rp/uart: report errors from dma receive

1 files changed, 228 insertions, 10 deletions

diff --git a/tests/rp/src/bin/uart_dma.rs b/tests/rp/src/bin/uart_dma.rs
index 963c22707..92aa205c9 100644
--- a/tests/rp/src/bin/uart_dma.rs
+++ b/tests/rp/src/bin/uart_dma.rs
@@ -4,28 +4,246 @@
 
 use defmt::{assert_eq, *};
 use embassy_executor::Spawner;
-use embassy_rp::uart::{Config, Uart};
+use embassy_rp::gpio::{Level, Output};
+use embassy_rp::interrupt;
+use embassy_rp::uart::{Async, Config, Error, Instance, Parity, Uart, UartRx};
+use embassy_time::{Duration, Timer};
 use {defmt_rtt as _, panic_probe as _};
 
+async fn read<const N: usize>(uart: &mut Uart<'_, impl Instance, Async>) -> Result<[u8; N], Error> {
+    let mut buf = [255; N];
+    uart.read(&mut buf).await?;
+    Ok(buf)
+}
+
+async fn read1<const N: usize>(uart: &mut UartRx<'_, impl Instance, Async>) -> Result<[u8; N], Error> {
+    let mut buf = [255; N];
+    uart.read(&mut buf).await?;
+    Ok(buf)
+}
+
+async fn send(pin: &mut Output<'_, impl embassy_rp::gpio::Pin>, v: u8, parity: Option<bool>) {
+    pin.set_low();
+    Timer::after(Duration::from_millis(1)).await;
+    for i in 0..8 {
+        if v & (1 << i) == 0 {
+            pin.set_low();
+        } else {
+            pin.set_high();
+        }
+        Timer::after(Duration::from_millis(1)).await;
+    }
+    if let Some(b) = parity {
+        if b {
+            pin.set_high();
+        } else {
+            pin.set_low();
+        }
+        Timer::after(Duration::from_millis(1)).await;
+    }
+    pin.set_high();
+    Timer::after(Duration::from_millis(1)).await;
+}
+
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
-    let p = embassy_rp::init(Default::default());
+    let mut p = embassy_rp::init(Default::default());
     info!("Hello World!");
 
-    let (tx, rx, uart) = (p.PIN_0, p.PIN_1, p.UART0);
+    let (mut tx, mut rx, mut uart) = (p.PIN_0, p.PIN_1, p.UART0);
+    let mut irq = interrupt::take!(UART0_IRQ);
 
-    let config = Config::default();
-    let mut uart = Uart::new(uart, tx, rx, p.DMA_CH0, p.DMA_CH1, config);
+    // TODO
+    // nuclear error reporting. just abort the entire transfer and invalidate the
+    // dma buffer, buffered buffer, fifo etc.
 
