Merge time-driver and time-queue-driver traits, make HALs own and handle the queue.

embassy-time-driver/src/lib.rs

@@ -38,6 +38,8 @@
 //! # Example
 //!
 //! ```
+//! use core::task::Waker;
+//!
 //! use embassy_time_driver::Driver;
 //!
 //! struct MyDriver{} // not public!
@@ -46,6 +48,10 @@
 //!     fn now(&self) -> u64 {
 //!         todo!()
 //!     }
+//!
+//!     fn schedule_wake(&self, at: u64, waker: &Waker) {
+//!         todo!()
+//!     }
 //! }
 //!
 //! embassy_time_driver::time_driver_impl!(static DRIVER: MyDriver = MyDriver{});
@@ -54,6 +60,8 @@
 //! ## Feature flags
 #![doc = document_features::document_features!(feature_label = r#"<span class="stab portability"><code>{feature}</code></span>"#)]
 
+use core::task::Waker;
+
 mod tick;
 
 /// Ticks per second of the global timebase.
@@ -74,6 +82,10 @@ pub trait Driver: Send + Sync + 'static {
     ///   you MUST extend them to 64-bit, for example by counting overflows in software,
     ///   or chaining multiple timers together.
     fn now(&self) -> u64;
+
+    /// Schedules a waker to be awoken at moment `at`.
+    /// If this moment is in the past, the waker might be awoken immediately.
+    fn schedule_wake(&self, at: u64, waker: &Waker);
 }
 
 extern "Rust" {
@@ -97,5 +109,10 @@ macro_rules! time_driver_impl {
         fn _embassy_time_now() -> u64 {
             <$t as $crate::Driver>::now(&$name)
         }
+
+        #[no_mangle]
+        fn _embassy_time_schedule_wake(at: u64, waker: &core::task::Waker) {
+            <$t as $crate::Driver>::schedule_wake(&$name, at, waker);
+        }
     };
 }