wpan: impl. draft control scheme

embassy-stm32-wpan/src/mac/control.rs

@@ -1,12 +1,16 @@
+use core::future::Future;
+use core::task;
+
+use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use embassy_sync::mutex::MutexGuard;
+use embassy_sync::signal::Signal;
+use futures::FutureExt;
+
+use super::commands::MacCommand;
+use super::typedefs::MacError;
 use crate::mac::runner::Runner;
 
-#[derive(Debug)]
-pub struct Error {
-    pub status: u32,
-}
-
 pub struct Control<'a> {
-    #[allow(dead_code)]
     runner: &'a Runner<'a>,
 }
 
@@ -15,7 +19,73 @@ impl<'a> Control<'a> {
         Self { runner: runner }
     }
 
-    pub async fn init(&mut self) {
-        // TODO
+    pub async fn send_command<T>(&self, cmd: &T) -> Result<(), MacError>
+    where
+        T: MacCommand,
+    {
+        let _wm = self.runner.write_mutex.lock().await;
+
+        self.runner.mac_subsystem.send_command(cmd).await
+    }
+
+    pub async fn send_command_and_get_response<T>(&self, cmd: &T) -> Result<EventToken<'a>, MacError>
+    where
+        T: MacCommand,
+    {
+        let _wm = self.runner.write_mutex.lock().await;
+        let rm = self.runner.read_mutex.lock().await;
+        let token = EventToken::new(self.runner, rm);
+
+        self.runner.mac_subsystem.send_command(cmd).await?;
+
+        Ok(token)
+    }
+}
+
+pub struct EventToken<'a> {
+    runner: &'a Runner<'a>,
+    _mutex_guard: MutexGuard<'a, CriticalSectionRawMutex, ()>,
+}
+
+impl<'a> EventToken<'a> {
+    pub(crate) fn new(runner: &'a Runner<'a>, mutex_guard: MutexGuard<'a, CriticalSectionRawMutex, ()>) -> Self {
+        // Enable event receiving
+        runner.rx_event_channel.lock(|s| {
+            *s.borrow_mut() = Some(Signal::new());
+        });
+
+        Self {
+            runner: runner,
+            _mutex_guard: mutex_guard,
+        }
+    }
+}
+
+impl<'a> Future for EventToken<'a> {
+    // TODO: output something
+    type Output = ();
+
+    fn poll(self: core::pin::Pin<&mut Self>, cx: &mut task::Context<'_>) -> task::Poll<Self::Output> {
+        self.get_mut().runner.rx_event_channel.lock(|s| {
+            let signal = s.borrow_mut();
+            let signal = match &*signal {
+                Some(s) => s,
+                _ => unreachable!(),
+            };
+
+            let _ = signal.wait().poll_unpin(cx);
+        });
+
+        todo!()
+    }
+}
+
+impl<'a> Drop for EventToken<'a> {
+    fn drop(&mut self) {
+        // Disable event receiving
+        // This will also drop the contained event, if it exists, and will free up receiving the next event
+        self.runner.rx_event_channel.lock(|s| {
+            *s.borrow_mut() = None;
+        });
     }
 }

embassy-stm32-wpan/src/mac/event.rs

@@ -144,6 +144,8 @@ impl<'a> MacEvent<'a> {
     }
 }
 
+unsafe impl<'a> Send for MacEvent<'a> {}
+
 impl<'a> Drop for MacEvent<'a> {
     fn drop(&mut self) {
         unsafe { mac::Mac::drop_event_packet(ptr::null_mut()) };

embassy-stm32-wpan/src/mac/mod.rs

@@ -10,7 +10,7 @@ pub mod responses;
 pub mod runner;
 pub mod typedefs;
 
-pub use crate::mac::control::{Control, Error as ControlError};
+pub use crate::mac::control::Control;
 use crate::mac::driver::Driver;
 pub use crate::mac::runner::Runner;
 

embassy-stm32-wpan/src/mac/runner.rs

@@ -1,6 +1,11 @@
+use core::cell::RefCell;
+
 use embassy_futures::join;
-use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use embassy_sync::blocking_mutex;
+use embassy_sync::blocking_mutex::raw::{CriticalSectionRawMutex, NoopRawMutex};
 use embassy_sync::channel::Channel;
+use embassy_sync::mutex::Mutex;
+use embassy_sync::signal::Signal;
 
 use crate::mac::commands::DataRequest;
 use crate::mac::event::MacEvent;
@@ -9,7 +14,13 @@ use crate::mac::MTU;
 use crate::sub::mac::Mac;
 
 pub struct Runner<'a> {
-    mac_subsystem: Mac,
+    pub(crate) mac_subsystem: Mac,
+
+    // rx event backpressure is already provided through the MacEvent drop mechanism
+    pub(crate) rx_event_channel:
+        blocking_mutex::Mutex<CriticalSectionRawMutex, RefCell<Option<Signal<NoopRawMutex, MacEvent<'a>>>>>,
+    pub(crate) read_mutex: Mutex<CriticalSectionRawMutex, ()>,
+    pub(crate) write_mutex: Mutex<CriticalSectionRawMutex, ()>,
     pub(crate) rx_channel: Channel<CriticalSectionRawMutex, MacEvent<'a>, 1>,
     pub(crate) tx_channel: Channel<CriticalSectionRawMutex, (&'a mut [u8; MTU], usize), 5>,
     pub(crate) tx_buf_channel: Channel<CriticalSectionRawMutex, &'a mut [u8; MTU], 5>,
@@ -19,6 +30,9 @@ impl<'a> Runner<'a> {
     pub fn new(mac: Mac, tx_buf_queue: [&'a mut [u8; MTU]; 5]) -> Self {
         let this = Self {
             mac_subsystem: mac,
+            rx_event_channel: blocking_mutex::Mutex::new(RefCell::new(None)),
+            read_mutex: Mutex::new(()),
+            write_mutex: Mutex::new(()),
             rx_channel: Channel::new(),
             tx_channel: Channel::new(),
             tx_buf_channel: Channel::new(),
@@ -40,7 +54,16 @@ impl<'a> Runner<'a> {
                             MacEvent::McpsDataInd(_) => {
                                 self.rx_channel.send(mac_event).await;
                             }
-                            _ => {}
+                            _ => {
+                                self.rx_event_channel.lock(|s| {
+                                    match &*s.borrow() {
+                                        Some(signal) => {
+                                            signal.signal(mac_event);
+                                        }
+                                        None => {}
+                                    };
+                                });
+                            }
                         }
                     }
                 }
@@ -50,7 +73,9 @@ impl<'a> Runner<'a> {
 
                 loop {
                     let (buf, len) = self.tx_channel.recv().await;
+                    let _wm = self.write_mutex.lock().await;
 
+                    // The mutex should be dropped on the next loop iteration
                     self.mac_subsystem
                         .send_command(
                             DataRequest {