feat: update ot synchronous gpio and rotate keys

pi/pi-service/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0"
 axum = "0.8"
+gpiod = "0.3.0"
 libc = "0.2"
 noisebell-common = { path = "../../remote/noisebell-common" }
 reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
@@ -13,6 +14,5 @@ sd-notify = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "sync", "signal", "time"] }
-tokio-gpiod = "0.3.0"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

pi/pi-service/src/main.rs

@@ -7,10 +7,10 @@ use axum::extract::State;
 use axum::http::{HeaderMap, StatusCode};
 use axum::routing::get;
 use axum::{Json, Router};
+use gpiod::{Bias, Chip, Edge, EdgeDetect, Options};
 use noisebell_common::{
     validate_bearer, DoorStatus, PiStatusResponse, SignalLevel, WebhookPayload,
 };
-use tokio_gpiod::{Bias, Chip, Edge, EdgeDetect, Options};
 use tracing::{error, info, warn};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -135,9 +135,7 @@ async fn main() -> Result<()> {
 
     info!(gpio_pin, debounce_secs, port, %endpoint_url, "starting noisebell");
 
-    let chip = Chip::new("gpiochip0")
-        .await
-        .context("failed to open gpiochip0")?;
+    let chip = Chip::new("gpiochip0").context("failed to open gpiochip0")?;
 
     let bias = if active_level == SignalLevel::Low {
         Bias::PullUp
@@ -152,13 +150,11 @@ async fn main() -> Result<()> {
         .consumer("noisebell");
     let mut inputs = chip
         .request_lines(opts)
-        .await
         .context(format!("failed to request GPIO line {gpio_pin}"))?;
 
     // Read initial value
     let initial_values = inputs
         .get_values([false])
-        .await
         .context("failed to read initial GPIO value")?;
     // Value is true when line is active. With Active::High (default),
     // true means the physical level is high.
@@ -187,19 +183,22 @@ async fn main() -> Result<()> {
     // Sync initial state with the cache on startup
     let _ = tx.send((initial_state.as_door_status(), now));
 
-    // Spawn async edge detection task
+    // Spawn blocking edge detection task. The async tokio-gpiod path was
+    // returning repeated EAGAIN on Raspberry Pi OS even when no real GPIO
+    // error occurred.
     let state_for_edges = state.clone();
     let edge_tx = tx.clone();
-    let edge_handle = tokio::spawn(async move {
-        let mut last_event_time = std::time::Instant::now();
+    let _edge_handle = std::thread::spawn(move || {
+        let mut last_event_time = std::time::Instant::now() - Duration::from_secs(debounce_secs);
         let debounce = Duration::from_secs(debounce_secs);
 
         loop {
-            let event = match inputs.read_event().await {
+            let event = match inputs.read_event() {
                 Ok(event) => event,
+                Err(e) if e.kind() == std::io::ErrorKind::Interrupted => continue,
                 Err(e) => {
                     error!(error = %e, "failed to read GPIO event");
-                    tokio::time::sleep(Duration::from_secs(1)).await;
+                    std::thread::sleep(Duration::from_secs(1));
                     continue;
                 }
             };
@@ -303,7 +302,6 @@ async fn main() -> Result<()> {
         .context("server error")?;
 
     info!("shutting down, draining notification queue");
-    edge_handle.abort();
     let _ = notify_handle.await;
 
     info!("shutdown complete");