WIP: Attempt at DMA traits

src/dma.rs

@@ -0,0 +1,32 @@
+//! DMA Interface
+
+/// Static alias for DMA
+pub type Static<T> = &'static mut T;
+
+/// DMA Errors
+#[derive(Debug)]
+pub enum Error {
+    /// Previous data got overwritten before it could be read because it was
+    /// not accessed in a timely fashion
+    Overrun,
+    /// Transfer error
+    Transfer,
+}
+
+
+/// DMA Transfer future
+pub trait Transfer {
+    /// Return type
+    type Item;
+    /// Return type
+    type Payload;
+
+    /// Get buffer
+    fn deref(&self) -> &Self::Item;
+
+    /// Check completion
+    fn is_done(&self) -> Result<bool, Error>;
+
+    /// Block
+    fn wait(self) -> Result<(Self::Item, Self::Payload), Error>;
+}

src/lib.rs

@@ -607,6 +607,7 @@
 #![deny(missing_docs)]
 #![deny(warnings)]
 #![feature(never_type)]
+#![feature(unsize)]
 #![no_std]
 
 #[macro_use]
@@ -617,6 +618,7 @@ pub mod digital;
 pub mod prelude;
 pub mod serial;
 pub mod spi;
+pub mod dma;
 
 /// Input capture
 ///

src/spi.rs

@@ -1,6 +1,7 @@
 //! Serial Peripheral Interface
-
+use core::marker::Unsize;
 use nb;
+use dma;
 
 /// Full duplex (master mode)
 ///
@@ -33,6 +34,46 @@ pub trait FullDuplex<Word> {
     fn send(&mut self, word: Word) -> nb::Result<(), Self::Error>;
 }
 
+/// DMA Write mode
+pub trait DmaWrite<B, Word>
+where
+    Self: Sized,
+    B: Unsize<[Word]> + 'static
+{
+    /// Sends `words` to the slave.
+    type Transfer: dma::Transfer<Item = &'static mut B, Payload = Self>;
+
+    /// Sends `words` to the slave.
+    fn send_dma(self, words: &'static mut B) -> Self::Transfer;
+}
+
+
+/// DMA Write mode
+pub trait DmaRead<Word> {
+    /// Return type
+    type Transfer: dma::Transfer + ?Sized;
+
+    /// Recieve `words` from the slave.
+    fn recieve_dma<Buffer, Payload>(self, words: &'static mut Buffer) -> Self::Transfer
+    where
+        Buffer: Unsize<[Word]>;
+}
+
+/// DMA Write mode
+pub trait DmaReadWrite<Word> {
+    /// Return type
+    type Transfer: dma::Transfer + ?Sized;
+
+    /// Send and recieve from the slave.
+    fn transfer_dma<Buffer, Payload>(
+        self,
+        tx_words: &'static mut Buffer,
+        rx_words: &'static mut Buffer,
+    ) -> Self::Transfer
+    where
+        Buffer: Unsize<[Word]>;
+}
+
 /// Clock polarity
 #[derive(Clone, Copy, PartialEq)]
 pub enum Polarity {