[PATCH v3 04/10] dt-bindings: iio: dac: ad3552r: add io-backend support

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>

There is a version AXI DAC IP block (for FPGAs) that provides
a physical bus for AD3552R and similar chips, and acts as
an SPI controller.

For this case, the binding is modified to include some
additional properties.

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
 .../devicetree/bindings/iio/dac/adi,ad3552r.yaml   | 42 ++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
index 41fe00034742..aca4a41c2633 100644
--- a/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
@@ -60,6 +60,18 @@ properties:
     $ref: /schemas/types.yaml#/definitions/uint32
     enum: [0, 1, 2, 3]
 
+  io-backends:
+    description: The iio backend reference.
+      An example backend can be found at
+        https://analogdevicesinc.github.io/hdl/library/axi_ad3552r/index.html
+    maxItems: 1
+
+  adi,synchronous-mode:
+    description: Enable waiting for external synchronization signal.
+      Some AXI IP configuration can implement a dual-IP layout, with internal
+      wirings for streaming synchronization.
+    type: boolean
+
   '#address-cells':
     const: 1
 
@@ -128,6 +140,7 @@ patternProperties:
           - custom-output-range-config
 
 allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
   - if:
       properties:
         compatible:
@@ -238,4 +251,33 @@ examples:
             };
         };
     };
+
+  - |
+    axi_dac: spi@44a70000 {
+        compatible = "adi,axi-ad3552r";
+        reg = <0x44a70000 0x1000>;
+        dmas = <&dac_tx_dma 0>;
+        dma-names = "tx";
+        #io-backend-cells = <0>;
+        clocks = <&ref_clk>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dac@0 {
+            compatible = "adi,ad3552r";
+            reg = <0>;
+            reset-gpios = <&gpio0 92 0>;
+            io-backends = <&axi_dac>;
+            spi-max-frequency = <66000000>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            channel@0 {
+                reg = <0>;
+                adi,output-range-microvolt = <(-10000000) (10000000)>;
+            };
+        };
+    };
 ...

-- 
2.45.0.rc1