async: add Delay

Author: Dirbaio

embedded-hal-async/src/delay.rs

@@ -0,0 +1,52 @@
+//! Delays
+
+use core::future::Future;
+
+/// Microsecond delay
+pub trait DelayUs {
+    /// Enumeration of errors
+    type Error: core::fmt::Debug;
+
+    /// The future returned by the `delay_us` function.
+    type DelayUsFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Pauses execution for at minimum `us` microseconds. Pause can be longer
+    /// if the implementation requires it due to precision/timing issues.
+    fn delay_us(&mut self, us: u32) -> Self::DelayUsFuture<'_>;
+
+    /// The future returned by the `delay_ms` function.
+    type DelayMsFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Pauses execution for at minimum `ms` milliseconds. Pause can be longer
+    /// if the implementation requires it due to precision/timing issues.
+    fn delay_ms(&mut self, ms: u32) -> Self::DelayMsFuture<'_>;
+}
+
+impl<T> DelayUs for &mut T
+where
+    T: DelayUs,
+{
+    type Error = T::Error;
+
+    type DelayUsFuture<'a>
+    where
+        Self: 'a,
+    = T::DelayUsFuture<'a>;
+
+    fn delay_us(&mut self, us: u32) -> Self::DelayUsFuture<'_> {
+        T::delay_us(self, us)
+    }
+
+    type DelayMsFuture<'a>
+    where
+        Self: 'a,
+    = T::DelayMsFuture<'a>;
+
+    fn delay_ms(&mut self, ms: u32) -> Self::DelayMsFuture<'_> {
+        T::delay_ms(self, ms)
+    }
+}

embedded-hal-async/src/lib.rs

@@ -10,3 +10,5 @@
 #![deny(missing_docs)]
 #![no_std]
 #![feature(generic_associated_types)]
+
+pub mod delay;