embassy/embassy-net-enc28j60/src/lib.rs
2023-08-15 14:09:36 +02:00

694 lines
22 KiB
Rust

#![no_std]
#![doc = include_str!("../README.md")]
// must go first.
mod fmt;
#[macro_use]
mod macros;
mod bank0;
mod bank1;
mod bank2;
mod bank3;
mod common;
mod header;
mod phy;
mod traits;
use core::cmp;
use core::convert::TryInto;
use embassy_net_driver::{Capabilities, HardwareAddress, LinkState, Medium};
use embassy_time::Duration;
use embedded_hal::digital::OutputPin;
use embedded_hal::spi::{Operation, SpiDevice};
use traits::U16Ext;
// Total buffer size (see section 3.2)
const BUF_SZ: u16 = 8 * 1024;
// Maximum frame length
const MAX_FRAME_LENGTH: u16 = 1518; // value recommended in the data sheet
// Size of the Frame check sequence (32-bit CRC)
const CRC_SZ: u16 = 4;
// define the boundaries of the TX and RX buffers
// to workaround errata #5 we do the opposite of what section 6.1 of the data sheet
// says: we place the RX buffer at address 0 and the TX buffer after it
const RXST: u16 = 0x0000;
const RXND: u16 = 0x19ff;
const TXST: u16 = 0x1a00;
const _TXND: u16 = 0x1fff;
const MTU: usize = 1514; // 1500 IP + 14 ethernet header
pub struct Enc28j60<S, O> {
mac_addr: [u8; 6],
spi: S,
rst: Option<O>,
bank: Bank,
// address of the next packet in buffer memory
next_packet: u16,
}
impl<S, O> Enc28j60<S, O>
where
S: SpiDevice,
O: OutputPin,
{
pub fn new(spi: S, rst: Option<O>, mac_addr: [u8; 6]) -> Self {
let mut res = Self {
mac_addr,
spi,
rst,
bank: Bank::Bank0,
next_packet: RXST,
};
res.init();
res
}
fn init(&mut self) {
if let Some(rst) = &mut self.rst {
rst.set_low().unwrap();
embassy_time::block_for(Duration::from_millis(5));
rst.set_high().unwrap();
embassy_time::block_for(Duration::from_millis(5));
} else {
embassy_time::block_for(Duration::from_millis(5));
self.soft_reset();
embassy_time::block_for(Duration::from_millis(5));
}
debug!(
"enc28j60: erevid {=u8:x}",
self.read_control_register(bank3::Register::EREVID)
);
debug!("enc28j60: waiting for clk");
while common::ESTAT(self.read_control_register(common::Register::ESTAT)).clkrdy() == 0 {}
debug!("enc28j60: clk ok");
if self.read_control_register(bank3::Register::EREVID) == 0 {
panic!("ErevidIsZero");
}
// disable CLKOUT output
self.write_control_register(bank3::Register::ECOCON, 0);
// RX start
// "It is recommended that the ERXST Pointer be programmed with an even address"
self.write_control_register(bank0::Register::ERXSTL, RXST.low());
self.write_control_register(bank0::Register::ERXSTH, RXST.high());
// RX read pointer
// NOTE Errata #14 so we are using an *odd* address here instead of ERXST
self.write_control_register(bank0::Register::ERXRDPTL, RXND.low());
self.write_control_register(bank0::Register::ERXRDPTH, RXND.high());
// RX end
self.write_control_register(bank0::Register::ERXNDL, RXND.low());
self.write_control_register(bank0::Register::ERXNDH, RXND.high());
// TX start
// "It is recommended that an even address be used for ETXST"
debug_assert_eq!(TXST % 2, 0);
self.write_control_register(bank0::Register::ETXSTL, TXST.low());
self.write_control_register(bank0::Register::ETXSTH, TXST.high());
// TX end is set in `transmit`
// MAC initialization (see section 6.5)
// 1. Set the MARXEN bit in MACON1 to enable the MAC to receive frames.
self.write_control_register(
bank2::Register::MACON1,
bank2::MACON1::default().marxen(1).passall(0).rxpaus(1).txpaus(1).bits(),
);
// 2. Configure the PADCFG, TXCRCEN and FULDPX bits of MACON3.
self.write_control_register(
bank2::Register::MACON3,
bank2::MACON3::default().frmlnen(1).txcrcen(1).padcfg(0b001).bits(),
);
// 4. Program the MAMXFL registers with the maximum frame length to be permitted to be
// received or transmitted
self.write_control_register(bank2::Register::MAMXFLL, MAX_FRAME_LENGTH.low());
self.write_control_register(bank2::Register::MAMXFLH, MAX_FRAME_LENGTH.high());
// 5. Configure the Back-to-Back Inter-Packet Gap register, MABBIPG.
