rp/timer: add

This commit is contained in:
Dario Nieuwenhuis 2021-07-12 02:45:42 +02:00
parent c210a6efd1
commit 7547c8d8d6
6 changed files with 207 additions and 4 deletions

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@ -3,10 +3,16 @@ use proc_macro2::TokenStream;
use quote::quote;
pub fn generate(embassy_prefix: &ModulePrefix, config: syn::Expr) -> TokenStream {
let embassy_path = embassy_prefix.append("embassy").path();
let embassy_rp_path = embassy_prefix.append("embassy_rp").path();
quote!(
use #embassy_rp_path::{interrupt, peripherals};
let p = #embassy_rp_path::init(#config);
let alarm = unsafe { <#embassy_rp_path::peripherals::TIMER_ALARM0 as #embassy_path::util::Steal>::steal() };
let mut alarm = #embassy_rp_path::timer::Alarm::new(alarm);
let alarm = unsafe { make_static(&mut alarm) };
executor.set_alarm(alarm);
)
}

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@ -22,6 +22,6 @@ cortex-m-rt = "0.6.13"
cortex-m = "0.7.1"
critical-section = "0.2.1"
rp2040-pac2 = { git = "https://github.com/embassy-rs/rp2040-pac2", rev="91fa122b4923fdc02462a39ec109b161aedb29b4", features = ["rt"] }
#rp2040-pac2 = { path = "../../rp/rp2040-pac2" }
rp2040-pac2 = { git = "https://github.com/embassy-rs/rp2040-pac2", rev="2ce29ba58ad904d3995ce65bb46807e853f1fbf9", features = ["rt"] }
#rp2040-pac2 = { path = "../../rp/rp2040-pac2", features = ["rt"] }
embedded-hal = { version = "0.2.4", features = [ "unproven" ] }

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@ -4,6 +4,7 @@ use crate::{pac, reset};
const XOSC_MHZ: u32 = 12;
/// safety: must be called exactly once at bootup
pub unsafe fn init() {
// Reset everything except:
// - QSPI (we're using it to run this code!)

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@ -11,10 +11,12 @@ pub use rp2040_pac2 as pac;
pub(crate) mod fmt;
pub mod interrupt;
pub use embassy_macros::interrupt;
pub mod dma;
pub mod gpio;
pub mod spi;
pub mod timer;
pub mod uart;
mod clocks;
@ -64,6 +66,11 @@ embassy_extras::peripherals! {
SPI0,
SPI1,
TIMER_ALARM0,
TIMER_ALARM1,
TIMER_ALARM2,
TIMER_ALARM3,
DMA_CH0,
DMA_CH1,
DMA_CH2,
@ -100,6 +107,7 @@ pub fn init(_config: config::Config) -> Peripherals {
unsafe {
clocks::init();
timer::init();
}
peripherals

