2023-11-29 17:01:36 +01:00

202 lines
7.1 KiB
Rust

//! Blocking shared SPI bus
//!
//! # Example (nrf52)
//!
//! ```rust,ignore
//! use embassy_embedded_hal::shared_bus::blocking::spi::SpiDevice;
//! use embassy_sync::blocking_mutex::{NoopMutex, raw::NoopRawMutex};
//!
//! static SPI_BUS: StaticCell<NoopMutex<RefCell<Spim<SPI3>>>> = StaticCell::new();
//! let spi = Spim::new_txonly(p.SPI3, Irqs, p.P0_15, p.P0_18, Config::default());
//! let spi_bus = NoopMutex::new(RefCell::new(spi));
//! let spi_bus = SPI_BUS.init(spi_bus);
//!
//! // Device 1, using embedded-hal compatible driver for ST7735 LCD display
//! let cs_pin1 = Output::new(p.P0_24, Level::Low, OutputDrive::Standard);
//! let spi_dev1 = SpiDevice::new(spi_bus, cs_pin1);
//! let display1 = ST7735::new(spi_dev1, dc1, rst1, Default::default(), false, 160, 128);
//! ```
use core::cell::RefCell;
use embassy_sync::blocking_mutex::raw::RawMutex;
use embassy_sync::blocking_mutex::Mutex;
use embedded_hal_1::digital::OutputPin;
use embedded_hal_1::spi::{self, Operation, SpiBus};
use crate::shared_bus::SpiDeviceError;
use crate::SetConfig;
/// SPI device on a shared bus.
pub struct SpiDevice<'a, M: RawMutex, BUS, CS> {
bus: &'a Mutex<M, RefCell<BUS>>,
cs: CS,
}
impl<'a, M: RawMutex, BUS, CS> SpiDevice<'a, M, BUS, CS> {
/// Create a new `SpiDevice`.
pub fn new(bus: &'a Mutex<M, RefCell<BUS>>, cs: CS) -> Self {
Self { bus, cs }
}
}
impl<'a, M: RawMutex, BUS, CS> spi::ErrorType for SpiDevice<'a, M, BUS, CS>
where
BUS: spi::ErrorType,
CS: OutputPin,
{
type Error = SpiDeviceError<BUS::Error, CS::Error>;
}
impl<BUS, M, CS> embedded_hal_1::spi::SpiDevice for SpiDevice<'_, M, BUS, CS>
where
M: RawMutex,
BUS: SpiBus,
CS: OutputPin,
{
fn transaction(&mut self, operations: &mut [Operation<'_, u8>]) -> Result<(), Self::Error> {
if cfg!(not(feature = "time")) && operations.iter().any(|op| matches!(op, Operation::DelayNs(_))) {
return Err(SpiDeviceError::DelayNotSupported);
}
self.bus.lock(|bus| {
let mut bus = bus.borrow_mut();
self.cs.set_low().map_err(SpiDeviceError::Cs)?;
let op_res = operations.iter_mut().try_for_each(|op| match op {
Operation::Read(buf) => bus.read(buf),
Operation::Write(buf) => bus.write(buf),
Operation::Transfer(read, write) => bus.transfer(read, write),
Operation::TransferInPlace(buf) => bus.transfer_in_place(buf),
#[cfg(not(feature = "time"))]
Operation::DelayNs(_) => unreachable!(),
#[cfg(feature = "time")]
Operation::DelayNs(ns) => {
embassy_time::block_for(embassy_time::Duration::from_nanos(*ns as _));
Ok(())
}
});
// On failure, it's important to still flush and deassert CS.
