From eeb1481413a5ce3cdadbbe0d47f4bec2586b9a37 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 4 Feb 2022 12:20:31 +0100
Subject: [PATCH] [nfc] refactor set_compare to be more readable

---
 src/lib.rs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 42c7498..4d876c9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -103,19 +103,19 @@ impl<const TIMER_HZ: u32> Monotonic for DwtSystick<TIMER_HZ> {
         // We need to convert into its domain.
         let now = self.now();
 
-        let max = 0x00ff_ffff;
-
-        let dur = match val.checked_duration_since(now) {
-            None => 1, // In the past
-
+        let reload = val
+            .checked_duration_since(now)
+            // Minimum reload value if `val` is in the past
+            .map_or(0, |t| t.ticks())
             // ARM Architecture Reference Manual says:
             // "Setting SYST_RVR to zero has the effect of
             // disabling the SysTick counter independently
             // of the counter enable bit.", so the min is 1
-            Some(x) => max.min(x.ticks()).max(1),
-        };
+            .max(1)
+            // SysTick is a 24 bit counter.
+            .min(0xff_ffff) as u32;
 
-        self.systick.set_reload(dur as u32);
+        self.systick.set_reload(reload);
         self.systick.clear_current();
     }