Some cleanup

lib/src/event.rs

@@ -41,7 +41,7 @@ pub mod button {
 
     /// A usb keyboard button was pressed or released.
     ///
-    /// This is a lower-level event than a [SwitchEvent], as things like ModTap and Compose are
+    /// This is a lower-level event than a [switch::Event], as things like ModTap and Compose are
     /// converted to Presses and Releases.
     #[derive(Clone, Debug, PartialEq, Eq)]
     pub enum Event {

lib/src/keyboard.rs

@@ -51,8 +51,13 @@ struct State {
     lights: Lights<PIO1, SWITCH_COUNT>,
 }
 
+/// Number of [KbEvents] returned by [KeyboardConfig::create].
 pub const KB_SUBSCRIBERS: usize = 2;
+
+/// Max number of subscribers for [KB_EVENTS]. Equals [KB_SUBSCRIBERS] plus the two used by
+/// [layer_switch_task] and [lights::task].
 const ACTUAL_KB_SUBSCRIBERS: usize = KB_SUBSCRIBERS + 2;
+
 const KB_EVENT_CAP: usize = 128;
 static KB_EVENTS: PubSubChannel<CS, Event, KB_EVENT_CAP, ACTUAL_KB_SUBSCRIBERS, 0> =
     PubSubChannel::new();
@@ -115,7 +120,9 @@ impl KeyboardConfig {
         spawner.must_spawn(layer_switch_task(
             KbEvents {
                 publisher: KB_EVENTS.immediate_publisher(),
-                subscriber: KB_EVENTS.subscriber().unwrap(),
+                subscriber: KB_EVENTS
+                    .subscriber()
+                    .expect("Not enough KbEvents allocated"),
             },
             state,
         ));
@@ -123,14 +130,20 @@ impl KeyboardConfig {
         spawner.must_spawn(lights::task(
             KbEvents {
                 publisher: KB_EVENTS.immediate_publisher(),
-                subscriber: KB_EVENTS.subscriber().unwrap(),
+                subscriber: KB_EVENTS
+                    .subscriber()
+                    .expect("Not enough KbEvents allocated"),
             },
             state,
         ));
 
-        Some([(); KB_SUBSCRIBERS].map(|_| KbEvents {
+        Some([(); KB_SUBSCRIBERS].map(|_| {
+            KbEvents {
                 publisher: KB_EVENTS.immediate_publisher(),
-            subscriber: KB_EVENTS.subscriber().unwrap(),
+                subscriber: KB_EVENTS
+                    .subscriber()
+                    .expect("Not enough KbEvents allocated"),
+            }
         }))
     }
 }
@@ -187,8 +200,11 @@ async fn switch_task(switch_num: usize, pin: AnyPin, state: &'static State) -> !
         // get current layer
         let (x, y) = state.current_layer.load(Ordering::Relaxed);
 
-        let Some(Layer { buttons }) = state.layers.get(usize::from(y))
+        let Some(Layer { buttons }) = state
-            .and_then(|row| row.get(usize::from(x))) else {
+            .layers
+            .get(usize::from(y))
+            .and_then(|row| row.get(usize::from(x)))
+        else {
             // currently layer is null, do nothing
             pin.wait_for_high().await;
             continue;

lib/src/usb/keyboard.rs

@@ -22,21 +22,15 @@ use usbd_hid::descriptor::SerializedDescriptor;
 use crate::{
     event::button,
     keyboard::KbEvents,
+    keypress_handler::keypress_handler,
     usb::keyboard::report::{KeyboardReport, EMPTY_KEYBOARD_REPORT},
-    util::CS, keypress_handler::keypress_handler,
+    util::CS,
 };
 
 use super::MAX_PACKET_SIZE;
 
 struct Handler;
 
-static CONTEXT: StaticCell<Context> = StaticCell::new();
-
-static KB_REPORT: Mutex<CS, Reports> = Mutex::new(Reports {
-    actual: EMPTY_KEYBOARD_REPORT,
-    unsent: EMPTY_KEYBOARD_REPORT,
-});
-
 struct Reports {
     /// The report to be sent to the host machine.
     actual: KeyboardReport,
@@ -50,13 +44,26 @@ struct Context {
     state: hid::State<'static>,
 }
 
+/// Set up a USB HID keyboard. This function panics if called more than once.
 pub async fn setup(builder: &mut Builder<'static, Driver<'static, USB>>, events: KbEvents) {
     log::info!("setting up usb hid");
 
