Round out the async fns for can
This commit is contained in:
Eric Yanush
parent
9876571887
commit
8d7abeb06f
2 changed files with 237 additions and 16 deletions
|
|
@ -68,6 +68,7 @@ stm32-fmc = "0.2.4"
|
|||
seq-macro = "0.3.0"
|
||||
cfg-if = "1.0.0"
|
||||
embedded-io = { version = "0.4.0", features = ["async"], optional = true }
|
||||
heapless = { version = "0.7.5", default-features = false }
|
||||
|
||||
[dev-dependencies]
|
||||
critical-section = { version = "1.1", features = ["std"] }
|
||||
|
|
|
|||
|
|
@ -3,18 +3,39 @@ use core::ops::{Deref, DerefMut};
|
|||
use core::task::Poll;
|
||||
|
||||
pub use bxcan;
|
||||
use bxcan::Frame;
|
||||
use bxcan::{Data, ExtendedId, Frame, Id, StandardId};
|
||||
use embassy_hal_common::{into_ref, PeripheralRef};
|
||||
|
||||
use crate::gpio::sealed::AFType;
|
||||
use crate::interrupt::{Interrupt, InterruptExt};
|
||||
use crate::interrupt::InterruptExt;
|
||||
use crate::pac::can::vals::{Lec, RirIde};
|
||||
use crate::rcc::RccPeripheral;
|
||||
use crate::time::Hertz;
|
||||
use crate::{peripherals, Peripheral};
|
||||
|
||||
pub struct Can<'d, T: Instance> {
|
||||
can: bxcan::Can<BxcanInstance<'d, T>>,
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
pub enum BusError {
|
||||
Stuff,
|
||||
Form,
|
||||
Acknowledge,
|
||||
BitRecessive,
|
||||
BitDominant,
|
||||
Crc,
|
||||
Software,
|
||||
BusOff,
|
||||
BusPassive,
|
||||
BusWarning,
|
||||
}
|
||||
|
||||
pub enum FrameOrError {
|
||||
Frame(Frame),
|
||||
Error(BusError),
|
||||
}
|
||||
|
||||
impl<'d, T: Instance> Can<'d, T> {
|
||||
/// Creates a new Bxcan instance, blocking for 11 recessive bits to sync with the CAN bus.
|
||||
pub fn new(
|
||||
|
|
@ -74,12 +95,16 @@ impl<'d, T: Instance> Can<'d, T> {
|
|||
sce_irq.set_handler(Self::sce_interrupt);
|
||||
sce_irq.enable();
|
||||
|
||||
Self {
|
||||
can: bxcan::Can::builder(BxcanInstance(peri)).leave_disabled(),
|
||||
}
|
||||
let can = bxcan::Can::builder(BxcanInstance(peri)).leave_disabled();
|
||||
Self { can }
|
||||
}
|
||||
|
||||
pub async fn transmit_async(&mut self, frame: &Frame) {
|
||||
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 transmit(&mut self, frame: &Frame) {
|
||||
let tx_status = self.queue_transmit(frame).await;
|
||||
self.wait_transission(tx_status.mailbox()).await;
|
||||
}
|
||||
|
|
@ -95,7 +120,7 @@ impl<'d, T: Instance> Can<'d, T> {
|
|||
.await
|
||||
}
|
||||
|
||||
async fn wait_transission(&mut self, mb: bxcan::Mailbox) {
|
||||
async fn wait_transission(&self, mb: bxcan::Mailbox) {
|
||||
poll_fn(|cx| unsafe {
|
||||
if T::regs().tsr().read().tme(mb.index()) {
|
||||
return Poll::Ready(());
|
||||
|
|
@ -106,6 +131,45 @@ impl<'d, T: Instance> Can<'d, T> {
|
|||
.await;
|
||||
}
|
||||
|
||||
pub async fn receive_frame_or_error(&mut self) -> FrameOrError {
|
||||
poll_fn(|cx| {
|
||||
if let Some(frame) = T::state().rx_queue.dequeue() {
|
||||
return Poll::Ready(FrameOrError::Frame(frame));
|
||||
} else if let Some(err) = self.curr_error() {
|
||||
return Poll::Ready(FrameOrError::Error(err));
