embassy/embassy-stm32/src/can/bxcan.rs
Andrew Ealovega 5914d80968 Add non blocking Bxcan constructor.
Signed-off-by: Andrew Ealovega <Andrew@Ealovega.dev>
2022-09-21 22:29:57 -04:00

150 lines
4.2 KiB
Rust

use core::ops::{Deref, DerefMut};
pub use bxcan;
use embassy_hal_common::{into_ref, PeripheralRef};
use crate::gpio::sealed::AFType;
use crate::rcc::RccPeripheral;
use crate::{peripherals, Peripheral};
pub struct Can<'d, T: Instance> {
can: bxcan::Can<BxcanInstance<'d, T>>,
}
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(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
) -> Self {
into_ref!(peri, rx, tx);
unsafe {
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
}
T::enable();
T::reset();
Self {
can: bxcan::Can::builder(BxcanInstance(peri)).enable(),
}
}
/// Creates a new Bxcan instance, keeping the peripheral in sleep mode.
/// You must call [Can::enable_non_blocking] to use the peripheral.
pub fn new_disabled(
peri: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
) -> Self {
into_ref!(peri, rx, tx);
unsafe {
rx.set_as_af(rx.af_num(), AFType::Input);
tx.set_as_af(tx.af_num(), AFType::OutputPushPull);
}
T::enable();
T::reset();
Self {
can: bxcan::Can::builder(BxcanInstance(peri)).leave_disabled(),
}
}
}
impl<'d, T: Instance> Drop for Can<'d, T> {
fn drop(&mut self) {
// Cannot call `free()` because it moves the instance.
// Manually reset the peripheral.
unsafe { 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 {
pub trait Instance {
const REGISTERS: *mut bxcan::RegisterBlock;
fn regs() -> &'static crate::pac::can::Can;
}
}
pub trait Instance: sealed::Instance + RccPeripheral {}
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::$inst.0 as *mut _;
fn regs() -> &'static crate::pac::can::Can {
&crate::pac::$inst
}
}
impl Instance for peripherals::$inst {}
};
);
foreach_peripheral!(
(can, CAN) => {
unsafe impl<'d> bxcan::FilterOwner for BxcanInstance<'d, peripherals::CAN> {
const NUM_FILTER_BANKS: u8 = 14;
}
};
// CAN1 and CAN2 is a combination of master and slave instance.
// CAN1 owns the filter bank and needs to be enabled in order
// for CAN2 to receive messages.
(can, CAN1) => {
cfg_if::cfg_if! {
if #[cfg(all(
any(stm32l4, stm32f72, stm32f73),
not(any(stm32l49, stm32l4a))
))] {
// Most L4 devices and some F7 devices use the name "CAN1"
// even if there is no "CAN2" peripheral.
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);