let flush_res = bus.flush();
let cs_res = self.cs.set_high();
let op_res = op_res.map_err(SpiDeviceError::Spi)?;
flush_res.map_err(SpiDeviceError::Spi)?;
cs_res.map_err(SpiDeviceError::Cs)?;
Ok(op_res)
})
}
}
impl<'d, M, BUS, CS, BusErr, CsErr> embedded_hal_02::blocking::spi::Transfer<u8> for SpiDevice<'_, M, BUS, CS>
where
M: RawMutex,
BUS: embedded_hal_02::blocking::spi::Transfer<u8, Error = BusErr>,
CS: OutputPin<Error = CsErr>,
{
type Error = SpiDeviceError<BusErr, CsErr>;
fn transfer<'w>(&mut self, words: &'w mut [u8]) -> Result<&'w [u8], Self::Error> {
self.bus.lock(|bus| {
let mut bus = bus.borrow_mut();
self.cs.set_low().map_err(SpiDeviceError::Cs)?;
let op_res = bus.transfer(words);
let cs_res = self.cs.set_high();
let op_res = op_res.map_err(SpiDeviceError::Spi)?;
cs_res.map_err(SpiDeviceError::Cs)?;
Ok(op_res)
})
}
}
impl<'d, M, BUS, CS, BusErr, CsErr> embedded_hal_02::blocking::spi::Write<u8> for SpiDevice<'_, M, BUS, CS>
where
M: RawMutex,
BUS: embedded_hal_02::blocking::spi::Write<u8, Error = BusErr>,
CS: OutputPin<Error = CsErr>,
{
type Error = SpiDeviceError<BusErr, CsErr>;
fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> {
self.bus.lock(|bus| {
let mut bus = bus.borrow_mut();
self.cs.set_low().map_err(SpiDeviceError::Cs)?;
let op_res = bus.write(words);
let cs_res = self.cs.set_high();
let op_res = op_res.map_err(SpiDeviceError::Spi)?;
cs_res.map_err(SpiDeviceError::Cs)?;
Ok(op_res)
})
}
}
/// SPI device on a shared bus, with its own configuration.
///
/// This is like [`SpiDevice`], with an additional bus configuration that's applied
/// to the bus before each use using [`SetConfig`]. This allows different
/// devices on the same bus to use different communication settings.
pub struct SpiDeviceWithConfig<'a, M: RawMutex, BUS: SetConfig, CS> {
bus: &'a Mutex<M, RefCell<BUS>>,
cs: CS,
config: BUS::Config,
}
impl<'a, M: RawMutex, BUS: SetConfig, CS> SpiDeviceWithConfig<'a, M, BUS, CS> {
/// Create a new `SpiDeviceWithConfig`.
pub fn new(bus: &'a Mutex<M, RefCell<BUS>>, cs: CS, config: BUS::Config) -> Self {
Self { bus, cs, config }
}
}
impl<'a, M, BUS, CS> spi::ErrorType for SpiDeviceWithConfig<'a, M, BUS, CS>
where
M: RawMutex,
BUS: spi::ErrorType + SetConfig,
CS: OutputPin,
{
type Error = SpiDeviceError<BUS::Error, CS::Error>;
}
impl<BUS, M, CS> embedded_hal_1::spi::SpiDevice for SpiDeviceWithConfig<'_, M, BUS, CS>
where
M: RawMutex,
BUS: SpiBus + SetConfig,
CS: OutputPin,
{
fn transaction(&mut self, operations: &mut [Operation<'_, u8>]) -> Result<(), Self::Error> {
if cfg!(not(feature = "time")) && operations.iter().any(|op| matches!(op, Operation::DelayNs(_))) {
return Err(SpiDeviceError::DelayNotSupported);
}
self.bus.lock(|bus| {
let mut bus = bus.borrow_mut();
bus.set_config(&self.config).map_err(|_| SpiDeviceError::Config)?;
self.cs.set_low().map_err(SpiDeviceError::Cs)?;
let op_res = operations.iter_mut().try_for_each(|op| match op {
Operation::Read(buf) => bus.read(buf),
Operation::Write(buf) => bus.write(buf),
Operation::Transfer(read, write) => bus.transfer(read, write),
Operation::TransferInPlace(buf) => bus.transfer_in_place(buf),
#[cfg(not(feature = "time"))]
Operation::DelayNs(_) => unreachable!(),
#[cfg(feature = "time")]
Operation::DelayNs(ns) => {
embassy_time::block_for(embassy_time::Duration::from_nanos(*ns as _));
Ok(())
}
});
// On failure, it's important to still flush and deassert CS.
let flush_res = bus.flush();
let cs_res = self.cs.set_high();
let op_res = op_res.map_err(SpiDeviceError::Spi)?;
flush_res.map_err(SpiDeviceError::Spi)?;
cs_res.map_err(SpiDeviceError::Cs)?;
Ok(op_res)
})
}
}