feat(rp): add Wait impl to OutputOpenDrain

A while ago `OutputOpenDrain` was made to implement `InputPin`,
something that allowed drivers for various one-wire protocols to be
written, but it's been lacking a `Wait` implementation — something
that's needed to write async versions of these drivers.

This commit also adds `get_level()` to `OutputOpenDrain`, since
`is_high()` and `is_low()` were already implemented, but `get_level()`
itself was missing.

embassy-rp/src/gpio.rs

@@ -437,6 +437,37 @@ impl<'d, T: Pin> OutputOpenDrain<'d, T> {
     pub fn is_low(&self) -> bool {
         self.pin.is_low()
     }
+
+    /// Returns current pin level
+    #[inline]
+    pub fn get_level(&self) -> Level {
+        self.is_high().into()
+    }
+
+    #[inline]
+    pub async fn wait_for_high(&mut self) {
+        self.pin.wait_for_high().await;
+    }
+
+    #[inline]
+    pub async fn wait_for_low(&mut self) {
+        self.pin.wait_for_low().await;
+    }
+
+    #[inline]
+    pub async fn wait_for_rising_edge(&mut self) {
+        self.pin.wait_for_rising_edge().await;
+    }
+
+    #[inline]
+    pub async fn wait_for_falling_edge(&mut self) {
+        self.pin.wait_for_falling_edge().await;
+    }
+
+    #[inline]
+    pub async fn wait_for_any_edge(&mut self) {
+        self.pin.wait_for_any_edge().await;
+    }
 }
 
 /// GPIO flexible pin.
@@ -1117,4 +1148,32 @@ mod eh1 {
             Ok(())
         }
     }
+
+    #[cfg(feature = "nightly")]
+    impl<'d, T: Pin> embedded_hal_async::digital::Wait for OutputOpenDrain<'d, T> {
+        async fn wait_for_high(&mut self) -> Result<(), Self::Error> {
+            self.wait_for_high().await;
+            Ok(())
+        }
+
+        async fn wait_for_low(&mut self) -> Result<(), Self::Error> {
+            self.wait_for_low().await;
+            Ok(())
+        }
+
+        async fn wait_for_rising_edge(&mut self) -> Result<(), Self::Error> {
+            self.wait_for_rising_edge().await;
+            Ok(())
+        }
+
+        async fn wait_for_falling_edge(&mut self) -> Result<(), Self::Error> {
+            self.wait_for_falling_edge().await;
+            Ok(())
+        }
+
+        async fn wait_for_any_edge(&mut self) -> Result<(), Self::Error> {
+            self.wait_for_any_edge().await;
+            Ok(())
+        }
+    }
 }