Async

.gitignore

@@ -1,4 +1,4 @@
 **/*.rs.bk
 .#*
-/target/
+target
 Cargo.lock

CHANGELOG.md

@@ -10,6 +10,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 - `Error` traits for Can, SPI, I2C and Serial are implemented for Infallible
 
+### Changed
+- `spi`: traits now enforce all impls on the same struct (eg `Transfer` and `Write`) have the same `Error` type. 
+- `spi/blocking`: unified traits into `Read`, `Write`, `ReadWrite`.
+- `spi/blocking`: renamed Transactional `exec` to `batch`.
+- `spi/blocking`: Added `read_batch`, `write_batch` methods.
+
 ## [v1.0.0-alpha.6] - 2021-11-19
 
 *** This is (also) an alpha release with breaking changes (sorry) ***

embedded-hal-async/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "embedded-hal-async"
+version = "0.1.0"
+edition = "2021"
+categories = ["asynchronous", "embedded", "hardware-support", "no-std"]
+description = " A Hardware Abstraction Layer (HAL) for embedded systems, async version"
+documentation = "https://docs.rs/embedded-hal-async"
+keywords = ["hal", "IO", "async"]
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/rust-embedded/embedded-hal"
+
+[dependencies]
+nb = "1"
+embedded-hal = { version = "1.0.0-alpha.6", path = ".." }

embedded-hal-async/src/delay.rs

@@ -0,0 +1,52 @@
+//! Delays
+
+use core::future::Future;
+
+/// Microsecond delay
+pub trait DelayUs {
+    /// Enumeration of errors
+    type Error: core::fmt::Debug;
+
+    /// The future returned by the `delay_us` function.
+    type DelayUsFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Pauses execution for at minimum `us` microseconds. Pause can be longer
+    /// if the implementation requires it due to precision/timing issues.
+    fn delay_us(&mut self, us: u32) -> Self::DelayUsFuture<'_>;
+
+    /// The future returned by the `delay_ms` function.
+    type DelayMsFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Pauses execution for at minimum `ms` milliseconds. Pause can be longer
+    /// if the implementation requires it due to precision/timing issues.
+    fn delay_ms(&mut self, ms: u32) -> Self::DelayMsFuture<'_>;
+}
+
+impl<T> DelayUs for &mut T
+where
+    T: DelayUs,
+{
+    type Error = T::Error;
+
+    type DelayUsFuture<'a>
+    where
+        Self: 'a,
+    = T::DelayUsFuture<'a>;
+
+    fn delay_us(&mut self, us: u32) -> Self::DelayUsFuture<'_> {
+        T::delay_us(self, us)
+    }
+
+    type DelayMsFuture<'a>
+    where
+        Self: 'a,
+    = T::DelayMsFuture<'a>;
+
+    fn delay_ms(&mut self, ms: u32) -> Self::DelayMsFuture<'_> {
+        T::delay_ms(self, ms)
+    }
+}

