Working CDC-ACM host->device

7 files changed, 345 insertions, 94 deletions

diff --git a/embassy-nrf/src/usb.rs b/embassy-nrf/src/usb.rs
index 0f7d68d8c..163b2c794 100644
--- a/embassy-nrf/src/usb.rs
+++ b/embassy-nrf/src/usb.rs
@@ -8,7 +8,7 @@ use embassy::time::{with_timeout, Duration};
 use embassy::util::Unborrow;
 use embassy::waitqueue::AtomicWaker;
 use embassy_hal_common::unborrow;
-use embassy_usb::driver::{self, ReadError, WriteError};
+use embassy_usb::driver::{self, Event, ReadError, WriteError};
 use embassy_usb::types::{EndpointAddress, EndpointInfo, EndpointType, UsbDirection};
 use futures::future::poll_fn;
 use futures::Future;
@@ -19,7 +19,10 @@ pub use embassy_usb;
 use crate::interrupt::Interrupt;
 use crate::pac;
 
-static EP0_WAKER: AtomicWaker = AtomicWaker::new();
+const NEW_AW: AtomicWaker = AtomicWaker::new();
+static BUS_WAKER: AtomicWaker = NEW_AW;
+static EP_IN_WAKERS: [AtomicWaker; 9] = [NEW_AW; 9];
+static EP_OUT_WAKERS: [AtomicWaker; 9] = [NEW_AW; 9];
 
 pub struct Driver<'d, T: Instance> {
     phantom: PhantomData<&'d mut T>,
@@ -47,13 +50,48 @@ impl<'d, T: Instance> Driver<'d, T> {
     fn on_interrupt(_: *mut ()) {
         let regs = T::regs();
 
+        if regs.events_usbreset.read().bits() != 0 {
+            regs.intenclr.write(|w| w.usbreset().clear());
+            BUS_WAKER.wake();
+        }
+
         if regs.events_ep0setup.read().bits() != 0 {
             regs.intenclr.write(|w| w.ep0setup().clear());
-            EP0_WAKER.wake();
+            EP_OUT_WAKERS[0].wake();
         }
+
         if regs.events_ep0datadone.read().bits() != 0 {
             regs.intenclr.write(|w| w.ep0datadone().clear());
-            EP0_WAKER.wake();
+            EP_IN_WAKERS[0].wake();
+        }
+
+        // USBEVENT and EPDATA events are weird. They're the "aggregate"
+        // of individual bits in EVENTCAUSE and EPDATASTATUS. We handle them
+        // differently than events normally.
+        //
+        // They seem to be edge-triggered, not level-triggered: when an
+        // individual bit goes 0->1, the event fires *just once*.
+        // Therefore, it's fine to clear just the event, and let main thread
+        // check the individual bits in EVENTCAUSE and EPDATASTATUS. It
+        // doesn't cause an infinite irq loop.
+        if regs.events_usbevent.read().bits() != 0 {
+            regs.events_usbevent.reset();
+            //regs.intenclr.write(|w| w.usbevent().clear());
+            BUS_WAKER.wake();
+        }
+
+        if regs.events_epdata.read().bits() != 0 {
+            regs.events_epdata.reset();
+
+            let r = regs.epdatastatus.read().bits();
+            for i in 1..=7 {
+                if r & (1 << i) != 0 {
+                    EP_IN_WAKERS[i].wake();
+                }
+                if r & (1 << (i + 16)) != 0 {
+                    EP_OUT_WAKERS[i].wake();
+                }
+            }
         }
     }
 
@@ -153,6 +191,12 @@ impl<'d, T: Instance> driver::Driver<'d> for Driver<'d, T> {
 
         unsafe { NVIC::unmask(pac::Interrupt::USBD) };
 
+        regs.intenset.write(|w| {
+            w.usbreset().set_bit();
+            w.usbevent().set_bit();
+            w.epdata().set_bit();
+            w
+        });
         // Enable the USB pullup, allowing enumeration.
         regs.usbpullup.write(|w| w.connect().enabled());
         info!("enabled");
@@ -172,6 +216,49 @@ pub struct Bus<'d, T: Instance> {
 }
 
