feat: support Tmobile TMOHS1 hotspot

Add support for the Tmobile TMOHS1, a Wingtech CT2MHS01-based hotspot
with a Qualcomm mdm9607. The TMOHS1 has no screen, only 5 LEDs, two of
which are RGB.

daemon/src/display/mod.rs

@@ -1,5 +1,11 @@
+#[cfg(any(feature = "orbic", feature = "tplink", feature = "wingtech"))]
 mod generic_framebuffer;
 
+#[cfg(feature = "tmobile")]
+mod tmobile;
+#[cfg(feature = "tmobile")]
+pub use tmobile::update_ui;
+
 #[cfg(feature = "tplink")]
 mod tplink;
 #[cfg(feature = "tplink")]
@@ -20,6 +26,7 @@ mod wingtech;
 #[cfg(feature = "wingtech")]
 pub use wingtech::update_ui;
 
+#[derive(Clone, Copy, PartialEq)]
 pub enum DisplayState {
     Recording,
     Paused,

daemon/src/display/tmobile.rs

@@ -0,0 +1,85 @@
+/// Display module for Tmobile TMOHS1, blink LEDs on the front of the device.
+/// DisplayState::Recording => Signal LED slowly blinks blue.
+/// DisplayState::Paused => WiFi LED blinks white.
+/// DisplayState::WarningDetected => Signal LED slowly blinks red.
+use log::{error, info};
+use tokio::sync::mpsc;
+use tokio::sync::oneshot;
+use tokio_util::task::TaskTracker;
+
+use std::fs::write;
+use std::thread::sleep;
+use std::time::Duration;
+
+use crate::config;
+use crate::display::DisplayState;
+
+macro_rules! led {
+    ($l:expr) => {{
+        format!("/sys/class/leds/led:{}/blink", $l)
+    }};
+}
+
+fn start_blinking(path: String) {
+    write(&path, "1").ok();
+}
+
+fn stop_blinking(path: String) {
+    write(&path, "0").ok();
+}
+
+pub fn update_ui(
+    task_tracker: &TaskTracker,
+    config: &config::Config,
+    mut ui_shutdown_rx: oneshot::Receiver<()>,
+    mut ui_update_rx: mpsc::Receiver<DisplayState>,
+) {
+    let mut invisible: bool = false;
+    if config.ui_level == 0 {
+        info!("Invisible mode, not spawning UI.");
+        invisible = true;
+    }
+    task_tracker.spawn_blocking(move || {
+        let mut state = DisplayState::Recording;
+        let mut last_state = DisplayState::Paused;
+
+        loop {
+            match ui_shutdown_rx.try_recv() {
+                Ok(_) => {
+                    info!("received UI shutdown");
+                    break;
+                }
+                Err(oneshot::error::TryRecvError::Empty) => {}
+                Err(e) => panic!("error receiving shutdown message: {e}"),
+            }
+            match ui_update_rx.try_recv() {
+                Ok(new_state) => state = new_state,
+                Err(mpsc::error::TryRecvError::Empty) => {}
+                Err(e) => error!("error receiving ui update message: {e}"),
+            };
+            if invisible || state == last_state {
+                sleep(Duration::from_secs(1));
+                continue;
+            }
+            match state {
+                DisplayState::Paused => {
+                    stop_blinking(led!("signal_blue"));
+                    stop_blinking(led!("signal_red"));
+                    start_blinking(led!("wlan_white"));
+                }
+                DisplayState::Recording => {
+                    stop_blinking(led!("wlan_white"));
+                    stop_blinking(led!("signal_red"));
+                    start_blinking(led!("signal_blue"));
+                }
+                DisplayState::WarningDetected => {
+                    stop_blinking(led!("wlan_white"));
+                    stop_blinking(led!("signal_blue"));
+                    start_blinking(led!("signal_red"));
+                }
+            }
+            last_state = state;
+            sleep(Duration::from_secs(1));
+        }
+    });
+}