20 files changed, 53 insertions, 22 deletions

diff --git a/.cargo/config b/.cargo/config
new file mode 100644
index 000000000..a14129b9d
--- /dev/null
+++ b/.cargo/config
@@ -0,0 +1,2 @@
+[unstable]
+namespaced-features = true
diff --git a/Cargo.toml b/Cargo.toml
index 4feeb2624..80ae93745 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 [workspace]
 members = [
     "embassy",
+    "embassy-traits",
     "embassy-nrf",
     "embassy-stm32f4",
     "embassy-nrf-examples",
diff --git a/README.md b/README.md
index 0f1cb1be5..3cf1b61fa 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ Embassy is a project to make async/await a first-class option for embedded devel
 `embassy` provides a set of traits and types specifically designed for `async` usage.
 
 - `embassy::io`: `AsyncBufRead`, `AsyncWrite`. Traits for byte-stream IO, essentially `no_std` compatible versions of `futures::io`.
-- `embassy::flash`: Flash device trait.
+- `embassy::traits::flash`: Flash device trait.
 - `embassy::time`: `Clock` and `Alarm` traits. Std-like `Duration` and `Instant`.
 - More traits for SPI, I2C, UART async HAL coming soon.
 
diff --git a/embassy-nrf-examples/src/bin/gpiote_port.rs b/embassy-nrf-examples/src/bin/gpiote_port.rs
index 0f1637faf..ccb5bb97c 100644
--- a/embassy-nrf-examples/src/bin/gpiote_port.rs
+++ b/embassy-nrf-examples/src/bin/gpiote_port.rs
@@ -12,7 +12,7 @@ use defmt::panic;
 use nrf52840_hal::gpio;
 
 use embassy::executor::{task, Executor};
-use embassy::gpio::{WaitForHigh, WaitForLow};
+use embassy::traits::gpio::{WaitForHigh, WaitForLow};
 use embassy::util::Forever;
 use embassy_nrf::gpiote::{Gpiote, GpiotePin};
 use embassy_nrf::interrupt;
diff --git a/embassy-nrf-examples/src/bin/qspi.rs b/embassy-nrf-examples/src/bin/qspi.rs
index 790dedc91..587ed7ddb 100644
--- a/embassy-nrf-examples/src/bin/qspi.rs
+++ b/embassy-nrf-examples/src/bin/qspi.rs
@@ -12,7 +12,7 @@ use futures::pin_mut;
 use nrf52840_hal::gpio;
 
 use embassy::executor::{task, Executor};
-use embassy::flash::Flash;
+use embassy::traits::flash::Flash;
 use embassy::util::Forever;
 use embassy_nrf::{interrupt, qspi};
 
diff --git a/embassy-nrf-examples/src/bin/uart.rs b/embassy-nrf-examples/src/bin/uart.rs
index 50cdfd1e6..41f9e1276 100644
--- a/embassy-nrf-examples/src/bin/uart.rs
+++ b/embassy-nrf-examples/src/bin/uart.rs
@@ -10,7 +10,7 @@ use cortex_m_rt::entry;
 use defmt::panic;
 use embassy::executor::{task, Executor};
 use embassy::time::{Duration, Timer};
-use embassy::uart::Uart;
+use embassy::traits::uart::Uart;
 use embassy::util::Forever;
 use embassy_nrf::{interrupt, pac, rtc, uarte};
 use futures::future::{select, Either};
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index 78bb2aeb6..7cc649107 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -4,7 +4,7 @@ use core::ops::Deref;
 use core::pin::Pin;
 use core::ptr;
 use core::task::{Context, Poll};
-use embassy::gpio::{WaitForHigh, WaitForLow};
+use embassy::traits::gpio::{WaitForHigh, WaitForLow};
 use embassy::interrupt::InterruptExt;
 use embassy::util::Signal;
 
diff --git a/embassy-nrf/src/qspi.rs b/embassy-nrf/src/qspi.rs
index bee6abfa1..cb7f5a5be 100644
--- a/embassy-nrf/src/qspi.rs
+++ b/embassy-nrf/src/qspi.rs
@@ -23,7 +23,7 @@ use crate::util::peripheral::{PeripheralMutex, PeripheralState};
 // - activate/deactivate
 // - set gpio in high drive
 