embedded-hal-async/src/digital.rs

@@ -0,0 +1,100 @@
+//! Asynchronous digital I/O
+//!
+//! # Example
+//!
+//! ```rust
+//! # use embedded_hal_async::digital::WaitForHigh;
+//! /// Asynchronously wait until the `ready_pin` becomes high.
+//! async fn wait_until_ready<P>(ready_pin: &mut P)
+//! where
+//!     P: WaitForHigh,
+//! {
+//!     ready_pin
+//!         .wait_for_high()
+//!         .await
+//!         .expect("failed to await input pin")
+//! }
+//! ```
+
+use core::future::Future;
+
+/// Asynchronously wait for a pin to be high.
+pub trait WaitForHigh {
+    /// Enumeration of errors.
+    type Error: core::fmt::Debug;
+
+    /// The future returned by the `wait_for_high` function.
+    type WaitForHighFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Returns a future that resolves when this pin _is_ high. If the pin
+    /// is already high, the future resolves immediately.
+    ///
+    /// # Note for implementers
+    /// The pin may have switched back to low before the task was run after
+    /// being woken. The future should still resolve in that case.
+    fn wait_for_high<'a>(&'a mut self) -> Self::WaitForHighFuture<'a>;
+}
+
+/// Asynchronously wait for a pin to be low.
+pub trait WaitForLow {
+    /// Enumeration of errors.
+    type Error: core::fmt::Debug;
+
+    /// The future returned by `wait_for_low`.
+    type WaitForLowFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Returns a future that resolves when this pin _is_ low. If the pin
+    /// is already low, the future resolves immediately.
+    ///
+    /// # Note for implementers
+    /// The pin may have switched back to high before the task was run after
+    /// being woken. The future should still resolve in that case.
+    fn wait_for_low<'a>(&'a mut self) -> Self::WaitForLowFuture<'a>;
+}
+
+/// Wait for a rising edge (transition from low to high).
+pub trait WaitForRisingEdge {
+    /// Enumeration of errors.
+    type Error: core::fmt::Debug;
+
+    /// The future returned from `wait_for_rising_edge`.
+    type WaitForRisingEdgeFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Returns a future that resolves when this pin transitions from low to high.
+    fn wait_for_rising_edge<'a>(&'a mut self) -> Self::WaitForRisingEdgeFuture<'a>;
+}
+
+/// Wait for a falling edge (transition from high to low).
+pub trait WaitForFallingEdge {
+    /// Enumeration of errors.
+    type Error: core::fmt::Debug;
+
+    /// The future returned from `wait_for_falling_edge`.
+    type WaitForFallingEdgeFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Returns a future that resolves when this pin transitions from high to low.
+    fn wait_for_falling_edge<'a>(&'a mut self) -> Self::WaitForFallingEdgeFuture<'a>;
+}
+
+/// Wait for any edge (transition from low to high OR high to low).
+pub trait WaitForAnyEdge {
+    /// Enumeration of errors.
+    type Error: core::fmt::Debug;
+
+    /// The future returned from `wait_for_any_edge`.
+    type WaitForAnyEdgeFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Returns a future that resolves when this pin undergoes any transition, e.g.
+    /// low to high OR high to low.
+    fn wait_for_any_edge<'a>(&'a mut self) -> Self::WaitForAnyEdgeFuture<'a>;
+}

