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

From: David Lechner
Date: Wed Oct 23 2024 - 17:01:27 EST


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.
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+
+ dmas:
+ description:
+ DMA channels connected to the output stream interface of an offload instance.
+ minItems: 1
+ maxItems: 32
+
+ dma-names:
+ minItems: 1
+ maxItems: 32
+ items:
+ pattern: "^offload(?:[12]?[0-9]|3[01])-rx$"
+
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