docs: document public apis of embassy-net-driver-channel

embassy-net-driver-channel/src/lib.rs

@@ -1,5 +1,6 @@
 #![no_std]
 #![doc = include_str!("../README.md")]
+#![warn(missing_docs)]
 
 // must go first!
 mod fmt;
@@ -15,6 +16,9 @@ use embassy_sync::blocking_mutex::Mutex;
 use embassy_sync::waitqueue::WakerRegistration;
 use embassy_sync::zerocopy_channel;
 
+/// Channel state.
+///
+/// Holds a buffer of packets with size MTU, for both TX and RX.
 pub struct State<const MTU: usize, const N_RX: usize, const N_TX: usize> {
     rx: [PacketBuf<MTU>; N_RX],
     tx: [PacketBuf<MTU>; N_TX],
@@ -24,6 +28,7 @@ pub struct State<const MTU: usize, const N_RX: usize, const N_TX: usize> {
 impl<const MTU: usize, const N_RX: usize, const N_TX: usize> State<MTU, N_RX, N_TX> {
     const NEW_PACKET: PacketBuf<MTU> = PacketBuf::new();
 
+    /// Create a new channel state.
     pub const fn new() -> Self {
         Self {
             rx: [Self::NEW_PACKET; N_RX],
@@ -39,33 +44,45 @@ struct StateInner<'d, const MTU: usize> {
     shared: Mutex<NoopRawMutex, RefCell<Shared>>,
 }
 
-/// State of the LinkState
 struct Shared {
     link_state: LinkState,
     waker: WakerRegistration,
     hardware_address: driver::HardwareAddress,
 }
 
+/// Channel runner.
+///
+/// Holds the shared state and the lower end of channels for inbound and outbound packets.
 pub struct Runner<'d, const MTU: usize> {
     tx_chan: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
     rx_chan: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
     shared: &'d Mutex<NoopRawMutex, RefCell<Shared>>,
 }
 
+/// State runner.
+///
+/// Holds the shared state of the channel such as link state.
 #[derive(Clone, Copy)]
 pub struct StateRunner<'d> {
     shared: &'d Mutex<NoopRawMutex, RefCell<Shared>>,
 }
 
+/// RX runner.
+///
+/// Holds the lower end of the channel for passing inbound packets up the stack.
 pub struct RxRunner<'d, const MTU: usize> {
     rx_chan: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
 }
 
+/// TX runner.
+///
+/// Holds the lower end of the channel for passing outbound packets down the stack.
 pub struct TxRunner<'d, const MTU: usize> {
     tx_chan: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
 }
 
 impl<'d, const MTU: usize> Runner<'d, MTU> {
+    /// Split the runner into separate runners for controlling state, rx and tx.
     pub fn split(self) -> (StateRunner<'d>, RxRunner<'d, MTU>, TxRunner<'d, MTU>) {
         (
             StateRunner { shared: self.shared },
@@ -74,6 +91,7 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         )
     }
 
+    /// Split the runner into separate runners for controlling state, rx and tx borrowing the underlying state.
     pub fn borrow_split(&mut self) -> (StateRunner<'_>, RxRunner<'_, MTU>, TxRunner<'_, MTU>) {
         (
             StateRunner { shared: self.shared },
@@ -86,10 +104,12 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         )
     }
 
+    /// Create a state runner sharing the state channel.
     pub fn state_runner(&self) -> StateRunner<'d> {
         StateRunner { shared: self.shared }
     }
 
+    /// Set the link state.
     pub fn set_link_state(&mut self, state: LinkState) {
         self.shared.lock(|s| {
             let s = &mut *s.borrow_mut();
@@ -98,6 +118,7 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         });
     }
 
+    /// Set the hardware address.
     pub fn set_hardware_address(&mut self, address: driver::HardwareAddress) {
         self.shared.lock(|s| {
             let s = &mut *s.borrow_mut();
@@ -106,16 +127,19 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         });
     }
 
+    /// Wait until there is space for more inbound packets and return a slice they can be copied into.
     pub async fn rx_buf(&mut self) -> &mut [u8] {
         let p = self.rx_chan.send().await;
         &mut p.buf
     }
 
+    /// Check if there is space for more inbound packets right now.
     pub fn try_rx_buf(&mut self) -> Option<&mut [u8]> {
         let p = self.rx_chan.try_send()?;
         Some(&mut p.buf)
     }
 
+    /// Polling the inbound channel if there is space for packets.
     pub fn poll_rx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
         match self.rx_chan.poll_send(cx) {
             Poll::Ready(p) => Poll::Ready(&mut p.buf),
@@ -123,22 +147,26 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         }
     }
 
+    /// Mark packet of len bytes as pushed to the inbound channel.
     pub fn rx_done(&mut self, len: usize) {
         let p = self.rx_chan.try_send().unwrap();
         p.len = len;
         self.rx_chan.send_done();
     }
 
+    /// Wait until there is space for more outbound packets and return a slice they can be copied into.
     pub async fn tx_buf(&mut self) -> &mut [u8] {
         let p = self.tx_chan.receive().await;
         &mut p.buf[..p.len]
     }
 
+    /// Check if there is space for more outbound packets right now.
     pub fn try_tx_buf(&mut self) -> Option<&mut [u8]> {
         let p = self.tx_chan.try_receive()?;
         Some(&mut p.buf[..p.len])
     }
 
