timer: Allow board code to define its own timer_is_before implementation

Move sched_is_before() from sched.c to timer_is_before() in the board
specific timer code.  This allows the board code to provide its own
definition.

Also, remove the sched_from_us() and sched_read_time() wrapper
functions and change the callers to directly invoke timer_from_us() /
timer_read_time().

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 10 insertions, 1 deletions

diff --git a/src/generic/timer.c b/src/generic/timer.c
index 13a8bfe5..436ecb68 100644
--- a/src/generic/timer.c
+++ b/src/generic/timer.c
@@ -24,6 +24,15 @@ timer_from_us(uint32_t us)
     return us * (CONFIG_CLOCK_FREQ / 1000000);
 }
 
+// Return true if time1 is before time2.  Always use this function to
+// compare times as regular C comparisons can fail if the counter
+// rolls over.
+uint8_t
+timer_is_before(uint32_t time1, uint32_t time2)
+{
+    return (int32_t)(time1 - time2) < 0;
+}
+
 // Called by main code once every millisecond.  (IRQs disabled.)
 void
 timer_periodic(void)
@@ -50,7 +59,7 @@ timer_try_set_next(uint32_t next)
         goto done;
 
     // Next timer is in the past or near future - can't reschedule to it
-    if (likely(sched_is_before(now, timer_repeat_until))) {
+    if (likely(timer_is_before(now, timer_repeat_until))) {
         // Can run more timers from this irq; briefly allow irqs
         irq_enable();
         while (diff >= 0) {