// Use recommended value of 0x12
self.write_control_register(bank2::Register::MABBIPG, 0x12);
// 6. Configure the Non-Back-to-Back Inter-Packet Gap register low byte, MAIPGL.
// Use recommended value of 0x12
self.write_control_register(bank2::Register::MAIPGL, 0x12);
self.write_control_register(bank2::Register::MAIPGH, 0x0c);
// 9. Program the local MAC address into the MAADR1:MAADR6 registers
self.write_control_register(bank3::Register::MAADR1, self.mac_addr[0]);
self.write_control_register(bank3::Register::MAADR2, self.mac_addr[1]);
self.write_control_register(bank3::Register::MAADR3, self.mac_addr[2]);
self.write_control_register(bank3::Register::MAADR4, self.mac_addr[3]);
self.write_control_register(bank3::Register::MAADR5, self.mac_addr[4]);
self.write_control_register(bank3::Register::MAADR6, self.mac_addr[5]);
// Set the PHCON2.HDLDIS bit to prevent automatic loopback of the data which is transmitted
self.write_phy_register(phy::Register::PHCON2, phy::PHCON2::default().hdldis(1).bits());
// Globally enable interrupts
//self.bit_field_set(common::Register::EIE, common::EIE::mask().intie());
// Set the per packet control byte; we'll always use the value 0
self.write_buffer_memory(Some(TXST), &mut [0]);
// decrease the packet count to 0
while self.read_control_register(bank1::Register::EPKTCNT) != 0 {
self.bit_field_set(common::Register::ECON2, common::ECON2::mask().pktdec());
}
// Enable reception
self.bit_field_set(common::Register::ECON1, common::ECON1::mask().rxen());
}
/// Flushes the transmit buffer, ensuring all pending transmissions have completed
/// NOTE: The returned packet *must* be `read` or `ignore`-d, otherwise this method will always
/// return `None` on subsequent invocations
pub fn receive<'a>(&mut self, buf: &'a mut [u8]) -> Option<&'a mut [u8]> {
if self.pending_packets() == 0 {
// Errata #6: we can't rely on PKTIF so we check PKTCNT
return None;
}
let curr_packet = self.next_packet;
// read out the first 6 bytes
let mut temp_buf = [0; 6];
self.read_buffer_memory(Some(curr_packet), &mut temp_buf);
// next packet pointer
let next_packet = u16::from_parts(temp_buf[0], temp_buf[1]);
if next_packet > RXND {
panic!("CorruptRxBuffer");
}
// status vector
let status = header::RxStatus(u32::from_le_bytes(temp_buf[2..].try_into().unwrap()));
let len = status.byte_count() as u16 - CRC_SZ;
if len > RXND {
panic!("CorruptRxBuffer 2");
}
self.read_buffer_memory(None, &mut buf[..len as usize]);
// update ERXRDPT
// due to Errata #14 we must write an odd address to ERXRDPT
// we know that ERXST = 0, that ERXND is odd and that next_packet is even
let rxrdpt = if self.next_packet < 1 || self.next_packet > RXND + 1 {
RXND
} else {
self.next_packet - 1
};
// "To move ERXRDPT, the host controller must write to ERXRDPTL first."
self.write_control_register(bank0::Register::ERXRDPTL, rxrdpt.low());
self.write_control_register(bank0::Register::ERXRDPTH, rxrdpt.high());
// decrease the packet count
self.bit_field_set(common::Register::ECON2, common::ECON2::mask().pktdec());
self.next_packet = next_packet;
Some(&mut buf[..len as usize])
}
fn wait_tx_ready(&mut self) {
for _ in 0u32..10000 {
if common::ECON1(self.read_control_register(common::Register::ECON1)).txrts() == 0 {
return;
}
}
// work around errata #12 by resetting the transmit logic before every new
// transmission
self.bit_field_set(common::Register::ECON1, common::ECON1::mask().txrst());
self.bit_field_clear(common::Register::ECON1, common::ECON1::mask().txrst());
//self.bit_field_clear(common::Register::EIR, {
// let mask = common::EIR::mask();
// mask.txerif() | mask.txif()
//});
}
/// Starts the transmission of `bytes`
///
/// It's up to the caller to ensure that `bytes` is a valid Ethernet frame. The interface will
/// take care of appending a (4 byte) CRC to the frame and of padding the frame to the minimum
/// size allowed by the Ethernet specification (64 bytes, or 46 bytes of payload).
