Re: [PATCH RFC v4 08/15] spi: dt-bindings: axi-spi-engine: add SPI offload properties
From: Nuno Sá
Date: Fri Oct 25 2024 - 08:26:47 EST
On Wed, 2024-10-23 at 15:59 -0500, David Lechner wrote:
> The AXI SPI Engine has support for hardware offloading capabilities.
> This includes a connection to a DMA controller for streaming RX data
> and a trigger input for starting execution of the SPI message programmed
> in the offload.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
> ---
> v4 changes:
> * Dropped #spi-offload-cells property.
> * Changed subject line.
>
> v3 changes:
> * Added #spi-offload-cells property.
> * Added properties for triggers and RX data stream connected to DMA.
>
> v2 changes:
>
> This is basically a new patch. It partially replaces "dt-bindings: iio:
> offload: add binding for PWM/DMA triggered buffer".
>
> The controller no longer has an offloads object node and the
> spi-offloads property is now a standard SPI peripheral property.
> ---
> .../bindings/spi/adi,axi-spi-engine.yaml | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml
> b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml
> index d48faa42d025..5281b4871209 100644
> --- a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml
> +++ b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml
> @@ -41,6 +41,24 @@ properties:
> - const: s_axi_aclk
> - const: spi_clk
>
> + trigger-sources:
> + description:
> + An array of trigger source phandles for offload instances. The index in
> + the array corresponds to the offload instance number.
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> +
> + dmas:
> + description:
> + DMA channels connected to the output stream interface of an offload
> instance.
> + minItems: 1
> + maxItems: 32
> +
> + dma-names:
> + minItems: 1
> + maxItems: 32
> + items:
> + pattern: "^offload(?:[12]?[0-9]|3[01])-rx$"
I think the core is already capable of tx offload? If so, we could already have that
in the bindings.
- Nuno Sá