avr: support sleep

embassy-executor/Cargo.toml

@@ -36,10 +36,11 @@ embassy-executor-macros = { version = "0.4.0", path = "../embassy-executor-macro
 embassy-time = { version = "0.2", path = "../embassy-time", optional = true}
 critical-section = "1.1"
 
-# needed for riscv
+# needed for riscv and avr
 # remove when https://github.com/rust-lang/rust/pull/114499 is merged
 portable-atomic = { version = "1.5", optional = true }
 
+
 # arch-cortex-m dependencies
 cortex-m = { version = "0.7.6", optional = true }
 
@@ -47,6 +48,9 @@ cortex-m = { version = "0.7.6", optional = true }
 wasm-bindgen = { version = "0.2.82", optional = true }
 js-sys = { version = "0.3", optional = true }
 
+# arch-avr dependencies
+avr-device = { version = "0.5.3", optional = true }
+
 [dev-dependencies]
 critical-section = { version = "1.1", features = ["std"] }
 
@@ -55,7 +59,7 @@ critical-section = { version = "1.1", features = ["std"] }
 
 # Architecture
 _arch = [] # some arch was picked
-arch-avr = ["_arch", "dep:portable-atomic"]
+arch-avr = ["_arch", "dep:portable-atomic", "dep:avr-device"]
 arch-std = ["_arch", "critical-section/std"]
 arch-cortex-m = ["_arch", "dep:cortex-m"]
 arch-riscv32 = ["_arch", "dep:portable-atomic"]

embassy-executor/src/arch/avr.rs

@@ -8,11 +8,16 @@ mod thread {
     use core::marker::PhantomData;
 
     pub use embassy_executor_macros::main_avr as main;
+    use portable_atomic::{AtomicBool, Ordering};
 
     use crate::{raw, Spawner};
 
+    static SIGNAL_WORK_THREAD_MODE: AtomicBool = AtomicBool::new(false);
+
     #[export_name = "__pender"]
-    fn __pender(_context: *mut ()) {}
+    fn __pender(_context: *mut ()) {
+        SIGNAL_WORK_THREAD_MODE.store(true, Ordering::SeqCst);
+    }
 
     /// avr Executor
     pub struct Executor {
@@ -52,7 +57,11 @@ mod thread {
 
             loop {
                 unsafe {
-                    self.inner.poll();
+                    if SIGNAL_WORK_THREAD_MODE.swap(false, Ordering::SeqCst) {
+                        self.inner.poll();
+                    } else {
+                        avr_device::asm::sleep();
+                    }
                 }
             }
         }