From d47c61830a3c975982b1c62048c304985e1cfefc Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Mon, 27 Nov 2017 04:30:39 +0100
Subject: [PATCH] blocking SPI API

---
 src/blocking/mod.rs |  3 +++
 src/blocking/spi.rs | 16 ++++++++++++++++
 src/lib.rs          |  2 ++
 3 files changed, 21 insertions(+)
 create mode 100644 src/blocking/mod.rs
 create mode 100644 src/blocking/spi.rs

diff --git a/src/blocking/mod.rs b/src/blocking/mod.rs
new file mode 100644
index 000000000..16d090086
--- /dev/null
+++ b/src/blocking/mod.rs
@@ -0,0 +1,3 @@
+//! Blocking API
+
+pub mod spi;
diff --git a/src/blocking/spi.rs b/src/blocking/spi.rs
new file mode 100644
index 000000000..326b6f78c
--- /dev/null
+++ b/src/blocking/spi.rs
@@ -0,0 +1,16 @@
+//! Blocking SPI API
+
+use Spi;
+
+/// Transfers bytes to the slave, returns the bytes received from the slave
+pub fn transfer<'a, S>(spi: &mut S, bytes: &'a mut [u8]) -> Result<&'a [u8], S::Error>
+where
+    S: Spi<u8>,
+{
+    for byte in bytes.iter_mut() {
+        block!(spi.send(*byte))?;
+        *byte = block!(spi.read())?;
+    }
+
+    Ok(bytes)
+}
diff --git a/src/lib.rs b/src/lib.rs
index 4e8644671..2ffd701c1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -609,8 +609,10 @@
 #![feature(never_type)]
 #![no_std]
 
+#[macro_use]
 extern crate nb;
 
+pub mod blocking;
 pub mod prelude;
 pub mod serial;