embedded_hal_nb/spi.rs
1//! SPI master mode traits using `nb`.
2
3pub use embedded_hal::spi::{
4 Error, ErrorKind, ErrorType, Mode, Phase, Polarity, MODE_0, MODE_1, MODE_2, MODE_3,
5};
6
7/// Full duplex SPI (master mode).
8///
9/// # Notes
10///
11/// - It's the task of the user of this interface to manage the slave select lines.
12///
13/// - Due to how full duplex SPI works each `read` call must be preceded by a `write` call.
14///
15/// - `read` calls only return the data received with the last `write` call.
16/// Previously received data is discarded
17///
18/// - Data is only guaranteed to be clocked out when the `read` call succeeds.
19/// The slave select line shouldn't be released before that.
20///
21/// - Some SPIs can work with 8-bit *and* 16-bit words. You can overload this trait with different
22/// `Word` types to allow operation in both modes.
23pub trait FullDuplex<Word: Copy = u8>: ErrorType {
24 /// Reads the word stored in the shift register
25 ///
26 /// **NOTE** A word must be sent to the slave before attempting to call this
27 /// method.
28 fn read(&mut self) -> nb::Result<Word, Self::Error>;
29
30 /// Writes a word to the slave
31 fn write(&mut self, word: Word) -> nb::Result<(), Self::Error>;
32}
33
34impl<T: FullDuplex<Word> + ?Sized, Word: Copy> FullDuplex<Word> for &mut T {
35 #[inline]
36 fn read(&mut self) -> nb::Result<Word, Self::Error> {
37 T::read(self)
38 }
39
40 #[inline]
41 fn write(&mut self, word: Word) -> nb::Result<(), Self::Error> {
42 T::write(self, word)
43 }
44}