3 files changed, 114 insertions, 3 deletions

diff --git a/embassy-stm32/src/usb/usb.rs b/embassy-stm32/src/usb/usb.rs
index 04b1b35e8..f39915906 100644
--- a/embassy-stm32/src/usb/usb.rs
+++ b/embassy-stm32/src/usb/usb.rs
@@ -13,7 +13,6 @@ use embassy_usb_driver::{
 };
 
 use super::{DmPin, DpPin, Instance};
-use crate::gpio::sealed::AFType;
 use crate::interrupt::typelevel::Interrupt;
 use crate::pac::usb::regs;
 use crate::pac::usb::vals::{EpType, Stat};
@@ -286,8 +285,13 @@ impl<'d, T: Instance> Driver<'d, T> {
         #[cfg(not(usb_v4))]
         regs.btable().write(|w| w.set_btable(0));
 
-        dp.set_as_af(dp.af_num(), AFType::OutputPushPull);
-        dm.set_as_af(dm.af_num(), AFType::OutputPushPull);
+        #[cfg(not(stm32l1))]
+        {
+            dp.set_as_af(dp.af_num(), crate::gpio::sealed::AFType::OutputPushPull);
+            dm.set_as_af(dm.af_num(), crate::gpio::sealed::AFType::OutputPushPull);
+        }
+        #[cfg(stm32l1)]
+        let _ = (dp, dm); // suppress "unused" warnings.
 
         // Initialize the bus so that it signals that power is available
         BUS_WAKER.wake();
@@ -444,6 +448,9 @@ impl<'d, T: Instance> driver::Driver<'d> for Driver<'d, T> {
         #[cfg(any(usb_v3, usb_v4))]
         regs.bcdr().write(|w| w.set_dppu(true));
 
+        #[cfg(stm32l1)]
+        crate::pac::SYSCFG.pmc().modify(|w| w.set_usb_pu(true));
+
         trace!("enabled");
 
         let mut ep_types = [EpType::BULK; EP_COUNT - 1];
diff --git a/examples/stm32l1/Cargo.toml b/examples/stm32l1/Cargo.toml
index c0b35b716..322c41262 100644
--- a/examples/stm32l1/Cargo.toml
+++ b/examples/stm32l1/Cargo.toml
@@ -9,6 +9,7 @@ embassy-sync = { version = "0.5.0", path = "../../embassy-sync", features = ["de
 embassy-executor = { version = "0.5.0", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.3.0", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = [ "defmt", "stm32l151cb-a", "time-driver-any", "memory-x"]  }
+embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
 
 defmt = "0.3"
 defmt-rtt = "0.4"
diff --git a/examples/stm32l1/src/bin/usb_serial.rs b/examples/stm32l1/src/bin/usb_serial.rs
new file mode 100644
index 000000000..7b1e84cbc
--- /dev/null
+++ b/examples/stm32l1/src/bin/usb_serial.rs
@@ -0,0 +1,103 @@
+#![no_std]
+#![no_main]
+
+use defmt::{panic, *};
+use embassy_executor::Spawner;
+use embassy_stm32::usb::{self, Driver, Instance};
+use embassy_stm32::{bind_interrupts, peripherals};
+use embassy_usb::class::cdc_acm::{CdcAcmClass, State};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::Builder;
+use futures::future::join;
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    USB_LP => usb::InterruptHandler<peripherals::USB>;
+
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = embassy_stm32::Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hsi = true;
+        config.rcc.pll = Some(Pll {
+            source: PllSource::HSI,
+            mul: PllMul::MUL6, // PLLVCO = 16*6 = 96Mhz
+            div: PllDiv::DIV3, // 32Mhz clock (16 * 6 / 3)
+        });
+        config.rcc.mux = ClockSrc::PLL1_R;
+    }
+
+    let p = embassy_stm32::init(config);
+
+    info!("Hello World!");
+
+    let driver = Driver::new(p.USB, Irqs, p.PA12, p.PA11);
+
+    let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("USB-Serial Example");
+    config.serial_number = Some("123456");
+
+    config.device_class = 0xEF;
+    config.device_sub_class = 0x02;
+    config.device_protocol = 0x01;
+    config.composite_with_iads = true;
+
+    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 builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut [], // no msos descriptors
+        &mut control_buf,
+    );
+
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    let mut usb = builder.build();
+
+    let usb_fut = usb.run();
+
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            info!("Connected");
+            let _ = echo(&mut class).await;
+            info!("Disconnected");
+        }
+    };
+
+    join(usb_fut, echo_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?;
+    }
+}