embedded-can-04: Add a receive function for an arbitrary embedded_can…

…::Frame.

Classic CAN only, as no CAN-FD support in embedded_can yet.

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## [Unreleased]
 
 * Update MSRV to 1.60
-* Add `embedded-can-04` feature flag which enables conversions from and into `embedded_can::Id` types, and compatible transmit functions.
+* Add `embedded-can-04` feature flag which enables conversions from and into `embedded_can::Id` types, and compatible receive and transmit functions.
 
 ## [v0.2.1] 2024-09-04
 

src/lib.rs

@@ -14,7 +14,7 @@
 //!
 //! | Feature | Description |
 //! |---------|-------------|
-//! | `embedded-can-04` | Enables conversions from and into [`embedded_can`] 0.4 CAN ID types, and compatible transmit functions. |
+//! | `embedded-can-04` | Enables conversions from and into [`embedded_can`] 0.4 CAN ID types, and compatible receive transmit functions. Note that only classic CAN is currently supported in `embedded_can`. |
 //!
 //! [`embedded-can`]: https://docs.rs/embedded-can
 
@@ -52,7 +52,7 @@ use filter::{
     StandardFilterSlot, EXTENDED_FILTER_MAX, STANDARD_FILTER_MAX,
 };
 use frame::MergeTxFrameHeader;
-use frame::{RxFrameInfo, TxFrameHeader};
+use frame::{FrameFormat, RxFrameInfo, TxFrameHeader};
 use id::{Id, IdReg};
 use interrupt::{Interrupt, InterruptLine, Interrupts};
 
@@ -1140,6 +1140,36 @@ where
         // Safety: We have a `&mut self` and have unique access to the peripheral.
         unsafe { Rx::<I, M, Fifo1>::conjure().receive(buffer) }
     }
+
+    /// Returns a received Classic CAN frame of a given type from FIFO_0 if available.
+    ///
+    /// # Panics
+    ///
+    /// Panics if an `CAN-FD` frame is received, as embedded_can::Frame has no FD support.
+    #[cfg(feature = "embedded-can-04")]
+    #[inline]
+    pub fn receive0_frame<F>(&mut self) -> nb::Result<ReceiveOverrun<F>, Infallible>
+    where
+        F: embedded_can::Frame,
+    {
+        // Safety: We have a `&mut self` and have unique access to the peripheral.
+        unsafe { Rx::<I, M, Fifo0>::conjure().receive_frame() }
+    }
+
+    /// Returns a received Classic CAN frame of a given type from FIFO_1 if available.
+    ///
+    /// # Panics
+    ///
+    /// Panics if an `CAN-FD` frame is received, as embedded_can::Frame has no FD support.
+    #[cfg(feature = "embedded-can-04")]
+    #[inline]
+    pub fn receive1_frame<F>(&mut self) -> nb::Result<ReceiveOverrun<F>, Infallible>
+    where
+        F: embedded_can::Frame,
+    {
+        // Safety: We have a `&mut self` and have unique access to the peripheral.
+        unsafe { Rx::<I, M, Fifo1>::conjure().receive_frame() }
+    }
 }
 
 /// FdCanControl Struct
@@ -1567,8 +1597,6 @@ where
 
     /// Returns a received frame if available.
     ///
-    /// Returns `Err` when a frame was lost due to buffer overrun.
-    ///
     /// # Panics
     ///
     /// Panics if `buffer` is smaller than the header length.
@@ -1607,6 +1635,33 @@ where
         }
     }
 
+    /// Returns a received Classic CAN frame of a given type if available.
+    ///
+    /// # Panics
+    ///
+    /// Panics if an `CAN-FD` frame is received, as embedded_can::Frame has no FD support.
+    #[cfg(feature = "embedded-can-04")]
+    pub fn receive_frame<F>(mut self) -> nb::Result<ReceiveOverrun<F>, Infallible>
+    where
+        F: embedded_can::Frame,
+    {
+        let mut buffer = [0_u8; 8];
+        let overrun = self.receive(&mut buffer)?;
+        let info = overrun.unwrap();
+        if info.frame_format != FrameFormat::Standard {
+            panic!("Received CAN-FD frame");
+        }
+        let frame = if info.rtr {
+            F::new_remote(info.id, info.len as usize)
+        } else {
+            F::new(info.id, &buffer[..info.len as usize])
+        }.unwrap();
+        match overrun {
+            ReceiveOverrun::NoOverrun(_) => Ok(ReceiveOverrun::NoOverrun(frame)),
+            ReceiveOverrun::Overrun(_) => Ok(ReceiveOverrun::Overrun(frame)),
+        }
+    }
+
     #[inline]
     fn registers(&self) -> &RegisterBlock {
         unsafe { &*I::REGISTERS }