humpback-dds/src/spi_slave.rs

use embedded_hal::{
    blocking::spi::Transfer,
    digital::v2::OutputPin,
};
use crate::cpld::CPLD;
use crate::urukul::Error;

pub struct SPISlave<'a, SPI, CS0, CS1, CS2, GPIO> (
    // SPI device to be multiplexed
    &'a CPLD<SPI, CS0, CS1, CS2, GPIO>,
    // Channel of SPI slave
    u8,
    // Need I/O Update
    bool,
);

pub struct Parts<'a, SPI, CS0, CS1, CS2, GPIO> {
    pub spi1: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi2: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi3: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi4: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi5: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi6: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
    pub spi7: SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>,
}

impl<'a, SPI, CS0, CS1, CS2, GPIO> Parts<'a, SPI, CS0, CS1, CS2, GPIO> {
    pub(crate) fn new(cpld: &'a CPLD<SPI, CS0, CS1, CS2, GPIO>) -> Self {
        Parts {
            spi1: SPISlave(&cpld, 1, false),
            spi2: SPISlave(&cpld, 2, false),
            spi3: SPISlave(&cpld, 3, false),
            spi4: SPISlave(&cpld, 4, true),
            spi5: SPISlave(&cpld, 5, true),
            spi6: SPISlave(&cpld, 6, true),
            spi7: SPISlave(&cpld, 7, true),
        }
    }
}

impl<'a, SPI, CS0, CS1, CS2, GPIO, E> Transfer<u8> for SPISlave<'a, SPI, CS0, CS1, CS2, GPIO>
where
    CS2: OutputPin,
    CS1: OutputPin,
    CS0: OutputPin,
    SPI: Transfer<u8, Error = E>,
    GPIO: OutputPin,
{
    type Error = Error<E>;

    fn transfer<'w>(&mut self, words: &'w mut[u8]) -> Result<&'w [u8], Self::Error> {
        let mut dev = self.0.data.try_borrow_mut().map_err(|_| Error::GetRefMutDataError)?;
        dev.select_chip(self.1).map_err(|_| Error::CSError)?;
        let result = dev.spi.transfer(words).map_err(Error::SPI)?;
        dev.select_chip(0).map_err(|_| Error::CSError)?;
        if self.2 {
            dev.issue_io_update().map_err(|_| Error::IOUpdateError)?;
        }
        Ok(result)
    }
}