embassy/embassy-stm32/src/exti.rs
2021-11-02 12:05:24 -04:00

308 lines
8.0 KiB
Rust

use core::convert::Infallible;
use core::future::Future;
use core::marker::PhantomData;
use core::pin::Pin;
use core::task::{Context, Poll};
use embassy::traits::gpio::{WaitForAnyEdge, WaitForFallingEdge, WaitForRisingEdge};
use embassy::util::Unborrow;
use embassy::waitqueue::AtomicWaker;
use embassy_hal_common::unsafe_impl_unborrow;
use embedded_hal::digital::v2::InputPin;
use crate::gpio::{AnyPin, Input, Pin as GpioPin};
use crate::interrupt;
use crate::pac;
use crate::pac::exti::regs::Lines;
use crate::pac::EXTI;
use crate::peripherals;
const EXTI_COUNT: usize = 16;
const NEW_AW: AtomicWaker = AtomicWaker::new();
static EXTI_WAKERS: [AtomicWaker; EXTI_COUNT] = [NEW_AW; EXTI_COUNT];
#[cfg(exti_w)]
fn cpu_regs() -> pac::exti::Cpu {
EXTI.cpu(crate::pac::CORE_INDEX)
}
#[cfg(not(exti_w))]
fn cpu_regs() -> pac::exti::Exti {
EXTI
}
#[cfg(not(any(exti_g0, exti_l5, gpio_v1, exti_u5)))]
fn exticr_regs() -> pac::syscfg::Syscfg {
pac::SYSCFG
}
#[cfg(any(exti_g0, exti_l5, exti_u5))]
fn exticr_regs() -> pac::exti::Exti {
EXTI
}
#[cfg(gpio_v1)]
fn exticr_regs() -> pac::afio::Afio {
pac::AFIO
}
pub unsafe fn on_irq() {
#[cfg(not(any(exti_g0, exti_l5, exti_u5)))]
let bits = EXTI.pr(0).read().0;
#[cfg(any(exti_g0, exti_l5, exti_u5))]
let bits = EXTI.rpr(0).read().0 | EXTI.fpr(0).read().0;
// Mask all the channels that fired.
cpu_regs().imr(0).modify(|w| w.0 &= !bits);
// Wake the tasks
for pin in BitIter(bits) {
EXTI_WAKERS[pin as usize].wake();
}
// Clear pending
#[cfg(not(any(exti_g0, exti_l5, exti_u5)))]
EXTI.pr(0).write_value(Lines(bits));
#[cfg(any(exti_g0, exti_l5, exti_u5))]
{
EXTI.rpr(0).write_value(Lines(bits));
EXTI.fpr(0).write_value(Lines(bits));
}
}
struct BitIter(u32);
impl Iterator for BitIter {
type Item = u32;
fn next(&mut self) -> Option<Self::Item> {
match self.0.trailing_zeros() {
32 => None,
b => {
self.0 &= !(1 << b);
Some(b)
}
}
}
}
/// EXTI input driver
pub struct ExtiInput<'d, T: GpioPin> {
pin: Input<'d, T>,
}
impl<'d, T: GpioPin> Unpin for ExtiInput<'d, T> {}
impl<'d, T: GpioPin> ExtiInput<'d, T> {
pub fn new(pin: Input<'d, T>, _ch: impl Unborrow<Target = T::ExtiChannel> + 'd) -> Self {
Self { pin }
}
}
impl<'d, T: GpioPin> InputPin for ExtiInput<'d, T> {
type Error = Infallible;
fn is_high(&self) -> Result<bool, Self::Error> {
self.pin.is_high()
}
fn is_low(&self) -> Result<bool, Self::Error> {
self.pin.is_low()
}
}
impl<'d, T: GpioPin> WaitForRisingEdge for ExtiInput<'d, T> {
type Future<'a> = ExtiInputFuture<'a>;
fn wait_for_rising_edge<'a>(&'a mut self) -> Self::Future<'a> {
ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), true, false)
}
}
impl<'d, T: GpioPin> WaitForFallingEdge for ExtiInput<'d, T> {
type Future<'a> = ExtiInputFuture<'a>;
fn wait_for_falling_edge<'a>(&'a mut self) -> Self::Future<'a> {
ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), false, true)
}
}
impl<'d, T: GpioPin> WaitForAnyEdge for ExtiInput<'d, T> {
type Future<'a> = ExtiInputFuture<'a>;
fn wait_for_any_edge<'a>(&'a mut self) -> Self::Future<'a> {
ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), true, true)
}
}
pub struct ExtiInputFuture<'a> {
pin: u8,
phantom: PhantomData<&'a mut AnyPin>,
}
impl<'a> ExtiInputFuture<'a> {
fn new(pin: u8, port: u8, rising: bool, falling: bool) -> Self {
cortex_m::interrupt::free(|_| unsafe {
let pin = pin as usize;
exticr_regs()
.exticr(pin / 4)
