Add embedded_dma feature

Author: qwerty19106

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added `Extend` impls for `Deque`.
 - Added `Deque::make_contiguous`.
 - Added `VecView`, the `!Sized` version of `Vec`.
+- Add `embedded_dma` feature to one can send `Vec`, `pool::object::Object` and `pool::boxed::Box` to DMA as read/write buffers [#362].
 
 ### Changed
 

Cargo.toml

@@ -46,6 +46,10 @@ serde = { version = "1", optional = true, default-features = false }
 ufmt-write = { version = "0.1", optional = true }
 defmt = { version = ">=0.2.0,<0.4", optional = true }
 
+[dependencies.embedded-dma]
+version = "0.2"
+optional = true
+
 # for the pool module
 [target.'cfg(any(target_arch = "arm", target_arch = "x86"))'.dependencies]
 stable_deref_trait = { version = "1", default-features = false }

src/vec.rs

@@ -2078,6 +2078,32 @@ where
     }
 }
 
+#[cfg(feature = "embedded-dma")]
+unsafe impl<T, const N: usize> embedded_dma::ReadTarget for Vec<T, N>
+where
+    T: embedded_dma::ReadTarget,
+{
+    type Word = T::Word;
+
+    // Replace default implementation to return self.len() as buffer size
+    fn as_read_buffer(&self) -> (*const Self::Word, usize) {
+        (self.as_ptr() as *const T::Word, self.len)
+    }
+}
+
+#[cfg(feature = "embedded-dma")]
+unsafe impl<T, const N: usize> embedded_dma::WriteTarget for Vec<T, N>
+where
+    T: embedded_dma::WriteTarget,
+{
+    type Word = T::Word;
+
+    // Replace default implementation to return N as buffer size
+    fn as_write_buffer(&mut self) -> (*mut Self::Word, usize) {
+        (self.as_mut_ptr() as *mut T::Word, N)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::Vec;