Add gpio::Exti::is_pending

Author: newAM

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Added
+- Added a `is_pending` method to the `gpio::Exti` trait.
+
 ## [0.3.0] - 2021-12-20
 ### Added
 - Added `info::Core::CT` to get the CPU core at compile time.

examples/examples/gpio-button-irq.rs

@@ -17,6 +17,7 @@ fn main() -> ! {
 
     let gpioc: PortC = PortC::split(dp.GPIOC, &mut dp.RCC);
     let _c6: Input<pins::C6> = cortex_m::interrupt::free(|cs| Input::new(gpioc.c6, Pull::Up, cs));
+    defmt::assert!(!pins::C6::is_pending());
 
     pins::C6::setup_exti_c1(&mut dp.EXTI, &mut dp.SYSCFG, ExtiTrg::Both);
     unsafe { pins::C6::unmask() };
@@ -30,5 +31,6 @@ fn main() -> ! {
 #[allow(non_snake_case)]
 fn EXTI9_5() {
     defmt::info!("B3 pressed or released!");
+    defmt::assert!(pins::C6::is_pending());
     pins::C6::clear_exti();
 }

hal/src/gpio.rs

@@ -370,6 +370,15 @@ pub trait Exti {
     /// [`gpio-button-irq.rs`]: https://github.com/stm32-rs/stm32wlxx-hal/blob/main/examples/examples/gpio-button-irq.rs
     fn clear_exti();
 
+    /// Returns true if a trigger request occured.
+    ///
+    /// # Example
+    ///
+    /// See [`gpio-button-irq.rs`].
+    ///
+    /// [`gpio-button-irq.rs`]: https://github.com/stm32-rs/stm32wlxx-hal/blob/main/examples/examples/gpio-button-irq.rs
+    fn is_pending() -> bool;
+
     /// Setup an input pin as an EXTI interrupt source on core 1.
     ///
     /// This is a helper function that wraps:
@@ -757,6 +766,12 @@ pub mod pins {
                         // safety: atomic write with no side effects
                         unsafe { (*pac::EXTI::PTR).pr1.write(|w| w.[<pif $n>]().set_bit()) }
                     }
+
+                    #[inline]
+                    fn is_pending() -> bool {
+                        // safety: atomic read with no side effects
+                        unsafe { (*pac::EXTI::PTR).pr1.read().[<pif $n>]().bit_is_set() }
+                    }
                 }
             }
         };