embedded-hal-async/src/i2c.rs

@@ -0,0 +1,163 @@
+//! Async I2C API
+//!
+//! This API supports 7-bit and 10-bit addresses. Traits feature an `AddressMode`
+//! marker type parameter. Two implementation of the `AddressMode` exist:
+//! `SevenBitAddress` and `TenBitAddress`.
+//!
+//! Through this marker types it is possible to implement each address mode for
+//! the traits independently in `embedded-hal` implementations and device drivers
+//! can depend only on the mode that they support.
+//!
+//! Additionally, the I2C 10-bit address mode has been developed to be fully
+//! backwards compatible with the 7-bit address mode. This allows for a
+//! software-emulated 10-bit addressing implementation if the address mode
+//! is not supported by the hardware.
+//!
+//! Since 7-bit addressing is the mode of the majority of I2C devices,
+//! `SevenBitAddress` has been set as default mode and thus can be omitted if desired.
+
+use core::future::Future;
+pub use embedded_hal::i2c::{
+    AddressMode, Error, ErrorKind, NoAcknowledgeSource, SevenBitAddress, TenBitAddress,
+};
+
+/// Async read
+pub trait Read<A: AddressMode = SevenBitAddress> {
+    /// Error type
+    type Error: Error;
+    /// The future associated with the `read` method.
+    type ReadFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Reads enough bytes from slave with `address` to fill `buffer`
+    ///
+    /// # I2C Events (contract)
+    ///
+    /// ``` text
+    /// Master: ST SAD+R        MAK    MAK ...    NMAK SP
+    /// Slave:           SAK B0     B1     ... BN
+    /// ```
+    ///
+    /// Where
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+R` = slave address followed by bit 1 to indicate reading
+    /// - `SAK` = slave acknowledge
+    /// - `Bi` = ith byte of data
+    /// - `MAK` = master acknowledge
+    /// - `NMAK` = master no acknowledge
+    /// - `SP` = stop condition
+    fn read<'a>(&'a mut self, address: A, read: &'a mut [u8]) -> Self::ReadFuture<'a>;
+}
+
+impl<A: AddressMode, T: Read<A>> Read<A> for &mut T {
+    type Error = T::Error;
+
+    type ReadFuture<'a>
+    where
+        Self: 'a,
+    = T::ReadFuture<'a>;
+
+    fn read<'a>(&'a mut self, address: A, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
+        T::read(self, address, buffer)
+    }
+}
+
+/// Async write
+pub trait Write<A: AddressMode = SevenBitAddress> {
+    /// Error type
+    type Error: Error;
+    /// The future associated with the `write` method.
+    type WriteFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Writes bytes to slave with address `address`
+    ///
+    /// # I2C Events (contract)
+    ///
+    /// ``` text
+    /// Master: ST SAD+W     B0     B1     ... BN     SP
+    /// Slave:           SAK    SAK    SAK ...    SAK
+    /// ```
+    ///
+    /// Where
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+W` = slave address followed by bit 0 to indicate writing
+    /// - `SAK` = slave acknowledge
+    /// - `Bi` = ith byte of data
+    /// - `SP` = stop condition
+    fn write<'a>(&'a mut self, address: A, write: &'a [u8]) -> Self::WriteFuture<'a>;
+}
+
+impl<A: AddressMode, T: Write<A>> Write<A> for &mut T {
+    type Error = T::Error;
+
+    type WriteFuture<'a>
+    where
+        Self: 'a,
+    = T::WriteFuture<'a>;
+
+    fn write<'a>(&'a mut self, address: A, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
+        T::write(self, address, bytes)
+    }
+}
+
+/// Async write + read
+pub trait WriteRead<A: AddressMode = SevenBitAddress> {
+    /// Error type
+    type Error: Error;
+    /// The future associated with the `write_read` method.
+    type WriteReadFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    where
+        Self: 'a;
+
+    /// Writes bytes to slave with address `address` and then reads enough bytes to fill `read` *in a
+    /// single transaction*.
+    ///
+    /// # I2C Events (contract)
+    ///
+    /// ``` text
+    /// Master: ST SAD+W     O0     O1     ... OM     SR SAD+R        MAK    MAK ...    NMAK SP
+    /// Slave:           SAK    SAK    SAK ...    SAK          SAK I0     I1     ... IN
+    /// ```
+    ///
+    /// Where
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+W` = slave address followed by bit 0 to indicate writing
+    /// - `SAK` = slave acknowledge
+    /// - `Oi` = ith outgoing byte of data
+    /// - `SR` = repeated start condition
+    /// - `SAD+R` = slave address followed by bit 1 to indicate reading
+    /// - `Ii` = ith incoming byte of data
+    /// - `MAK` = master acknowledge
+    /// - `NMAK` = master no acknowledge
+    /// - `SP` = stop condition
+    fn write_read<'a>(
+        &'a mut self,
+        address: A,
+        write: &'a [u8],
+        read: &'a mut [u8],
+    ) -> Self::WriteReadFuture<'a>;
+}
+
+impl<A: AddressMode, T: WriteRead<A>> WriteRead<A> for &mut T {
+    type Error = T::Error;
+
+    type WriteReadFuture<'a>
+    where
+        Self: 'a,
+    = T::WriteReadFuture<'a>;
+
+    fn write_read<'a>(
+        &'a mut self,
+        address: A,
+        bytes: &'a [u8],
+        buffer: &'a mut [u8],
+    ) -> Self::WriteReadFuture<'a> {
+        T::write_read(self, address, bytes, buffer)
+    }
+}

embedded-hal-async/src/lib.rs

@@ -0,0 +1,13 @@
+#![feature(generic_associated_types)]
+#![no_std]
+#![deny(missing_docs)]
+
+//! Asynchronous APIs
+//!
+//! This traits use `core::future::Future` and generic associated types.
+
+pub mod delay;
+pub mod digital;
+pub mod i2c;
+pub mod serial;
+pub mod spi;