fm175: add timeouts to loops.

Author: Dirbaio

rnfc-fm175xx/src/iso14443a.rs

@@ -1,5 +1,5 @@
 use embassy_futures::yield_now;
-use embassy_time::{Duration, Timer};
+use embassy_time::{Duration, Instant, Timer};
 use embedded_hal::digital::{InputPin, OutputPin};
 use embedded_hal_async::digital::Wait;
 use rnfc_traits::iso14443a_ll as ll;
@@ -175,7 +175,14 @@ where
         });
 
         let mut tx_done = false;
+        let deadline = Instant::now() + Duration::from_secs(1);
         loop {
+            // make sure to not loop forever if timeri never fires for whatever reason.
+            if Instant::now() > deadline {
+                warn!("emergency timeout");
+                return Err(Error::Other);
+            }
+
             let mut irqs = r.regs().commirq().read();
 
             if irqs.timeri() {

rnfc-fm175xx/src/lib.rs

@@ -10,7 +10,7 @@ mod regs;
 
 use core::convert::Infallible;
 
-use embassy_time::{with_timeout, Duration, TimeoutError, Timer};
+use embassy_time::{with_timeout, Duration, Instant, TimeoutError, Timer};
 use embedded_hal::digital::{InputPin, OutputPin};
 use embedded_hal_async::digital::Wait;
 pub use interface::*;
@@ -133,7 +133,14 @@ where
 
         debug!("softreset");
         self.regs().command().write(|w| w.set_command(regs::CommandVal::SOFTRESET));
-        while self.regs().command().read().command() != regs::CommandVal::IDLE {}
+
+        let deadline = Instant::now() + Duration::from_secs(1);
+        while self.regs().command().read().command() != regs::CommandVal::IDLE {
+            if Instant::now() > deadline {
+                warn!("timeout waiting for softreset.");
+                break;
+            }
+        }
 
         // again, just in case
         Timer::after(Duration::from_millis(1)).await;
@@ -456,7 +463,13 @@ where
         //cortex_m::asm::delay(640_000); // 100ms
 
         //info!("calib: waiting for irq..");
-        while !self.regs().lpcd_irq().read().calib_irq() {}
+        let deadline = Instant::now() + Duration::from_secs(1);
+        while !self.regs().lpcd_irq().read().calib_irq() {
+            if Instant::now() > deadline {
+                warn!("timeout waiting for adc calibration.");
+                break;
+            }
+        }
 
         // calibra_en = 0
         self.regs().lpcd_ctrl1().write(|w| {