Add check_interrupt method for GPIO pins

Author: mvirkkunen

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Reexport PAC as `pac` for consistency with other crates, consider `stm32` virtually deprecated
 - Added external interrupt (EXTI) support for output pins
+- Added `check_interrupt` method for GPIO pins
 
 ## [v0.8.3] - 2020-06-12
 

src/gpio.rs

@@ -90,6 +90,7 @@ pub trait ExtiPin {
     fn enable_interrupt(&mut self, exti: &mut EXTI);
     fn disable_interrupt(&mut self, exti: &mut EXTI);
     fn clear_interrupt_pending_bit(&mut self);
+    fn check_interrupt(&self) -> bool;
 }
 
 macro_rules! exti_erased {
@@ -163,6 +164,11 @@ macro_rules! exti_erased {
             fn clear_interrupt_pending_bit(&mut self) {
                 unsafe { (*EXTI::ptr()).pr.write(|w| w.bits(1 << self.i)) };
             }
+
+            /// Reads the interrupt pending bit for this pin
+            fn check_interrupt(&self) -> bool {
+                unsafe { ((*EXTI::ptr()).pr.read().bits() & (1 << self.i)) != 0 }
+            }
         }
     };
 }
@@ -220,6 +226,11 @@ macro_rules! exti {
             fn clear_interrupt_pending_bit(&mut self) {
                 unsafe { (*EXTI::ptr()).pr.write(|w| w.bits(1 << $i)) };
             }
+
+            /// Reads the interrupt pending bit for this pin
+            fn check_interrupt(&self) -> bool {
+                unsafe { ((*EXTI::ptr()).pr.read().bits() & (1 << $i)) != 0 }
+            }
         }
     };
 }