kernel/platform/
watchdog.rs

1// Licensed under the Apache License, Version 2.0 or the MIT License.
2// SPDX-License-Identifier: Apache-2.0 OR MIT
3// Copyright Tock Contributors 2022.
4
5//! Interface for configuring a watchdog
6
7/// A trait for implementing a watchdog in the kernel.
8///
9/// This trait is called from the `kernel_loop()` code to setup
10/// and maintain the watchdog timer.
11/// It is up to the specific `Chip` how it will handle watchdog interrupts.
12pub trait WatchDog {
13    /// This function must enable the watchdog timer and configure it to
14    /// trigger regulary. The period of the timer is left to the implementation
15    /// to decide. The implementation must ensure that it doesn't trigger too
16    /// early (when we haven't hung for example) or too late as to not catch
17    /// faults.
18    /// After calling this function the watchdog must be running.
19    fn setup(&self) {}
20
21    /// This function must tickle the watchdog to reset the timer.
22    /// If the watchdog was previously suspended then this should also
23    /// resume the timer.
24    fn tickle(&self) {}
25
26    /// Suspends the watchdog timer. After calling this the timer should not
27    /// fire until after `tickle()` has been called. This function is called
28    /// before sleeping.
29    fn suspend(&self) {}
30
31    /// Resumes the watchdog timer. After calling this the timer should be
32    /// running again. This is called after returning from sleep, after
33    /// `suspend()` was called.
34    fn resume(&self) {
35        self.tickle();
36    }
37}
38
39/// Implement default WatchDog trait for unit.
40impl WatchDog for () {}
kernel/platform/watchdog.rs

kernel/platform/
watchdog.rs
