5 files changed, 103 insertions, 161 deletions

diff --git a/embassy-embedded-hal/Cargo.toml b/embassy-embedded-hal/Cargo.toml
index 85ee856a6..fa74be8c4 100644
--- a/embassy-embedded-hal/Cargo.toml
+++ b/embassy-embedded-hal/Cargo.toml
@@ -20,7 +20,7 @@ nightly = ["embedded-hal-async", "embedded-storage-async"]
 embassy-sync = { version = "0.1.0", path = "../embassy-sync" }
 embedded-hal-02 = { package = "embedded-hal", version = "0.2.6", features = ["unproven"] }
 embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-alpha.9" }
-embedded-hal-async = { version = "=0.1.0-alpha.3", optional = true }
+embedded-hal-async = { version = "=0.2.0-alpha.0", optional = true }
 embedded-storage = "0.3.0"
 embedded-storage-async = { version = "0.3.0", optional = true }
 nb = "1.0.0"
diff --git a/embassy-embedded-hal/src/adapter.rs b/embassy-embedded-hal/src/adapter.rs
index 1c43f015f..3680984f1 100644
--- a/embassy-embedded-hal/src/adapter.rs
+++ b/embassy-embedded-hal/src/adapter.rs
@@ -38,32 +38,31 @@ where
     E: embedded_hal_1::i2c::Error + 'static,
     T: blocking::i2c::WriteRead<Error = E> + blocking::i2c::Read<Error = E> + blocking::i2c::Write<Error = E>,
 {
-    type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-    type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-    type WriteReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        async move { self.wrapped.read(address, buffer) }
+    async fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Result<(), Self::Error> {
+        self.wrapped.read(address, buffer)
     }
 
-    fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
-        async move { self.wrapped.write(address, bytes) }
+    async fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Result<(), Self::Error> {
+        self.wrapped.write(address, bytes)
     }
 
-    fn write_read<'a>(&'a mut self, address: u8, bytes: &'a [u8], buffer: &'a mut [u8]) -> Self::WriteReadFuture<'a> {
-        async move { self.wrapped.write_read(address, bytes, buffer) }
+    async fn write_read<'a>(
+        &'a mut self,
+        address: u8,
+        bytes: &'a [u8],
+        buffer: &'a mut [u8],
+    ) -> Result<(), Self::Error> {
+        self.wrapped.write_read(address, bytes, buffer)
     }
 
-    type TransactionFuture<'a, 'b> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a, 'b: 'a;
-
-    fn transaction<'a, 'b>(
+    async fn transaction<'a, 'b>(
         &'a mut self,
         address: u8,
         operations: &'a mut [embedded_hal_async::i2c::Operation<'b>],
-    ) -> Self::TransactionFuture<'a, 'b> {
+    ) -> Result<(), Self::Error> {
         let _ = address;
         let _ = operations;
-        async move { todo!() }
+        todo!()
     }
 }
 
@@ -84,23 +83,17 @@ where
     E: embedded_hal_1::spi::Error + 'static,
     T: blocking::spi::Transfer<u8, Error = E> + blocking::spi::Write<u8, Error = E>,
 {
-    type TransferFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn transfer<'a>(&'a mut self, read: &'a mut [u8], write: &'a [u8]) -> Self::TransferFuture<'a> {
-        async move {
-            // Ensure we write the expected bytes
-            for i in 0..core::cmp::min(read.len(), write.len()) {
-                read[i] = write[i].clone();
-            }
-            self.wrapped.transfer(read)?;
-            Ok(())
+    async fn transfer<'a>(&'a mut self, read: &'a mut [u8], write: &'a [u8]) -> Result<(), Self::Error> {
+        // Ensure we write the expected bytes
+        for i in 0..core::cmp::min(read.len(), write.len()) {
+            read[i] = write[i].clone();
         }
+        self.wrapped.transfer(read)?;
+        Ok(())
     }
 
-    type TransferInPlaceFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn transfer_in_place<'a>(&'a mut self, _: &'a mut [u8]) -> Self::TransferInPlaceFuture<'a> {
-        async move { todo!() }
+    async fn transfer_in_place<'a>(&'a mut self, _: &'a mut [u8]) -> Result<(), Self::Error> {
+        todo!()
     }
 }
 
@@ -109,10 +102,8 @@ where
     E: embedded_hal_1::spi::Error + 'static,
     T: blocking::spi::Transfer<u8, Error = E> + blocking::spi::Write<u8, Error = E>,
 {
-    type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
-        async move { Ok(()) }
+    async fn flush(&mut self) -> Result<(), Self::Error> {
+        Ok(())
     }
 }
 
@@ -121,13 +112,9 @@ where
     E: embedded_hal_1::spi::Error + 'static,
     T: blocking::spi::Transfer<u8, Error = E> + blocking::spi::Write<u8, Error = E>,
 {
-    type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn write<'a>(&'a mut self, data: &'a [u8]) -> Self::WriteFuture<'a> {
-        async move {
-            self.wrapped.write(data)?;
-            Ok(())
-        }
+    async fn write(&mut self, data: &[u8]) -> Result<(), Self::Error> {
+        self.wrapped.write(data)?;
+        Ok(())
     }
 }
 
