unsafe handling

bluepill-rs/src/dmx.rs

@@ -1,57 +1,143 @@
-use cortex_m::singleton;
+use stm32f1xx_hal::{afio, dma, gpio, pac, prelude::*, rcc, serial};
-use stm32f1xx_hal::{dma, pac, prelude::*, rcc, serial};
 
-const DMX_LEN_MAX: usize = 512;
 type TxDma = dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>;
 type DMXUniverse<const DMX_LEN: usize> = &'static mut [u8; DMX_LEN];
 type DMXTransfer<const DMX_LEN: usize> = dma::Transfer<dma::R, DMXUniverse<DMX_LEN>, TxDma>;
 
-pub enum DMX<const DMX_LEN: usize = DMX_LEN_MAX> {
+struct TxDMAIdle<const DMX_LEN: usize> {
-    Idle(Option<TxDma>, Option<DMXUniverse<DMX_LEN>>),
+    tx: TxDma,
-    Busy(Option<DMXTransfer<DMX_LEN>>),
+    buffer: DMXUniverse<DMX_LEN>,
+}
+
+struct TxDMABusy<const DMX_LEN: usize> {
+    transfer: DMXTransfer<DMX_LEN>,
+}
+
+enum TxDMA<const DMX_LEN: usize> {
+    Idle(Option<TxDMAIdle<DMX_LEN>>),
+    Busy(Option<TxDMABusy<DMX_LEN>>),
+}
+
+impl<const DMX_LEN: usize> TxDMA<DMX_LEN> {
+    fn new(tx: TxDma, buffer: DMXUniverse<DMX_LEN>) -> Self {
+        TxDMA::Idle(Some(TxDMAIdle { tx, buffer }))
+    }
+
+    fn start_sending(&mut self, tx_universe: &[u8]) {
+        let TxDMA::Idle(idle) = self else {
+            return;
+        };
+
+        let Some(TxDMAIdle { tx, buffer }) = idle.take() else {
+            panic!();
+        };
+
+        buffer.copy_from_slice(tx_universe);
+        *self = TxDMA::Busy(Some(TxDMABusy {
+            transfer: tx.write(buffer),
+        }));
+    }
+
+    fn wait(&mut self) {
+        let TxDMA::Busy(busy) = self else {
+            return;
+        };
+
+        let Some(TxDMABusy { transfer }) = busy.take() else {
+            panic!();
+        };
+
+        let (buffer, tx) = transfer.wait();
+
+        *self = TxDMA::Idle(Some(TxDMAIdle { tx, buffer }));
+    }
+
+    fn is_idle(&mut self) -> bool {
+        match self {
+            TxDMA::Idle(_) => true,
+
+            TxDMA::Busy(busy) => {
+                let Some(TxDMABusy { transfer }) = busy.take() else {
+                    panic!();
+                };
+
+                let is_done = transfer.is_done();
+                busy.replace(TxDMABusy { transfer });
+                if is_done {
+                    self.wait();
+                }
+
+                is_done
+            }
+        }
+    }
+}
+
+#[allow(clippy::upper_case_acronyms)]
+pub struct DMX<const DMX_LEN: usize> {
+    tx_universe: DMXUniverse<DMX_LEN>,
+    sender: TxDMA<DMX_LEN>,
 }
 
 impl<const DMX_LEN: usize> DMX<DMX_LEN> {
-    pub fn new<PINS>(
+    #[allow(unsafe_code)]
-        mut serial: serial::Serial<pac::USART1, PINS>,
+    pub fn new(
-        channel: dma::dma1::C4,
+        mem: &'static mut [u8],
+        mut dma_channel: dma::dma1::C4,
+        pa9: gpio::PA9,
+        pa10: gpio::PA10,
+        acrh: &mut gpio::Cr<'A', true>,
+        mapr: &mut afio::MAPR,
         clocks: &rcc::Clocks,
-    ) -> Self
+    ) -> Self {
-    where
+        // use provided memory region
-        PINS: serial::Pins<pac::USART1>,
+        assert!(mem.len() >= DMX_LEN * 2);
-    {
-        assert!(DMX_LEN <= DMX_LEN_MAX);
 
-        serial.reconfigure(250_000.bps(), &clocks).unwrap();
+        let (tx_universe, tx_buffer) = {
+            let (tx_universe, rest) = mem.split_at_mut(DMX_LEN);
+            let (tx_buffer, _) = rest.split_at_mut(DMX_LEN);
 
-        Self::Idle(Some(serial.tx.with_dma(channel)), None)
+            let tx_universe: DMXUniverse<DMX_LEN> = tx_universe.try_into().unwrap();
-    }
+            let tx_buffer: DMXUniverse<DMX_LEN> = tx_buffer.try_into().unwrap();
 
-    pub fn send(&mut self, data: &[u8]) {
+            (tx_universe, tx_buffer)
-        if let Self::Busy(_) = self {
-            self.wait();
-        }
-
-        let Self::Idle(tx, txbuffer) = self else {
-            panic!("Broken DMX State!")
         };
 