     // We can't send too many bytes, they have to fit in the FIFO.
     // This is because we aren't sending+receiving at the same time.
+    {
+        let config = Config::default();
+        let mut uart = Uart::new(
+            &mut uart,
+            &mut tx,
+            &mut rx,
+            &mut irq,
+            &mut p.DMA_CH0,
+            &mut p.DMA_CH1,
+            config,
+        );
+
+        let data = [0xC0, 0xDE];
+        uart.write(&data).await.unwrap();
+
+        let mut buf = [0; 2];
+        uart.read(&mut buf).await.unwrap();
+        assert_eq!(buf, data);
+    }
+
+    info!("test overflow detection");
+    {
+        let config = Config::default();
+        let mut uart = Uart::new(
+            &mut uart,
+            &mut tx,
+            &mut rx,
+            &mut irq,
+            &mut p.DMA_CH0,
+            &mut p.DMA_CH1,
+            config,
+        );
+
+        uart.blocking_write(&[42; 32]).unwrap();
+        uart.blocking_write(&[1, 2, 3]).unwrap();
+        uart.blocking_flush().unwrap();
+
+        // can receive regular fifo contents
+        assert_eq!(read(&mut uart).await, Ok([42; 16]));
+        assert_eq!(read(&mut uart).await, Ok([42; 16]));
+        // receiving the rest fails with overrun
+        assert_eq!(read::<16>(&mut uart).await, Err(Error::Overrun));
+        // new data is accepted, latest overrunning byte first
+        assert_eq!(read(&mut uart).await, Ok([3]));
+        uart.blocking_write(&[8, 9]).unwrap();
+        Timer::after(Duration::from_millis(1)).await;
+        assert_eq!(read(&mut uart).await, Ok([8, 9]));
+    }
+
+    info!("test break detection");
+    {
+        let config = Config::default();
+        let (mut tx, mut rx) = Uart::new(
+            &mut uart,
+            &mut tx,
+            &mut rx,
+            &mut irq,
+            &mut p.DMA_CH0,
+            &mut p.DMA_CH1,
+            config,
+        )
+        .split();
+
+        // break before read
+        tx.send_break(20).await;
+        tx.write(&[64]).await.unwrap();
+        assert_eq!(read1::<1>(&mut rx).await.unwrap_err(), Error::Break);
+        assert_eq!(read1(&mut rx).await.unwrap(), [64]);
+
+        // break during read
+        {
+            let r = read1::<2>(&mut rx);
+            tx.write(&[2]).await.unwrap();
+            tx.send_break(20).await;
+            tx.write(&[3]).await.unwrap();
+            assert_eq!(r.await.unwrap_err(), Error::Break);
+            assert_eq!(read1(&mut rx).await.unwrap(), [3]);
+        }
+
+        // break after read
+        {
+            let r = read1(&mut rx);
+            tx.write(&[2]).await.unwrap();
+            tx.send_break(20).await;
+            tx.write(&[3]).await.unwrap();
+            assert_eq!(r.await.unwrap(), [2]);
+            assert_eq!(read1::<1>(&mut rx).await.unwrap_err(), Error::Break);
+            assert_eq!(read1(&mut rx).await.unwrap(), [3]);
+        }
+    }
+
+    // parity detection. here we bitbang to not require two uarts.
+    info!("test parity error detection");
+    {
+        let mut pin = Output::new(&mut tx, Level::High);
+        // choose a very slow baud rate to make tests reliable even with O0
+        let mut config = Config::default();
+        config.baudrate = 1000;
+        config.parity = Parity::ParityEven;
+        let mut uart = UartRx::new(&mut uart, &mut rx, &mut irq, &mut p.DMA_CH0, config);
+
+        async fn chr(pin: &mut Output<'_, impl embassy_rp::gpio::Pin>, v: u8, parity: u32) {
+            send(pin, v, Some(parity != 0)).await;
+        }
+
+        // first check that we can send correctly
+        chr(&mut pin, 32, 1).await;
+        assert_eq!(read1(&mut uart).await.unwrap(), [32]);
+
+        // parity error before read
+        chr(&mut pin, 32, 0).await;
+        chr(&mut pin, 31, 1).await;
+        assert_eq!(read1::<1>(&mut uart).await.unwrap_err(), Error::Parity);
+        assert_eq!(read1(&mut uart).await.unwrap(), [31]);
+
+        // parity error during read
+        {
+            let r = read1::<2>(&mut uart);
+            chr(&mut pin, 2, 1).await;
+            chr(&mut pin, 32, 0).await;
+            chr(&mut pin, 3, 0).await;
+            assert_eq!(r.await.unwrap_err(), Error::Parity);
+            assert_eq!(read1(&mut uart).await.unwrap(), [3]);
+        }
+
+        // parity error after read
+        {
+            let r = read1(&mut uart);
+            chr(&mut pin, 2, 1).await;
+            chr(&mut pin, 32, 0).await;
+            chr(&mut pin, 3, 0).await;
+            assert_eq!(r.await.unwrap(), [2]);
+            assert_eq!(read1::<1>(&mut uart).await.unwrap_err(), Error::Parity);
+            assert_eq!(read1(&mut uart).await.unwrap(), [3]);
+        }
+    }
+
+    // framing error detection. here we bitbang because there's no other way.
+    info!("test framing error detection");
+    {
+        let mut pin = Output::new(&mut tx, Level::High);
+        // choose a very slow baud rate to make tests reliable even with O0
+        let mut config = Config::default();
+        config.baudrate = 1000;
+        let mut uart = UartRx::new(&mut uart, &mut rx, &mut irq, &mut p.DMA_CH0, config);
+
+        async fn chr(pin: &mut Output<'_, impl embassy_rp::gpio::Pin>, v: u8, good: bool) {
+            if good {
+                send(pin, v, None).await;
+            } else {
+                send(pin, v, Some(false)).await;
+            }
+        }
+
+        // first check that we can send correctly
+        chr(&mut pin, 32, true).await;
+        assert_eq!(read1(&mut uart).await.unwrap(), [32]);
+
+        // parity error before read
+        chr(&mut pin, 32, false).await;
+        chr(&mut pin, 31, true).await;
+        assert_eq!(read1::<1>(&mut uart).await.unwrap_err(), Error::Framing);
+        assert_eq!(read1(&mut uart).await.unwrap(), [31]);
 
-    let data = [0xC0, 0xDE];
-    uart.write(&data).await.unwrap();
+        // parity error during read
+        {
+            let r = read1::<2>(&mut uart);
+            chr(&mut pin, 2, true).await;
+            chr(&mut pin, 32, false).await;
+            chr(&mut pin, 3, true).await;
+            assert_eq!(r.await.unwrap_err(), Error::Framing);
+            assert_eq!(read1(&mut uart).await.unwrap(), [3]);
+        }
 
-    let mut buf = [0; 2];
-    uart.read(&mut buf).await.unwrap();
-    assert_eq!(buf, data);
+        // parity error after read
+        {
+            let r = read1(&mut uart);
+            chr(&mut pin, 2, true).await;
+            chr(&mut pin, 32, false).await;
+            chr(&mut pin, 3, true).await;
+            assert_eq!(r.await.unwrap(), [2]);
+            assert_eq!(read1::<1>(&mut uart).await.unwrap_err(), Error::Framing);
+            assert_eq!(read1(&mut uart).await.unwrap(), [3]);
+        }
+    }
 
     info!("Test OK");
     cortex_m::asm::bkpt();