-    let context = CONTEXT.init(Context {
+    let context = {
+        static CONTEXT: StaticCell<Context> = StaticCell::new();
+        // this panics if the functon is called twice
+        CONTEXT.init(Context {
             handler: Handler,
             state: hid::State::new(),
+        })
+    };
+
+    let reports = {
+        static KB_REPORT: Mutex<CS, Reports> = Mutex::new(Reports {
+            actual: EMPTY_KEYBOARD_REPORT,
+            unsent: EMPTY_KEYBOARD_REPORT,
         });
+        &KB_REPORT
+    };
 
     let config = hid::Config {
         //report_descriptor: MouseReport::desc(),
@@ -70,8 +77,8 @@ pub async fn setup(builder: &mut Builder<'static, Driver<'static, USB>>, events:
 
     let spawner = Spawner::for_current_executor().await;
 
-    spawner.must_spawn(task(stream, &context.handler));
+    spawner.must_spawn(report_task(stream, &context.handler, reports));
-    spawner.must_spawn(listen_to_events(events));
+    spawner.must_spawn(event_listener_task(events, reports));
 
     log::info!("done setting up usb keyboard");
 }
@@ -103,7 +110,7 @@ impl RequestHandler for Handler {
 type HidStream = HidReaderWriter<'static, Driver<'static, USB>, 256, 256>;
 
 #[embassy_executor::task]
-async fn listen_to_events(mut events: KbEvents) {
+async fn event_listener_task(mut events: KbEvents, reports: &'static Mutex<CS, Reports>) {
     let button_events = PubSubChannel::<NoopRawMutex, button::Event, 10, 1, 1>::new();
     let mut button_pub = button_events.publisher().unwrap();
     let mut button_sub = button_events.subscriber().unwrap();
@@ -117,7 +124,7 @@ async fn listen_to_events(mut events: KbEvents) {
                 };
 
                 loop {
-                    let mut r = KB_REPORT.lock().await;
+                    let mut r = reports.lock().await;
                     match event {
                         button::Event::PressKey(k) => {
                             r.actual.press_key(k);
@@ -154,21 +161,29 @@ async fn listen_to_events(mut events: KbEvents) {
 }
 
 #[embassy_executor::task]
-async fn task(stream: HidStream, handler: &'static Handler) {
+async fn report_task(
-    if let Err(e) = keyboard_report(stream, handler).await {
+    stream: HidStream,
+    handler: &'static Handler,
+    reports: &'static Mutex<CS, Reports>,
+) {
+    if let Err(e) = keyboard_report(stream, handler, reports).await {
         log::error!("keyboard error: {e:?}");
     }
 }
 
-async fn keyboard_report(mut stream: HidStream, _handler: &'static Handler) -> Result<(), Error> {
+async fn keyboard_report(
+    mut stream: HidStream,
+    _handler: &'static Handler,
+    reports: &'static Mutex<CS, Reports>,
+) -> Result<(), Error> {
     stream.ready().await;
     loop {
         Timer::after(Duration::from_millis(2)).await;
 
         let report = {
-            let mut reports = KB_REPORT.lock().await;
+            let mut reports = reports.lock().await;
             reports.unsent = EMPTY_KEYBOARD_REPORT;
-            reports.actual.clone()
+            reports.actual
         };
 
         if report.keycodes != EMPTY_KEYBOARD_REPORT.keycodes {

lib/src/usb/keyboard/report.rs

@@ -50,9 +50,9 @@ fn key_to_byte_mask(key: Key) -> (usize, u8) {
 impl KeyboardReport {
     #[inline(always)]
     pub fn set_key(&mut self, key: Key, pressed: bool) {
-        let (byte, mask) = key_to_byte_mask(key);
+        let (byte_i, mask) = key_to_byte_mask(key);
 
-        if let Some(k) = self.keycodes.get_mut(byte as usize) {
+        if let Some(k) = self.keycodes.get_mut(byte_i) {
             if pressed {
                 *k |= mask;
             } else {
@@ -75,8 +75,8 @@ impl KeyboardReport {
 
     #[inline(always)]
     pub fn key_pressed(&mut self, key: Key) -> bool {
-        let (byte, mask) = key_to_byte_mask(key);
+        let (byte_i, mask) = key_to_byte_mask(key);
-        if let Some(k) = self.keycodes.get_mut(byte as usize) {
+        if let Some(k) = self.keycodes.get_mut(byte_i) {
             (*k & mask) != 0
         } else {
             log::warn!("Tried to get out-of-range keycode: 0x{:x}", u8::from(key));