From 0da028e193a36312d9b712def5962f18e6d7bb27 Mon Sep 17 00:00:00 2001
From: Justin Beaurivage <code@beaurivage.io>
Date: Wed, 4 Dec 2024 13:21:26 -0500
Subject: [PATCH] chore(atsamd-hal-macros): Add MSRV to atsamd-hal-macros

Suppresses clippy lints for unsupported APIs
in the standard library
---
 atsamd-hal-macros/Cargo.toml       |   1 +
 boards/feather_m0/examples/eic2.rs | 112 +++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 boards/feather_m0/examples/eic2.rs

diff --git a/atsamd-hal-macros/Cargo.toml b/atsamd-hal-macros/Cargo.toml
index d1b9b4c6a12..6cba419b6f0 100644
--- a/atsamd-hal-macros/Cargo.toml
+++ b/atsamd-hal-macros/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
 authors = ["Tethys Svensson"]
 name = "atsamd-hal-macros"
+rust-version = "1.77.2"
 version = "0.2.2"
 edition = "2021"
 license = "MIT OR Apache-2.0"
diff --git a/boards/feather_m0/examples/eic2.rs b/boards/feather_m0/examples/eic2.rs
new file mode 100644
index 00000000000..d580e6b0cc5
--- /dev/null
+++ b/boards/feather_m0/examples/eic2.rs
@@ -0,0 +1,112 @@
+#![no_std]
+#![no_main]
+
+use panic_halt as _;
+
+use feather_m0 as bsp;
+
+use bsp::{entry, hal, pac};
+
+use pac::{interrupt, CorePeripherals, Peripherals};
+
+use core::cell::RefCell;
+use core::sync::atomic::{AtomicBool, Ordering};
+
+use bsp::hal::ehal::digital::StatefulOutputPin;
+use cortex_m::{interrupt::Mutex, peripheral::NVIC};
+
+use hal::{
+    clock::GenericClockController,
+    eic::{Ch2, Eic, ExtInt, Sense},
+    gpio::{Pin, PullUpInterrupt, PA18},
+};
+
+type ButtonPin = ExtInt<Pin<PA18, PullUpInterrupt>, Ch2>;
+
+// To avoid unsafely passing the button pin to the interrupt handler,
+// we must use a Mutex. This can also be done safely by using a framework
+// like RTIC.
+static BUTTON_PIN: Mutex<RefCell<Option<ButtonPin>>> = Mutex::new(RefCell::new(None));
+
+// Used to signal to the main thread that the interrupt has fired
+// from the interrupt handler
+static INTERRUPT_FIRED: AtomicBool = AtomicBool::new(false);
+
+#[embassy_executor::main]
+async fn main() {
+    // -- Setup clocks and peripherals
+    let mut peripherals = Peripherals::take().unwrap();
+    let mut core = CorePeripherals::take().unwrap();
+    let mut clocks = GenericClockController::with_external_32kosc(
+        peripherals.gclk,
+        &mut peripherals.pm,
+        &mut peripherals.sysctrl,
+        &mut peripherals.nvmctrl,
+    );
+    let gclk0 = clocks.gclk0();
+    let pins = bsp::Pins::new(peripherals.port);
+
+    // Take the LED pin and set it to output mode
+    let mut red_led: bsp::RedLed = pins.d13.into();
+
+    // Setup the external interrupt controller
+    let eic_clock = clocks.eic(&gclk0).unwrap();
+    // Split the controller into its individual channels
+    let eic_channels = Eic::new(&mut peripherals.pm, eic_clock, peripherals.eic).split();
+
+    // Enable EIC interrupt in the NVIC
+    unsafe {
+        core.NVIC.set_priority(interrupt::EIC, 1);
+        NVIC::unmask(interrupt::EIC);
+    }
+
+    // Take the user button pin
+    let button: Pin<_, PullUpInterrupt> = pins.d10.into();
+    // Turn the pin into an ExtInt using EIC channel 2
+    let mut extint = eic_channels.2.with_pin(button);
+
+    // Setup the button pin to wake the CPU upon interrupt
+    extint.enable_interrupt_wake();
+
+    // Setup the pin to sense falling edges. It will generate
+    // interrupts on every falling edge, not juste the first one
+    extint.sense(Sense::Fall);
+
+    // Enable the pin's interrupt
+    extint.enable_interrupt();
+
+    // Store the button pin in static storage so that the interrupt
+    // handler can access it
+    cortex_m::interrupt::free(|cs| BUTTON_PIN.borrow(cs).borrow_mut().replace(extint));
+
+    loop {
+        // Check if our interrupt has fired
+        if INTERRUPT_FIRED.load(Ordering::Acquire) {
+            // Toggle the LED! We don't use the return
+            // value, because toggling a pin is infaillible
+            // in atsamd-hal.
+            let _ = red_led.toggle();
+
+            // Reset the signal for the next loop
+            INTERRUPT_FIRED.store(false, Ordering::Release);
+        }
+        // Put the CPU to sleep while we wait for an interrupt
+        // to happen
+        cortex_m::asm::wfi();
+    }
+}
+
+/// The external interrupt controller handler
+#[interrupt]
+fn EIC() {
+    // Clear the interrupt so we don't reenter the handler
+    // infinitely
+    cortex_m::interrupt::free(|cs| {
+        let mut button = BUTTON_PIN.borrow(cs).borrow_mut();
+        let button = button.as_mut().unwrap();
+        button.clear_interrupt();
+    });
+
+    // Send a signal to the main thread
+    INTERRUPT_FIRED.store(true, Ordering::Release);
+}