Bonus

Use a Task to schedule a power off after a certain amount of time defined in a module parameter. Use a workqueue.

/// Stores all the possible tasks (Work)
#[pin_data]
struct DeferredWork {
    module: &'static ThisModule,
    #[pin]
    work: Work<DeferredWork>,
}

/// Initializes the possible tasks
impl DeferredWork {
    fn new(module: &'static ThisModule) -> Result<Arc<DeferredWork>> {
        Arc::pin_init(
            pin_init!(DeferredWork {
                module,
                work <- new_work!("DeferredWork::work"),
            }),
            GFP_KERNEL,
        )
    }
}

/// Must be implemented
impl_has_work! {
    impl HasWork<Self> for DeferredWork { self.work }
}

/// Implement the task
impl WorkItem for DeferredWork {
    type Pointer = Arc<DeferredWork>;

    fn run(_this: Self::Pointer) {
        // ...
    }
}

/// Setup the work
fn setup_work() {
    match DeferredWork::new(module) {
        Ok(work) => {
            let _ = workqueue::system().enqueue(work);
        }
        Err(err) => {
            pr_warn!("Failed to setup work: {:?}", err);
        }
    }
}