2025-03-27 15:18:06 +01:00

443 lines
15 KiB
Rust

//! Pin Interrupt module.
use core::cell::RefCell;
use core::future::Future;
use core::pin::Pin as FuturePin;
use core::task::{Context, Poll};
use critical_section::Mutex;
use embassy_sync::waitqueue::AtomicWaker;
use crate::gpio::{self, AnyPin, Level, SealedPin};
use crate::pac::interrupt;
use crate::pac_utils::*;
use crate::Peri;
struct PinInterrupt {
assigned: bool,
waker: AtomicWaker,
/// If true, the interrupt was triggered due to this PinInterrupt. This is used to determine if
/// an [InputFuture] should return Poll::Ready.
at_fault: bool,
}
impl PinInterrupt {
pub fn interrupt_active(&self) -> bool {
self.assigned
}
/// Mark the interrupt as assigned to a pin.
pub fn enable(&mut self) {
self.assigned = true;
self.at_fault = false;
}
/// Mark the interrupt as available.
pub fn disable(&mut self) {
self.assigned = false;
self.at_fault = false;
}
/// Returns true if the interrupt was triggered due to this PinInterrupt.
///
/// If this function returns true, it will also reset the at_fault flag.
pub fn at_fault(&mut self) -> bool {
let val = self.at_fault;
self.at_fault = false;
val
}
/// Set the at_fault flag to true.
pub fn fault(&mut self) {
self.at_fault = true;
}
}
const INTERUPT_COUNT: usize = 8;
static PIN_INTERRUPTS: Mutex<RefCell<[PinInterrupt; INTERUPT_COUNT]>> = Mutex::new(RefCell::new(
[const {
PinInterrupt {
assigned: false,
waker: AtomicWaker::new(),
at_fault: false,
}
}; INTERUPT_COUNT],
));
fn next_available_interrupt() -> Option<usize> {
critical_section::with(|cs| {
for (i, pin_interrupt) in PIN_INTERRUPTS.borrow(cs).borrow().iter().enumerate() {
if !pin_interrupt.interrupt_active() {
return Some(i);
}
}
None
})
}
#[derive(Clone, Copy, PartialEq, Eq)]
enum Edge {
Rising,
Falling,
Both,
}
#[derive(Clone, Copy, PartialEq, Eq)]
enum InterruptOn {
Level(Level),
Edge(Edge),
}
pub(crate) fn init() {
syscon_reg().ahbclkctrl0.modify(|_, w| w.pint().enable());
// Enable interrupts
unsafe {
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT0);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT1);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT2);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT3);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT4);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT5);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT6);
crate::pac::NVIC::unmask(crate::pac::Interrupt::PIN_INT7);
};
}
#[must_use = "futures do nothing unless you `.await` or poll them"]
struct InputFuture<'d> {
#[allow(dead_code)]
pin: Peri<'d, AnyPin>,
interrupt_number: usize,
}
impl<'d> InputFuture<'d> {
/// Create a new input future. Returns None if all interrupts are in use.
fn new(pin: Peri<'d, impl gpio::Pin>, interrupt_on: InterruptOn) -> Option<Self> {
let pin = pin.into();
let interrupt_number = next_available_interrupt()?;
// Clear interrupt, just in case
pint_reg()
.rise
.write(|w| unsafe { w.rdet().bits(1 << interrupt_number) });
pint_reg()
.fall
.write(|w| unsafe { w.fdet().bits(1 << interrupt_number) });
// Enable input multiplexing on pin interrupt register 0 for pin (32*bank + pin_number)
inputmux_reg().pintsel[interrupt_number]
.write(|w| unsafe { w.intpin().bits(32 * pin.pin_bank() as u8 + pin.pin_number()) });
match interrupt_on {
InterruptOn::Level(level) => {
// Set pin interrupt register to edge sensitive or level sensitive
// 0 = edge sensitive, 1 = level sensitive
pint_reg()
.isel
.modify(|r, w| unsafe { w.bits(r.bits() | (1 << interrupt_number)) });
// Enable level interrupt.
