rust: device: implement impl_device_context_into_aref!

Implement a macro to implement all From conversions of a certain device
to ARef<Device>.

This avoids unnecessary boiler plate code for every device
implementation.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250413173758.12068-3-dakr@kernel.org
[ Add missing `::` prefix in macros. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 9520e054996d..7b96c99879a6 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -281,6 +281,27 @@ macro_rules! impl_device_context_deref {
 
 #[doc(hidden)]
 #[macro_export]
+macro_rules! __impl_device_context_into_aref {
+    ($src:ty, $device:tt) => {
+        impl ::core::convert::From<&$device<$src>> for $crate::types::ARef<$device> {
+            fn from(dev: &$device<$src>) -> Self {
+                (&**dev).into()
+            }
+        }
+    };
+}
+
+/// Implement [`core::convert::From`], such that all `&Device<Ctx>` can be converted to an
+/// `ARef<Device>`.
+#[macro_export]
+macro_rules! impl_device_context_into_aref {
+    ($device:tt) => {
+        ::kernel::__impl_device_context_into_aref!($crate::device::Core, $device);
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
 macro_rules! dev_printk {
     ($method:ident, $dev:expr, $($f:tt)*) => {
         {