w5100-rs/src/raw_device.rs
2023-06-23 13:59:54 +02:00

99 lines
3.6 KiB
Rust

use crate::{bus::Bus, register, socket::Socket, uninitialized_device::InitializeError};
/// The W5500 operating in MACRAW mode to send and receive ethernet frames.
#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct RawDevice<SpiBus: Bus> {
bus: SpiBus,
raw_socket: Socket,
}
impl<SpiBus: Bus> RawDevice<SpiBus> {
/// Create the raw device.
///
/// # Note
/// The device is configured with MAC filtering enabled.
///
/// # Args
/// * `bus` - The bus to communicate with the device.
pub(crate) fn new(mut bus: SpiBus) -> Result<Self, InitializeError<SpiBus::Error>> {
// Set the raw socket to 16KB RX/TX buffer space.
let raw_socket = Socket::new(0);
bus.write_frame(raw_socket.register(), register::socketn::TXBUF_SIZE, &[16])?;
bus.write_frame(raw_socket.register(), register::socketn::RXBUF_SIZE, &[16])?;
// Set all socket buffers to 0KB size.
for socket_index in 1..8 {
let socket = Socket::new(socket_index);
bus.write_frame(socket.register(), register::socketn::TXBUF_SIZE, &[0])?;
bus.write_frame(socket.register(), register::socketn::RXBUF_SIZE, &[0])?;
}
// Configure the chip in MACRAW mode with MAC filtering.
let mode: u8 = (1 << 7) | // MAC address filtering
(register::socketn::Protocol::MacRaw as u8);
bus.write_frame(raw_socket.register(), register::socketn::MODE, &[mode])?;
raw_socket.command(&mut bus, register::socketn::Command::Open)?;
Ok(Self { bus, raw_socket })
}
/// Read an ethernet frame from the device.
///
/// # Args
/// * `frame` - The location to store the received frame
///
/// # Returns
/// The number of bytes read into the provided frame buffer.
pub fn read_frame(&mut self, frame: &mut [u8]) -> Result<usize, SpiBus::Error> {
let mut rx_cursor = crate::cursor::RxCursor::new(&self.raw_socket, &mut self.bus)?;
// Check if there is anything to receive.
if rx_cursor.available() == 0 {
return Ok(0);
}
// The W5500 specifies the size of the received ethernet frame in the first two bytes.
// Refer to https://forum.wiznet.io/t/topic/979/2 for more information.
let expected_frame_size = {
let mut frame_bytes = [0u8; 2];
assert!(rx_cursor.read(&mut frame_bytes[..])? == 2);
u16::from_be_bytes(frame_bytes).saturating_sub(2)
};
let received_frame_size = rx_cursor.read_upto(frame, expected_frame_size)?;
if received_frame_size < expected_frame_size {
rx_cursor.skip(expected_frame_size - received_frame_size);
}
rx_cursor.commit()?;
Ok(received_frame_size as _)
}
/// Write an ethernet frame to the device.
///
/// # Args
/// * `frame` - The ethernet frame to transmit.
///
/// # Returns
/// The number of bytes successfully transmitted from the provided buffer.
pub fn write_frame(&mut self, frame: &[u8]) -> Result<usize, SpiBus::Error> {
// Reset the transmission complete flag, we'll wait on it later.
self.raw_socket
.reset_interrupt(&mut self.bus, register::socketn::Interrupt::SendOk)?;
let mut tx_cursor = crate::cursor::TxCursor::new(&self.raw_socket, &mut self.bus)?;
let count = tx_cursor.write(frame)?;
tx_cursor.commit()?;
// Wait for the socket transmission to complete.
while !self
.raw_socket
.has_interrupt(&mut self.bus, register::socketn::Interrupt::SendOk)?
{}
Ok(count as _)
}
}