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)
	}
}