|
||||
}
|
||||
T::state().rx_waker.register(cx.waker());
|
||||
T::state().err_waker.register(cx.waker());
|
||||
Poll::Pending
|
||||
})
|
||||
.await
|
||||
}
|
||||
|
||||
fn curr_error(&self) -> Option<BusError> {
|
||||
let err = unsafe { 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
|
||||
}
|
||||
|
||||
unsafe fn sce_interrupt(_: *mut ()) {
|
||||
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();
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
unsafe fn tx_interrupt(_: *mut ()) {
|
||||
T::regs().tsr().write(|v| {
|
||||
v.set_rqcp(0, true);
|
||||
|
|
@ -115,11 +179,146 @@ impl<'d, T: Instance> Can<'d, T> {
|
|||
T::state().tx_waker.wake();
|
||||
}
|
||||
|
||||
unsafe fn rx0_interrupt(_: *mut ()) {}
|
||||
unsafe fn rx0_interrupt(_: *mut ()) {
|
||||
Self::receive_fifo(RxFifo::Fifo0);
|
||||
}
|
||||
|
||||
unsafe fn rx1_interrupt(_: *mut ()) {}
|
||||
unsafe fn rx1_interrupt(_: *mut ()) {
|
||||
Self::receive_fifo(RxFifo::Fifi1);
|
||||
}
|
||||
|
||||
unsafe fn sce_interrupt(_: *mut ()) {}
|
||||
unsafe fn receive_fifo(fifo: RxFifo) {
|
||||
let state = T::state();
|
||||
let regs = T::regs();
|
||||
let fifo_idx = match fifo {
|
||||
RxFifo::Fifo0 => 0usize,
|
||||
RxFifo::Fifi1 => 1usize,
|
||||
};
|
||||
let rfr = regs.rfr(fifo_idx);
|
||||
let fifo = regs.rx(fifo_idx);
|
||||
|
||||
// If there are no pending messages, there is nothing to do
|
||||
if rfr.read().fmp() == 0 {
|
||||
return;
|
||||
}
|
||||
|
||||
let rir = fifo.rir().read();
|
||||
let id = if rir.ide() == RirIde::STANDARD {
|
||||
Id::from(StandardId::new_unchecked(rir.stid()))
|
||||
} else {
|
||||
Id::from(ExtendedId::new_unchecked(rir.exid()))
|
||||
};
|
||||
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());
|
||||
|
||||
rfr.modify(|v| v.set_rfom(true));
|
||||
|
||||
match state.rx_queue.enqueue(frame) {
|
||||
Ok(_) => {}
|
||||
Err(_) => defmt::error!("RX queue overflow"),
|
||||
}
|
||||
state.rx_waker.wake();
|
||||
}
|
||||
|
||||
pub 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;
|
||||
}
|
||||
|
||||
// Ref. "Automatic Baudrate Detection in CANopen Networks", U. Koppe, MicroControl GmbH & Co. KG
|
||||
// CAN in Automation, 2003
|
||||
//
|
||||
// According to the source, optimal quanta per bit are:
|
||||
// Bitrate Optimal Maximum
|
||||
// 1000 kbps 8 10
|
||||
// 500 kbps 16 17
|
||||
// 250 kbps 16 17
|
||||
// 125 kbps 16 17
|
||||
let max_quanta_per_bit: u8 = if can_bitrate >= 1_000_000 { 10 } else { 17 };
|
||||
|
||||
// Computing (prescaler * BS):
|
||||
// BITRATE = 1 / (PRESCALER * (1 / PCLK) * (1 + BS1 + BS2)) -- See the Reference Manual
|
||||
// BITRATE = PCLK / (PRESCALER * (1 + BS1 + BS2)) -- Simplified
|
||||
// let:
|
||||
// BS = 1 + BS1 + BS2 -- Number of time quanta per bit
|
||||
// PRESCALER_BS = PRESCALER * BS
|
||||
// ==>
|
||||
// PRESCALER_BS = PCLK / BITRATE
|
||||
let prescaler_bs = periph_clock / can_bitrate;
|
||||
|
||||
// Searching for such prescaler value so that the number of quanta per bit is highest.
