26b2..bc85598151ef 100644
>> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> @@ -18,9 +18,13 @@ allOf:
>>
>>  properties:
>>    compatible:
>> -    enum:
>> -      - snps,axi-dma-1.01a
>> -      - intel,kmb-axi-dma
>> +    oneOf:
>> +      - items:
>> +          - const: canaan,k210-axi-dma
>> +          - const: snps,axi-dma-1.01a
>> +      - enum:
>> +          - snps,axi-dma-1.01a
>> +          - intel,kmb-axi-dma
>>
>>    reg:
>>      minItems: 1
>> @@ -33,9 +37,6 @@ properties:
>>        - const: axidma_ctrl_regs
>>        - const: axidma_apb_regs
>>
>> -  interrupts:
>> -    maxItems: 1
>> -
>>    clocks:
>>      items:
>>        - description: Bus Clock
>> @@ -92,6 +93,22 @@ properties:
>>      minimum: 1
>>      maximum: 256
>>
>> +if:
>> +  properties:
>> +    compatible:
>> +      contains:
>> +        const: canaan,k210-axi-dma
>> +
>> +then:
>> +  properties:
>> +    interrupts:
>> +      maxItems: 6
>> +
>> +else:
>> +  properties:
>> +    interrupts:
>> +      maxItems: 1
>> +
>>  required:
>>    - compatible
>>    - reg
>> @@ -105,7 +122,7 @@ required:
>>    - snps,priority
>>    - snps,block-size
>>
>> -additionalProperties: false
>> +unevaluatedProperties: false
>>
>>  examples:
>>    - |
>> @@ -113,12 +130,12 @@ examples:
>>       #include <dt-bindings/interrupt-controller/irq.h>
>>       /* example with snps,dw-axi-dmac */
>>       dmac: dma-controller@80000 {
>> -         compatible = "snps,axi-dma-1.01a";
>> +         compatible = "canaan,k210-axi-dma", "snps,axi-dma-1.01a";
>>           reg = <0x80000 0x400>;
>>           clocks = <&core_clk>, <&cfgr_clk>;
>>           clock-names = "core-clk", "cfgr-clk";
>>           interrupt-parent = <&intc>;
>> -         interrupts = <27>;
>> +         interrupts = <27>, <28>, <29>, <30>, <31>, <32>;
>>           #dma-cells = <1>;
>>           dma-channels = <4>;
>>           snps,dma-masters = <2>;
>> --
>> 2.36.1
>>