Add examples for STM32L0

11 files changed, 300 insertions, 3 deletions

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index d95c388f..b48b9feb 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -84,6 +84,8 @@ jobs:
             target: thumbv7em-none-eabi
           - package: examples/stm32h7
             target: thumbv7em-none-eabi
+          - package: examples/stm32l0
+            target: thumbv6m-none-eabi
 
     steps:
       - uses: actions/checkout@v2
diff --git a/embassy-stm32/src/rcc/l0/mod.rs b/embassy-stm32/src/rcc/l0/mod.rs
index ac32a6c4..d08c32b1 100644
--- a/embassy-stm32/src/rcc/l0/mod.rs
+++ b/embassy-stm32/src/rcc/l0/mod.rs
@@ -263,9 +263,7 @@ impl<'d> Rcc<'d> {
     pub fn enable_debug_wfe(&mut self, _dbg: &mut peripherals::DBGMCU, enable_dma: bool) {
         // NOTE(unsafe) We have exclusive access to the RCC and DBGMCU
         unsafe {
-            if enable_dma {
-                pac::RCC.ahbenr().modify(|w| w.set_dmaen(true));
-            }
+            pac::RCC.ahbenr().modify(|w| w.set_dmaen(enable_dma));
 
             pac::DBGMCU.cr().modify(|w| {
                 w.set_dbg_sleep(DbgSleep::ENABLED);
diff --git a/examples/stm32l0/.cargo/config.toml b/examples/stm32l0/.cargo/config.toml
new file mode 100644
index 00000000..0528db9f
--- /dev/null
+++ b/examples/stm32l0/.cargo/config.toml
@@ -0,0 +1,21 @@
+[unstable]
+build-std = ["core"]
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# replace your chip as listed in `probe-run --list-chips`
+runner = "probe-run --chip STM32L072CZ"
+
+rustflags = [
+  # LLD (shipped with the Rust toolchain) is used as the default linker
+  "-C", "link-arg=--nmagic",
+  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tdefmt.x",
+
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+  "-C", "inline-threshold=5",
+  "-C", "no-vectorize-loops",
+]
+
+[build]
+target = "thumbv6m-none-eabi"
diff --git a/examples/stm32l0/Cargo.toml b/examples/stm32l0/Cargo.toml
new file mode 100644
index 00000000..68291b00
--- /dev/null
+++ b/examples/stm32l0/Cargo.toml
@@ -0,0 +1,34 @@
+[package]
+authors = ["Dario Nieuwenhuis <dirbaio@dirbaio.net>", "Ulf Lilleengen <ulf.lilleengen@gmail.com>"]
+edition = "2018"
+name = "embassy-stm32l0-examples"
+version = "0.1.0"
+resolver = "2"
+
+[features]
+default = [
+    "defmt-default",
+]
+defmt-default = []
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-trace"] }
+embassy-traits = { version = "0.1.0", path = "../../embassy-traits", features = ["defmt"] }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "defmt-trace", "stm32l072cz"]  }
+embassy-extras = {version = "0.1.0", path = "../../embassy-extras" }
+
+defmt = "0.2.0"
+defmt-rtt = "0.2.0"
+
+cortex-m = "0.7.1"
+cortex-m-rt = "0.6.14"
+embedded-hal = { version = "0.2.4" }
+panic-probe = { version = "0.2.0", features= ["print-defmt"] }
+futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
+rtt-target = { version = "0.3", features = ["cortex-m"] }
+heapless = { version = "0.7.1", default-features = false }
diff --git a/examples/stm32l0/build.rs b/examples/stm32l0/build.rs
new file mode 100644
index 00000000..d534cc3d
--- /dev/null
+++ b/examples/stm32l0/build.rs
@@ -0,0 +1,31 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+}
diff --git a/examples/stm32l0/memory.x b/examples/stm32l0/memory.x
new file mode 100644
index 00000000..67a50a5f
--- /dev/null
+++ b/examples/stm32l0/memory.x
@@ -0,0 +1,5 @@
+MEMORY
+{
+  FLASH : ORIGIN = 0x08000000, LENGTH = 192K
+  RAM : ORIGIN = 0x20000000, LENGTH = 20K
+}
diff --git a/examples/stm32l0/src/bin/blinky.rs b/examples/stm32l0/src/bin/blinky.rs
new file mode 100644
index 00000000..e7433c26
--- /dev/null
+++ b/examples/stm32l0/src/bin/blinky.rs
@@ -0,0 +1,36 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_stm32::{rcc::*, gpio::{Level, Output}};
+use embedded_hal::digital::v2::OutputPin;
+use example_common::*;
+
+use cortex_m_rt::entry;
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let mut p = embassy_stm32::init(Default::default());
+
+    Rcc::new(p.RCC).enable_debug_wfe(&mut p.DBGMCU, true);
+
+    let mut led = Output::new(p.PB5, Level::High);
+
+    loop {
+        info!("high");
+        led.set_high().unwrap();
+        cortex_m::asm::delay(1_000_000);
+
+        info!("low");
+        led.set_low().unwrap();
