Re: [PATCH v3 15/16] rust: platform: add basic platform device / driver abstractions

[Alice Ryhl]

On Tue, Oct 22, 2024 at 11:33 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
> +    /// Find the [`of::DeviceId`] within [`Driver::ID_TABLE`] matching the given [`Device`], if any.
> +    fn of_match_device(pdev: &Device) -> Option<&of::DeviceId> {
> +        let table = Self::ID_TABLE;
> +
> +        // SAFETY:
> +        // - `table` has static lifetime, hence it's valid for read,
> +        // - `dev` is guaranteed to be valid while it's alive, and so is
> +        //   `pdev.as_dev().as_raw()`.
> +        let raw_id = unsafe { bindings::of_match_device(table.as_ptr(), pdev.as_dev().as_raw()) };
> +
> +        if raw_id.is_null() {
> +            None
> +        } else {
> +            // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and
> +            // does not add additional invariants, so it's safe to transmute.
> +            Some(unsafe { &*raw_id.cast::<of::DeviceId>() })
> +        }
> +    }

Sorry if this has already been mentioned, but this method should
probably be marked #[cfg(CONFIG_OF)] so that you can use these
abstractions even if OF is disabled.

Alice