//
// Note: Level sensitive interrupts are enabled by the same register as rising edge
// is activated.
// 0 = no-op, 1 = enable
pint_reg()
.sienr
.write(|w| unsafe { w.setenrl().bits(1 << interrupt_number) });
// Set active level
match level {
Level::Low => {
// 0 = no-op, 1 = select LOW
pint_reg()
.cienf
.write(|w| unsafe { w.cenaf().bits(1 << interrupt_number) });
}
Level::High => {
// 0 = no-op, 1 = select HIGH
pint_reg()
.sienf
.write(|w| unsafe { w.setenaf().bits(1 << interrupt_number) });
}
}
}
InterruptOn::Edge(edge) => {
// Set pin interrupt register to edge sensitive or level sensitive
// 0 = edge sensitive, 1 = level sensitive
pint_reg()
.isel
.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << interrupt_number)) });
// Enable rising/falling edge detection
match edge {
Edge::Rising => {
// 0 = no-op, 1 = enable rising edge
pint_reg()
.sienr
.write(|w| unsafe { w.setenrl().bits(1 << interrupt_number) });
// 0 = no-op, 1 = disable falling edge
pint_reg()
.cienf
.write(|w| unsafe { w.cenaf().bits(1 << interrupt_number) });
}
Edge::Falling => {
// 0 = no-op, 1 = enable falling edge
pint_reg()
.sienf
.write(|w| unsafe { w.setenaf().bits(1 << interrupt_number) });
// 0 = no-op, 1 = disable rising edge
pint_reg()
.cienr
.write(|w| unsafe { w.cenrl().bits(1 << interrupt_number) });
}
Edge::Both => {
// 0 = no-op, 1 = enable
pint_reg()
.sienr
.write(|w| unsafe { w.setenrl().bits(1 << interrupt_number) });
pint_reg()
.sienf
.write(|w| unsafe { w.setenaf().bits(1 << interrupt_number) });
}
}
}
}
critical_section::with(|cs| {
let mut pin_interrupts = PIN_INTERRUPTS.borrow(cs).borrow_mut();
let pin_interrupt = &mut pin_interrupts[interrupt_number];
pin_interrupt.enable();
});
Some(Self { pin, interrupt_number })
}
/// Returns true if the interrupt was triggered for this pin.
fn interrupt_triggered(&self) -> bool {
let interrupt_number = self.interrupt_number;
// Initially, we determine if the interrupt was triggered by this InputFuture by checking
// the flags of the interrupt_number. However, by the time we get to this point, the
// interrupt may have been triggered again, so we needed to clear the cpu flags immediately.
// As a solution, we mark which [PinInterrupt] is responsible for the interrupt ("at fault")
critical_section::with(|cs| {
let mut pin_interrupts = PIN_INTERRUPTS.borrow(cs).borrow_mut();
let pin_interrupt = &mut pin_interrupts[interrupt_number];
pin_interrupt.at_fault()
})
}
}
impl<'d> Drop for InputFuture<'d> {
fn drop(&mut self) {
let interrupt_number = self.interrupt_number;
// Disable pin interrupt
// 0 = no-op, 1 = disable
pint_reg()
.cienr
.write(|w| unsafe { w.cenrl().bits(1 << interrupt_number) });
pint_reg()
.cienf
.write(|w| unsafe { w.cenaf().bits(1 << interrupt_number) });
critical_section::with(|cs| {
let mut pin_interrupts = PIN_INTERRUPTS.borrow(cs).borrow_mut();
let pin_interrupt = &mut pin_interrupts[interrupt_number];
pin_interrupt.disable();
});
}
}
impl<'d> Future for InputFuture<'d> {
type Output = ();
fn poll(self: FuturePin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let interrupt_number = self.interrupt_number;
critical_section::with(|cs| {
let mut pin_interrupts = PIN_INTERRUPTS.borrow(cs).borrow_mut();
let pin_interrupt = &mut pin_interrupts[interrupt_number];
pin_interrupt.waker.register(cx.waker());
});
if self.interrupt_triggered() {
Poll::Ready(())
} else {
Poll::Pending
}
}
}
fn handle_interrupt(interrupt_number: usize) {
pint_reg()
.rise
.write(|w| unsafe { w.rdet().bits(1 << interrupt_number) });
pint_reg()
.fall
.write(|w| unsafe { w.fdet().bits(1 << interrupt_number) });
critical_section::with(|cs| {
let mut pin_interrupts = PIN_INTERRUPTS.borrow(cs).borrow_mut();
let pin_interrupt = &mut pin_interrupts[interrupt_number];
pin_interrupt.fault();
pin_interrupt.waker.wake();
});
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT0() {
handle_interrupt(0);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT1() {
handle_interrupt(1);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT2() {
handle_interrupt(2);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT3() {
handle_interrupt(3);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT4() {
handle_interrupt(4);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT5() {
handle_interrupt(5);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT6() {
handle_interrupt(6);
}
#[allow(non_snake_case)]
#[interrupt]
fn PIN_INT7() {
handle_interrupt(7);
}
impl gpio::Flex<'_> {
/// Wait for a falling or rising edge on the pin. You can have at most 8 pins waiting. If you
/// try to wait for more than 8 pins, this function will return `None`.