///
/// NOTE This method will flush any previous transmission that's in progress
///
/// # Panics
///
/// If `bytes` length is greater than 1514, the maximum frame length allowed by the interface,
/// or greater than the transmit buffer
pub fn transmit(&mut self, bytes: &[u8]) {
assert!(bytes.len() <= self.mtu() as usize);
self.wait_tx_ready();
// NOTE the plus one is to not overwrite the per packet control byte
let wrpt = TXST + 1;
// 1. ETXST was set during initialization
// 2. write the frame to the IC memory
self.write_buffer_memory(Some(wrpt), bytes);
let txnd = wrpt + bytes.len() as u16 - 1;
// 3. Set the end address of the transmit buffer
self.write_control_register(bank0::Register::ETXNDL, txnd.low());
self.write_control_register(bank0::Register::ETXNDH, txnd.high());
// 4. reset interrupt flag
//self.bit_field_clear(common::Register::EIR, common::EIR::mask().txif());
// 5. start transmission
self.bit_field_set(common::Register::ECON1, common::ECON1::mask().txrts());
// Wait until transmission finishes
//while common::ECON1(self.read_control_register(common::Register::ECON1)).txrts() == 1 {}
/*
// read the transmit status vector
let mut tx_stat = [0; 7];
self.read_buffer_memory(None, &mut tx_stat);
let stat = common::ESTAT(self.read_control_register(common::Register::ESTAT));
if stat.txabrt() == 1 {
// work around errata #12 by reading the transmit status vector
if stat.latecol() == 1 || (tx_stat[2] & (1 << 5)) != 0 {
panic!("LateCollision")
} else {
panic!("TransmitAbort")
}
}*/
}
pub fn is_link_up(&mut self) -> bool {
let bits = self.read_phy_register(phy::Register::PHSTAT2);
phy::PHSTAT2(bits).lstat() == 1
}
/// Returns the interface Maximum Transmission Unit (MTU)
///
/// The value returned by this function will never exceed 1514 bytes. The actual value depends
/// on the memory assigned to the transmission buffer when initializing the device
pub fn mtu(&self) -> u16 {
cmp::min(BUF_SZ - RXND - 1, MAX_FRAME_LENGTH - CRC_SZ)
}
/* Miscellaneous */
/// Returns the number of packets that have been received but have not been processed yet
pub fn pending_packets(&mut self) -> u8 {
self.read_control_register(bank1::Register::EPKTCNT)
}
/// Adjusts the receive filter to *accept* these packet types
pub fn accept(&mut self, packets: &[Packet]) {
let mask = bank1::ERXFCON::mask();
let mut val = 0;
for packet in packets {
match packet {
Packet::Broadcast => val |= mask.bcen(),
Packet::Multicast => val |= mask.mcen(),
Packet::Unicast => val |= mask.ucen(),
}
}
self.bit_field_set(bank1::Register::ERXFCON, val)
}
/// Adjusts the receive filter to *ignore* these packet types
pub fn ignore(&mut self, packets: &[Packet]) {
let mask = bank1::ERXFCON::mask();
let mut val = 0;
for packet in packets {
match packet {
Packet::Broadcast => val |= mask.bcen(),
Packet::Multicast => val |= mask.mcen(),
Packet::Unicast => val |= mask.ucen(),
}
}
self.bit_field_clear(bank1::Register::ERXFCON, val)
}
/* Private */
/* Read */
fn read_control_register<R>(&mut self, register: R) -> u8
where
R: Into<Register>,
{
self._read_control_register(register.into())
}
fn _read_control_register(&mut self, register: Register) -> u8 {
self.change_bank(register);
let mut buffer = [Instruction::RCR.opcode() | register.addr(), 0];
self.spi.transfer_in_place(&mut buffer).unwrap();
buffer[1]
}
fn read_phy_register(&mut self, register: phy::Register) -> u16 {
embassy_time::block_for(Duration::from_millis(1));
// set PHY register address
self.write_control_register(bank2::Register::MIREGADR, register.addr());
// start read operation
