[PATCH RFC v4 08/15] spi: dt-bindings: axi-spi-engine: add SPI offload properties

David Lechner posted 15 patches 1 month ago
There is a newer version of this series
[PATCH RFC v4 08/15] spi: dt-bindings: axi-spi-engine: add SPI offload properties
Posted by David Lechner 1 month ago
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@baylibre.com>
---
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.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+
+  dmas:
+    description:
+      DMA channels connected to the output stream interface of an offload instance.
+    minItems: 1
+    maxItems: 32
+
+  dma-names:
+    minItems: 1
+    maxItems: 32
+    items:
+      pattern: "^offload(?:[12]?[0-9]|3[01])-rx$"
+
 required:
   - compatible
   - reg
@@ -59,6 +77,10 @@ examples:
         clocks = <&clkc 15>, <&clkc 15>;
         clock-names = "s_axi_aclk", "spi_clk";
 
+        trigger-sources = <&trigger_clock>;
+        dmas = <&dma 0>;
+        dma-names = "offload0-rx";
+
         #address-cells = <1>;
         #size-cells = <0>;
 

-- 
2.43.0
Re: [PATCH RFC v4 08/15] spi: dt-bindings: axi-spi-engine: add SPI offload properties
Posted by Nuno Sá 1 month ago
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@baylibre.com>
> ---
> 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