rust: device: support dev_printk on all devices

Currently, `dev_*` only works on the core `Device`, but not on any other
bus or class device objects. This causes a pattern of
`dev_info!(pdev.as_ref())` which is not ideal.

This adds support of using these devices directly with `dev_*` macros, by
adding `AsRef` call inside the macro. To make sure we can still use just
`kernel::device::Device`, as `AsRef` implementation is added for it; this
is typical for types that is designed to use with `AsRef` anyway, for
example, `str` implements `AsRef<str>` and `Path` implements `AsRef<Path>`.

Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260123175854.176735-1-gary@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: nbdd0121

rust/kernel/device.rs

@@ -596,6 +596,13 @@ impl DeviceContext for Core {}
 impl DeviceContext for CoreInternal {}
 impl DeviceContext for Normal {}
 
+impl<Ctx: DeviceContext> AsRef<Device<Ctx>> for Device<Ctx> {
+    #[inline]
+    fn as_ref(&self) -> &Device<Ctx> {
+        self
+    }
+}
+
 /// Convert device references to bus device references.
 ///
 /// Bus devices can implement this trait to allow abstractions to provide the bus device in
@@ -715,7 +722,7 @@ macro_rules! impl_device_context_into_aref {
 macro_rules! dev_printk {
     ($method:ident, $dev:expr, $($f:tt)*) => {
         {
-            ($dev).$method($crate::prelude::fmt!($($f)*));
+            $crate::device::Device::$method($dev.as_ref(), $crate::prelude::fmt!($($f)*))
         }
     }
 }