@@ -136,13 +123,9 @@ where
     E: embedded_hal_1::spi::Error + 'static,
     T: blocking::spi::Transfer<u8, Error = E> + blocking::spi::Write<u8, Error = E>,
 {
-    type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn read<'a>(&'a mut self, data: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        async move {
-            self.wrapped.transfer(data)?;
-            Ok(())
-        }
+    async fn read(&mut self, data: &mut [u8]) -> Result<(), Self::Error> {
+        self.wrapped.transfer(data)?;
+        Ok(())
     }
 }
 
@@ -192,7 +175,7 @@ where
     }
 
     type FlushFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where T: 'a;
-    fn flush<'a>(&'a mut self) -> Self::FlushFuture<'a> {
+    fn flush(&mut self) -> Result<(), Self::Error> {
         async move { self.wrapped.bflush() }
     }
 }
diff --git a/embassy-embedded-hal/src/lib.rs b/embassy-embedded-hal/src/lib.rs
index a12a3a3a0..8da042228 100644
--- a/embassy-embedded-hal/src/lib.rs
+++ b/embassy-embedded-hal/src/lib.rs
@@ -1,5 +1,9 @@
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(feature = "nightly", feature(type_alias_impl_trait))]
+#![cfg_attr(
+    feature = "nightly",
+    feature(type_alias_impl_trait, async_fn_in_trait, impl_trait_projections)
+)]
+#![cfg_attr(feature = "nightly", allow(incomplete_features))]
 #![warn(missing_docs)]
 
 //! Utilities to use `embedded-hal` traits with Embassy.
diff --git a/embassy-embedded-hal/src/shared_bus/asynch/i2c.rs b/embassy-embedded-hal/src/shared_bus/asynch/i2c.rs
index 0bc6afd98..c5e1fd415 100644
--- a/embassy-embedded-hal/src/shared_bus/asynch/i2c.rs
+++ b/embassy-embedded-hal/src/shared_bus/asynch/i2c.rs
@@ -22,7 +22,6 @@
 //! let i2c_dev2 = I2cDevice::new(i2c_bus);
 //! let mpu = Mpu6050::new(i2c_dev2);
 //! ```
-use core::future::Future;
 
 use embassy_sync::blocking_mutex::raw::RawMutex;
 use embassy_sync::mutex::Mutex;
@@ -55,53 +54,39 @@ where
     M: RawMutex + 'static,
     BUS: i2c::I2c + 'static,
 {
-    type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    async fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    async fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type WriteReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn write_read<'a>(
+    async fn write_read<'a>(
         &'a mut self,
         address: u8,
         wr_buffer: &'a [u8],
         rd_buffer: &'a mut [u8],
-    ) -> Self::WriteReadFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.write_read(address, wr_buffer, rd_buffer)
-                .await
-                .map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    ) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.write_read(address, wr_buffer, rd_buffer)
+            .await
+            .map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type TransactionFuture<'a, 'b> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a, 'b: 'a;
-
-    fn transaction<'a, 'b>(
+    async fn transaction<'a, 'b>(
         &'a mut self,
         address: u8,
         operations: &'a mut [embedded_hal_async::i2c::Operation<'b>],
-    ) -> Self::TransactionFuture<'a, 'b> {
+    ) -> Result<(), I2cDeviceError<BUS::Error>> {
         let _ = address;
         let _ = operations;
-        async move { todo!() }
+        todo!()
     }
 }
 
@@ -136,55 +121,41 @@ where
     M: RawMutex + 'static,
     BUS: i2c::I2c + SetConfig + 'static,
 {
-    type ReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.set_config(&self.config);
-            bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    async fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.set_config(&self.config);
+        bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type WriteFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.set_config(&self.config);
-            bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    async fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.set_config(&self.config);
+        bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type WriteReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
-
-    fn write_read<'a>(
+    async fn write_read<'a>(
         &'a mut self,
         address: u8,
         wr_buffer: &'a [u8],
         rd_buffer: &'a mut [u8],
-    ) -> Self::WriteReadFuture<'a> {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.set_config(&self.config);
-            bus.write_read(address, wr_buffer, rd_buffer)
-                .await
-                .map_err(I2cDeviceError::I2c)?;
-            Ok(())
-        }
+    ) -> Result<(), I2cDeviceError<BUS::Error>> {
+        let mut bus = self.bus.lock().await;
+        bus.set_config(&self.config);
+        bus.write_read(address, wr_buffer, rd_buffer)
+            .await
+            .map_err(I2cDeviceError::I2c)?;
+        Ok(())
     }
 
