embedded_hal_bus/spi/
shared.rs

Help
1use embedded_hal::delay::DelayNs;
2use embedded_hal::digital::OutputPin;
3use embedded_hal::spi::{ErrorType, Operation, SpiBus};
4
5use crate::spi::DeviceError;
6
7/// Common implementation to perform a transaction against the device.
8#[inline]
9pub fn transaction<Word, BUS, CS, D>(
10    operations: &mut [Operation<Word>],
11    bus: &mut BUS,
12    delay: &mut D,
13    cs: &mut CS,
14) -> Result<(), DeviceError<BUS::Error, CS::Error>>
15where
16    BUS: SpiBus<Word> + ErrorType,
17    CS: OutputPin,
18    D: DelayNs,
19    Word: Copy,
20{
21    cs.set_low().map_err(DeviceError::Cs)?;
22
23    let op_res = operations.iter_mut().try_for_each(|op| match op {
24        Operation::Read(buf) => bus.read(buf),
25        Operation::Write(buf) => bus.write(buf),
26        Operation::Transfer(read, write) => bus.transfer(read, write),
27        Operation::TransferInPlace(buf) => bus.transfer_in_place(buf),
28        Operation::DelayNs(ns) => {
29            bus.flush()?;
30            delay.delay_ns(*ns);
31            Ok(())
32        }
33    });
34
35    // On failure, it's important to still flush and deassert CS.
36    let flush_res = bus.flush();
37    let cs_res = cs.set_high();
38
39    op_res.map_err(DeviceError::Spi)?;
40    flush_res.map_err(DeviceError::Spi)?;
41    cs_res.map_err(DeviceError::Cs)?;
42
43    Ok(())
44}
embedded_hal_bus/spi/shared.rs

embedded_hal_bus/spi/
shared.rs
