[rtl872x] fix millis() may jump after ~37 hours.

hal/src/rtl872x/timer_hal.cpp

@@ -68,6 +68,7 @@ constexpr int TIMER_PRESCALAR = 39; // Input clock = 40M
 constexpr int TIMER_COUNTER_US_THRESHOLD = 1; // 1us = 1tick
 constexpr uint64_t US_PER_OVERFLOW = 65536; // 65536us
 constexpr int TIMER_IRQ_PRIORITY = 0; // Default priority in the close-source timer driver per FAE
+constexpr uint64_t SYS_TIMER_US_PER_OVERFLOW = 134217727968; // (0xffffffff * TIMER_TICK_US_X4) / 4
 constexpr IRQn_Type TIMER_IRQ[] = {
  TIMER0_IRQ,
  TIMER1_IRQ,
@@ -77,10 +78,6 @@ constexpr IRQn_Type TIMER_IRQ[] = {
  TIMER5_IRQ
 };
 
-inline uint64_t calibrationTickToTimeUs(uint64_t tick) {
- return tick * 1000000 / 32768;
-}
-
 #if MODULE_FUNCTION == MOD_FUNC_BOOTLOADER
 #define HAL_TIMER_USE_SYSTIMER_ONLY
 #endif // MODULE_FUNCTION == MOD_FUNC_BOOTLOADER
@@ -257,18 +254,20 @@ class RtlTimer {
 
  TimerState getOverflowAdjustment() {
  TimerState state = {};
+ uint64_t timeElapsedSysTimer = 0;
  {
  AtomicSection lk;
  state.curSysTimerUs = sysTimerUs();
  if (state.curSysTimerUs < lastOverflowSysTimer_) {
  // Wraparound
- state.curSysTimerUs += 0xffffffff;
+ timeElapsedSysTimer = state.curSysTimerUs + SYS_TIMER_US_PER_OVERFLOW - lastOverflowSysTimer_;
+ } else {
+ timeElapsedSysTimer = state.curSysTimerUs - lastOverflowSysTimer_;
  }
  state.curTimerTicks = getCounter();
  state.overflowCounter = overflowCounter_ + 1;
  }
  uint64_t curTimerUs = rtcCounterAndTicksToUs(state.overflowCounter, state.curTimerTicks);
- uint64_t timeElapsedSysTimer = state.curSysTimerUs - lastOverflowSysTimer_;
  uint64_t timeElapsedTimer = curTimerUs - lastOverflowTimer_;
  if (timeElapsedSysTimer > timeElapsedTimer) {
  uint32_t diff = timeElapsedSysTimer - timeElapsedTimer;