use core::convert::AsMut;
use core::future::poll_fn;
use core::marker::PhantomData;
use core::ops::{Deref, DerefMut};
use core::task::Poll;
pub use bxcan;
use bxcan::{Data, ExtendedId, Frame, Id, StandardId};
use embassy_hal_internal::{into_ref, PeripheralRef};
use futures::FutureExt;
use crate::gpio::sealed::AFType;
use crate::interrupt::typelevel::Interrupt;
use crate::pac::can::vals::{Ide, Lec};
use crate::rcc::RccPeripheral;
use crate::time::Hertz;
use crate::{interrupt, peripherals, Peripheral};
#[derive(Debug, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct Envelope {
#[cfg(feature = "time")]
pub ts: embassy_time::Instant,
pub frame: bxcan::Frame,
}
pub struct TxInterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::TXInterrupt> for TxInterruptHandler<T> {
unsafe fn on_interrupt() {
T::regs().tsr().write(|v| {
v.set_rqcp(0, true);
v.set_rqcp(1, true);
v.set_rqcp(2, true);
});
T::state().tx_waker.wake();
}
}
pub struct Rx0InterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::RX0Interrupt> for Rx0InterruptHandler<T> {
unsafe fn on_interrupt() {
Can::<T>::receive_fifo(RxFifo::Fifo0);
}
}
pub struct Rx1InterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::RX1Interrupt> for Rx1InterruptHandler<T> {
unsafe fn on_interrupt() {
Can::<T>::receive_fifo(RxFifo::Fifo1);
}
}
pub struct SceInterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::SCEInterrupt> for SceInterruptHandler<T> {
unsafe fn on_interrupt() {
let msr = T::regs().msr();
let msr_val = msr.read();
if msr_val.erri() {
msr.modify(|v| v.set_erri(true));
T::state().err_waker.wake();
}
}
}
pub struct Can<'d, T: Instance> {
can: bxcan::Can<BxcanInstance<'d, T>>,
}
#[allow(missing_docs)]
#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum BusError {
Stuff,
Form,
Acknowledge,
BitRecessive,
BitDominant,
Crc,
Software,
BusOff,
BusPassive,
BusWarning,
}
#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum TryReadError {
BusError(BusError),
Empty,
}
#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum TryWriteError {
Full,
}
impl<'d, T: Instance> Can<'d, T> {
pub fn new(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
_irqs: impl interrupt::typelevel::Binding<T::TXInterrupt, TxInterruptHandler<T>>
+ interrupt::typelevel::Binding<T::RX0Interrupt, Rx0InterruptHandler<T>>
+ interrupt::typelevel::Binding<T::RX1Interrupt, Rx1InterruptHandler<T>>
+ interrupt::typelevel::Binding<T::SCEInterrupt, SceInterruptHandler<T>>
+ 'd,
) -> Self {
into_ref!(peri, rx, tx);
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
T::enable_and_reset();
{
T::regs().ier().write(|w| {
w.set_errie(true);
w.set_fmpie(0, true);
w.set_fmpie(1, true);
w.set_tmeie(true);
});
T::regs().mcr().write(|w| {
w.set_ttcm(true);
});
}
unsafe {
T::TXInterrupt::unpend();
T::TXInterrupt::enable();
T::RX0Interrupt::unpend();
T::RX0Interrupt::enable();
T::RX1Interrupt::unpend();
T::RX1Interrupt::enable();
T::SCEInterrupt::unpend();
T::SCEInterrupt::enable();
}
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
let can = bxcan::Can::builder(BxcanInstance(peri)).leave_disabled();
Self { can }
}
pub fn set_bitrate(&mut self, bitrate: u32) {
let bit_timing = Self::calc_bxcan_timings(T::frequency(), bitrate).unwrap();