+        cortex_m::asm::delay(1_000_000);
+    }
+}
diff --git a/examples/stm32l0/src/bin/button.rs b/examples/stm32l0/src/bin/button.rs
new file mode 100644
index 00000000..1a2e20b1
--- /dev/null
+++ b/examples/stm32l0/src/bin/button.rs
@@ -0,0 +1,40 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_stm32::{rcc::*, gpio::{Input, Level, Output, Pull}};
+use embedded_hal::digital::v2::{InputPin, OutputPin};
+use example_common::*;
+
+use cortex_m_rt::entry;
+
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let mut p = embassy_stm32::init(Default::default());
+    Rcc::new(p.RCC).enable_debug_wfe(&mut p.DBGMCU, true);
+
+    let button = Input::new(p.PB2, Pull::Up);
+    let mut led1 = Output::new(p.PA5, Level::High);
+    let mut led2 = Output::new(p.PB5, Level::High);
+
+    loop {
+        if button.is_high().unwrap() {
+            info!("high");
+            led1.set_high().unwrap();
+            led2.set_low().unwrap();
+        } else {
+            info!("low");
+            led1.set_low().unwrap();
+            led2.set_high().unwrap();
+        }
+    }
+}
diff --git a/examples/stm32l0/src/bin/button_exti.rs b/examples/stm32l0/src/bin/button_exti.rs
new file mode 100644
index 00000000..a7f73494
--- /dev/null
+++ b/examples/stm32l0/src/bin/button_exti.rs
@@ -0,0 +1,64 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy::executor::Executor;
+use embassy::time::Clock;
+use embassy::util::Forever;
+use embassy_stm32::exti::ExtiInput;
+use embassy_stm32::gpio::{Input, Pull};
+use embassy_stm32::rcc;
+use embassy_traits::gpio::{WaitForFallingEdge, WaitForRisingEdge};
+use example_common::*;
+
+use cortex_m_rt::entry;
+
+#[embassy::task]
+async fn main_task() {
+    let mut p = embassy_stm32::init(Default::default());
+    let mut rcc = rcc::Rcc::new(p.RCC);
+    rcc.enable_debug_wfe(&mut p.DBGMCU, true);
+    // Enables SYSCFG
+    let _ = rcc.enable_hsi48(&mut p.SYSCFG, p.CRS);
+
+    let button = Input::new(p.PB2, Pull::Up);
+    let mut button = ExtiInput::new(button, p.EXTI2);
+
+    info!("Press the USER button...");
+
+    loop {
+        button.wait_for_falling_edge().await;
+        info!("Pressed!");
+        button.wait_for_rising_edge().await;
+        info!("Released!");
+    }
+}
+
+struct ZeroClock;
+
+impl Clock for ZeroClock {
+    fn now(&self) -> u64 {
+        0
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    unsafe { embassy::time::set_clock(&ZeroClock) };
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}
diff --git a/examples/stm32l0/src/bin/spi.rs b/examples/stm32l0/src/bin/spi.rs
new file mode 100644
index 00000000..4eb9bfdd
--- /dev/null
+++ b/examples/stm32l0/src/bin/spi.rs
@@ -0,0 +1,49 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use embassy_stm32::gpio::{Level, Output};
+use embedded_hal::digital::v2::OutputPin;
+use example_common::*;
+
+use cortex_m_rt::entry;
+use embassy_stm32::rcc;
+use embassy_stm32::spi::{Config, Spi};
+use embassy_stm32::time::Hertz;
+use embedded_hal::blocking::spi::Transfer;
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World, dude!");
+
+    let mut p = embassy_stm32::init(Default::default());
+    let mut rcc = rcc::Rcc::new(p.RCC);
+    rcc.enable_debug_wfe(&mut p.DBGMCU, true);
+
+    let mut spi = Spi::new(
+        Hertz(16_000_000),
+        p.SPI1,
+        p.PB3,
+        p.PA7,
+        p.PA6,
+        Hertz(1_000_000),
+        Config::default(),
+    );
+
+    let mut cs = Output::new(p.PA15, Level::High);
+
+    loop {
+        let mut buf = [0x0A; 4];
+        unwrap!(cs.set_low());
+        unwrap!(spi.transfer(&mut buf));
+        unwrap!(cs.set_high());
+        info!("xfer {=[u8]:x}", buf);
+    }
+}
diff --git a/examples/stm32l0/src/example_common.rs b/examples/stm32l0/src/example_common.rs
new file mode 100644
index 00000000..54d63383
--- /dev/null
+++ b/examples/stm32l0/src/example_common.rs
@@ -0,0 +1,17 @@
+#![macro_use]
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+pub use defmt::*;
+
+use core::sync::atomic::{AtomicUsize, Ordering};
+
+defmt::timestamp! {"{=u64}", {
+        static COUNT: AtomicUsize = AtomicUsize::new(0);
+        // NOTE(no-CAS) `timestamps` runs with interrupts disabled
+        let n = COUNT.load(Ordering::Relaxed);
+        COUNT.store(n + 1, Ordering::Relaxed);
+        n as u64
+    }
+}