Async shared bus for SPI & I2C + rename embassy-traits (#769)

* Rename embassy-traits to embassy-embedded-hal

* Rename embassy-traits to embassy-embedded-hal

* Add shared bus for SPI and I2C

* rustfmt

* EHA alpha 1

* Rename embedded-traits in examples

* rustfmt

* rustfmt

Co-authored-by: Henrik Alsér <henrik@mindbite.se>
This commit is contained in:
Henrik Alsér
2022-05-26 18:54:58 +02:00
committed by GitHub
parent 36a1f20364
commit e10fc2bada
26 changed files with 262 additions and 26 deletions

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//! Asynchronous shared I2C bus
//!
//! # Example (nrf52)
//!
//! ```rust
//! use embassy_embedded_hal::shared_bus::i2c::I2cBusDevice;
//! use embassy::mutex::Mutex;
//! use embassy::blocking_mutex::raw::ThreadModeRawMutex;
//!
//! static I2C_BUS: Forever<Mutex::<ThreadModeRawMutex, Twim<TWISPI0>>> = Forever::new();
//! let config = twim::Config::default();
//! let irq = interrupt::take!(SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0);
//! let i2c = Twim::new(p.TWISPI0, irq, p.P0_03, p.P0_04, config);
//! let i2c_bus = Mutex::<ThreadModeRawMutex, _>::new(i2c);
//! let i2c_bus = I2C_BUS.put(i2c_bus);
//!
//! // Device 1, using embedded-hal-async compatible driver for QMC5883L compass
//! let i2c_dev1 = I2cBusDevice::new(i2c_bus);
//! let compass = QMC5883L::new(i2c_dev1).await.unwrap();
//!
//! // Device 2, using embedded-hal-async compatible driver for Mpu6050 accelerometer
//! let i2c_dev2 = I2cBusDevice::new(i2c_bus);
//! let mpu = Mpu6050::new(i2c_dev2);
//! ```
use core::{fmt::Debug, future::Future};
use embassy::blocking_mutex::raw::RawMutex;
use embassy::mutex::Mutex;
use embedded_hal_async::i2c;
#[derive(Copy, Clone, Eq, PartialEq, Debug)]
pub enum I2cBusDeviceError<BUS> {
I2c(BUS),
}
impl<BUS> i2c::Error for I2cBusDeviceError<BUS>
where
BUS: i2c::Error + Debug,
{
fn kind(&self) -> i2c::ErrorKind {
match self {
Self::I2c(e) => e.kind(),
}
}
}
pub struct I2cBusDevice<'a, M: RawMutex, BUS> {
bus: &'a Mutex<M, BUS>,
}
impl<'a, M: RawMutex, BUS> I2cBusDevice<'a, M, BUS> {
pub fn new(bus: &'a Mutex<M, BUS>) -> Self {
Self { bus }
}
}
impl<'a, M: RawMutex, BUS> i2c::ErrorType for I2cBusDevice<'a, M, BUS>
where
BUS: i2c::ErrorType,
{
type Error = I2cBusDeviceError<BUS::Error>;
}
impl<M, BUS> i2c::I2c for I2cBusDevice<'_, M, BUS>
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(I2cBusDeviceError::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(I2cBusDeviceError::I2c)?;
Ok(())
}
}
type WriteReadFuture<'a> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a;
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(I2cBusDeviceError::I2c)?;
Ok(())
}
}
type TransactionFuture<'a, 'b> = impl Future<Output = Result<(), Self::Error>> + 'a where Self: 'a, 'b: 'a;
fn transaction<'a, 'b>(
&'a mut self,
address: u8,
operations: &'a mut [embedded_hal_async::i2c::Operation<'b>],
) -> Self::TransactionFuture<'a, 'b> {
let _ = address;
let _ = operations;
async move { todo!() }
}
}

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//! Shared bus implementations for embedded-hal-async
pub mod i2c;
pub mod spi;

