Add InterruptHandler wrapper (#1299)

* Add InterruptHandler

* Which takes the handler and a prio.
* Updates the `#[handler]` macro to create this for us.

* changelog

esp-hal-procmacros/src/lib.rs

@@ -368,6 +368,8 @@ pub fn interrupt(args: TokenStream, input: TokenStream) -> TokenStream {
 pub fn handler(args: TokenStream, input: TokenStream) -> TokenStream {
     use darling::ast::NestedMeta;
     use proc_macro::Span;
+    use proc_macro2::Ident;
+    use proc_macro_crate::{crate_name, FoundCrate};
     use proc_macro_error::abort;
     use syn::{parse::Error as ParseError, spanned::Spanned, ItemFn, ReturnType, Type};
 
@@ -417,10 +419,28 @@ pub fn handler(args: TokenStream, input: TokenStream) -> TokenStream {
         .into();
     }
 
-    f.sig.abi = syn::parse_quote_spanned!(original_span => extern "C");
+    let root = Ident::new(
+        if let Ok(FoundCrate::Name(ref name)) = crate_name("esp-hal") {
+            &name
+        } else {
+            "crate"
+        },
+        Span::call_site().into(),
+    );
 
-    quote::quote_spanned!( original_span =>
+    f.sig.abi = syn::parse_quote_spanned!(original_span => extern "C");
+    let orig = f.sig.ident;
+    f.sig.ident = Ident::new(
+        &format!("__esp_hal_internal_{}", orig),
+        proc_macro2::Span::call_site(),
+    );
+    let new = f.sig.ident.clone();
+
+    quote::quote_spanned!(original_span =>
         #f
+
+        #[allow(non_upper_case_globals)]
+        static #orig: #root::interrupt::InterruptHandler = #root::interrupt::InterruptHandler::new(#new, #root::interrupt::Priority::min());
     )
     .into()
 }

esp-hal/CHANGELOG.md

@@ -65,6 +65,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensuring that the random number generator is TRNG. (#1200)
 - ESP32-C6: Add timer wakeup source for deepsleep (#1201)
 - Introduce `InterruptExecutor::spawner()` (#1211)
+- Add `InterruptHandler` struct, which couples interrupt handlers and their priority together (#1299)
 
 ### Fixed
 

esp-hal/src/gpio.rs

@@ -30,10 +30,13 @@ use procmacros::handler;
 #[cfg(any(adc, dac))]
 pub(crate) use crate::analog;
 pub(crate) use crate::gpio;
-use crate::peripherals::{GPIO, IO_MUX};
 #[cfg(any(xtensa, esp32c3))]
 pub(crate) use crate::rtc_pins;
 pub use crate::soc::gpio::*;
+use crate::{
+    interrupt::InterruptHandler,
+    peripherals::{GPIO, IO_MUX},
+};
 
 /// Convenience type-alias for a no-pin / don't care - pin
 pub type NoPinType = Gpio0<Unknown>;
@@ -41,8 +44,7 @@ pub type NoPinType = Gpio0<Unknown>;
 /// Convenience constant for `Option::None` pin
 pub const NO_PIN: Option<NoPinType> = None;
 
-static USER_INTERRUPT_HANDLER: Mutex<Cell<Option<unsafe extern "C" fn()>>> =
-    Mutex::new(Cell::new(None));
+static USER_INTERRUPT_HANDLER: Mutex<Cell<Option<InterruptHandler>>> = Mutex::new(Cell::new(None));
 
 #[derive(Copy, Clone)]
 pub enum Event {
@@ -1872,9 +1874,9 @@ pub struct IO {
 }
 
 impl IO {
+    /// Initialize the I/O driver.
     pub fn new(mut gpio: GPIO, io_mux: IO_MUX) -> Self {
-        gpio.bind_gpio_interrupt(gpio_interrupt_handler);
-
+        gpio.bind_gpio_interrupt(gpio_interrupt_handler.handler());
         let pins = gpio.split();
 
