added RTR example

va416xx-hal/src/can/asynch.rs

@@ -1,7 +1,6 @@
 use core::{
     future::Future,
     sync::atomic::{AtomicU8, Ordering},
-    usize,
 };
 
 use crate::can::regs::BufferState;

va416xx-hal/src/can/ll.rs

@@ -90,10 +90,7 @@ impl CanChannelLowLevel {
         });
     }
 
-    pub fn configure_for_transmission(
-        &mut self,
-        tx_priority: Option<u4>,
-    ) -> Result<(), InvalidBufferIndexError> {
+    pub fn configure_for_transmission(&mut self, tx_priority: Option<u4>) {
         self.msg_buf.modify_stat_ctrl(|mut val| {
             val.set_dlc(u4::new(0));
             if let Some(tx_priority) = tx_priority {
@@ -102,28 +99,18 @@ impl CanChannelLowLevel {
             val.set_state(BufferState::TxNotActive);
             val
         });
-        Ok(())
     }
 
-    pub fn set_standard_id(
-        &mut self,
-        standard_id: embedded_can::StandardId,
-        set_rtr: bool,
-    ) -> Result<(), InvalidBufferIndexError> {
+    pub fn set_standard_id(&mut self, standard_id: embedded_can::StandardId, set_rtr: bool) {
         let mut id1_reg = standard_id.as_raw() << 5;
         if set_rtr {
             id1_reg |= 1 << 4;
         }
         self.msg_buf
             .write_id1(BaseId::new_with_raw_value(id1_reg as u32));
-        Ok(())
     }
 
-    pub fn set_extended_id(
-        &mut self,
-        extended_id: embedded_can::ExtendedId,
-        set_rtr: bool,
-    ) -> Result<(), InvalidBufferIndexError> {
+    pub fn set_extended_id(&mut self, extended_id: embedded_can::ExtendedId, set_rtr: bool) {
         let id_raw = extended_id.as_raw();
         let id1_reg = (((id_raw >> 18) & 0x7FF) << 4) as u16 | ((id_raw >> 15) & 0b111) as u16;
         self.msg_buf
@@ -131,7 +118,6 @@ impl CanChannelLowLevel {
         let id0_reg = ((id_raw & 0x7FFF) << 1) as u16 | set_rtr as u16;
         self.msg_buf
             .write_id0(ExtendedId::new_with_raw_value(id0_reg as u32));
-        Ok(())
     }
 
     pub fn configure_for_reception(&mut self) {
@@ -313,7 +299,9 @@ impl CanChannelLowLevel {
         } else {
             let dlc = self.msg_buf.read_stat_ctrl().dlc();
             read_data(dlc);
-            CanFrameNormal::new(id, &data[0..dlc.as_usize()]).unwrap().into()
+            CanFrameNormal::new(id, &data[0..dlc.as_usize()])
+                .unwrap()
+                .into()
         }
     }
 }

va416xx-hal/src/can/mod.rs

@@ -486,16 +486,23 @@ pub struct CanTx {
 
 impl CanTx {
     pub fn new(mut ll: CanChannelLowLevel, tx_priority: Option<u4>) -> Self {
-        ll.configure_for_transmission(tx_priority).unwrap();
+        ll.configure_for_transmission(tx_priority);
         Self {
             ll,
             mode: TxState::Idle,
         }
     }
 
+    /// Start transmitting a frame.
+    ///
+    /// The frame transmission can be polled/awaited to completion using the [Self::transfer_done]
+    /// method.
+    ///
+    /// This function will return a [state error][InvalidTxStateError] if a transmission is already
+    /// active and/or the transmit buffer has an invalid state.
     pub fn transmit_frame(&mut self, frame: CanFrame) -> Result<(), InvalidTxStateError> {
         if self.mode == TxState::AwaitingRemoteFrameReply {
-            self.ll.configure_for_transmission(None).unwrap();
+            self.ll.configure_for_transmission(None);
             self.mode = TxState::Idle;
         }
         if self.mode != TxState::Idle {
@@ -515,7 +522,10 @@ impl CanTx {
         Ok(())
     }
 
-    pub fn data_frame_transfer_done(&mut self) -> nb::Result<(), InvalidTxStateError> {
+    /// Poll whether an active data frame transmission is done.
+    ///
+    /// Returns a [state error][InvalidTxStateError] if no transmission is active.
+    pub fn transfer_done(&mut self) -> nb::Result<(), InvalidTxStateError> {
         if self.mode != TxState::TransmittingDataFrame {
             return Err(nb::Error::Other(InvalidTxStateError(self.mode.into())));
         }
@@ -531,7 +541,10 @@ impl CanTx {
         Err(nb::Error::WouldBlock)
     }
 
-    pub fn remote_frame_transfer_done(&mut self) -> nb::Result<CanRx, InvalidTxStateError> {
+    /// Poll whether an active remote frame transmission is done.
+    ///
+    /// Returns a [state error][InvalidTxStateError] if no transmission is active.
+    pub fn remote_transfer_done(&mut self) -> nb::Result<CanRx, InvalidTxStateError> {
         if self.mode != TxState::TransmittingRemoteFrame {
             return Err(nb::Error::Other(InvalidTxStateError(self.mode.into())));
         }
@@ -549,6 +562,11 @@ impl CanTx {
         }
         Err(nb::Error::WouldBlock)
     }
+
+    pub fn reset(&mut self) {
+        self.ll.reset();
+        self.mode = TxState::Idle;
+    }
 }
 
 pub struct CanRx {
@@ -567,20 +585,18 @@ impl CanRx {
         &mut self,
         standard_id: embedded_can::StandardId,
         set_rtr: bool,
-    ) -> Result<(), InvalidBufferIndexError> {
-        self.ll.set_standard_id(standard_id, set_rtr)?;
+    ) {
+        self.ll.set_standard_id(standard_id, set_rtr);
         self.configure_for_reception();
-        Ok(())
     }
 
     pub fn configure_for_reception_with_extended_id(
         &mut self,
         extended_id: embedded_can::ExtendedId,
         set_rtr: bool,
-    ) -> Result<(), InvalidBufferIndexError> {
-        self.ll.set_extended_id(extended_id, set_rtr)?;
+    ) {
+        self.ll.set_extended_id(extended_id, set_rtr);
         self.configure_for_reception();
-        Ok(())
     }
 
     pub fn configure_for_reception(&mut self) {
@@ -588,6 +604,14 @@ impl CanRx {
         self.mode = RxState::Receiving;
     }
 
+    #[inline]
+    pub fn frame_available(&self) -> bool {
+        self.ll
+            .read_state()
+            .is_ok_and(|state| state == BufferState::RxFull || state == BufferState::RxOverrun)
+    }
+
+    /// Poll for frame reception. Returns the frame if one is available.
     pub fn receive(
         &mut self,
         reconfigure_for_reception: bool,