-use embassy::flash::{Error, Flash};
+use embassy::traits::flash::{Error, Flash};
 use embassy::util::{DropBomb, WakerRegistration};
 use futures::future::poll_fn;
 
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index 9d5ff81aa..0cc9790b2 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -207,7 +207,7 @@ where
     }
 }
 
-impl<T: Instance> embassy::uart::Uart for Uarte<T> {
+impl<T: Instance> embassy::traits::uart::Uart for Uarte<T> {
     type ReceiveFuture<'a> = ReceiveFuture<'a, T>;
     type SendFuture<'a> = SendFuture<'a, T>;
 
@@ -287,7 +287,7 @@ impl<'a, T> Future for SendFuture<'a, T>
 where
     T: Instance,
 {
-    type Output = Result<(), embassy::uart::Error>;
+    type Output = Result<(), embassy::traits::uart::Error>;
 
     fn poll(self: core::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let Self { uarte, buf } = unsafe { self.get_unchecked_mut() };
@@ -355,7 +355,7 @@ impl<'a, T> Future for ReceiveFuture<'a, T>
 where
     T: Instance,
 {
-    type Output = Result<(), embassy::uart::Error>;
+    type Output = Result<(), embassy::traits::uart::Error>;
 
     fn poll(self: core::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let Self { uarte, buf } = unsafe { self.get_unchecked_mut() };
diff --git a/embassy-stm32f4-examples/src/bin/exti.rs b/embassy-stm32f4-examples/src/bin/exti.rs
index d8de33816..6b3568d65 100644
--- a/embassy-stm32f4-examples/src/bin/exti.rs
+++ b/embassy-stm32f4-examples/src/bin/exti.rs
@@ -9,7 +9,7 @@ use example_common::{panic, *};
 
 use cortex_m_rt::entry;
 use embassy::executor::{task, Executor};
-use embassy::gpio::*;
+use embassy::traits::gpio::*;
 use embassy::util::Forever;
 use embassy_stm32f4::exti;
 use embassy_stm32f4::interrupt;
diff --git a/embassy-stm32f4-examples/src/bin/serial.rs b/embassy-stm32f4-examples/src/bin/serial.rs
index 2cd1c8c35..72fd1a2f9 100644
--- a/embassy-stm32f4-examples/src/bin/serial.rs
+++ b/embassy-stm32f4-examples/src/bin/serial.rs
@@ -10,7 +10,7 @@ use example_common::{panic, *};
 use cortex_m::singleton;
 use cortex_m_rt::entry;
 use embassy::executor::{task, Executor};
-use embassy::uart::Uart;
+use embassy::traits::uart::Uart;
 use embassy::util::Forever;
 use embassy_stm32f4::interrupt;
 use embassy_stm32f4::serial;
diff --git a/embassy-stm32f4/src/exti.rs b/embassy-stm32f4/src/exti.rs
index 6a1e13000..7ec2197ef 100644
--- a/embassy-stm32f4/src/exti.rs
+++ b/embassy-stm32f4/src/exti.rs
@@ -2,8 +2,8 @@ use core::future::Future;
 use core::mem;
 use core::pin::Pin;
 
