Merge #301

301: Backport non-breaking changes from v1.0 to v0.2.x r=eldruin a=burrbull



Co-authored-by: Andrey Zgarbul <zgarbul.andrey@gmail.com>

CHANGELOG.md

@@ -9,6 +9,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- `Transactional` SPI interface for executing groups of SPI transactions.
+- `Transactional` I2C interface for executing groups of I2C transactions.
+- 10-bit addressing mode for I2C traits.
+- `set_state` method for `OutputPin` using an input `PinState` value.
+- `IoPin` trait for pins that can change between being inputs or outputs
+  dynamically.
 
 ### Changed
 

src/blocking/i2c.rs

@@ -1,12 +1,122 @@
 //! Blocking I2C API
 //!
-//! Slave addresses used by this API are 7-bit I2C addresses ranging from 0 to 127.
+//! 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`.
 //!
-//! Operations on 10-bit slave addresses are not supported by the API yet (but applications might
-//! be able to emulate some operations).
+//! 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.
+//!
+//! ## Examples
+//!
+//! ### `embedded-hal` implementation for an MCU
+//! Here is an example of an embedded-hal implementation of the `Write` trait
+//! for both modes:
+//! ```
+//! # use embedded_hal::blocking::i2c::{SevenBitAddress, TenBitAddress, Write};
+//! /// I2C0 hardware peripheral which supports both 7-bit and 10-bit addressing.
+//! pub struct I2c0;
+//!
+//! impl Write<SevenBitAddress> for I2c0
+//! {
+//! #   type Error = ();
+//! #
+//!     fn write(&mut self, addr: u8, output: &[u8]) -> Result<(), Self::Error> {
+//!         // ...
+//! #       Ok(())
+//!     }
+//! }
+//!
+//! impl Write<TenBitAddress> for I2c0
+//! {
+//! #   type Error = ();
+//! #
+//!     fn write(&mut self, addr: u16, output: &[u8]) -> Result<(), Self::Error> {
+//!         // ...
+//! #       Ok(())
+//!     }
+//! }
+//! ```
+//!
+//! ### Device driver compatible only with 7-bit addresses
+//!
+//! For demonstration purposes the address mode parameter has been omitted in this example.
+//!
+//! ```
+//! # use embedded_hal::blocking::i2c::WriteRead;
+//! const ADDR: u8  = 0x15;
+//! # const TEMP_REGISTER: u8 = 0x1;
+//! pub struct TemperatureSensorDriver<I2C> {
+//!     i2c: I2C,
+//! }
+//!
+//! impl<I2C, E> TemperatureSensorDriver<I2C>
+//! where
+//!     I2C: WriteRead<Error = E>,
+//! {
+//!     pub fn read_temperature(&mut self) -> Result<u8, E> {
+//!         let mut temp = [0];
+//!         self.i2c
+//!             .write_read(ADDR, &[TEMP_REGISTER], &mut temp)
+//!             .and(Ok(temp[0]))
+//!     }
+//! }
+//! ```
+//!
+//! ### Device driver compatible only with 10-bit addresses
+//!
+//! ```
+//! # use embedded_hal::blocking::i2c::{TenBitAddress, WriteRead};
+//! const ADDR: u16  = 0x158;
+//! # const TEMP_REGISTER: u8 = 0x1;
+//! pub struct TemperatureSensorDriver<I2C> {
+//!     i2c: I2C,
+//! }
+//!
+//! impl<I2C, E> TemperatureSensorDriver<I2C>
+//! where
+//!     I2C: WriteRead<TenBitAddress, Error = E>,
+//! {
+//!     pub fn read_temperature(&mut self) -> Result<u8, E> {
+//!         let mut temp = [0];
+//!         self.i2c
+//!             .write_read(ADDR, &[TEMP_REGISTER], &mut temp)
+//!             .and(Ok(temp[0]))
+//!     }
+//! }
+//! ```
+
+use crate::private;
+
+impl private::Sealed for SevenBitAddress {}
+impl private::Sealed for TenBitAddress {}
+
+/// Address mode (7-bit / 10-bit)
+///
+/// Note: This trait is sealed and should not be implemented outside of this crate.
+pub trait AddressMode: private::Sealed {}
+
+/// 7-bit address mode type
+pub type SevenBitAddress = u8;
+
+/// 10-bit address mode type
+pub type TenBitAddress = u16;
+
+impl AddressMode for SevenBitAddress {}
+
+impl AddressMode for TenBitAddress {}
 
 /// Blocking read
-pub trait Read {
+pub trait Read<A: AddressMode = SevenBitAddress> {
     /// Error type
     type Error;
 
@@ -28,15 +138,15 @@ pub trait Read {
     /// - `MAK` = master acknowledge
     /// - `NMAK` = master no acknowledge
     /// - `SP` = stop condition
-    fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error>;
+    fn read(&mut self, address: A, buffer: &mut [u8]) -> Result<(), Self::Error>;
 }
 
 /// Blocking write
-pub trait Write {
+pub trait Write<A: AddressMode = SevenBitAddress> {
     /// Error type
     type Error;
 
-    /// Sends bytes to slave with address `addr`
+    /// Writes bytes to slave with address `address`
     ///
     /// # I2C Events (contract)
     ///
@@ -52,31 +162,30 @@ pub trait Write {
     /// - `SAK` = slave acknowledge
     /// - `Bi` = ith byte of data
     /// - `SP` = stop condition
-    fn write(&mut self, addr: u8, bytes: &[u8]) -> Result<(), Self::Error>;
+    fn write(&mut self, address: A, bytes: &[u8]) -> Result<(), Self::Error>;
 }
 