self.write_control_register(bank2::Register::MICMD, bank2::MICMD::default().miird(1).bits());
// wait until the read operation finishes
while self.read_control_register(bank3::Register::MISTAT) & 0b1 != 0 {}
let h = self.read_control_register(bank2::Register::MIRDH);
let l = self.read_control_register(bank2::Register::MIRDL);
self.write_control_register(bank2::Register::MICMD, bank2::MICMD::default().miird(0).bits());
(l as u16) | (h as u16) << 8
}
/* Write */
fn _write_control_register(&mut self, register: Register, value: u8) {
self.change_bank(register);
let buffer = [Instruction::WCR.opcode() | register.addr(), value];
self.spi.write(&buffer).unwrap();
}
fn write_control_register<R>(&mut self, register: R, value: u8)
where
R: Into<Register>,
{
self._write_control_register(register.into(), value)
}
fn write_phy_register(&mut self, register: phy::Register, value: u16) {
// set PHY register address
self.write_control_register(bank2::Register::MIREGADR, register.addr());
self.write_control_register(bank2::Register::MIWRL, (value & 0xff) as u8);
// this starts the write operation
self.write_control_register(bank2::Register::MIWRH, (value >> 8) as u8);
// wait until the write operation finishes
while self.read_control_register(bank3::Register::MISTAT) & 0b1 != 0 {}
}
/* RMW */
fn modify_control_register<R, F>(&mut self, register: R, f: F)
where
F: FnOnce(u8) -> u8,
R: Into<Register>,
{
self._modify_control_register(register.into(), f)
}
fn _modify_control_register<F>(&mut self, register: Register, f: F)
where
F: FnOnce(u8) -> u8,
{
let r = self._read_control_register(register);
self._write_control_register(register, f(r))
}
/* Auxiliary */
fn change_bank(&mut self, register: Register) {
let bank = register.bank();
if let Some(bank) = bank {
if self.bank == bank {
// already on the register bank
return;
}
// change bank
self.bank = bank;
match bank {
Bank::Bank0 => self.bit_field_clear(common::Register::ECON1, 0b11),
Bank::Bank1 => self.modify_control_register(common::Register::ECON1, |r| (r & !0b11) | 0b01),
Bank::Bank2 => self.modify_control_register(common::Register::ECON1, |r| (r & !0b11) | 0b10),
Bank::Bank3 => self.bit_field_set(common::Register::ECON1, 0b11),
}
} else {
// common register
}
}
/* Primitive operations */
fn bit_field_clear<R>(&mut self, register: R, mask: u8)
where
R: Into<Register>,
{
self._bit_field_clear(register.into(), mask)
}
fn _bit_field_clear(&mut self, register: Register, mask: u8) {
debug_assert!(register.is_eth_register());
self.change_bank(register);
self.spi
.write(&[Instruction::BFC.opcode() | register.addr(), mask])
.unwrap();
}
fn bit_field_set<R>(&mut self, register: R, mask: u8)
where
R: Into<Register>,
{
self._bit_field_set(register.into(), mask)
}
fn _bit_field_set(&mut self, register: Register, mask: u8) {
debug_assert!(register.is_eth_register());
self.change_bank(register);
self.spi
.write(&[Instruction::BFS.opcode() | register.addr(), mask])
.unwrap();
}
fn read_buffer_memory(&mut self, addr: Option<u16>, buf: &mut [u8]) {
if let Some(addr) = addr {
self.write_control_register(bank0::Register::ERDPTL, addr.low());
self.write_control_register(bank0::Register::ERDPTH, addr.high());
}
self.spi
.transaction(&mut [Operation::Write(&[Instruction::RBM.opcode()]), Operation::Read(buf)])
.unwrap();
}
fn soft_reset(&mut self) {
self.spi.write(&[Instruction::SRC.opcode()]).unwrap();
}
fn write_buffer_memory(&mut self, addr: Option<u16>, buffer: &[u8]) {
if let Some(addr) = addr {
self.write_control_register(bank0::Register::EWRPTL, addr.low());