         IO {
@@ -1883,6 +1885,15 @@ impl IO {
         }
     }
 
+    /// Initialize the I/O driver with a interrupt priority.
+    ///
+    /// This decides the priority for the interrupt when only using async.
+    pub fn new_with_priority(gpio: GPIO, io_mux: IO_MUX, prio: crate::interrupt::Priority) -> Self {
+        crate::interrupt::enable(crate::peripherals::Interrupt::GPIO, prio).unwrap();
+
+        Self::new(gpio, io_mux)
+    }
+
     /// Install the given interrupt handler replacing any previously set
     /// handler.
     ///
@@ -1890,20 +1901,20 @@ impl IO {
     /// the internal async handler will run after. In that case it's
     /// important to not reset the interrupt status when mixing sync and
     /// async (i.e. using async wait) interrupt handling.
-    pub fn set_interrupt_handler(&mut self, handler: unsafe extern "C" fn() -> ()) {
+    pub fn set_interrupt_handler(&mut self, handler: InterruptHandler) {
         critical_section::with(|cs| {
+            crate::interrupt::enable(crate::peripherals::Interrupt::GPIO, handler.priority())
+                .unwrap();
             USER_INTERRUPT_HANDLER.borrow(cs).set(Some(handler));
         });
     }
 }
 
 #[handler]
-unsafe fn gpio_interrupt_handler() {
+fn gpio_interrupt_handler() {
     if let Some(user_handler) = critical_section::with(|cs| USER_INTERRUPT_HANDLER.borrow(cs).get())
     {
-        unsafe {
-            user_handler();
-        }
+        user_handler.call();
     }
 
     #[cfg(feature = "async")]
@@ -3095,7 +3106,6 @@ mod asynch {
     use embedded_hal_async::digital::Wait;
 
     use super::*;
-    use crate::prelude::*;
 
     #[allow(clippy::declare_interior_mutable_const)]
     const NEW_AW: AtomicWaker = AtomicWaker::new();

esp-hal/src/interrupt/mod.rs

@@ -60,3 +60,31 @@ pub use self::xtensa::*;
 mod riscv;
 #[cfg(xtensa)]
 mod xtensa;
+
+/// An interrupt handler
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct InterruptHandler {
+    f: extern "C" fn(),
+    prio: Priority,
+}
+
+impl InterruptHandler {
+    pub const fn new(f: extern "C" fn(), prio: Priority) -> Self {
+        Self { f, prio }
+    }
+
+    #[inline]
+    pub fn handler(&self) -> extern "C" fn() {
+        self.f
+    }
+
+    #[inline]
+    pub fn priority(&self) -> Priority {
+        self.prio
+    }
+
+    #[inline]
+    pub(crate) extern "C" fn call(&self) {
+        (self.f)()
+    }
+}

esp-hal/src/interrupt/riscv.rs

@@ -88,6 +88,7 @@ pub enum CpuInterrupt {
 }
 
 /// Interrupt priority levels.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 #[repr(u8)]
 pub enum Priority {
@@ -118,7 +119,7 @@ pub enum Priority {
 }
 
 impl Priority {
-    pub fn max() -> Priority {
+    pub const fn max() -> Priority {
         cfg_if::cfg_if! {
             if #[cfg(not(clic))] {
                 Priority::Priority15
@@ -128,7 +129,7 @@ impl Priority {
         }
     }
 
-    pub fn min() -> Priority {
+    pub const fn min() -> Priority {
         Priority::Priority1
     }
 }

esp-hal/src/interrupt/xtensa.rs

@@ -241,11 +241,11 @@ mod vectored {
     }
 
     impl Priority {
-        pub fn max() -> Priority {
+        pub const fn max() -> Priority {
             Priority::Priority3
         }
 
-        pub fn min() -> Priority {
+        pub const fn min() -> Priority {
             Priority::Priority1
         }
     }

examples/src/bin/gpio_interrupt.rs

@@ -18,9 +18,8 @@ use esp_hal::{
     clock::ClockControl,
     delay::Delay,
     gpio::{self, Event, Input, PullDown, IO},
-    interrupt::{self, Priority},
     macros::ram,
-    peripherals::{Interrupt, Peripherals},
+    peripherals::Peripherals,
     prelude::*,
 };
 
@@ -46,12 +45,11 @@ fn main() -> ! {
     let mut button = io.pins.gpio0.into_pull_down_input();
     #[cfg(not(any(feature = "esp32", feature = "esp32s2", feature = "esp32s3")))]
     let mut button = io.pins.gpio9.into_pull_down_input();
-    button.listen(Event::FallingEdge);
-
-    critical_section::with(|cs| BUTTON.borrow_ref_mut(cs).replace(button));
-
-    interrupt::enable(Interrupt::GPIO, Priority::Priority2).unwrap();
 
+    critical_section::with(|cs| {
+        button.listen(Event::FallingEdge);
+        BUTTON.borrow_ref_mut(cs).replace(button)
+    });
     led.set_high().unwrap();
 
     // Initialize the Delay peripheral, and use it to toggle the LED state in a