ENC424J600/src/spi.rs

195 lines
6.6 KiB
Rust

use embedded_hal::{
blocking::spi::Transfer,
digital::v2::OutputPin,
};
pub mod interfaces {
use embedded_hal::spi;
/// Must use SPI mode cpol=0, cpha=0
pub const SPI_MODE: spi::Mode = spi::Mode {
polarity: spi::Polarity::IdleLow,
phase: spi::Phase::CaptureOnFirstTransition,
};
/// Max freq = 14 MHz
pub const SPI_CLOCK_FREQ: u32 = 14_000_000;
}
pub mod opcodes {
/// SPI Opcodes
pub const RCRU: u8 = 0b0010_0000;
pub const WCRU: u8 = 0b0010_0010;
pub const RERXDATA: u8 = 0b0010_1100; // 8-bit opcode followed by data
pub const WEGPDATA: u8 = 0b0010_1010; // 8-bit opcode followed by data
}
pub mod addrs {
/// SPI Register Mapping
/// Note: PSP interface use different address mapping
// SPI Init Reset Registers
pub const EUDAST: u8 = 0x16; // 16-bit data
pub const ESTAT: u8 = 0x1a; // 16-bit data
pub const ECON2: u8 = 0x6e; // 16-bit data
//
pub const ERXFCON: u8 = 0x34; // 16-bit data
//
pub const MAADR3: u8 = 0x60; // 16-bit data
pub const MAADR2: u8 = 0x62; // 16-bit data
pub const MAADR1: u8 = 0x64; // 16-bit data
// RX Registers
pub const ERXRDPT: u8 = 0x8a; // 16-bit data
pub const ERXST: u8 = 0x04; // 16-bit data
pub const ERXTAIL: u8 = 0x06; // 16-bit data
pub const EIR: u8 = 0x1c; // 16-bit data
pub const ECON1: u8 = 0x1e; // 16-bit data
pub const MAMXFL: u8 = 0x4a; // 16-bit data
// TX Registers
pub const EGPWRPT: u8 = 0x88; // 16-bit data
pub const ETXST: u8 = 0x00; // 16-bit data
pub const ETXSTAT: u8 = 0x12; // 16-bit data
pub const ETXLEN: u8 = 0x02; // 16-bit data
}
/// Struct for SPI I/O interface on ENC424J600
/// Note: stm32f4xx_hal::spi's pins include: SCK, MISO, MOSI
pub struct SpiPort<SPI: Transfer<u8>,
NSS: OutputPin> {
spi: SPI,
nss: NSS,
}
pub enum SpiPortError {
TransferError
}
#[allow(unused_must_use)]
impl <SPI: Transfer<u8>,
NSS: OutputPin> SpiPort<SPI, NSS> {
// TODO: return as Result()
pub fn new(spi: SPI, mut nss: NSS) -> Self {
nss.set_high();
SpiPort {
spi,
nss
}
}
pub fn read_reg_8b(&mut self, addr: u8) -> Result<u8, SpiPortError> {
// Using RCRU instruction to read using unbanked (full) address
let r_data = self.rw_addr_u8(opcodes::RCRU, addr, 0)?;
Ok(r_data)
}
pub fn read_reg_16b(&mut self, lo_addr: u8) -> Result<u16, SpiPortError> {
let r_data_lo = self.read_reg_8b(lo_addr)?;
let r_data_hi = self.read_reg_8b(lo_addr + 1)?;
// Combine top and bottom 8-bit to return 16-bit
Ok(((r_data_hi as u16) << 8) | r_data_lo as u16)
}
// Currently requires manual slicing (buf[1..]) for the data read back
pub fn read_rxdat<'a>(&mut self, buf: &'a mut [u8], data_length: usize)
-> Result<(), SpiPortError> {
let r_valid = self.r_n(buf, opcodes::RERXDATA, data_length)?;
Ok(r_valid)
}
// Currenly requires actual data to be stored in buf[1..] instead of buf[0..]
// TODO: Maybe better naming?
pub fn write_txdat<'a>(&mut self, buf: &'a mut [u8], data_length: usize)
-> Result<(), SpiPortError> {
let w_valid = self.w_n(buf, opcodes::WEGPDATA, data_length)?;
Ok(w_valid)
}
pub fn write_reg_8b(&mut self, addr: u8, data: u8) -> Result<(), SpiPortError> {
// TODO: addr should be separated from w_data
// Using WCRU instruction to write using unbanked (full) address
self.rw_addr_u8(opcodes::WCRU, addr, data)?;
Ok(())
}
pub fn write_reg_16b(&mut self, lo_addr: u8, data: u16) -> Result<(), SpiPortError> {
self.write_reg_8b(lo_addr, (data & 0xff) as u8)?;
self.write_reg_8b(lo_addr + 1, ((data & 0xff00) >> 8) as u8)?;
Ok(())
}
// TODO: Generalise transfer functions
// TODO: (Make data read/write as reference to array)
// Currently requires 1-byte addr, read/write data is only 1-byte
fn rw_addr_u8(&mut self, opcode: u8, addr: u8, data: u8)
-> Result<u8, SpiPortError> {
// Enable chip select
self.nss.set_low();
// Start writing to SLAVE
// TODO: don't just use 3 bytes
let mut buf: [u8; 3] = [0; 3];
buf[0] = opcode;
buf[1] = addr;
buf[2] = data;
match self.spi.transfer(&mut buf) {
Ok(_) => {
// Disable chip select
self.nss.set_high();
Ok(buf[2])
},
// TODO: Maybe too naive?
Err(_) => {
// Disable chip select
self.nss.set_high();
Err(SpiPortError::TransferError)
}
}
}
// TODO: Generalise transfer functions
// Currently does NOT accept addr, read data is N-byte long
// Returns a reference to the data returned
// Note: buf must be at least (data_length + 1)-byte long
// TODO: Check and raise error for array size < (data_length + 1)
fn r_n<'a>(&mut self, buf: &'a mut [u8], opcode: u8, data_length: usize)
-> Result<(), SpiPortError> {
// Enable chip select
self.nss.set_low();
// Start writing to SLAVE
buf[0] = opcode;
match self.spi.transfer(&mut buf[..data_length+1]) {
Ok(_) => {
// Disable chip select
self.nss.set_high();
Ok(())
},
// TODO: Maybe too naive?
Err(_) => {
// Disable chip select
self.nss.set_high();
Err(SpiPortError::TransferError)
}
}
}
// Note: buf[0] is currently reserved for opcode to overwrite
// TODO: Actual data should start from buf[0], not buf[1]
fn w_n<'a>(&mut self, buf: &'a mut [u8], opcode: u8, data_length: usize)
-> Result<(), SpiPortError> {
// Enable chip select
self.nss.set_low();
// Start writing to SLAVE
buf[0] = opcode;
// TODO: Maybe need to copy data to buf later on
match self.spi.transfer(&mut buf[..data_length+1]) {
Ok(_) => {
// Disable chip select
self.nss.set_high();
Ok(())
},
// TODO: Maybe too naive?
Err(_) => {
// Disable chip select
self.nss.set_high();
Err(SpiPortError::TransferError)
}
}
}
}