The ADI AXI SPI Engine driver supports offloading SPI transfers to hardware. This is essentially a feature that allows recording an arbitrary sequence of SPI transfers and then playing them back with no CPU intervention via a hardware trigger. This adds the bindings for this feature. Each SPI Engine instance can have from 0 to 32 offload instances. Each offload instance has a trigger input and a data stream output. As an example, this could be used with an ADC SPI peripheral. In this case the trigger is connected to a PWM/clock to determine the sampling rate for the ADC and the output stream is connected to a DMA channel to pipe the sample data to memory. SPI peripherals act as consumers of the offload instances. Typically, one SPI peripheral will be connected to one offload instance. But to make the bindings future-proof, the property is an array. Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> --- .../spi/adi,axi-spi-engine-peripheral-props.yaml | 24 +++++++++++ .../bindings/spi/adi,axi-spi-engine.yaml | 49 +++++++++++++++++++++- .../bindings/spi/spi-peripheral-props.yaml | 1 + 3 files changed, 73 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine-peripheral-props.yaml new file mode 100644 index 000000000000..19b685fc3b39 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine-peripheral-props.yaml @@ -0,0 +1,24 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/spi/adi,axi-spi-engine-peripheral-props.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Peripheral properties for Analog Devices AXI SPI Engine Controller + +maintainers: + - Michael Hennerich <Michael.Hennerich@xxxxxxxxxx> + - Nuno Sá <nuno.sa@xxxxxxxxxx> + +properties: + adi,offloads: + description: + List of AXI SPI Engine offload instances assigned to this peripheral. + $ref: /schemas/types.yaml#/definitions/uint32-array + maxItems: 32 + items: + items: + - minimum: 0 + maximum: 31 + +additionalProperties: true diff --git a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml index d48faa42d025..69f3261bab47 100644 --- a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml +++ b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml @@ -21,6 +21,23 @@ maintainers: allOf: - $ref: /schemas/spi/spi-controller.yaml# +$defs: + offload: + description: + Describes the connections of the trigger input and the data output stream + of one or more offload instances. + + properties: + reg: + description: + Index of the offload instance. + items: + - minimum: 0 + maximum: 31 + + required: + - reg + properties: compatible: const: adi,axi-spi-engine-1.00.a @@ -41,6 +58,22 @@ properties: - const: s_axi_aclk - const: spi_clk + offloads: + type: object + description: Zero or more offloads supported by the controller. + + properties: + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + + patternProperties: + "^offload@[0-8a-f]+$": + type: object + $ref: '#/$defs/offload' + required: - compatible - reg @@ -62,5 +95,19 @@ examples: #address-cells = <1>; #size-cells = <0>; - /* SPI devices */ + offloads { + #address-cells = <1>; + #size-cells = <0>; + + offload@0 { + compatible = "adi,example-offload"; + reg = <0>; + }; + }; + + adc@0 { + compatible = "adi,example-adc"; + reg = <0>; + adi,offloads = <0>; + }; }; diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml index 1c8e71c18234..7beb5a3798a5 100644 --- a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml @@ -132,6 +132,7 @@ properties: # The controller specific properties go here. allOf: + - $ref: adi,axi-spi-engine-peripheral-props.yaml# - $ref: arm,pl022-peripheral-props.yaml# - $ref: cdns,qspi-nor-peripheral-props.yaml# - $ref: samsung,spi-peripheral-props.yaml# -- 2.43.0
