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

[David Lechner <dlechner@xxxxxxxxxxxx>]

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