+    /// Polling the outbound channel if there is space for packets.
     pub fn poll_tx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
         match self.tx_chan.poll_receive(cx) {
             Poll::Ready(p) => Poll::Ready(&mut p.buf[..p.len]),
@@ -146,12 +174,14 @@ impl<'d, const MTU: usize> Runner<'d, MTU> {
         }
     }
 
+    /// Mark outbound packet as copied.
     pub fn tx_done(&mut self) {
         self.tx_chan.receive_done();
     }
 }
 
 impl<'d> StateRunner<'d> {
+    /// Set link state.
     pub fn set_link_state(&self, state: LinkState) {
         self.shared.lock(|s| {
             let s = &mut *s.borrow_mut();
@@ -160,6 +190,7 @@ impl<'d> StateRunner<'d> {
         });
     }
 
+    /// Set the hardware address.
     pub fn set_hardware_address(&self, address: driver::HardwareAddress) {
         self.shared.lock(|s| {
             let s = &mut *s.borrow_mut();
@@ -170,16 +201,19 @@ impl<'d> StateRunner<'d> {
 }
 
 impl<'d, const MTU: usize> RxRunner<'d, MTU> {
+    /// Wait until there is space for more inbound packets and return a slice they can be copied into.
     pub async fn rx_buf(&mut self) -> &mut [u8] {
         let p = self.rx_chan.send().await;
         &mut p.buf
     }
 
+    /// Check if there is space for more inbound packets right now.
     pub fn try_rx_buf(&mut self) -> Option<&mut [u8]> {
         let p = self.rx_chan.try_send()?;
         Some(&mut p.buf)
     }
 
+    /// Polling the inbound channel if there is space for packets.
     pub fn poll_rx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
         match self.rx_chan.poll_send(cx) {
             Poll::Ready(p) => Poll::Ready(&mut p.buf),
@@ -187,6 +221,7 @@ impl<'d, const MTU: usize> RxRunner<'d, MTU> {
         }
     }
 
+    /// Mark packet of len bytes as pushed to the inbound channel.
     pub fn rx_done(&mut self, len: usize) {
         let p = self.rx_chan.try_send().unwrap();
         p.len = len;
@@ -195,16 +230,19 @@ impl<'d, const MTU: usize> RxRunner<'d, MTU> {
 }
 
 impl<'d, const MTU: usize> TxRunner<'d, MTU> {
+    /// Wait until there is space for more outbound packets and return a slice they can be copied into.
     pub async fn tx_buf(&mut self) -> &mut [u8] {
         let p = self.tx_chan.receive().await;
         &mut p.buf[..p.len]
     }
 
+    /// Check if there is space for more outbound packets right now.
     pub fn try_tx_buf(&mut self) -> Option<&mut [u8]> {
         let p = self.tx_chan.try_receive()?;
         Some(&mut p.buf[..p.len])
     }
 
+    /// Polling the outbound channel if there is space for packets.
     pub fn poll_tx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
         match self.tx_chan.poll_receive(cx) {
             Poll::Ready(p) => Poll::Ready(&mut p.buf[..p.len]),
@@ -212,11 +250,18 @@ impl<'d, const MTU: usize> TxRunner<'d, MTU> {
         }
     }
 
+    /// Mark outbound packet as copied.
     pub fn tx_done(&mut self) {
         self.tx_chan.receive_done();
     }
 }
 
+/// Create a channel.
+///
+/// Returns a pair of handles for interfacing with the peripheral and the networking stack.
+///
+/// The runner is interfacing with the peripheral at the lower part of the stack.
+/// The device is interfacing with the networking stack on the layer above.
 pub fn new<'d, const MTU: usize, const N_RX: usize, const N_TX: usize>(
     state: &'d mut State<MTU, N_RX, N_TX>,
     hardware_address: driver::HardwareAddress,
@@ -257,17 +302,22 @@ pub fn new<'d, const MTU: usize, const N_RX: usize, const N_TX: usize>(
     )
 }
 
+/// Represents a packet of size MTU.
 pub struct PacketBuf<const MTU: usize> {
     len: usize,
     buf: [u8; MTU],
 }
 
 impl<const MTU: usize> PacketBuf<MTU> {
+    /// Create a new packet buffer.
     pub const fn new() -> Self {
         Self { len: 0, buf: [0; MTU] }
     }
 }
 
+/// Channel device.
+///
+/// Holds the shared state and upper end of channels for inbound and outbound packets.
 pub struct Device<'d, const MTU: usize> {
     rx: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
     tx: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
@@ -314,6 +364,9 @@ impl<'d, const MTU: usize> embassy_net_driver::Driver for Device<'d, MTU> {
     }
 }
 
+/// A rx token.
+///
+/// Holds inbound receive channel and interfaces with embassy-net-driver.
 pub struct RxToken<'a, const MTU: usize> {
     rx: zerocopy_channel::Receiver<'a, NoopRawMutex, PacketBuf<MTU>>,
 }
@@ -331,6 +384,9 @@ impl<'a, const MTU: usize> embassy_net_driver::RxToken for RxToken<'a, MTU> {
     }
 }
 
+/// A tx token.
+///
+/// Holds outbound transmit channel and interfaces with embassy-net-driver.
 pub struct TxToken<'a, const MTU: usize> {
     tx: zerocopy_channel::Sender<'a, NoopRawMutex, PacketBuf<MTU>>,
 }