-use embassy::gpio::{WaitForFallingEdge, WaitForRisingEdge};
 use embassy::interrupt::Interrupt;
+use embassy::traits::gpio::{WaitForFallingEdge, WaitForRisingEdge};
 use embassy::util::InterruptFuture;
 
 use crate::hal::gpio;
diff --git a/embassy-stm32f4/src/serial.rs b/embassy-stm32f4/src/serial.rs
index 8f594ca13..8a90e9fa3 100644
--- a/embassy-stm32f4/src/serial.rs
+++ b/embassy-stm32f4/src/serial.rs
@@ -9,7 +9,7 @@ use core::ptr;
 use core::sync::atomic::{self, Ordering};
 
 use embassy::interrupt::InterruptExt;
-use embassy::uart::{Error, Uart};
+use embassy::traits::uart::{Error, Uart};
 use embassy::util::Signal;
 
 use crate::hal::dma::config::DmaConfig;
diff --git a/embassy-traits/Cargo.toml b/embassy-traits/Cargo.toml
new file mode 100644
index 000000000..09db74ab9
--- /dev/null
+++ b/embassy-traits/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "embassy-traits"
+version = "0.1.0"
+authors = ["Dario Nieuwenhuis <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+defmt = { version = "0.2.0", optional = true }
+
+[features]
+std = []
+
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []
\ No newline at end of file
diff --git a/embassy/src/flash.rs b/embassy-traits/src/flash.rs
index 145cc7684..145cc7684 100644
--- a/embassy/src/flash.rs
+++ b/embassy-traits/src/flash.rs
diff --git a/embassy/src/gpio.rs b/embassy-traits/src/gpio.rs
index 4c3feac21..4c3feac21 100644
--- a/embassy/src/gpio.rs
+++ b/embassy-traits/src/gpio.rs
diff --git a/embassy-traits/src/lib.rs b/embassy-traits/src/lib.rs
new file mode 100644
index 000000000..55af46cff
--- /dev/null
+++ b/embassy-traits/src/lib.rs
@@ -0,0 +1,10 @@
+#![cfg_attr(not(feature = "std"), no_std)]
+#![feature(generic_associated_types)]
+#![feature(const_fn)]
+#![feature(const_fn_fn_ptr_basics)]
+#![feature(const_option)]
+#![allow(incomplete_features)]
+
+pub mod flash;
+pub mod gpio;
+pub mod uart;
diff --git a/embassy/src/uart.rs b/embassy-traits/src/uart.rs
index b40b9e9bd..b40b9e9bd 100644
--- a/embassy/src/uart.rs
+++ b/embassy-traits/src/uart.rs
diff --git a/embassy/Cargo.toml b/embassy/Cargo.toml
index 1c977d84d..116ab2245 100644
--- a/embassy/Cargo.toml
+++ b/embassy/Cargo.toml
@@ -5,12 +5,13 @@ authors = ["Dario Nieuwenhuis <[email protected]>"]
 edition = "2018"
 
 [features]
-std = ["futures/std"]
-defmt-trace = []
-defmt-debug = []
-defmt-info = []
-defmt-warn = []
-defmt-error = []
+std = ["futures/std", "embassy-traits/std"]
+defmt = ["embassy-traits/defmt", "dep:defmt"]
+defmt-trace = ["embassy-traits/defmt-trace"]
+defmt-debug = ["embassy-traits/defmt-debug"]
+defmt-info = ["embassy-traits/defmt-info"]
+defmt-warn = ["embassy-traits/defmt-warn"]
+defmt-error = ["embassy-traits/defmt-error"]
 
 [dependencies]
 defmt = { version = "0.2.0", optional = true }
@@ -20,4 +21,5 @@ cortex-m = "0.7.1"
 futures     = { version = "0.3.5", default-features = false }
 pin-project = { version = "1.0.2", default-features = false }
 embassy-macros  = { version = "0.1.0", path = "../embassy-macros"}
+embassy-traits  = { version = "0.1.0", path = "../embassy-traits"}
 
diff --git a/embassy/src/lib.rs b/embassy/src/lib.rs
index 0844df37c..f32a7a795 100644
--- a/embassy/src/lib.rs
+++ b/embassy/src/lib.rs
@@ -9,10 +9,9 @@
 pub(crate) mod fmt;
 
 pub mod executor;
-pub mod flash;
-pub mod gpio;
 pub mod interrupt;
 pub mod io;
 pub mod time;
-pub mod uart;
 pub mod util;
+
+pub use embassy_traits as traits;