self.can.modify_config().set_bit_timing(bit_timing).leave_disabled();
}
pub async fn enable(&mut self) {
while self.enable_non_blocking().is_err() {
embassy_futures::yield_now().await;
}
}
pub async fn write(&mut self, frame: &Frame) -> bxcan::TransmitStatus {
self.split().0.write(frame).await
}
pub fn try_write(&mut self, frame: &Frame) -> Result<bxcan::TransmitStatus, TryWriteError> {
self.split().0.try_write(frame)
}
pub async fn flush(&self, mb: bxcan::Mailbox) {
CanTx::<T>::flush_inner(mb).await
}
pub async fn flush_any(&self) {
CanTx::<T>::flush_any_inner().await
}
pub async fn flush_all(&self) {
CanTx::<T>::flush_all_inner().await
}
pub async fn read(&mut self) -> Result<Envelope, BusError> {
self.split().1.read().await
}
pub fn try_read(&mut self) -> Result<Envelope, TryReadError> {
self.split().1.try_read()
}
pub async fn wait_not_empty(&mut self) {
self.split().1.wait_not_empty().await
}
unsafe fn receive_fifo(fifo: RxFifo) {
#[cfg(feature = "time")]
let ts = embassy_time::Instant::now();
let state = T::state();
let regs = T::regs();
let fifo_idx = match fifo {
RxFifo::Fifo0 => 0usize,
RxFifo::Fifo1 => 1usize,
};
let rfr = regs.rfr(fifo_idx);
let fifo = regs.rx(fifo_idx);
loop {
if rfr.read().fmp() == 0 {
return;
}
let rir = fifo.rir().read();
let id = if rir.ide() == Ide::STANDARD {
Id::from(StandardId::new_unchecked(rir.stid()))
} else {
let stid = (rir.stid() & 0x7FF) as u32;
let exid = rir.exid() & 0x3FFFF;
let id = (stid << 18) | (exid);
Id::from(ExtendedId::new_unchecked(id))
};
let data_len = fifo.rdtr().read().dlc() as usize;
let mut data: [u8; 8] = [0; 8];
data[0..4].copy_from_slice(&fifo.rdlr().read().0.to_ne_bytes());
data[4..8].copy_from_slice(&fifo.rdhr().read().0.to_ne_bytes());
let frame = Frame::new_data(id, Data::new(&data[0..data_len]).unwrap());
let envelope = Envelope {
#[cfg(feature = "time")]
ts,
frame,
};
rfr.modify(|v| v.set_rfom(true));
let _ = state.rx_queue.try_send(envelope);
}
}
const fn calc_bxcan_timings(periph_clock: Hertz, can_bitrate: u32) -> Option<u32> {
const BS1_MAX: u8 = 16;
const BS2_MAX: u8 = 8;
const MAX_SAMPLE_POINT_PERMILL: u16 = 900;
let periph_clock = periph_clock.0;
if can_bitrate < 1000 {
return None;
}
let max_quanta_per_bit: u8 = if can_bitrate >= 1_000_000 { 10 } else { 17 };
let prescaler_bs = periph_clock / can_bitrate;
let mut bs1_bs2_sum = max_quanta_per_bit - 1;
while (prescaler_bs % (1 + bs1_bs2_sum) as u32) != 0 {
if bs1_bs2_sum <= 2 {
return None; }
bs1_bs2_sum -= 1;
}
let prescaler = prescaler_bs / (1 + bs1_bs2_sum) as u32;
if (prescaler < 1) || (prescaler > 1024) {
return None; }
let mut bs1 = ((7 * bs1_bs2_sum - 1) + 4) / 8; let mut bs2 = bs1_bs2_sum - bs1;
core::assert!(bs1_bs2_sum > bs1);
let sample_point_permill = 1000 * ((1 + bs1) / (1 + bs1 + bs2)) as u16;
if sample_point_permill > MAX_SAMPLE_POINT_PERMILL {
bs1 = (7 * bs1_bs2_sum - 1) / 8;
bs2 = bs1_bs2_sum - bs1;
}
if (bs1 < 1) || (bs1 > BS1_MAX) || (bs2 < 1) || (bs2 > BS2_MAX) {
return None;
}
if can_bitrate != (periph_clock / (prescaler * (1 + bs1 + bs2) as u32)) {
return None;
}
let sjw = 1;
Some((sjw - 1) << 24 | (bs1 as u32 - 1) << 16 | (bs2 as u32 - 1) << 20 | (prescaler - 1))
}
pub fn split<'c>(&'c mut self) -> (CanTx<'c, 'd, T>, CanRx<'c, 'd, T>) {
let (tx, rx0, rx1) = self.can.split_by_ref();
