digital_io: test: remove input reading emulation

It turns out we do not actually read any inputs in our tests,
so we can remove this implementation.
This change was prompted by cargo clippy complaining about the
u8 in LineEvent never being read.

Signed-off-by: Leonard Göhrs <[email protected]>

Author: hnez

src/digital_io/gpio/test.rs

@@ -16,11 +16,8 @@
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 use std::cell::RefCell;
-use std::iter::Iterator;
 use std::ops::BitOr;
 use std::sync::atomic::{AtomicU8, Ordering};
-use std::thread::sleep;
-use std::time::Duration;
 
 use anyhow::Result;
 use async_std::sync::Arc;
@@ -42,30 +39,6 @@ impl LineHandle {
     }
 }
 
-pub struct LineEvent(u8);
-
-pub struct LineEventHandle {
-    val: Arc<AtomicU8>,
-    prev_val: u8,
-}
-
-impl Iterator for LineEventHandle {
-    type Item = Result<LineEvent, ()>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        loop {
-            let val = self.val.load(Ordering::Relaxed);
-
-            if val != self.prev_val {
-                self.prev_val = val;
-                return Some(Ok(LineEvent(val)));
-            }
-
-            sleep(Duration::from_millis(100));
-        }
-    }
-}
-
 #[allow(clippy::upper_case_acronyms, non_camel_case_types)]
 #[derive(Clone, Copy)]
 pub enum LineRequestFlags {