-        let txbuffer = txbuffer.take().unwrap_or_else(|| {
+        // setup DMA1_CHANNEL4 interrupt on TransferComplete
-            let foo = singleton!(: [u8; DMX_LEN_MAX] = [0u8; DMX_LEN_MAX]).unwrap();
+        dma_channel.listen(dma::Event::TransferComplete);
-            (&mut foo[..DMX_LEN]).try_into().unwrap()
+        unsafe {
-        });
+            pac::CorePeripherals::steal()
-        let tx = tx.take().unwrap();
+                .NVIC
+                .set_priority(pac::Interrupt::DMA1_CHANNEL4, 1);
+        }
 
-        txbuffer.copy_from_slice(&data[..DMX_LEN]);
+        // Serial config
-        *self = Self::Busy(Some(tx.write(txbuffer)));
+        let serial = serial::Serial::new(
+            unsafe { pac::Peripherals::steal() }.USART1,
+            (
+                pa9.into_alternate_open_drain(acrh),
+                pa10, //.into_pull_up_input(acrh),
+            ),
+            mapr,
+            250_000.bps(),
+            clocks,
+        );
+
+        Self {
+            tx_universe,
+            sender: TxDMA::new(serial.tx.with_dma(dma_channel), tx_buffer),
+        }
     }
 
-    pub fn wait(&mut self) {
+    pub fn start_tx(&mut self) {
-        let Self::Busy(xfer) = self else { return };
+        self.sender.start_sending(self.tx_universe);
+    }
 
-        let xfer = xfer.take().unwrap();
+    pub fn wait_tx(&mut self) {
-        let (txbuffer, tx) = xfer.wait();
+        self.sender.wait();
+    }
 
-        *self = Self::Idle(Some(tx), Some(txbuffer));
+    pub fn tx_is_idle(&mut self) -> bool {
+        self.sender.is_idle()
     }
 }

bluepill-rs/src/dmx2.rs

@@ -1,79 +0,0 @@
-use stm32f1xx_hal::{dma, pac, prelude::*, serial};
-
-type TxDma = dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>;
-type DMXUniverse<const DMX_LEN: usize> = &'static mut [u8; DMX_LEN];
-type DMXTransfer<const DMX_LEN: usize> = dma::Transfer<dma::R, DMXUniverse<DMX_LEN>, TxDma>;
-
-struct TxDMAIdle<const DMX_LEN: usize> {
-    dma: Option<dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>>,
-    buffer: Option<DMXUniverse<DMX_LEN>>,
-}
-
-struct TxDMABusy<const DMX_LEN: usize> {
-    transfer: Option<DMXTransfer<DMX_LEN>>,
-}
-
-enum TxDMA<const DMX_LEN: usize> {
-    Idle(TxDMAIdle<DMX_LEN>),
-    Busy(TxDMABusy<DMX_LEN>),
-}
-
-pub struct DMX<const DMX_LEN: usize> {
-    tx_universe: Option<DMXUniverse<DMX_LEN>>,
-    sender: TxDMA<DMX_LEN>,
-}
-
-impl<const DMX_LEN: usize> DMX<DMX_LEN> {
-    pub fn new<PINS>(mem: &'static mut [u8]) -> Self {
-        // use provided memory region
-        assert!(mem.len() >= DMX_LEN * 2);
-
-        let (tx_universe, tx_buffer) = {
-            let (left1, rest) = mem.split_at_mut(DMX_LEN);
-            let (left2, _) = rest.split_at_mut(DMX_LEN);
-
-            let tx_universe: &mut [u8; DMX_LEN] = left1.try_into().unwrap();
-            let tx_buffer: &mut [u8; DMX_LEN] = left2.try_into().unwrap();
-
-            (tx_universe, tx_buffer)
-        };
-
-        // Peripherals
-        let dp = unsafe { pac::Peripherals::steal() };
-        let mut cp = unsafe { pac::CorePeripherals::steal() };
-
-        let clocks = dp
-            .RCC
-            .constrain()
-            .cfgr
-            .freeze(&mut dp.FLASH.constrain().acr);
-
-        let mut gpioa = dp.GPIOA.split();
-        let mut afio = dp.AFIO.constrain();
-        let mut dma1 = dp.DMA1.split();
-
-        // setup DMA1_CHANNEL4 interrupt on TransferComplete
-        dma1.4.listen(dma::Event::TransferComplete);
-        unsafe { cp.NVIC.set_priority(pac::Interrupt::DMA1_CHANNEL4, 1) };
-
-        // Serial config
-        let serial = serial::Serial::new(
-            dp.USART1,
-            (
-                gpioa.pa9.into_alternate_open_drain(&mut gpioa.crh),
-                gpioa.pa10, //.into_pull_up_input(&mut gpioa.crh),
-            ),
-            &mut afio.mapr,
-            250_000.bps(),
-            &clocks,
-        );
-
-        Self {
-            tx_universe: Some(tx_universe),
-            sender: TxDMA::Idle(TxDMAIdle {
-                dma: Some(serial.tx.with_dma(dma1.4)),
-                buffer: Some(tx_buffer),
-            }),
-        }
-    }
-}

bluepill-rs/src/main.rs

@@ -1,11 +1,10 @@
-// #![deny(unsafe_code)]
+#![deny(unsafe_code)]
 #![no_std]
 #![no_main]
 
