[v4 2/3] dt-bindings: fpga: Add Efinix SPI programming bindings

[iansdannapel@gmail.com]

From: Ian Dannapel <iansdannapel@gmail.com>

Add device tree bindings documentation for configuring Efinix FPGA
using serial SPI passive programming mode.

Signed-off-by: Ian Dannapel <iansdannapel@gmail.com>
---
 .../devicetree/bindings/fpga/efinix,spi.yaml  | 81 +++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/efinix,spi.yaml

diff --git a/Documentation/devicetree/bindings/fpga/efinix,spi.yaml b/Documentation/devicetree/bindings/fpga/efinix,spi.yaml
new file mode 100644
index 000000000000..145c96f38e45
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/efinix,spi.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/fpga/efinix,spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Efinix SPI FPGA Manager
+
+maintainers:
+  - Ian Dannapel <iansdannapel@gmail.com>
+
+description: |
+  Efinix FPGAs (Trion, Topaz, and Titanium families) support loading bitstreams
+  through "SPI Passive Mode".
+  Note 1: Only bus width 1x is supported.
+  Note 2: Additional pins hogs for bus width configuration must be set
+  elsewhere, if necessary.
+  Note 3: Topaz and Titanium support is based on documentation but remains
+  untested.
+
+  References:
+  - https://www.efinixinc.com/docs/an006-configuring-trion-fpgas-v6.3.pdf
+  - https://www.efinixinc.com/docs/an033-configuring-titanium-fpgas-v2.8.pdf
+  - https://www.efinixinc.com/docs/an061-configuring-topaz-fpgas-v1.1.pdf
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - efinix,trion-spi
+      - efinix,titanium-spi
+      - efinix,topaz-spi
+      - efinix,fpga-spi
+
+  spi-cpha: true
+
+  spi-cpol: true
+
+  spi-max-frequency:
+    maximum: 25000000
+
+  reg:
+    maxItems: 1
+
+  reset-gpios:
+    description:
+      reset and re-configuration trigger pin (low active)
+    maxItems: 1
+
+  cdone-gpios:
+    description:
+      optional configuration done status pin (high active)
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
+      fpga-mgr@0 {
+        compatible = "efinix,trion-spi";
+        reg = <0>;
+        spi-max-frequency = <25000000>;
+        spi-cpha;
+        spi-cpol;
+        reset-gpios = <&gpio4 17 GPIO_ACTIVE_LOW>;
+        cdone-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
+      };
+    };
+...
-- 
2.43.0