[PATCH v1 3/3] samples: rust: platform: Add property child and reference args examples

[Remo Senekowitsch <remo@buenzli.dev>]

Add some example usage of the device property methods for reading
DT/ACPI/swnode child nodes and reference args.

Signed-off-by: Remo Senekowitsch <remo@buenzli.dev>
---
 drivers/of/unittest-data/tests-platform.dtsi |  7 +++++++
 samples/rust/rust_driver_platform.rs         | 13 ++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
index 50a51f38afb6..509eb614ab2b 100644
--- a/drivers/of/unittest-data/tests-platform.dtsi
+++ b/drivers/of/unittest-data/tests-platform.dtsi
@@ -40,6 +40,13 @@ test-device@2 {
 
 				test,u32-prop = <0xdeadbeef>;
 				test,i16-array = /bits/ 16 <1 2 (-3) (-4)>;
+
+				ref_child_0: child@0 {
+					test,ref-arg = <&ref_child_1 0x20 0x32>;
+				};
+				ref_child_1: child@1 {
+					test,ref-arg = <&ref_child_0 0x10 0x64>;
+				};
 			};
 		};
 
diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index c0abf78d0683..4dcedb22a4bb 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -4,7 +4,11 @@
 
 use kernel::{
     c_str,
-    device::{self, Core},
+    device::{
+        self,
+        property::{FwNodeReferenceArgs, NArgs},
+        Core,
+    },
     of, platform,
     prelude::*,
     str::CString,
@@ -91,6 +95,13 @@ fn properties_parse(dev: &device::Device) -> Result {
         let prop: KVec<i16> = fwnode.property_read_array_vec(name, 4)?.required_by(dev)?;
         dev_info!(dev, "'{name}'='{prop:?}' (KVec)\n");
 
+        for child in fwnode.children() {
+            let name = c_str!("test,ref-arg");
+            let nargs = NArgs::N(2);
+            let prop: FwNodeReferenceArgs = child.property_get_reference_args(name, nargs, 0)?;
+            dev_info!(dev, "'{name}'='{prop:?}'\n");
+        }
+
         Ok(())
     }
 }
-- 
2.49.0