dt-bindings: fsl,fpga-qixis-i2c: add support for LX2160ARDB FPGA

Extend the list of supported compatible strings with fsl,lx2160ardb-fpga.

Since the register map exposed by the LX2160ARDB's FPGA also contains
two GPIO controllers, accept the necessary GPIO pattern property.
At the same time, add the #address-cells and #size-cells properties as
valid ones so that the child nodes of the fsl,lx2160ardb-fpga node are
addressable.

This is necessary because when defining child devices such as the GPIO
controller described in the added example, the child device needs a the
reg property to properly identify its register location in the parent
I2C device address space.

Impose this restriction for the new compatible through an if-statement.

The feature set exposed by these QIXIS FPGA devices is highly dependent
on the board type, meaning that even though the FPGA found on the
LX2160AQDS board (fsl,lx2160aqds-fpga) works in the same way in terms of
access over I2C as the one found on the LX2160ARDB (fsl,lx2160ardb-fpga
added here), the register map inside the device space is different since
there are different on-board devices to be controlled.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/board/fsl,fpga-qixis-i2c.yaml

@@ -22,6 +22,13 @@ properties:
               - fsl,lx2160aqds-fpga
           - const: fsl,fpga-qixis-i2c
           - const: simple-mfd
+      - const: fsl,lx2160ardb-fpga
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
 
   interrupts:
     maxItems: 1
@@ -32,10 +39,37 @@ properties:
   mux-controller:
     $ref: /schemas/mux/reg-mux.yaml
 
+patternProperties:
+  "^gpio@[0-9a-f]+$":
+    type: object
+    additionalProperties: true
+
+    properties:
+      compatible:
+        contains:
+          enum:
+            - fsl,lx2160ardb-fpga-gpio-sfp
+
 required:
   - compatible
   - reg
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - fsl,lx2160ardb-fpga
+    then:
+      required:
+        - "#address-cells"
+        - "#size-cells"
+    else:
+      properties:
+        "#address-cells": false
+        "#size-cells": false
+
 additionalProperties: false
 
 examples:
@@ -68,3 +102,27 @@ examples:
         };
     };
 
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        board-control@66 {
+            compatible = "fsl,lx2160ardb-fpga";
+            reg = <0x66>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            gpio@19 {
+                compatible = "fsl,lx2160ardb-fpga-gpio-sfp";
+                reg = <0x19>;
+                gpio-controller;
+                #gpio-cells = <2>;
+                gpio-line-names =
+                    "SFP2_TX_EN", "",
+                    "", "",
+                    "SFP2_RX_LOS", "SFP2_TX_FAULT",
+                    "", "SFP2_MOD_ABS";
+            };
+        };
+    };