 /// Blocking write (iterator version)
-#[cfg(feature = "unproven")]
-pub trait WriteIter {
+pub trait WriteIter<A: AddressMode = SevenBitAddress> {
     /// Error type
     type Error;
 
-    /// Sends bytes to slave with address `addr`
+    /// Writes bytes to slave with address `address`
     ///
     /// # I2C Events (contract)
     ///
     /// Same as `Write`
-    fn write<B>(&mut self, addr: u8, bytes: B) -> Result<(), Self::Error>
+    fn write<B>(&mut self, address: A, bytes: B) -> Result<(), Self::Error>
     where
         B: IntoIterator<Item = u8>;
 }
 
 /// Blocking write + read
-pub trait WriteRead {
+pub trait WriteRead<A: AddressMode = SevenBitAddress> {
     /// Error type
     type Error;
 
-    /// Sends bytes to slave with address `addr` and then reads enough bytes to fill `buffer` *in a
+    /// Writes bytes to slave with address `address` and then reads enough bytes to fill `buffer` *in a
     /// single transaction*
     ///
     /// # I2C Events (contract)
@@ -100,30 +209,89 @@ pub trait WriteRead {
     /// - `SP` = stop condition
     fn write_read(
         &mut self,
-        address: u8,
+        address: A,
         bytes: &[u8],
         buffer: &mut [u8],
     ) -> Result<(), Self::Error>;
 }
 
 /// Blocking write (iterator version) + read
-#[cfg(feature = "unproven")]
-pub trait WriteIterRead {
+pub trait WriteIterRead<A: AddressMode = SevenBitAddress> {
     /// Error type
     type Error;
 
-    /// Sends bytes to slave with address `addr` and then reads enough bytes to fill `buffer` *in a
+    /// Writes bytes to slave with address `address` and then reads enough bytes to fill `buffer` *in a
     /// single transaction*
     ///
     /// # I2C Events (contract)
     ///
     /// Same as the `WriteRead` trait
     fn write_iter_read<B>(
         &mut self,
-        address: u8,
+        address: A,
         bytes: B,
         buffer: &mut [u8],
     ) -> Result<(), Self::Error>
     where
         B: IntoIterator<Item = u8>;
 }
+
+/// Transactional I2C operation.
+///
+/// Several operations can be combined as part of a transaction.
+#[derive(Debug, PartialEq)]
+pub enum Operation<'a> {
+    /// Read data into the provided buffer
+    Read(&'a mut [u8]),
+    /// Write data from the provided buffer
+    Write(&'a [u8]),
+}
+
+/// Transactional I2C interface.
+///
+/// This allows combining operations within an I2C transaction.
+pub trait Transactional<A: AddressMode = SevenBitAddress> {
+    /// Error type
+    type Error;
+
+    /// Execute the provided operations on the I2C bus.
+    ///
+    /// Transaction contract:
+    /// - Before executing the first operation an ST is sent automatically. This is followed by SAD+R/W as appropriate.
+    /// - Data from adjacent operations of the same type are sent after each other without an SP or SR.
+    /// - Between adjacent operations of a different type an SR and SAD+R/W is sent.
+    /// - After executing the last operation an SP is sent automatically.
+    /// - If the last operation is a `Read` the master does not send an acknowledge for the last byte.
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+R/W` = slave address followed by bit 1 to indicate reading or 0 to indicate writing
+    /// - `SR` = repeated start condition
+    /// - `SP` = stop condition
+    fn exec<'a>(&mut self, address: A, operations: &mut [Operation<'a>])
+        -> Result<(), Self::Error>;
+}
+
+/// Transactional I2C interface (iterator version).
+///
+/// This allows combining operation within an I2C transaction.
+pub trait TransactionalIter<A: AddressMode = SevenBitAddress> {
+    /// Error type
+    type Error;
+
+    /// Execute the provided operations on the I2C bus (iterator version).
+    ///
+    /// Transaction contract:
+    /// - Before executing the first operation an ST is sent automatically. This is followed by SAD+R/W as appropriate.
+    /// - Data from adjacent operations of the same type are sent after each other without an SP or SR.
+    /// - Between adjacent operations of a different type an SR and SAD+R/W is sent.
+    /// - After executing the last operation an SP is sent automatically.
+    /// - If the last operation is a `Read` the master does not send an acknowledge for the last byte.
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+R/W` = slave address followed by bit 1 to indicate reading or 0 to indicate writing
+    /// - `SR` = repeated start condition
+    /// - `SP` = stop condition
+    fn exec_iter<'a, O>(&mut self, address: A, operations: O) -> Result<(), Self::Error>
+    where
+        O: IntoIterator<Item = Operation<'a>>;
+}

src/blocking/spi.rs

@@ -104,3 +104,24 @@ pub mod write_iter {
         }
     }
 }
+
+/// Operation for transactional SPI trait
+///
+/// This allows composition of SPI operations into a single bus transaction
+#[derive(Debug, PartialEq)]
+pub enum Operation<'a, W: 'static> {
+    /// Write data from the provided buffer, discarding read data
+    Write(&'a [W]),
+    /// Write data out while reading data into the provided buffer
+    Transfer(&'a mut [W]),
+}
+
+/// Transactional trait allows multiple actions to be executed
+/// as part of a single SPI transaction
+pub trait Transactional<W: 'static> {
+    /// Associated error type
+    type Error;
+
+    /// Execute the provided transactions
+    fn exec<'a>(&mut self, operations: &mut [Operation<'a, W>]) -> Result<(), Self::Error>;
+}