Allow the underlying interface to be released consuming the DisplayProperties

src/interface/i2c.rs

@@ -26,6 +26,7 @@ where
     I2C: hal::blocking::i2c::Write<Error = CommE>,
 {
     type Error = Error<CommE, ()>;
+    type Interface = I2C;
 
     fn init(&mut self) -> Result<(), Self::Error> {
         Ok(())
@@ -82,4 +83,8 @@ where
 
         Ok(())
     }
+
+    fn release(self) -> Self::Interface {
+        self.i2c
+    }
 }

src/interface/mod.rs

@@ -55,13 +55,17 @@ pub mod spi;
 pub trait DisplayInterface {
     /// Interface error type
     type Error;
+    /// Underlying interface type
+    type Interface;
 
     /// Initialize device.
     fn init(&mut self) -> Result<(), Self::Error>;
     /// Send a batch of up to 8 commands to display.
     fn send_commands(&mut self, cmd: &[u8]) -> Result<(), Self::Error>;
     /// Send data to display.
     fn send_data(&mut self, buf: &[u8]) -> Result<(), Self::Error>;
+    /// Release the interface
+    fn release(self) -> Self::Interface;
 }
 
 pub use self::{i2c::I2cInterface, spi::SpiInterface};

src/interface/spi.rs

@@ -33,6 +33,7 @@ where
     CS: OutputPin<Error = PinE>,
 {
     type Error = Error<CommE, PinE>;
+    type Interface = (SPI, DC, CS);
 
     fn init(&mut self) -> Result<(), Self::Error> {
         self.cs.set_high().map_err(Error::Pin)
@@ -58,4 +59,9 @@ where
 
         self.cs.set_high().map_err(Error::Pin)
     }
+
+    fn release(self) -> Self::Interface {
+        (self.spi, self.dc, self.cs)
+    }
+
 }

src/properties.rs

@@ -167,4 +167,9 @@ where
     pub fn set_contrast(&mut self, contrast: u8) -> Result<(), DI::Error> {
         Command::Contrast(contrast).send(&mut self.iface)
     }
+
+    /// Release the underlying interface
+    pub fn release_interface(self) -> DI::Interface {
+        self.iface.release()
+    }
 }