gpio: Add embedded-hal implementation (#33)

This adds the implementation of the embedded-hal traits for the various
GPIO struct definitions.

Author: astapleton

src/gpio.rs

@@ -59,6 +59,7 @@ mod dynamic;
 mod erased;
 mod exti;
 mod gpio_def;
+mod hal;
 mod partially_erased;
 
 use core::{fmt, marker::PhantomData};

src/gpio/hal.rs

@@ -0,0 +1,182 @@
+use core::convert::Infallible;
+
+use super::{
+    dynamic::PinModeError, marker, DynamicPin, ErasedPin, Output,
+    PartiallyErasedPin, Pin,
+};
+
+use embedded_hal::digital::{
+    Error, ErrorKind, ErrorType, InputPin, OutputPin, StatefulOutputPin,
+};
+
+// Implementations for `Pin`
+
+impl<const P: char, const N: u8, MODE> ErrorType for Pin<P, N, MODE> {
+    type Error = Infallible;
+}
+
+impl<const P: char, const N: u8, MODE> OutputPin for Pin<P, N, Output<MODE>> {
+    #[inline(always)]
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        self.set_high();
+        Ok(())
+    }
+
+    #[inline(always)]
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        self.set_low();
+        Ok(())
+    }
+}
+
+impl<const P: char, const N: u8, MODE> StatefulOutputPin
+    for Pin<P, N, Output<MODE>>
+{
+    #[inline(always)]
+    fn is_set_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_high())
+    }
+
+    #[inline(always)]
+    fn is_set_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_low())
+    }
+}
+
+impl<const P: char, const N: u8, MODE> InputPin for Pin<P, N, MODE>
+where
+    MODE: marker::Readable,
+{
+    #[inline(always)]
+    fn is_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_high())
+    }
+
+    #[inline(always)]
+    fn is_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_low())
+    }
+}
+
+// Implementations for `ErasedPin`
+impl<MODE> ErrorType for ErasedPin<MODE> {
+    type Error = Infallible;
+}
+
+impl<MODE> OutputPin for ErasedPin<Output<MODE>> {
+    #[inline(always)]
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        self.set_high();
+        Ok(())
+    }
+
+    #[inline(always)]
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        self.set_low();
+        Ok(())
+    }
+}
+
+impl<MODE> StatefulOutputPin for ErasedPin<Output<MODE>> {
+    #[inline(always)]
+    fn is_set_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_high())
+    }
+
+    #[inline(always)]
+    fn is_set_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_low())
+    }
+}
+
+impl<MODE> InputPin for ErasedPin<MODE>
+where
+    MODE: marker::Readable,
+{
+    #[inline(always)]
+    fn is_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_high())
+    }
+
+    #[inline(always)]
+    fn is_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_low())
+    }
+}
+
+// Implementations for `PartiallyErasedPin`
+impl<const P: char, MODE> ErrorType for PartiallyErasedPin<P, MODE> {
+    type Error = Infallible;
+}
+
+impl<const P: char, MODE> OutputPin for PartiallyErasedPin<P, Output<MODE>> {
+    #[inline(always)]
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        self.set_high();
+        Ok(())
+    }
+
+    #[inline(always)]
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        self.set_low();
+        Ok(())
+    }
+}
+
+impl<const P: char, MODE> StatefulOutputPin
+    for PartiallyErasedPin<P, Output<MODE>>
+{
+    #[inline(always)]
+    fn is_set_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_high())
+    }
+
+    #[inline(always)]
+    fn is_set_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(self.is_set_low())
+    }
+}
+
+impl<const P: char, MODE> InputPin for PartiallyErasedPin<P, MODE>
+where
+    MODE: marker::Readable,
+{
+    #[inline(always)]
+    fn is_high(&mut self) -> Result<bool, Self::Error> {
+        Ok(PartiallyErasedPin::is_high(self))
+    }
+
+    #[inline(always)]
+    fn is_low(&mut self) -> Result<bool, Self::Error> {
+        Ok(PartiallyErasedPin::is_low(self))
+    }
+}
+
+impl Error for PinModeError {
+    fn kind(&self) -> ErrorKind {
+        ErrorKind::Other
+    }
+}
+
+// Implementations for `DynamicPin`
+impl<const P: char, const N: u8> ErrorType for DynamicPin<P, N> {
+    type Error = PinModeError;
+}
+
+impl<const P: char, const N: u8> OutputPin for DynamicPin<P, N> {
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        self.set_high()
+    }
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        self.set_low()
+    }
+}
+
+impl<const P: char, const N: u8> InputPin for DynamicPin<P, N> {
+    fn is_high(&mut self) -> Result<bool, Self::Error> {
+        DynamicPin::is_high(self)
+    }
+    fn is_low(&mut self) -> Result<bool, Self::Error> {
+        DynamicPin::is_low(self)
+    }
+}