(CanTx { tx }, CanRx { rx0, rx1 })
}
}
impl<'d, T: Instance> AsMut<bxcan::Can<BxcanInstance<'d, T>>> for Can<'d, T> {
fn as_mut(&mut self) -> &mut bxcan::Can<BxcanInstance<'d, T>> {
&mut self.can
}
}
pub struct CanTx<'c, 'd, T: Instance> {
tx: &'c mut bxcan::Tx<BxcanInstance<'d, T>>,
}
impl<'c, 'd, T: Instance> CanTx<'c, 'd, T> {
pub async fn write(&mut self, frame: &Frame) -> bxcan::TransmitStatus {
poll_fn(|cx| {
T::state().tx_waker.register(cx.waker());
if let Ok(status) = self.tx.transmit(frame) {
return Poll::Ready(status);
}
Poll::Pending
})
.await
}
pub fn try_write(&mut self, frame: &Frame) -> Result<bxcan::TransmitStatus, TryWriteError> {
self.tx.transmit(frame).map_err(|_| TryWriteError::Full)
}
async fn flush_inner(mb: bxcan::Mailbox) {
poll_fn(|cx| {
T::state().tx_waker.register(cx.waker());
if T::regs().tsr().read().tme(mb.index()) {
return Poll::Ready(());
}
Poll::Pending
})
.await;
}
pub async fn flush(&self, mb: bxcan::Mailbox) {
Self::flush_inner(mb).await
}
async fn flush_any_inner() {
poll_fn(|cx| {
T::state().tx_waker.register(cx.waker());
let tsr = T::regs().tsr().read();
if tsr.tme(bxcan::Mailbox::Mailbox0.index())
|| tsr.tme(bxcan::Mailbox::Mailbox1.index())
|| tsr.tme(bxcan::Mailbox::Mailbox2.index())
{
return Poll::Ready(());
}
Poll::Pending
})
.await;
}
pub async fn flush_any(&self) {
Self::flush_any_inner().await
}
async fn flush_all_inner() {
poll_fn(|cx| {
T::state().tx_waker.register(cx.waker());
let tsr = T::regs().tsr().read();
if tsr.tme(bxcan::Mailbox::Mailbox0.index())
&& tsr.tme(bxcan::Mailbox::Mailbox1.index())
&& tsr.tme(bxcan::Mailbox::Mailbox2.index())
{
return Poll::Ready(());
}
Poll::Pending
})
.await;
}
pub async fn flush_all(&self) {
Self::flush_all_inner().await
}
}
#[allow(dead_code)]
pub struct CanRx<'c, 'd, T: Instance> {
rx0: &'c mut bxcan::Rx0<BxcanInstance<'d, T>>,
rx1: &'c mut bxcan::Rx1<BxcanInstance<'d, T>>,
}
impl<'c, 'd, T: Instance> CanRx<'c, 'd, T> {
pub async fn read(&mut self) -> Result<Envelope, BusError> {
poll_fn(|cx| {
T::state().err_waker.register(cx.waker());
if let Poll::Ready(envelope) = T::state().rx_queue.receive().poll_unpin(cx) {
return Poll::Ready(Ok(envelope));
} else if let Some(err) = self.curr_error() {
return Poll::Ready(Err(err));
}
Poll::Pending
})
.await
}
pub fn try_read(&mut self) -> Result<Envelope, TryReadError> {
if let Ok(envelope) = T::state().rx_queue.try_receive() {
return Ok(envelope);
}
if let Some(err) = self.curr_error() {
return Err(TryReadError::BusError(err));
}
Err(TryReadError::Empty)
}
pub async fn wait_not_empty(&mut self) {
poll_fn(|cx| T::state().rx_queue.poll_ready_to_receive(cx)).await
}
fn curr_error(&self) -> Option<BusError> {
let err = { T::regs().esr().read() };
if err.boff() {
return Some(BusError::BusOff);
} else if err.epvf() {
return Some(BusError::BusPassive);
} else if err.ewgf() {
return Some(BusError::BusWarning);
} else if let Some(err) = err.lec().into_bus_err() {
return Some(err);
}
None
}
}
enum RxFifo {
Fifo0,
Fifo1,
}
impl<'d, T: Instance> Drop for Can<'d, T> {
fn drop(&mut self) {
T::regs().mcr().write(|w| w.set_reset(true));
T::disable();
}
}
impl<'d, T: Instance> Deref for Can<'d, T> {
type Target = bxcan::Can<BxcanInstance<'d, T>>;
fn deref(&self) -> &Self::Target {
&self.can