 impl<'d, T: Instance> driver::Bus for Bus<'d, T> {
+    type PollFuture<'a>
+    where
+        Self: 'a,
+    = impl Future<Output = Event> + 'a;
+
+    fn poll<'a>(&'a mut self) -> Self::PollFuture<'a> {
+        poll_fn(|cx| {
+            BUS_WAKER.register(cx.waker());
+            let regs = T::regs();
+
+            if regs.events_usbreset.read().bits() != 0 {
+                regs.events_usbreset.reset();
+                regs.intenset.write(|w| w.usbreset().set());
+                return Poll::Ready(Event::Reset);
+            }
+
+            let r = regs.eventcause.read();
+
+            if r.isooutcrc().bit() {
+                regs.eventcause.write(|w| w.isooutcrc().set_bit());
+                info!("USB event: isooutcrc");
+            }
+            if r.usbwuallowed().bit() {
+                regs.eventcause.write(|w| w.usbwuallowed().set_bit());
+                info!("USB event: usbwuallowed");
+            }
+            if r.suspend().bit() {
+                regs.eventcause.write(|w| w.suspend().set_bit());
+                info!("USB event: suspend");
+            }
+            if r.resume().bit() {
+                regs.eventcause.write(|w| w.resume().set_bit());
+                info!("USB event: resume");
+            }
+            if r.ready().bit() {
+                regs.eventcause.write(|w| w.ready().set_bit());
+                info!("USB event: ready");
+            }
+
+            Poll::Pending
+        })
+    }
+
     #[inline]
     fn reset(&mut self) {
         let regs = T::regs();
@@ -260,40 +347,95 @@ impl<'d, T: Instance> driver::EndpointOut for Endpoint<'d, T, Out> {
     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Self::ReadFuture<'a> {
         async move {
             let regs = T::regs();
+            let i = self.info.addr.index();
 
-            if buf.len() == 0 {
-                regs.tasks_ep0status.write(|w| unsafe { w.bits(1) });
-                return Ok(0);
-            }
+            if i == 0 {
+                if buf.len() == 0 {
+                    regs.tasks_ep0status.write(|w| unsafe { w.bits(1) });
+                    return Ok(0);
+                }
+
+                // Wait for SETUP packet
+                regs.events_ep0setup.reset();
+                regs.intenset.write(|w| w.ep0setup().set());
+                poll_fn(|cx| {
+                    EP_OUT_WAKERS[0].register(cx.waker());
+                    let regs = T::regs();
+                    if regs.events_ep0setup.read().bits() != 0 {
+                        Poll::Ready(())
+                    } else {
+                        Poll::Pending
+                    }
+                })
+                .await;
+                info!("got SETUP");
 
-            // Wait for SETUP packet
-            regs.events_ep0setup.reset();
-            regs.intenset.write(|w| w.ep0setup().set());
-            poll_fn(|cx| {
-                EP0_WAKER.register(cx.waker());
-                if regs.events_ep0setup.read().bits() != 0 {
-                    Poll::Ready(())
-                } else {
-                    Poll::Pending
+                if buf.len() < 8 {
+                    return Err(ReadError::BufferOverflow);
                 }
-            })
-            .await;
-            info!("got SETUP");
 
-            if buf.len() < 8 {
-                return Err(ReadError::BufferOverflow);
-            }
+                buf[0] = regs.bmrequesttype.read().bits() as u8;
+                buf[1] = regs.brequest.read().brequest().bits();
+                buf[2] = regs.wvaluel.read().wvaluel().bits();
+                buf[3] = regs.wvalueh.read().wvalueh().bits();
+                buf[4] = regs.windexl.read().windexl().bits();
+                buf[5] = regs.windexh.read().windexh().bits();
+                buf[6] = regs.wlengthl.read().wlengthl().bits();
+                buf[7] = regs.wlengthh.read().wlengthh().bits();
+
+                Ok(8)
+            } else {
+                poll_fn(|cx| {
+                    EP_OUT_WAKERS[i].register(cx.waker());
+                    let regs = T::regs();
+                    let r = regs.epdatastatus.read().bits();
+                    if r & (1 << (i + 16)) != 0 {
+                        Poll::Ready(())
+                    } else {
+                        Poll::Pending
+                    }
+                })
+                .await;
 
-            buf[0] = regs.bmrequesttype.read().bits() as u8;
-            buf[1] = regs.brequest.read().brequest().bits();
-            buf[2] = regs.wvaluel.read().wvaluel().bits();
-            buf[3] = regs.wvalueh.read().wvalueh().bits();
-            buf[4] = regs.windexl.read().windexl().bits();
-            buf[5] = regs.windexh.read().windexh().bits();
-            buf[6] = regs.wlengthl.read().wlengthl().bits();
-            buf[7] = regs.wlengthh.read().wlengthh().bits();
+                // Clear status
+                regs.epdatastatus
+                    .write(|w| unsafe { w.bits(1 << (i + 16)) });
 
-            Ok(8)
+                // Check that the packet fits into the buffer
+                let size = regs.size.epout[i].read().bits();
+                if size as usize > buf.len() {
+                    return Err(ReadError::BufferOverflow);
+                }
+
+                let epout = [
+                    &regs.epout0,
+                    &regs.epout1,
+                    &regs.epout2,
+                    &regs.epout3,
+                    &regs.epout4,
+                    &regs.epout5,
+                    &regs.epout6,
+                    &regs.epout7,
+                ];
+                epout[i]
+                    .ptr
+                    .write(|w| unsafe { w.bits(buf.as_ptr() as u32) });
+                // MAXCNT must match SIZE
+                epout[i].maxcnt.write(|w| unsafe { w.bits(size) });
+
+                dma_start();
+                regs.events_endepout[i].reset();
+                regs.tasks_startepout[i].write(|w| w.tasks_startepout().set_bit());
+                while regs.events_endepout[i]
+                    .read()
+                    .events_endepout()
+                    .bit_is_clear()
+                {}
+                regs.events_endepout[i].reset();
+                dma_end();
+
+                Ok(size as usize)
+            }
         }
     }
 }
@@ -331,7 +473,8 @@ impl<'d, T: Instance> driver::EndpointIn for Endpoint<'d, T, In> {
             let res = with_timeout(
                 Duration::from_millis(10),
                 poll_fn(|cx| {
-                    EP0_WAKER.register(cx.waker());
+                    EP_IN_WAKERS[0].register(cx.waker());
+                    let regs = T::regs();
                     if regs.events_ep0datadone.read().bits() != 0 {
                         Poll::Ready(())
                     } else {
diff --git a/embassy-usb/Cargo.toml b/embassy-usb/Cargo.toml
index dfdc8fbac..5a5a6d7ab 100644
--- a/embassy-usb/Cargo.toml
+++ b/embassy-usb/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "embassy-usb"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 embassy = { version = "0.1.0", path = "../embassy" }
diff --git a/embassy-usb/src/driver.rs b/embassy-usb/src/driver.rs
index ed4edb576..a7b16efa5 100644
--- a/embassy-usb/src/driver.rs
+++ b/embassy-usb/src/driver.rs
@@ -2,40 +2,6 @@ use core::future::Future;
 
 use super::types::*;
 
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct EndpointAllocError;
-
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-
-/// Operation is unsupported by the driver.
-pub struct Unsupported;
-
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-
-/// Errors returned by [`EndpointIn::write`]
-pub enum WriteError {
-    /// The packet is too long to fit in the
-    ///   transmission buffer. This is generally an error in the class implementation, because the
-    ///   class shouldn't provide more data than the `max_packet_size` it specified when allocating
-    ///   the endpoint.
-    BufferOverflow,
-}
-
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-
-/// Errors returned by [`EndpointOut::read`]
-pub enum ReadError {
-    /// The received packet is too long to
-    /// fit in `buf`. This is generally an error in the class implementation, because the class
-    /// should use a buffer that is large enough for the `max_packet_size` it specified when
-    /// allocating the endpoint.
-    BufferOverflow,
-}
-
 /// Driver for a specific USB peripheral. Implement this to add support for a new hardware
 /// platform.
 pub trait Driver<'a> {
@@ -82,6 +48,12 @@ pub trait Driver<'a> {
 }
 
 pub trait Bus {
+    type PollFuture<'a>: Future<Output = Event> + 'a
+    where
+        Self: 'a;
+
+    fn poll<'a>(&'a mut self) -> Self::PollFuture<'a>;
+
     /// Called when the host resets the device. This will be soon called after
     /// [`poll`](crate::device::UsbDevice::poll) returns [`PollResult::Reset`]. This method should
     /// reset the state of all endpoints and peripheral flags back to a state suitable for
@@ -158,3 +130,50 @@ pub trait EndpointIn: Endpoint {
     /// Writes a single packet of data to the endpoint.
     fn write<'a>(&'a mut self, buf: &'a [u8]) -> Self::WriteFuture<'a>;
 }
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Event returned by [`Bus::poll`].
+pub enum Event {
+    /// The USB reset condition has been detected.
+    Reset,
+
+    /// A USB suspend request has been detected or, in the case of self-powered devices, the device
+    /// has been disconnected from the USB bus.
+    Suspend,
+
+    /// A USB resume request has been detected after being suspended or, in the case of self-powered
+    /// devices, the device has been connected to the USB bus.
+    Resume,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct EndpointAllocError;
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Operation is unsupported by the driver.
+pub struct Unsupported;
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Errors returned by [`EndpointIn::write`]
+pub enum WriteError {
+    /// The packet is too long to fit in the
+    ///   transmission buffer. This is generally an error in the class implementation, because the
+    ///   class shouldn't provide more data than the `max_packet_size` it specified when allocating
+    ///   the endpoint.
+    BufferOverflow,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Errors returned by [`EndpointOut::read`]
+pub enum ReadError {
+    /// The received packet is too long to
+    /// fit in `buf`. This is generally an error in the class implementation, because the class
+    /// should use a buffer that is large enough for the `max_packet_size` it specified when
+    /// allocating the endpoint.
+    BufferOverflow,
+}
diff --git a/embassy-usb/src/lib.rs b/embassy-usb/src/lib.rs
index 397db96c4..33f3d4712 100644
--- a/embassy-usb/src/lib.rs
+++ b/embassy-usb/src/lib.rs
@@ -9,11 +9,13 @@ mod control;
 pub mod descriptor;
 pub mod driver;
 pub mod types;
+mod util;
 
 use self::control::*;
 use self::descriptor::*;
 use self::driver::*;
 use self::types::*;
+use self::util::*;
 
 pub use self::builder::Config;
 pub use self::builder::UsbDeviceBuilder;
@@ -47,7 +49,7 @@ pub const CONFIGURATION_VALUE: u8 = 1;
 pub const DEFAULT_ALTERNATE_SETTING: u8 = 0;
 
 pub struct UsbDevice<'d, D: Driver<'d>> {
-    driver: D::Bus,
+    bus: D::Bus,
     control_in: D::EndpointIn,
     control_out: D::EndpointOut,
 
@@ -93,7 +95,7 @@ impl<'d, D: Driver<'d>> UsbDevice<'d, D> {
         let driver = driver.enable();
 
         Self {
-            driver,
+            bus: driver,
             config,
             control_in,
             control_out,
@@ -108,20 +110,47 @@ impl<'d, D: Driver<'d>> UsbDevice<'d, D> {
     }
 
     pub async fn run(&mut self) {
+        let mut buf = [0; 8];
+
         loop {
-            let mut buf = [0; 8];
-            let n = self.control_out.read(&mut buf).await.unwrap();
-            assert_eq!(n, 8);
-            let req = Request::parse(&buf).unwrap();
-            info!("setup request: {:x}", req);
-
-            // Now that we have properly parsed the setup packet, ensure the end-point is no longer in
-            // a stalled state.
-            self.control_out.set_stalled(false);
-
-            match req.direction {
-                UsbDirection::In => self.handle_control_in(req).await,
-                UsbDirection::Out => self.handle_control_out(req).await,
+            let control_fut = self.control_out.read(&mut buf);
+            let bus_fut = self.bus.poll();
+            match select(bus_fut, control_fut).await {
+                Either::Left(evt) => match evt {
+                    Event::Reset => {
+                        self.bus.reset();
+
+                        self.device_state = UsbDeviceState::Default;
+                        self.remote_wakeup_enabled = false;
+                        self.pending_address = 0;
+
+                        // TODO
+                        //self.control.reset();
+                        //for cls in classes {
+                        //    cls.reset();
+                        //}
+                    }
+                    Event::Resume => {}
+                    Event::Suspend => {
+                        self.bus.suspend();
+                        self.device_state = UsbDeviceState::Suspend;
+                    }
+                },
+                Either::Right(n) => {
+                    let n = n.unwrap();
+                    assert_eq!(n, 8);
+                    let req = Request::parse(&buf).unwrap();
+                    info!("control request: {:x}", req);
+
+                    // Now that we have properly parsed the setup packet, ensure the end-point is no longer in
+                    // a stalled state.
+                    self.control_out.set_stalled(false);
+
+                    match req.direction {
+                        UsbDirection::In => self.handle_control_in(req).await,
+                        UsbDirection::Out => self.handle_control_out(req).await,
+                    }
+                }
             }
         }
     }
@@ -205,7 +234,8 @@ impl<'d, D: Driver<'d>> UsbDevice<'d, D> {
                 }
 
                 (Recipient::Endpoint, Request::SET_FEATURE, Request::FEATURE_ENDPOINT_HALT) => {
-                    //self.bus.set_stalled(((req.index as u8) & 0x8f).into(), true);
+                    self.bus
+                        .set_stalled(((req.index as u8) & 0x8f).into(), true);
                     self.control_out_accept(req).await;
                 }
 
@@ -266,7 +296,7 @@ impl<'d, D: Driver<'d>> UsbDevice<'d, D> {
                 (Recipient::Endpoint, Request::GET_STATUS) => {
                     let ep_addr: EndpointAddress = ((req.index as u8) & 0x8f).into();
                     let mut status: u16 = 0x0000;
-                    if self.driver.is_stalled(ep_addr) {
+                    if self.bus.is_stalled(ep_addr) {
                         status |= 0x0001;
                     }
                     self.control_in_accept(req, &status.to_le_bytes()).await;
diff --git a/embassy-usb/src/util.rs b/embassy-usb/src/util.rs
new file mode 100644
index 000000000..18cc875c6
--- /dev/null
+++ b/embassy-usb/src/util.rs
@@ -0,0 +1,45 @@
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+#[derive(Debug, Clone)]
+pub enum Either<A, B> {
+    Left(A),
+    Right(B),
+}
+
+pub fn select<A, B>(a: A, b: B) -> Select<A, B>
+where
+    A: Future,
+    B: Future,
+{
+    Select { a, b }
+}
+
+pub struct Select<A, B> {
+    a: A,
+    b: B,
+}
+
+impl<A: Unpin, B: Unpin> Unpin for Select<A, B> {}
+
+impl<A, B> Future for Select<A, B>
+where
+    A: Future,
+    B: Future,
+{
+    type Output = Either<A::Output, B::Output>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = unsafe { self.get_unchecked_mut() };
+        let a = unsafe { Pin::new_unchecked(&mut this.a) };
+        let b = unsafe { Pin::new_unchecked(&mut this.b) };
+        match a.poll(cx) {
+            Poll::Ready(x) => Poll::Ready(Either::Left(x)),
+            Poll::Pending => match b.poll(cx) {
+                Poll::Ready(x) => Poll::Ready(Either::Right(x)),
+                Poll::Pending => Poll::Pending,
+            },
+        }
+    }
+}
diff --git a/examples/nrf/src/bin/usb/cdc_acm.rs b/examples/nrf/src/bin/usb/cdc_acm.rs
index 345d00389..b7c112ae6 100644
--- a/examples/nrf/src/bin/usb/cdc_acm.rs
+++ b/examples/nrf/src/bin/usb/cdc_acm.rs
@@ -38,14 +38,15 @@ const REQ_SET_CONTROL_LINE_STATE: u8 = 0x22;
 ///   can be sent if there is no other data to send. This is because USB bulk transactions must be
 ///   terminated with a short packet, even if the bulk endpoint is used for stream-like data.
 pub struct CdcAcmClass<'d, D: Driver<'d>> {
-    comm_if: InterfaceNumber,
-    comm_ep: D::EndpointIn,
-    data_if: InterfaceNumber,
-    read_ep: D::EndpointOut,
-    write_ep: D::EndpointIn,
-    line_coding: LineCoding,
-    dtr: bool,
-    rts: bool,
+    // TODO not pub
+    pub comm_if: InterfaceNumber,
+    pub comm_ep: D::EndpointIn,
+    pub data_if: InterfaceNumber,
+    pub read_ep: D::EndpointOut,
+    pub write_ep: D::EndpointIn,
+    pub line_coding: LineCoding,
+    pub dtr: bool,
+    pub rts: bool,
 }
 
 impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
diff --git a/examples/nrf/src/bin/usb/main.rs b/examples/nrf/src/bin/usb/main.rs
index 21ca2ba4f..d175766bb 100644
--- a/examples/nrf/src/bin/usb/main.rs
+++ b/examples/nrf/src/bin/usb/main.rs
@@ -14,7 +14,9 @@ use embassy_nrf::interrupt;
 use embassy_nrf::pac;
 use embassy_nrf::usb::{self, Driver};
 use embassy_nrf::Peripherals;
+use embassy_usb::driver::EndpointOut;
 use embassy_usb::{Config, UsbDeviceBuilder};
+use futures::future::{join, select};
 
 use crate::cdc_acm::CdcAcmClass;
 
@@ -49,5 +51,16 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     let mut class = CdcAcmClass::new(&mut builder, 64);
 
     let mut usb = builder.build();
-    usb.run().await;
+
+    let fut1 = usb.run();
+    let fut2 = async {
+        let mut buf = [0; 64];
+        loop {
+            let n = class.read_ep.read(&mut buf).await.unwrap();
+            let data = &buf[..n];
+            info!("data: {:x}", data);
+        }
+    };
+
+    join(fut1, fut2).await;
 }