pub async fn wait_for_any_edge(&mut self) -> Option<()> {
InputFuture::new(self.pin.reborrow(), InterruptOn::Edge(Edge::Both))?.await;
Some(())
}
/// Wait for a falling edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_falling_edge(&mut self) -> Option<()> {
InputFuture::new(self.pin.reborrow(), InterruptOn::Edge(Edge::Falling))?.await;
Some(())
}
/// Wait for a rising edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_rising_edge(&mut self) -> Option<()> {
InputFuture::new(self.pin.reborrow(), InterruptOn::Edge(Edge::Rising))?.await;
Some(())
}
/// Wait for a low level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_low(&mut self) -> Option<()> {
InputFuture::new(self.pin.reborrow(), InterruptOn::Level(Level::Low))?.await;
Some(())
}
/// Wait for a high level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_high(&mut self) -> Option<()> {
InputFuture::new(self.pin.reborrow(), InterruptOn::Level(Level::High))?.await;
Some(())
}
}
impl gpio::Input<'_> {
/// Wait for a falling or rising edge on the pin. You can have at most 8 pins waiting. If you
/// try to wait for more than 8 pins, this function will return `None`.
pub async fn wait_for_any_edge(&mut self) -> Option<()> {
self.pin.wait_for_any_edge().await
}
/// Wait for a falling edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_falling_edge(&mut self) -> Option<()> {
self.pin.wait_for_falling_edge().await
}
/// Wait for a rising edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_rising_edge(&mut self) -> Option<()> {
self.pin.wait_for_rising_edge().await
}
/// Wait for a low level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_low(&mut self) -> Option<()> {
self.pin.wait_for_low().await
}
/// Wait for a high level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_high(&mut self) -> Option<()> {
self.pin.wait_for_high().await
}
}
impl gpio::Output<'_> {
/// Wait for a falling or rising edge on the pin. You can have at most 8 pins waiting. If you
/// try to wait for more than 8 pins, this function will return `None`.
pub async fn wait_for_any_edge(&mut self) -> Option<()> {
self.pin.wait_for_any_edge().await
}
/// Wait for a falling edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_falling_edge(&mut self) -> Option<()> {
self.pin.wait_for_falling_edge().await
}
/// Wait for a rising edge on the pin. You can have at most 8 pins waiting. If you try to wait
/// for more than 8 pins, this function will return `None`.
pub async fn wait_for_rising_edge(&mut self) -> Option<()> {
self.pin.wait_for_rising_edge().await
}
/// Wait for a low level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_low(&mut self) -> Option<()> {
self.pin.wait_for_low().await
}
/// Wait for a high level on the pin. You can have at most 8 pins waiting. If you try to wait for
/// more than 8 pins, this function will return `None`.
pub async fn wait_for_high(&mut self) -> Option<()> {
self.pin.wait_for_high().await
}
}