|
||||
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; // No solution
|
||||
}
|
||||
bs1_bs2_sum -= 1;
|
||||
}
|
||||
|
||||
let prescaler = prescaler_bs / (1 + bs1_bs2_sum) as u32;
|
||||
if (prescaler < 1) || (prescaler > 1024) {
|
||||
return None; // No solution
|
||||
}
|
||||
|
||||
// Now we have a constraint: (BS1 + BS2) == bs1_bs2_sum.
|
||||
// We need to find such values so that the sample point is as close as possible to the optimal value,
|
||||
// which is 87.5%, which is 7/8.
|
||||
//
|
||||
// Solve[(1 + bs1)/(1 + bs1 + bs2) == 7/8, bs2] (* Where 7/8 is 0.875, the recommended sample point location *)
|
||||
// {{bs2 -> (1 + bs1)/7}}
|
||||
//
|
||||
// Hence:
|
||||
// bs2 = (1 + bs1) / 7
|
||||
// bs1 = (7 * bs1_bs2_sum - 1) / 8
|
||||
//
|
||||
// Sample point location can be computed as follows:
|
||||
// Sample point location = (1 + bs1) / (1 + bs1 + bs2)
|
||||
//
|
||||
// Since the optimal solution is so close to the maximum, we prepare two solutions, and then pick the best one:
|
||||
// - With rounding to nearest
|
||||
// - With rounding to zero
|
||||
let mut bs1 = ((7 * bs1_bs2_sum - 1) + 4) / 8; // Trying rounding to nearest first
|
||||
let mut bs2 = bs1_bs2_sum - bs1;
|
||||
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 {
|
||||
// Nope, too far; now rounding to zero
|
||||
bs1 = (7 * bs1_bs2_sum - 1) / 8;
|
||||
bs2 = bs1_bs2_sum - bs1;
|
||||
}
|
||||
|
||||
// Check is BS1 and BS2 are in range
|
||||
if (bs1 < 1) || (bs1 > BS1_MAX) || (bs2 < 1) || (bs2 > BS2_MAX) {
|
||||
return None;
|
||||
}
|
||||
|
||||
// Check if final bitrate matches the requested
|
||||
if can_bitrate != (periph_clock / (prescaler * (1 + bs1 + bs2) as u32)) {
|
||||
return None;
|
||||
}
|
||||
|
||||
// One is recommended by DS-015, CANOpen, and DeviceNet
|
||||
let sjw = 1;
|
||||
|
||||
// Pack into BTR register values
|
||||
Some((sjw - 1) << 24 | (bs1 as u32 - 1) << 16 | (bs2 as u32 - 1) << 20 | (prescaler as u32 - 1))
|
||||
}
|
||||
}
|
||||
|
||||
enum RxFifo {
|
||||
Fifo0,
|
||||
Fifi1,
|
||||
}
|
||||
|
||||
impl<'d, T: Instance> Drop for Can<'d, T> {
|
||||
|
|
@ -147,20 +346,22 @@ impl<'d, T: Instance> DerefMut for Can<'d, T> {
|
|||
|
||||
pub(crate) mod sealed {
|
||||
use embassy_sync::waitqueue::AtomicWaker;
|
||||
use heapless::mpmc::Q8;
|
||||
|
||||
pub struct State {
|
||||
pub tx_waker: AtomicWaker,
|
||||
pub rx0_waker: AtomicWaker,
|
||||
pub rx1_waker: AtomicWaker,
|
||||
pub sce_waker: AtomicWaker,
|
||||
pub rx_waker: AtomicWaker,
|
||||
pub err_waker: AtomicWaker,
|
||||
pub rx_queue: Q8<bxcan::Frame>,
|
||||
}
|
||||
|
||||
impl State {
|
||||
pub const fn new() -> Self {
|
||||
Self {
|
||||
tx_waker: AtomicWaker::new(),
|
||||
rx0_waker: AtomicWaker::new(),
|
||||
rx1_waker: AtomicWaker::new(),
|
||||
sce_waker: AtomicWaker::new(),
|
||||
rx_waker: AtomicWaker::new(),
|
||||
err_waker: AtomicWaker::new(),
|
||||
rx_queue: Q8::new(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -293,3 +494,22 @@ impl Index for bxcan::Mailbox {
|
|||
}
|
||||
}
|
||||
}
|
||||
|
||||
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,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue