2 files changed, 184 insertions, 17 deletions

diff --git a/embassy-usb-logger/src/lib.rs b/embassy-usb-logger/src/lib.rs
index 45d780bf8..da5ff0f36 100644
--- a/embassy-usb-logger/src/lib.rs
+++ b/embassy-usb-logger/src/lib.rs
@@ -6,7 +6,7 @@ use core::fmt::Write as _;
 
 use embassy_futures::join::join;
 use embassy_sync::pipe::Pipe;
-use embassy_usb::class::cdc_acm::{CdcAcmClass, State};
+use embassy_usb::class::cdc_acm::{CdcAcmClass, Receiver, Sender, State};
 use embassy_usb::driver::Driver;
 use embassy_usb::{Builder, Config};
 use log::{Metadata, Record};
@@ -37,6 +37,9 @@ impl<'d> LoggerState<'d> {
     }
 }
 
+/// The packet size used in the usb logger, to be used with `create_future_from_class`
+pub const MAX_PACKET_SIZE: u8 = 64;
+
 /// The logger handle, which contains a pipe with configurable size for buffering log messages.
 pub struct UsbLogger<const N: usize> {
     buffer: Pipe<CS, N>,
@@ -54,7 +57,6 @@ impl<const N: usize> UsbLogger<N> {
         D: Driver<'d>,
         Self: 'd,
     {
-        const MAX_PACKET_SIZE: u8 = 64;
         let mut config = Config::new(0xc0de, 0xcafe);
         config.manufacturer = Some("Embassy");
         config.product = Some("USB-serial logger");
@@ -87,22 +89,46 @@ impl<const N: usize> UsbLogger<N> {
         let mut device = builder.build();
         loop {
             let run_fut = device.run();
-            let log_fut = async {
-                let mut rx: [u8; MAX_PACKET_SIZE as usize] = [0; MAX_PACKET_SIZE as usize];
-                sender.wait_connection().await;
-                loop {
-                    let len = self.buffer.read(&mut rx[..]).await;
-                    let _ = sender.write_packet(&rx[..len]).await;
-                }
-            };
-            let discard_fut = async {
-                let mut discard_buf: [u8; MAX_PACKET_SIZE as usize] = [0; MAX_PACKET_SIZE as usize];
-                receiver.wait_connection().await;
-                loop {
-                    let _ = receiver.read_packet(&mut discard_buf).await;
+            let class_fut = self.run_logger_class(&mut sender, &mut receiver);
+            join(run_fut, class_fut).await;
+        }
+    }
+
+    async fn run_logger_class<'d, D>(&self, sender: &mut Sender<'d, D>, receiver: &mut Receiver<'d, D>)
+    where
+        D: Driver<'d>,
+    {
+        let log_fut = async {
+            let mut rx: [u8; MAX_PACKET_SIZE as usize] = [0; MAX_PACKET_SIZE as usize];
+            sender.wait_connection().await;
+            loop {
+                let len = self.buffer.read(&mut rx[..]).await;
+                let _ = sender.write_packet(&rx[..len]).await;
+                if len as u8 == MAX_PACKET_SIZE {
+                    let _ = sender.write_packet(&[]).await;
                 }
-            };
-            join(run_fut, join(log_fut, discard_fut)).await;
+            }
+        };
+        let discard_fut = async {
+            let mut discard_buf: [u8; MAX_PACKET_SIZE as usize] = [0; MAX_PACKET_SIZE as usize];
+            receiver.wait_connection().await;
+            loop {
+                let _ = receiver.read_packet(&mut discard_buf).await;
+            }
+        };
+
+        join(log_fut, discard_fut).await;
+    }
+
+    /// Creates the futures needed for the logger from a given class
+    /// This can be used in cases where the usb device is already in use for another connection
+    pub async fn create_future_from_class<'d, D>(&'d self, class: CdcAcmClass<'d, D>)
+    where
+        D: Driver<'d>,
+    {
+        let (mut sender, mut receiver) = class.split();
+        loop {
+            self.run_logger_class(&mut sender, &mut receiver).await;
         }
     }
 }
@@ -153,3 +179,27 @@ macro_rules! run {
         let _ = LOGGER.run(&mut ::embassy_usb_logger::LoggerState::new(), $p).await;
     };
 }
+
+/// Initialize the USB serial logger from a serial class and return the future to run it.
+///
+/// Arguments specify the buffer size, log level and the serial class, respectively.
+///
+/// # Usage
+///
+/// ```
+/// embassy_usb_logger::with_class!(1024, log::LevelFilter::Info, class);
+/// ```
+///
+/// # Safety
+///
+/// This macro should only be invoked only once since it is setting the global logging state of the application.
+#[macro_export]
+macro_rules! with_class {
+    ( $x:expr, $l:expr, $p:ident ) => {{
+        static LOGGER: ::embassy_usb_logger::UsbLogger<$x> = ::embassy_usb_logger::UsbLogger::new();
+        unsafe {
+            let _ = ::log::set_logger_racy(&LOGGER).map(|()| log::set_max_level_racy($l));
+        }
+        LOGGER.create_future_from_class($p)
+    }};
+}
diff --git a/examples/rp/src/bin/usb_serial_with_logger.rs b/examples/rp/src/bin/usb_serial_with_logger.rs
new file mode 100644
index 000000000..4ba4fc25c
--- /dev/null
+++ b/examples/rp/src/bin/usb_serial_with_logger.rs
@@ -0,0 +1,117 @@
+//! This example shows how to use USB (Universal Serial Bus) in the RP2040 chip as well as how to create multiple usb classes for one device
+//!
+//! This creates a USB serial port that echos. It will also print out logging information on a separate serial device
+
+#![no_std]
+#![no_main]
+
+use defmt::{info, panic};
+use embassy_executor::Spawner;
+use embassy_futures::join::join;
+use embassy_rp::bind_interrupts;
+use embassy_rp::peripherals::USB;
+use embassy_rp::usb::{Driver, Instance, InterruptHandler};
+use embassy_usb::class::cdc_acm::{CdcAcmClass, State};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::{Builder, Config};
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    USBCTRL_IRQ => InterruptHandler<USB>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    info!("Hello there!");
+
+    let p = embassy_rp::init(Default::default());
+
+    // Create the driver, from the HAL.
+    let driver = Driver::new(p.USB, Irqs);
+
+    // Create embassy-usb Config
+    let mut config = Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("USB-serial example");
+    config.serial_number = Some("12345678");
+    config.max_power = 100;
+    config.max_packet_size_0 = 64;
+
+    // Required for windows compatibility.
+    // https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.9.1/kconfig/CONFIG_CDC_ACM_IAD.html#help
+    config.device_class = 0xEF;
+    config.device_sub_class = 0x02;
+    config.device_protocol = 0x01;
+    config.composite_with_iads = true;
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut device_descriptor = [0; 256];
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 64];
+
+    let mut state = State::new();
+    let mut logger_state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut [], // no msos descriptors
+        &mut control_buf,
+    );
+
+    // Create classes on the builder.
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    // Create a class for the logger
+    let logger_class = CdcAcmClass::new(&mut builder, &mut logger_state, 64);
+
+    // Creates the logger and returns the logger future
+    // Note: You'll need to use log::info! afterwards instead of info! for this to work (this also applies to all the other log::* macros)
+    let log_fut = embassy_usb_logger::with_class!(1024, log::LevelFilter::Info, logger_class);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            log::info!("Connected");
+            let _ = echo(&mut class).await;
+            log::info!("Disconnected");
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, join(echo_fut, log_fut)).await;
+}
+
+struct Disconnected {}
+
+impl From<EndpointError> for Disconnected {
+    fn from(val: EndpointError) -> Self {
+        match val {
+            EndpointError::BufferOverflow => panic!("Buffer overflow"),
+            EndpointError::Disabled => Disconnected {},
+        }
+    }
+}
+
+async fn echo<'d, T: Instance + 'd>(class: &mut CdcAcmClass<'d, Driver<'d, T>>) -> Result<(), Disconnected> {
+    let mut buf = [0; 64];
+    loop {
+        let n = class.read_packet(&mut buf).await?;
+        let data = &buf[..n];
+        info!("data: {:x}", data);
+        class.write_packet(data).await?;
+    }
+}