Finalizing updates to MACRAW support after testing

src/raw_device.rs

@@ -15,10 +15,22 @@ impl<SpiBus: Bus> RawDevice<SpiBus> {
     /// # 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])?;
 
-        // Configure the chip in MACRAW mode with MAC filtering.
+        // Set all socket buffers to 0KB size.
-        let mode: u8 = (1 << 7) | (register::socketn::Protocol::MacRaw as u8);
+        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 + Multicast blocking + IPv6
+        // Blocking + Broadcast blocking.
+        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)?;
@@ -26,6 +38,29 @@ impl<SpiBus: Bus> RawDevice<SpiBus> {
         Ok(Self { bus, raw_socket })
     }
 
+    fn read_bytes(&mut self, buffer: &mut [u8], offset: u16) -> Result<usize, SpiBus::Error> {
+        let rx_size = self.raw_socket.get_receive_size(&mut self.bus)? as usize;
+
+        let read_buffer = if rx_size > buffer.len() + offset as usize {
+            buffer
+        } else {
+            &mut buffer[..rx_size - offset as usize]
+        };
+
+        let read_pointer = self
+            .raw_socket
+            .get_rx_read_pointer(&mut self.bus)?
+            .wrapping_add(offset);
+        self.bus
+            .read_frame(self.raw_socket.rx_buffer(), read_pointer, read_buffer)?;
+        self.raw_socket.set_rx_read_pointer(
+            &mut self.bus,
+            read_pointer.wrapping_add(read_buffer.len() as u16),
+        )?;
+
+        Ok(read_buffer.len())
+    }
+
     /// Read an ethernet frame from the device.
     ///
     /// # Args
@@ -34,37 +69,41 @@ impl<SpiBus: Bus> RawDevice<SpiBus> {
     /// # Returns
     /// The number of bytes read into the provided frame buffer.
     pub fn read_frame(&mut self, frame: &mut [u8]) -> Result<usize, SpiBus::Error> {
-        if !self
+        // Check if there is anything to receive.
-            .raw_socket
+        let rx_size = self.raw_socket.get_receive_size(&mut self.bus)? as usize;
-            .has_interrupt(&mut self.bus, register::socketn::Interrupt::Receive)?
+        if rx_size == 0 {
-        {
             return Ok(0);
         }
 
-        let rx_size = self.raw_socket.get_receive_size(&mut self.bus)? as usize;
+        // 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: usize = {
+            let mut frame_bytes = [0u8; 2];
+            assert!(self.read_bytes(&mut frame_bytes[..], 0)? == 2);
 
-        let read_buffer = if rx_size > frame.len() {
+            u16::from_be_bytes(frame_bytes) as usize - 2
-            frame
-        } else {
-            &mut frame[..rx_size]
         };
 
-        // Read from the RX ring buffer.
+        // Read the ethernet frame
-        let read_pointer = self.raw_socket.get_rx_read_pointer(&mut self.bus)?;
+        let read_buffer = if frame.len() > expected_frame_size {
-        self.bus
+            &mut frame[..expected_frame_size]
-            .read_frame(self.raw_socket.rx_buffer(), read_pointer, read_buffer)?;
+        } else {
-        self.raw_socket.set_rx_read_pointer(
+            frame
-            &mut self.bus,
+        };
-            read_pointer.wrapping_add(read_buffer.len() as u16),
+
-        )?;
+        let received_frame_size = self.read_bytes(read_buffer, 2)?;
 
         // Register the reception as complete.
         self.raw_socket
             .command(&mut self.bus, register::socketn::Command::Receive)?;
-        self.raw_socket
-            .reset_interrupt(&mut self.bus, register::socketn::Interrupt::Receive)?;
 
-        Ok(read_buffer.len())
+        // If we couldn't read the whole check sequence or if we read less bytes than expected,
+        // drop the frame.
+        if received_frame_size < expected_frame_size {
+            Ok(0)
+        } else {
+            Ok(received_frame_size)
+        }
     }
 
     /// Write an ethernet frame to the device.

src/register.rs

@@ -217,6 +217,10 @@ pub mod socketn {
 
     pub const DESTINATION_PORT: u16 = 0x10;
 
+    pub const RXBUF_SIZE: u16 = 0x1E;
+
+    pub const TXBUF_SIZE: u16 = 0x1F;
+
     pub const TX_FREE_SIZE: u16 = 0x20;
 
     pub const TX_DATA_READ_POINTER: u16 = 0x22;

src/uninitialized_device.rs

@@ -103,8 +103,13 @@ impl<SpiBus: Bus> UninitializedDevice<SpiBus> {
         mut self,
         mac: MacAddress,
     ) -> Result<RawDevice<SpiBus>, InitializeError<SpiBus::Error>> {
+        // Reset the device.
+        self.bus
+            .write_frame(register::COMMON, register::common::MODE, &[0x80])?;
+
         self.bus
             .write_frame(register::COMMON, register::common::MAC, &mac.octets)?;
+
         RawDevice::new(self.bus)
     }