-    type TransactionFuture<'a, 'b> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a, 'b: 'a;
-
-    fn transaction<'a, 'b>(
+    async fn transaction<'a, 'b>(
         &'a mut self,
         address: u8,
         operations: &'a mut [embedded_hal_async::i2c::Operation<'b>],
-    ) -> Self::TransactionFuture<'a, 'b> {
+    ) -> Result<(), I2cDeviceError<BUS::Error>> {
         let _ = address;
         let _ = operations;
-        async move { todo!() }
+        todo!()
     }
 }
diff --git a/embassy-embedded-hal/src/shared_bus/asynch/spi.rs b/embassy-embedded-hal/src/shared_bus/asynch/spi.rs
index a3814d6d0..d25716655 100644
--- a/embassy-embedded-hal/src/shared_bus/asynch/spi.rs
+++ b/embassy-embedded-hal/src/shared_bus/asynch/spi.rs
@@ -65,33 +65,25 @@ where
 {
     type Bus = BUS;
 
-    type TransactionFuture<'a, R, F, Fut> = impl Future<Output = Result<R, Self::Error>> + 'a
+    async fn transaction<R, F, Fut>(&mut self, f: F) -> Result<R, Self::Error>
     where
-        Self: 'a, R: 'a, F: FnOnce(*mut Self::Bus) -> Fut + 'a,
-        Fut: Future<Output =  Result<R, <Self::Bus as ErrorType>::Error>> + 'a;
-
-    fn transaction<'a, R, F, Fut>(&'a mut self, f: F) -> Self::TransactionFuture<'a, R, F, Fut>
-    where
-        R: 'a,
-        F: FnOnce(*mut Self::Bus) -> Fut + 'a,
-        Fut: Future<Output = Result<R, <Self::Bus as ErrorType>::Error>> + 'a,
+        F: FnOnce(*mut Self::Bus) -> Fut,
+        Fut: Future<Output = Result<R, <Self::Bus as ErrorType>::Error>>,
     {
-        async move {
-            let mut bus = self.bus.lock().await;
-            self.cs.set_low().map_err(SpiDeviceError::Cs)?;
+        let mut bus = self.bus.lock().await;
+        self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
-            let f_res = f(&mut *bus).await;
+        let f_res = f(&mut *bus).await;
 
-            // On failure, it's important to still flush and deassert CS.
-            let flush_res = bus.flush().await;
-            let cs_res = self.cs.set_high();
+        // On failure, it's important to still flush and deassert CS.
+        let flush_res = bus.flush().await;
+        let cs_res = self.cs.set_high();
 
-            let f_res = f_res.map_err(SpiDeviceError::Spi)?;
-            flush_res.map_err(SpiDeviceError::Spi)?;
-            cs_res.map_err(SpiDeviceError::Cs)?;
+        let f_res = f_res.map_err(SpiDeviceError::Spi)?;
+        flush_res.map_err(SpiDeviceError::Spi)?;
+        cs_res.map_err(SpiDeviceError::Cs)?;
 
-            Ok(f_res)
-        }
+        Ok(f_res)
     }
 }
 
@@ -130,33 +122,25 @@ where
 {
     type Bus = BUS;
 
-    type TransactionFuture<'a, R, F, Fut> = impl Future<Output = Result<R, Self::Error>> + 'a
-    where
-        Self: 'a, R: 'a, F: FnOnce(*mut Self::Bus) -> Fut + 'a,
-        Fut: Future<Output =  Result<R, <Self::Bus as ErrorType>::Error>> + 'a;
-
-    fn transaction<'a, R, F, Fut>(&'a mut self, f: F) -> Self::TransactionFuture<'a, R, F, Fut>
+    async fn transaction<R, F, Fut>(&mut self, f: F) -> Result<R, Self::Error>
     where
-        R: 'a,
-        F: FnOnce(*mut Self::Bus) -> Fut + 'a,
-        Fut: Future<Output = Result<R, <Self::Bus as ErrorType>::Error>> + 'a,
+        F: FnOnce(*mut Self::Bus) -> Fut,
+        Fut: Future<Output = Result<R, <Self::Bus as ErrorType>::Error>>,
     {
-        async move {
-            let mut bus = self.bus.lock().await;
-            bus.set_config(&self.config);
-            self.cs.set_low().map_err(SpiDeviceError::Cs)?;
+        let mut bus = self.bus.lock().await;
+        bus.set_config(&self.config);
+        self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
-            let f_res = f(&mut *bus).await;
+        let f_res = f(&mut *bus).await;
 
-            // On failure, it's important to still flush and deassert CS.
-            let flush_res = bus.flush().await;
-            let cs_res = self.cs.set_high();
+        // On failure, it's important to still flush and deassert CS.
+        let flush_res = bus.flush().await;
+        let cs_res = self.cs.set_high();
 
-            let f_res = f_res.map_err(SpiDeviceError::Spi)?;
-            flush_res.map_err(SpiDeviceError::Spi)?;
-            cs_res.map_err(SpiDeviceError::Cs)?;
+        let f_res = f_res.map_err(SpiDeviceError::Spi)?;
+        flush_res.map_err(SpiDeviceError::Spi)?;
+        cs_res.map_err(SpiDeviceError::Cs)?;
 
-            Ok(f_res)
-        }
+        Ok(f_res)
     }
 }