rust: faux: add Device type with AsBusDevice support

Add a faux::Device type that wraps struct faux_device and implements
AsBusDevice, enabling faux devices to be used as parent devices for
subsystems that require a bus device, such as DRM.

Update Registration to return &faux::Device<Bound> via AsRef.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260628145406.2107056-4-dakr@kernel.org
[ Drop redundant 'struct device' invariant; implied by valid
  struct faux_device. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/samples/rust/rust_driver_faux.rs b/samples/rust/rust_driver_faux.rs
index 99876c8e3743..27b6d3e2bb44 100644
--- a/samples/rust/rust_driver_faux.rs
+++ b/samples/rust/rust_driver_faux.rs
@@ -25,8 +25,9 @@ impl Module for SampleModule {
         pr_info!("Initialising Rust Faux Device Sample\n");
 
         let reg = faux::Registration::new(c"rust-faux-sample-device", None)?;
+        let fdev = reg.as_ref();
 
-        dev_info!(reg, "Hello from faux device!\n");
+        dev_info!(fdev, "Hello from faux device!\n");
 
         Ok(Self { _reg: reg })
     }