stm32/can: add hw test and cleanup

tests/stm32/Cargo.toml

@@ -7,7 +7,7 @@ autobins = false
 
 [features]
 stm32f103c8 = ["embassy-stm32/stm32f103c8", "not-gpdma"]     # Blue Pill
-stm32f429zi = ["embassy-stm32/stm32f429zi", "sdmmc", "chrono", "not-gpdma"]     # Nucleo
+stm32f429zi = ["embassy-stm32/stm32f429zi", "sdmmc", "chrono", "can", "not-gpdma"]     # Nucleo
 stm32g071rb = ["embassy-stm32/stm32g071rb", "not-gpdma"]     # Nucleo
 stm32c031c6 = ["embassy-stm32/stm32c031c6", "not-gpdma"]     # Nucleo
 stm32g491re = ["embassy-stm32/stm32g491re", "not-gpdma"]     # Nucleo
@@ -19,6 +19,7 @@ stm32u585ai = ["embassy-stm32/stm32u585ai"]     # IoT board
 sdmmc = []
 chrono = ["embassy-stm32/chrono", "dep:chrono"]
 ble = []
+can = []
 not-gpdma = []
 
 [dependencies]
@@ -49,6 +50,11 @@ name = "ble"
 path = "src/bin/ble.rs"
 required-features = [ "ble",]
 
+[[bin]]
+name = "can"
+path = "src/bin/can.rs"
+required-features = [ "can",]
+
 [[bin]]
 name = "gpio"
 path = "src/bin/gpio.rs"

tests/stm32/src/bin/can.rs

@@ -0,0 +1,78 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+// required-features: can
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_executor::Spawner;
+use embassy_stm32::bind_interrupts;
+use embassy_stm32::can::bxcan::filter::Mask32;
+use embassy_stm32::can::bxcan::{Fifo, Frame, StandardId};
+use embassy_stm32::can::{Can, Rx0InterruptHandler, Rx1InterruptHandler, SceInterruptHandler, TxInterruptHandler};
+use embassy_stm32::gpio::{Input, Pull};
+use embassy_stm32::peripherals::CAN1;
+use example_common::*;
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    CAN1_RX0 => Rx0InterruptHandler<CAN1>;
+    CAN1_RX1 => Rx1InterruptHandler<CAN1>;
+    CAN1_SCE => SceInterruptHandler<CAN1>;
+    CAN1_TX => TxInterruptHandler<CAN1>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut p = embassy_stm32::init(config());
+    info!("Hello World!");
+
+    // HW is connected as follows:
+    // PB13 -> PD0
+    // PB12 -> PD1
+
+    // The next two lines are a workaround for testing without transceiver.
+    // To synchronise to the bus the RX input needs to see a high level.
+    // Use `mem::forget()` to release the borrow on the pin but keep the
+    // pull-up resistor enabled.
+    let rx_pin = Input::new(&mut p.PD0, Pull::Up);
+    core::mem::forget(rx_pin);
+
+    let mut can = Can::new(p.CAN1, p.PD0, p.PD1, Irqs);
+
+    info!("Configuring can...");
+
+    can.modify_filters().enable_bank(0, Fifo::Fifo0, Mask32::accept_all());
+
+    can.set_bitrate(1_000_000);
+    can.modify_config()
+        .set_loopback(true) // Receive own frames
+        .set_silent(true)
+        // .set_bit_timing(0x001c0003)
+        .enable();
+
+    info!("Can configured");
+
+    let mut i: u8 = 0;
+    loop {
+        let tx_frame = Frame::new_data(unwrap!(StandardId::new(i as _)), [i]);
+
+        info!("Transmitting frame...");
+        can.write(&tx_frame).await;
+
+        info!("Receiving frame...");
+        let (time, rx_frame) = can.read().await.unwrap();
+
+        info!("loopback time {}", time);
+        info!("loopback frame {=u8}", rx_frame.data().unwrap()[0]);
+
+        i += 1;
+        if i > 10 {
+            break;
+        }
+    }
+
+    info!("Test OK");
+    cortex_m::asm::bkpt();
+}