187
embassy-rp/src/timer.rs Normal file
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@ -0,0 +1,187 @@
use core::cell::Cell;
use critical_section::CriticalSection;
use embassy::interrupt::{Interrupt, InterruptExt};
use embassy::util::CriticalSectionMutex as Mutex;
use crate::{interrupt, pac};
struct AlarmState {
timestamp: Cell<u64>,
callback: Cell<Option<(fn(*mut ()), *mut ())>>,
}
unsafe impl Send for AlarmState {}
const ALARM_COUNT: usize = 4;
const DUMMY_ALARM: AlarmState = AlarmState {
timestamp: Cell::new(0),
callback: Cell::new(None),
};
static ALARMS: Mutex<[AlarmState; ALARM_COUNT]> = Mutex::new([DUMMY_ALARM; ALARM_COUNT]);
fn now() -> u64 {
loop {
unsafe {
let hi = pac::TIMER.timerawh().read();
let lo = pac::TIMER.timerawl().read();
let hi2 = pac::TIMER.timerawh().read();
if hi == hi2 {
return (hi as u64) << 32 | (lo as u64);
}
}
}
}
struct Timer;
impl embassy::time::Clock for Timer {
fn now(&self) -> u64 {
now()
}
}
pub trait AlarmInstance {
fn alarm_num(&self) -> usize;
}
impl AlarmInstance for crate::peripherals::TIMER_ALARM0 {
fn alarm_num(&self) -> usize {
0
}
}
impl AlarmInstance for crate::peripherals::TIMER_ALARM1 {
fn alarm_num(&self) -> usize {
1
}
}
impl AlarmInstance for crate::peripherals::TIMER_ALARM2 {
fn alarm_num(&self) -> usize {
2
}
}
impl AlarmInstance for crate::peripherals::TIMER_ALARM3 {
fn alarm_num(&self) -> usize {
3
}
}
pub struct Alarm<T: AlarmInstance> {
inner: T,
}
impl<T: AlarmInstance> Alarm<T> {
pub fn new(inner: T) -> Self {
Self { inner }
}
}
impl<T: AlarmInstance> embassy::time::Alarm for Alarm<T> {
fn set_callback(&self, callback: fn(*mut ()), ctx: *mut ()) {
let n = self.inner.alarm_num();
critical_section::with(|cs| {
let alarm = &ALARMS.borrow(cs)[n];
alarm.callback.set(Some((callback, ctx)));
})
}
fn set(&self, timestamp: u64) {
let n = self.inner.alarm_num();
critical_section::with(|cs| {
let alarm = &ALARMS.borrow(cs)[n];
alarm.timestamp.set(timestamp);
// Arm it.
// Note that we're not checking the high bits at all. This means the irq may fire early
// if the alarm is more than 72 minutes (2^32 us) in the future. This is OK, since on irq fire
// it is checked if the alarm time has passed.
unsafe { pac::TIMER.alarm(n).write_value(timestamp as u32) };
let now = now();
// If alarm timestamp has passed, trigger it instantly.
// This disarms it.
if timestamp <= now {
trigger_alarm(n, cs);
}
})
}
fn clear(&self) {
self.set(u64::MAX);
}
}
fn check_alarm(n: usize) {
critical_section::with(|cs| {
let alarm = &ALARMS.borrow(cs)[n];
let timestamp = alarm.timestamp.get();
if timestamp <= now() {
trigger_alarm(n, cs)
} else {
// Not elapsed, arm it again.
// This can happen if it was set more than 2^32 us in the future.
unsafe { pac::TIMER.alarm(n).write_value(timestamp as u32) };
}
});
// clear the irq
unsafe { pac::TIMER.intr().write(|w| w.set_alarm(n, true)) }
}
fn trigger_alarm(n: usize, cs: CriticalSection) {
// disarm
unsafe { pac::TIMER.armed().write(|w| w.set_armed(1 << n)) }
let alarm = &ALARMS.borrow(cs)[n];
alarm.timestamp.set(u64::MAX);
// Call after clearing alarm, so the callback can set another alarm.
if let Some((f, ctx)) = alarm.callback.get() {
f(ctx);
}
}
/// safety: must be called exactly once at bootup
pub unsafe fn init() {
// init alarms
critical_section::with(|cs| {
let alarms = ALARMS.borrow(cs);
for a in alarms {
a.timestamp.set(u64::MAX);
}
});
// enable all irqs
pac::TIMER.inte().write(|w| {
w.set_alarm(0, true);
w.set_alarm(1, true);
w.set_alarm(2, true);
w.set_alarm(3, true);
});
interrupt::TIMER_IRQ_0::steal().enable();
interrupt::TIMER_IRQ_1::steal().enable();
interrupt::TIMER_IRQ_2::steal().enable();
interrupt::TIMER_IRQ_3::steal().enable();
embassy::time::set_clock(&Timer);
}
#[interrupt]
unsafe fn TIMER_IRQ_0() {
check_alarm(0)
}
#[interrupt]
unsafe fn TIMER_IRQ_1() {
check_alarm(1)
}
#[interrupt]
unsafe fn TIMER_IRQ_2() {
check_alarm(2)
}
#[interrupt]
unsafe fn TIMER_IRQ_3() {
check_alarm(3)
}

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@ -11,6 +11,7 @@ mod example_common;
use defmt::*;
use embassy::executor::Spawner;
use embassy::time::{Duration, Timer};
use embassy_rp::{gpio, Peripherals};
use gpio::{Level, Output};
@ -21,10 +22,10 @@ async fn main(_spawner: Spawner, p: Peripherals) {
loop {
info!("led on!");
led.set_high();
cortex_m::asm::delay(1_000_000);
Timer::after(Duration::from_secs(1)).await;
info!("led off!");
led.set_low();
cortex_m::asm::delay(1_000_000);
Timer::after(Duration::from_secs(1)).await;
}
}