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| -rw-r--r-- | rust/kernel/device.rs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 0353c5552769..0d237cebd65e 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -67,6 +67,25 @@ impl<Ctx: DeviceContext> Device<Ctx> { self.0.get() } + /// Returns a reference to the parent device, if any. + #[expect(unused)] + pub(crate) fn parent(&self) -> Option<&Self> { + // SAFETY: + // - By the type invariant `self.as_raw()` is always valid. + // - The parent device is only ever set at device creation. + let parent = unsafe { (*self.as_raw()).parent }; + + if parent.is_null() { + None + } else { + // SAFETY: + // - Since `parent` is not NULL, it must be a valid pointer to a `struct device`. + // - `parent` is valid for the lifetime of `self`, since a `struct device` holds a + // reference count of its parent. + Some(unsafe { Self::as_ref(parent) }) + } + } + /// Convert a raw C `struct device` pointer to a `&'a Device`. /// /// # Safety |