Re: [PATCH v5 03/13] dt-bindings: dma: dw-axi-dmac: extend the number of interrupts

From: Ben Dooks <ben.dooks@codethink.co.uk>
To: Conor Dooley <mail@conchuod.ie>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Sam Ravnborg <sam@ravnborg.org>,
	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
	Vinod Koul <vkoul@kernel.org>,
	Serge Semin <fancer.lancer@gmail.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Conor Dooley <conor.dooley@microchip.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Damien Le Moal <damien.lemoal@opensource.wdc.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Niklas Cassel <niklas.cassel@wdc.com>,
	Dillon Min <dillon.minfei@gmail.com>,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
	linux-riscv@lists.infradead.org, Rob Herring <robh@kernel.org>
Subject: Re: [PATCH v5 03/13] dt-bindings: dma: dw-axi-dmac: extend the number of interrupts
Date: Mon, 18 Jul 2022 16:12:28 +0100	[thread overview]
Message-ID: <7c68e645-efd7-c48c-77aa-9aa607c77033@codethink.co.uk> (raw)
In-Reply-To: <20220705215213.1802496-4-mail@conchuod.ie>

On 05/07/2022 22:52, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> 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. Support the 6 interrupt
> configuration by unconditionally extending the binding to a maximum of
> 8 per-channel interrupts thereby matching the number of possible
> channels.

I think you can still configure it to produce a single interrupt
even if there are per-channel interrupts available. This is from
my reading of the driver a little while ago so may not be totally
correct now.

Having per-channel irqs might be useful in the future, but as above
I think it'll require the driver to be updated to do it (and possibly
some sort of detection)

> Link: https://canaan-creative.com/wp-content/uploads/2020/03/kendryte_standalone_programming_guide_20190311144158_en.pdf #Page 51
> Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
>   .../devicetree/bindings/dma/snps,dw-axi-dmac.yaml          | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> index 4324a94b26b2..67aa7bb6d36a 100644
> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -34,7 +34,12 @@ properties:
>         - const: axidma_apb_regs
>   
>     interrupts:
> -    maxItems: 1
> +    description:
> +      If the IP-core synthesis parameter DMAX_INTR_IO_TYPE is set to 1, this
> +      will be per-channel interrupts. Otherwise, this is a single combined IRQ
> +      for all channels.
> +    minItems: 1
> +    maxItems: 8
>   
>     clocks:
>       items:

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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