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//! Asynchronous shared SPI bus
//!
//! # Example (nrf52)
//!
//! ```rust
//! use embassy_embedded_hal::shared_bus::spi::SpiBusDevice;
//! use embassy::mutex::Mutex;
//! use embassy::blocking_mutex::raw::ThreadModeRawMutex;
//!
//! static SPI_BUS: Forever<Mutex<ThreadModeRawMutex, spim::Spim<SPI3>>> = Forever::new();
//! let mut config = spim::Config::default();
//! config.frequency = spim::Frequency::M32;
//! let irq = interrupt::take!(SPIM3);
//! let spi = spim::Spim::new_txonly(p.SPI3, irq, p.P0_15, p.P0_18, config);
//! let spi_bus = Mutex::<ThreadModeRawMutex, _>::new(spi);
//! let spi_bus = SPI_BUS.put(spi_bus);
//!
//! // Device 1, using embedded-hal-async compatible driver for ST7735 LCD display
//! let cs_pin1 = Output::new(p.P0_24, Level::Low, OutputDrive::Standard);
//! let spi_dev1 = SpiBusDevice::new(spi_bus, cs_pin1);
//! let display1 = ST7735::new(spi_dev1, dc1, rst1, Default::default(), 160, 128);
//!
//! // Device 2
//! let cs_pin2 = Output::new(p.P0_24, Level::Low, OutputDrive::Standard);
//! let spi_dev2 = SpiBusDevice::new(spi_bus, cs_pin2);
//! let display2 = ST7735::new(spi_dev2, dc2, rst2, Default::default(), 160, 128);
//! ```
use core::{fmt::Debug, future::Future};
use embassy::blocking_mutex::raw::RawMutex;
use embassy::mutex::Mutex;
use embedded_hal_1::digital::blocking::OutputPin;
use embedded_hal_1::spi::ErrorType;
use embedded_hal_async::spi;
#[derive(Copy, Clone, Eq, PartialEq, Debug)]
pub enum SpiBusDeviceError<BUS, CS> {
Spi(BUS),
Cs(CS),
}
impl<BUS, CS> spi::Error for SpiBusDeviceError<BUS, CS>
where
BUS: spi::Error + Debug,
CS: Debug,
{
fn kind(&self) -> spi::ErrorKind {
match self {
Self::Spi(e) => e.kind(),
Self::Cs(_) => spi::ErrorKind::Other,
}
}
}
pub struct SpiBusDevice<'a, M: RawMutex, BUS, CS> {
bus: &'a Mutex<M, BUS>,
cs: CS,
}
impl<'a, M: RawMutex, BUS, CS> SpiBusDevice<'a, M, BUS, CS> {
pub fn new(bus: &'a Mutex<M, BUS>, cs: CS) -> Self {
Self { bus, cs }
}
}
impl<'a, M: RawMutex, BUS, CS> spi::ErrorType for SpiBusDevice<'a, M, BUS, CS>
where
BUS: spi::ErrorType,
CS: OutputPin,
{
type Error = SpiBusDeviceError<BUS::Error, CS::Error>;
}
impl<M, BUS, CS> spi::SpiDevice for SpiBusDevice<'_, M, BUS, CS>
where
M: RawMutex + 'static,
BUS: spi::SpiBusFlush + 'static,
CS: OutputPin,
{
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>
where
R: 'a,
F: FnOnce(*mut Self::Bus) -> Fut + 'a,
Fut: Future<Output = Result<R, <Self::Bus as ErrorType>::Error>> + 'a,
{
async move {
let mut bus = self.bus.lock().await;
self.cs.set_low().map_err(SpiBusDeviceError::Cs)?;
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();
let f_res = f_res.map_err(SpiBusDeviceError::Spi)?;
flush_res.map_err(SpiBusDeviceError::Spi)?;
cs_res.map_err(SpiBusDeviceError::Cs)?;
Ok(f_res)
}
}
}