 // mod i2c_reg_slave;
 // mod i2c_slave;
 mod dmx;
-mod dmx2;
 
 // extern crate panic_halt;
 extern crate panic_semihosting;
@@ -13,12 +12,11 @@ extern crate panic_semihosting;
 #[rtic::app(device = stm32f1xx_hal::pac, dispatchers = [SPI1, SPI2, SPI3])]
 mod app {
     use crate::dmx::DMX;
-    use cortex_m::singleton;
     use stm32f1xx_hal::{
         gpio::{self, ExtiPin},
         pac,
         prelude::*,
-        serial, timer,
+        timer,
     };
     use systick_monotonic::Systick;
 
@@ -30,9 +28,8 @@ mod app {
 
     #[shared]
     struct Shared {
-        buffer: &'static mut [u8],
-        delay_us: timer::DelayUs<pac::TIM2>,
         dmx: DMX<DMX_LEN>,
+        delay_us: timer::DelayUs<pac::TIM2>,
         int_led: gpio::gpiob::PB0<gpio::Output<gpio::OpenDrain>>,
     }
 
@@ -42,7 +39,8 @@ mod app {
         int_pin: gpio::gpiob::PB10<gpio::Input<gpio::PullUp>>,
     }
 
-    #[init]
+    #[allow(unsafe_code)]
+    #[init(local = [buffer: [u8; DMX_LEN * 2] = [0b0101_0101; DMX_LEN * 2]])]
     fn init(mut cx: init::Context) -> (Shared, Local, init::Monotonics) {
         // Take ownership over the raw flash and rcc devices and convert them into the corresponding
         // HAL structs
@@ -68,7 +66,7 @@ mod app {
         let mut gpioc = cx.device.GPIOC.split();
 
         let mut afio = cx.device.AFIO.constrain();
-        let mut dma1 = cx.device.DMA1.split();
+        let dma1 = cx.device.DMA1.split();
 
         // setup EXTI10 for Pin B10
         let mut int_pin = gpiob.pb10.into_pull_up_input(&mut gpiob.crh);
@@ -77,33 +75,23 @@ mod app {
         int_pin.trigger_on_edge(&mut cx.device.EXTI, gpio::Edge::Falling);
         unsafe { cx.core.NVIC.set_priority(pac::Interrupt::EXTI15_10, 1) }; // EXTI10 priority
 
-        // setup DMA1_CHANNEL4 interrupt on TransferComplete
-        dma1.4.listen(stm32f1xx_hal::dma::Event::TransferComplete);
-        unsafe { cx.core.NVIC.set_priority(pac::Interrupt::DMA1_CHANNEL4, 1) };
-
-        // Serial config
-        let serial = serial::Serial::new(
-            cx.device.USART1,
-            (
-                gpioa.pa9.into_alternate_open_drain(&mut gpioa.crh),
-                gpioa.pa10, //.into_pull_up_input(&mut gpioa.crh),
-            ),
-            &mut afio.mapr,
-            serial::Config::default(),
-            &clocks,
-        );
-
         sender::spawn().unwrap();
 
         (
             Shared {
-                buffer: singleton!(: [u8; DMX_LEN] = [0b01010101; DMX_LEN]).unwrap(),
+                dmx: DMX::new(
+                    cx.local.buffer,
+                    dma1.4,
+                    gpioa.pa9,
+                    gpioa.pa10,
+                    &mut gpioa.crh,
+                    &mut afio.mapr,
+                    &clocks,
+                ),
 
                 // Configure timer
                 delay_us: cx.device.TIM2.delay_us(&clocks),
 
-                dmx: DMX::new(serial, dma1.4, &clocks),
-
                 int_led: gpiob
                     .pb0
                     .into_open_drain_output_with_state(&mut gpiob.crl, gpio::PinState::Low),
@@ -115,7 +103,7 @@ mod app {
                     .pc13
                     .into_push_pull_output_with_state(&mut gpioc.crh, gpio::PinState::High),
 
-                int_pin: int_pin,
+                int_pin,
             },
             init::Monotonics(mono),
         )
@@ -128,9 +116,9 @@ mod app {
         }
     }
 
-    #[task(local = [led], shared = [&buffer, delay_us, dmx])]
+    #[task(local = [led], shared = [delay_us, dmx])]
     fn sender(mut cx: sender::Context) {
-        cx.shared.dmx.lock(|dmx| dmx.send(cx.shared.buffer));
+        cx.shared.dmx.lock(DMX::start_tx);
 
         cx.local.led.toggle();
         cx.shared.delay_us.lock(|d| d.delay(1.secs()));
@@ -141,7 +129,7 @@ mod app {
     #[task(binds = DMA1_CHANNEL4, shared = [dmx, int_led])]
     fn waiter(cx: waiter::Context) {
         (cx.shared.dmx, cx.shared.int_led).lock(|dmx, int_led| {
-            dmx.wait();
+            assert!(dmx.tx_is_idle());
             int_led.toggle();
         });
     }