rust: device: add device name method

Add a name() method to the `Device` type, which returns a CStr that
contains the device name.

Signed-off-by: Timur Tabi <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Alexandre Courbot <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Tested-by: John Hubbard <[email protected]>
Tested-by: Eliot Courtney <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>

rust/helpers/device.c

@@ -25,3 +25,8 @@ __rust_helper void rust_helper_dev_set_drvdata(struct device *dev, void *data)
 {
 	dev_set_drvdata(dev, data);
 }
+
+__rust_helper const char *rust_helper_dev_name(const struct device *dev)
+{
+	return dev_name(dev);
+}

rust/kernel/device.rs

@@ -489,6 +489,17 @@ impl<Ctx: DeviceContext> Device<Ctx> {
         // defined as a `#[repr(transparent)]` wrapper around `fwnode_handle`.
         Some(unsafe { &*fwnode_handle.cast() })
     }
+
+    /// Returns the name of the device.
+    ///
+    /// This is the kobject name of the device, or its initial name if the kobject is not yet
+    /// available.
+    #[inline]
+    pub fn name(&self) -> &CStr {
+        // SAFETY: By its type invariant `self.as_raw()` is a valid pointer to a `struct device`.
+        // The returned string is valid for the lifetime of the device.
+        unsafe { CStr::from_char_ptr(bindings::dev_name(self.as_raw())) }
+    }
 }
 
 // SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic