Add asynchronous trait for CAN

embedded-can/Cargo.toml

@@ -13,3 +13,6 @@ repository = "https://github.com/rust-embedded/embedded-hal"
 
 [dependencies]
 nb = "1"
+
+[features]
+async = []

embedded-can/src/asynchronous.rs

@@ -0,0 +1,19 @@
+//! Async CAN API
+
+#![allow(async_fn_in_trait)]
+
+/// An async CAN interface that is able to transmit and receive frames.
+pub trait Can {
+    /// Associated frame type.
+    type Frame: crate::Frame;
+
+    /// Associated error type.
+    type Error: crate::Error;
+
+    /// Puts a frame in the transmit buffer. Waits until space is available in
+    /// the transmit buffer.
+    async fn transmit(&mut self, frame: &Self::Frame) -> Result<(), Self::Error>;
+
+    /// Waits until a frame was received or an error occurred.
+    async fn receive(&mut self) -> Result<Self::Frame, Self::Error>;
+}

embedded-can/src/lib.rs

@@ -3,6 +3,8 @@
 #![warn(missing_docs)]
 #![no_std]
 
+#[cfg(feature = "async")]
+pub mod asynchronous;
 pub mod blocking;
 pub mod nb;