.modify(|w| w.set_exti(pin % 4, port));
EXTI.rtsr(0).modify(|w| w.set_line(pin, rising));
EXTI.ftsr(0).modify(|w| w.set_line(pin, falling));
// clear pending bit
#[cfg(not(any(exti_g0, exti_l5, exti_u5)))]
EXTI.pr(0).write(|w| w.set_line(pin, true));
#[cfg(any(exti_g0, exti_l5, exti_u5))]
{
EXTI.rpr(0).write(|w| w.set_line(pin, true));
EXTI.fpr(0).write(|w| w.set_line(pin, true));
}
cpu_regs().imr(0).modify(|w| w.set_line(pin, true));
});
Self {
pin,
phantom: PhantomData,
}
}
}
impl<'a> Drop for ExtiInputFuture<'a> {
fn drop(&mut self) {
cortex_m::interrupt::free(|_| unsafe {
let pin = self.pin as _;
cpu_regs().imr(0).modify(|w| w.set_line(pin, false));
});
}
}
impl<'a> Future for ExtiInputFuture<'a> {
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
EXTI_WAKERS[self.pin as usize].register(cx.waker());
let imr = unsafe { cpu_regs().imr(0).read() };
if !imr.line(self.pin as _) {
Poll::Ready(())
} else {
Poll::Pending
}
}
}
macro_rules! foreach_exti_irq {
($action:ident) => {
crate::pac::interrupts!(
(EXTI0) => { $action!(EXTI0); };
(EXTI1) => { $action!(EXTI1); };
(EXTI2) => { $action!(EXTI2); };
(EXTI3) => { $action!(EXTI3); };
(EXTI4) => { $action!(EXTI4); };
(EXTI5) => { $action!(EXTI5); };
(EXTI6) => { $action!(EXTI6); };
(EXTI7) => { $action!(EXTI7); };
(EXTI8) => { $action!(EXTI8); };
(EXTI9) => { $action!(EXTI9); };
(EXTI10) => { $action!(EXTI10); };
(EXTI11) => { $action!(EXTI11); };
(EXTI12) => { $action!(EXTI12); };
(EXTI13) => { $action!(EXTI13); };
(EXTI14) => { $action!(EXTI14); };
(EXTI15) => { $action!(EXTI15); };
// plus the weird ones
(EXTI0_1) => { $action!( EXTI0_1 ); };
(EXTI15_10) => { $action!(EXTI15_10); };
(EXTI15_4) => { $action!(EXTI15_4); };
(EXTI1_0) => { $action!(EXTI1_0); };
(EXTI2_3) => { $action!(EXTI2_3); };
(EXTI2_TSC) => { $action!(EXTI2_TSC); };
(EXTI3_2) => { $action!(EXTI3_2); };
(EXTI4_15) => { $action!(EXTI4_15); };
(EXTI9_5) => { $action!(EXTI9_5); };
);
};
}
macro_rules! impl_irq {
($e:ident) => {
#[interrupt]
unsafe fn $e() {
on_irq()
}
};
}
foreach_exti_irq!(impl_irq);
pub(crate) mod sealed {
pub trait Channel {}
}
pub trait Channel: sealed::Channel + Sized {
fn number(&self) -> usize;
fn degrade(self) -> AnyChannel {
AnyChannel {
number: self.number() as u8,
}
}
}
pub struct AnyChannel {
number: u8,
}
unsafe_impl_unborrow!(AnyChannel);
impl sealed::Channel for AnyChannel {}
impl Channel for AnyChannel {
fn number(&self) -> usize {
self.number as usize
}
}
macro_rules! impl_exti {
($type:ident, $number:expr) => {
impl sealed::Channel for peripherals::$type {}
impl Channel for peripherals::$type {
fn number(&self) -> usize {
$number as usize
}
}
};
}
impl_exti!(EXTI0, 0);
impl_exti!(EXTI1, 1);
impl_exti!(EXTI2, 2);
impl_exti!(EXTI3, 3);
impl_exti!(EXTI4, 4);
impl_exti!(EXTI5, 5);
impl_exti!(EXTI6, 6);
impl_exti!(EXTI7, 7);
impl_exti!(EXTI8, 8);
impl_exti!(EXTI9, 9);
impl_exti!(EXTI10, 10);
impl_exti!(EXTI11, 11);
impl_exti!(EXTI12, 12);
impl_exti!(EXTI13, 13);
impl_exti!(EXTI14, 14);
impl_exti!(EXTI15, 15);
macro_rules! enable_irq {
($e:ident) => {
crate::interrupt::$e::steal().enable();
};
}
/// safety: must be called only once
pub(crate) unsafe fn init() {
use embassy::interrupt::Interrupt;
use embassy::interrupt::InterruptExt;
foreach_exti_irq!(enable_irq);
#[cfg(not(any(rcc_wb, rcc_wl5, rcc_f1)))]
<crate::peripherals::SYSCFG as crate::rcc::sealed::RccPeripheral>::enable();
#[cfg(rcc_f1)]
<crate::peripherals::AFIO as crate::rcc::sealed::RccPeripheral>::enable();
}