}
}
impl<'d, T: Instance> DerefMut for Can<'d, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.can
}
}
pub(crate) mod sealed {
use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
use embassy_sync::channel::Channel;
use embassy_sync::waitqueue::AtomicWaker;
use super::Envelope;
pub struct State {
pub tx_waker: AtomicWaker,
pub err_waker: AtomicWaker,
pub rx_queue: Channel<CriticalSectionRawMutex, Envelope, 32>,
}
impl State {
pub const fn new() -> Self {
Self {
tx_waker: AtomicWaker::new(),
err_waker: AtomicWaker::new(),
rx_queue: Channel::new(),
}
}
}
pub trait Instance {
const REGISTERS: *mut bxcan::RegisterBlock;
fn regs() -> crate::pac::can::Can;
fn state() -> &'static State;
}
}
pub trait Instance: sealed::Instance + RccPeripheral + 'static {
type TXInterrupt: crate::interrupt::typelevel::Interrupt;
type RX0Interrupt: crate::interrupt::typelevel::Interrupt;
type RX1Interrupt: crate::interrupt::typelevel::Interrupt;
type SCEInterrupt: crate::interrupt::typelevel::Interrupt;
}
pub struct BxcanInstance<'a, T>(PeripheralRef<'a, T>);
unsafe impl<'d, T: Instance> bxcan::Instance for BxcanInstance<'d, T> {
const REGISTERS: *mut bxcan::RegisterBlock = T::REGISTERS;
}
foreach_peripheral!(
(can, $inst:ident) => {
impl sealed::Instance for peripherals::$inst {
const REGISTERS: *mut bxcan::RegisterBlock = crate::pac::$inst.as_ptr() as *mut _;
fn regs() -> crate::pac::can::Can {
crate::pac::$inst
}
fn state() -> &'static sealed::State {
static STATE: sealed::State = sealed::State::new();
&STATE
}
}
impl Instance for peripherals::$inst {
type TXInterrupt = crate::_generated::peripheral_interrupts::$inst::TX;
type RX0Interrupt = crate::_generated::peripheral_interrupts::$inst::RX0;
type RX1Interrupt = crate::_generated::peripheral_interrupts::$inst::RX1;
type SCEInterrupt = crate::_generated::peripheral_interrupts::$inst::SCE;
}
};
);
foreach_peripheral!(
(can, CAN) => {
unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN> {
const NUM_FILTER_BANKS: u8 = 14;
}
};
(can, CAN1) => {
cfg_if::cfg_if! {
if #[cfg(all(
any(stm32l4, stm32f72, stm32f73),
not(any(stm32l49, stm32l4a))
))] {
unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN1> {
const NUM_FILTER_BANKS: u8 = 14;
}
} else {
unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN1> {
const NUM_FILTER_BANKS: u8 = 28;
}
unsafe impl<'d> bxcan::MasterInstance for BxcanInstance<'d, peripherals::CAN1> {}
}
}
};
(can, CAN3) => {
unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN3> {
const NUM_FILTER_BANKS: u8 = 14;
}
};
);
pin_trait!(RxPin, Instance);
pin_trait!(TxPin, Instance);
trait Index {
fn index(&self) -> usize;
}
impl Index for bxcan::Mailbox {
fn index(&self) -> usize {
match self {
bxcan::Mailbox::Mailbox0 => 0,
bxcan::Mailbox::Mailbox1 => 1,
bxcan::Mailbox::Mailbox2 => 2,
}
}
}
trait IntoBusError {
fn into_bus_err(self) -> Option<BusError>;
}
impl IntoBusError for Lec {
fn into_bus_err(self) -> Option<BusError> {
match self {
Lec::STUFF => Some(BusError::Stuff),
Lec::FORM => Some(BusError::Form),
Lec::ACK => Some(BusError::Acknowledge),
Lec::BITRECESSIVE => Some(BusError::BitRecessive),
Lec::BITDOMINANT => Some(BusError::BitDominant),
Lec::CRC => Some(BusError::Crc),
Lec::CUSTOM => Some(BusError::Software),
_ => None,
}
}
}