Add timer

Cargo.toml

@@ -60,10 +60,14 @@ log-semihost = ["log"]
 cortex-m = { version = "^0.7.7", features = ["critical-section-single-core"] }
 stm32h5 = { package = "stm32h5", version = "0.16.0" }
 fugit = "0.3.7"
+embedded-hal-02 = { package = "embedded-hal", version = "0.2.6", features = ["unproven"] }
 embedded-hal = "1.0.0"
 defmt = { version = "1.0.0", optional = true }
 paste = "1.0.15"
 log = { version = "0.4.20", optional = true}
+nb = "1.0.0"
+void = { version = "1.0.2", default-features = false }
+cast = { version = "0.3.0", default-features = false }
 
 [dev-dependencies]
 log = { version = "0.4.20"}
@@ -89,6 +93,10 @@ opt-level = "s" # optimize for binary size
 [[example]]
 name = "blinky"
 
+[[example]]
+name = "blinky_timer"
+required-features = ["stm32h533"]
+
 [[example]]
 name = "i2c"
 required-features = ["stm32h503"]

examples/blinky_timer.rs

@@ -0,0 +1,84 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+mod utilities;
+
+use core::{
+    cell::RefCell,
+    sync::atomic::{AtomicBool, Ordering},
+};
+
+use cortex_m::interrupt::Mutex;
+use cortex_m::peripheral::NVIC;
+use cortex_m_rt::entry;
+
+use stm32h5xx_hal::gpio::gpioa::PA5; // LED pin
+use stm32h5xx_hal::gpio::{Output, PushPull};
+use stm32h5xx_hal::{pac, pac::interrupt, prelude::*, timer};
+use utilities::logger::info;
+
+static LED_IS_ON: AtomicBool = AtomicBool::new(false);
+static LED: Mutex<RefCell<Option<PA5<Output<PushPull>>>>> =
+    Mutex::new(RefCell::new(None));
+static TIMER: Mutex<RefCell<Option<timer::Timer<pac::TIM2>>>> =
+    Mutex::new(RefCell::new(None));
+
+#[entry]
+fn main() -> ! {
+    utilities::logger::init();
+
+    let mut cp = cortex_m::Peripherals::take().unwrap();
+    let dp = pac::Peripherals::take().unwrap();
+
+    let pwr = dp.PWR.constrain();
+    let pwrcfg = pwr.vos0().freeze();
+
+    // Constrain and Freeze clock
+    let rcc = dp.RCC.constrain();
+    let ccdr = rcc.sys_ck(250.MHz()).freeze(pwrcfg, &dp.SBS);
+
+    let gpioa = dp.GPIOA.split(ccdr.peripheral.GPIOA);
+    let mut led = gpioa.pa5.into_push_pull_output();
+    led.set_low();
+
+    let mut timer = dp.TIM2.timer(2.Hz(), ccdr.peripheral.TIM2, &ccdr.clocks);
+    timer.listen(timer::Event::TimeOut);
+
+    cortex_m::interrupt::free(|cs| {
+        LED.borrow(cs).replace(Some(led));
+        TIMER.borrow(cs).replace(Some(timer));
+    });
+
+    info!("Start blinking with timer...");
+    // Enable TIM2 interrupt
+    unsafe {
+        cp.NVIC.set_priority(interrupt::TIM2, 1);
+        NVIC::unmask::<interrupt>(interrupt::TIM2);
+    }
+
+    loop {
+        // do_nothing
+    }
+}
+
+/// Handle timer overflow
+///
+/// The interrupt should be configured at maximum priority, it won't take very long.
+#[interrupt]
+fn TIM2() {
+    cortex_m::interrupt::free(|cs| {
+        if let Some(timer) = TIMER.borrow(cs).borrow_mut().as_mut() {
+            timer.clear_irq();
+        }
+        // Signal that the interrupt fired
+        let led_is_on = LED_IS_ON.fetch_not(Ordering::Relaxed);
+        if let Some(led) = LED.borrow(cs).borrow_mut().as_mut() {
+            if led_is_on {
+                led.set_low();
+            } else {
+                led.set_high();
+            }
+        }
+    })
+}

src/lib.rs

@@ -2,6 +2,9 @@
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![allow(non_camel_case_types)]
 
+pub use nb;
+pub use nb::block;
+
 #[cfg(not(feature = "device-selected"))]
 compile_error!(
     "This crate requires one of the following device features enabled:
@@ -73,6 +76,9 @@ pub mod icache;
 #[cfg(feature = "device-selected")]
 pub mod delay;
 
+#[cfg(feature = "device-selected")]
+pub mod timer;
+
 #[cfg(feature = "device-selected")]
 mod sealed {
     pub trait Sealed {}

src/prelude.rs

@@ -1,11 +1,13 @@
 //! Prelude
+pub use embedded_hal_02::prelude::*;
 
 pub use crate::delay::DelayExt as _stm32h5xx_hal_delay_DelayExt;
 pub use crate::gpio::GpioExt as _stm32h5xx_hal_gpio_GpioExt;
 pub use crate::i2c::I2cExt as _stm32h5xx_hal_i2c_I2cExt;
 pub use crate::icache::ICacheExt as _stm32h5xx_hal_icache_ICacheExt;
 pub use crate::pwr::PwrExt as _stm32h5xx_hal_pwr_PwrExt;
 pub use crate::rcc::RccExt as _stm32h5xx_hal_rcc_RccExt;
+pub use crate::timer::TimerExt as _stm32h5xx_hal_timer_TimerExt;
 
 pub use crate::time::U32Ext as _;
 pub use fugit::{ExtU32 as _, RateExtU32 as _};