self.write_control_register(bank0::Register::EWRPTH, addr.high());
}
self.spi
.transaction(&mut [Operation::Write(&[Instruction::WBM.opcode()]), Operation::Write(buffer)])
.unwrap();
}
}
#[derive(Clone, Copy, PartialEq)]
enum Bank {
Bank0,
Bank1,
Bank2,
Bank3,
}
#[derive(Clone, Copy)]
enum Instruction {
/// Read Control Register
RCR = 0b000_00000,
/// Read Buffer Memory
RBM = 0b001_11010,
/// Write Control Register
WCR = 0b010_00000,
/// Write Buffer Memory
WBM = 0b011_11010,
/// Bit Field Set
BFS = 0b100_00000,
/// Bit Field Clear
BFC = 0b101_00000,
/// System Reset Command
SRC = 0b111_11111,
}
impl Instruction {
fn opcode(&self) -> u8 {
*self as u8
}
}
#[derive(Clone, Copy)]
enum Register {
Bank0(bank0::Register),
Bank1(bank1::Register),
Bank2(bank2::Register),
Bank3(bank3::Register),
Common(common::Register),
}
impl Register {
fn addr(&self) -> u8 {
match *self {
Register::Bank0(r) => r.addr(),
Register::Bank1(r) => r.addr(),
Register::Bank2(r) => r.addr(),
Register::Bank3(r) => r.addr(),
Register::Common(r) => r.addr(),
}
}
fn bank(&self) -> Option<Bank> {
Some(match *self {
Register::Bank0(_) => Bank::Bank0,
Register::Bank1(_) => Bank::Bank1,
Register::Bank2(_) => Bank::Bank2,
Register::Bank3(_) => Bank::Bank3,
Register::Common(_) => return None,
})
}
fn is_eth_register(&self) -> bool {
match *self {
Register::Bank0(r) => r.is_eth_register(),
Register::Bank1(r) => r.is_eth_register(),
Register::Bank2(r) => r.is_eth_register(),
Register::Bank3(r) => r.is_eth_register(),
Register::Common(r) => r.is_eth_register(),
}
}
}
/// Packet type, used to configure receive filters
#[non_exhaustive]
#[derive(Clone, Copy, Eq, PartialEq)]
pub enum Packet {
/// Broadcast packets
Broadcast,
/// Multicast packets
Multicast,
/// Unicast packets
Unicast,
}
static mut TX_BUF: [u8; MTU] = [0; MTU];
static mut RX_BUF: [u8; MTU] = [0; MTU];
impl<S, O> embassy_net_driver::Driver for Enc28j60<S, O>
where
S: SpiDevice,
O: OutputPin,
{
type RxToken<'a> = RxToken<'a>
where
Self: 'a;
type TxToken<'a> = TxToken<'a, S, O>
where
Self: 'a;
fn receive(&mut self, cx: &mut core::task::Context) -> Option<(Self::RxToken<'_>, Self::TxToken<'_>)> {
let rx_buf = unsafe { &mut RX_BUF };
let tx_buf = unsafe { &mut TX_BUF };
if let Some(pkt) = self.receive(rx_buf) {
let n = pkt.len();
Some((RxToken { buf: &mut pkt[..n] }, TxToken { buf: tx_buf, eth: self }))
} else {
cx.waker().wake_by_ref();
None
}
}
fn transmit(&mut self, _cx: &mut core::task::Context) -> Option<Self::TxToken<'_>> {
let tx_buf = unsafe { &mut TX_BUF };
Some(TxToken { buf: tx_buf, eth: self })
}
fn link_state(&mut self, cx: &mut core::task::Context) -> LinkState {
cx.waker().wake_by_ref();
match self.is_link_up() {
true => LinkState::Up,
false => LinkState::Down,
}
}
fn capabilities(&self) -> Capabilities {
let mut caps = Capabilities::default();
caps.max_transmission_unit = MTU;
caps.medium = Medium::Ethernet;
caps
}
fn hardware_address(&self) -> HardwareAddress {
HardwareAddress::Ethernet(self.mac_addr)
}
}
pub struct RxToken<'a> {
buf: &'a mut [u8],
}
impl<'a> embassy_net_driver::RxToken for RxToken<'a> {
fn consume<R, F>(self, f: F) -> R
where
F: FnOnce(&mut [u8]) -> R,
{
f(self.buf)
}
}
pub struct TxToken<'a, S, O>
where
S: SpiDevice,
O: OutputPin,
{
eth: &'a mut Enc28j60<S, O>,
buf: &'a mut [u8],
}
impl<'a, S, O> embassy_net_driver::TxToken for TxToken<'a, S, O>
where
S: SpiDevice,
O: OutputPin,
{
fn consume<R, F>(self, len: usize, f: F) -> R
where
F: FnOnce(&mut [u8]) -> R,
{
assert!(len <= self.buf.len());
let r = f(&mut self.buf[..len]);
self.eth.transmit(&self.buf[..len]);
r
}
}