add timer since last trigger tooth (#2004)

* add elapsed time to timer

* store trigger time

* fsio method

* don't do a 64b divide

Co-authored-by: Matthew Kennedy <makenne@microsoft.com>

firmware/controllers/core/fsio_impl.cpp

@@ -71,6 +71,7 @@ static LENameOrdinalPair leExhaustVVT(LE_METHOD_EXHAUST_VVT, "evvt");
 static LENameOrdinalPair leCrankingRpm(LE_METHOD_CRANKING_RPM, "cranking_rpm");
 static LENameOrdinalPair leStartupFuelPumpDuration(LE_METHOD_STARTUP_FUEL_PUMP_DURATION, "startup_fuel_pump_duration");
 static LENameOrdinalPair leInShutdown(LE_METHOD_IN_SHUTDOWN, "in_shutdown");
+static LENameOrdinalPair leTimeSinceTrigger(LE_METHOD_TIME_SINCE_TRIGGER_EVENT, "time_since_trigger");
 
 #include "fsio_names.def"
 
@@ -140,6 +141,7 @@ FsioValue getEngineValue(le_action_e action DECLARE_ENGINE_PARAMETER_SUFFIX) {
 		return engine->triggerCentral.getVVTPosition();
 #endif
 	case LE_METHOD_TIME_SINCE_TRIGGER_EVENT:
+		return engine->triggerCentral.getTimeSinceTriggerEvent();
 	case LE_METHOD_TIME_SINCE_BOOT:
 #if EFI_MAIN_RELAY_CONTROL
 		// in main relay control mode, we return the number of seconds since the ignition is turned on

firmware/controllers/trigger/trigger_central.cpp

@@ -426,6 +426,8 @@ void TriggerCentral::handleShaftSignal(trigger_event_e signal, efitick_t timesta
 
 	engine->onTriggerSignalEvent(timestamp);
 
+	m_lastEventTimer.reset(timestamp);
+
 	int eventIndex = (int) signal;
 	efiAssertVoid(CUSTOM_TRIGGER_EVENT_TYPE, eventIndex >= 0 && eventIndex < HW_EVENT_TYPES, "signal type");
 	hwEventCounters[eventIndex]++;

firmware/controllers/trigger/trigger_central.h

@@ -11,6 +11,7 @@
 #include "listener_array.h"
 #include "trigger_decoder.h"
 #include "trigger_central_generated.h"
+#include "timer.h"
 
 class Engine;
 typedef void (*ShaftPositionListener)(trigger_event_e signal, uint32_t index, efitick_t edgeTimestamp DECLARE_ENGINE_PARAMETER_SUFFIX);
@@ -43,6 +44,10 @@ public:
 	void resetCounters();
 	void validateCamVvtCounters();
 
+	float getTimeSinceTriggerEvent() const {
+		return m_lastEventTimer.getElapsedSeconds();
+	}
+
 	TriggerNoiseFilter noiseFilter;
 
 	trigger_type_e vvtTriggerType;
@@ -67,6 +72,9 @@ public:
 	TriggerWaveform vvtShape;
 
 	TriggerFormDetails triggerFormDetails;
+
+	// Keep track of the last time we got a valid trigger event
+	Timer m_lastEventTimer;
 };
 
 void triggerInfo(void);

firmware/util/timer.cpp

@@ -5,6 +5,10 @@ void Timer::reset() {
 	m_lastReset = getTimeNowNt();
 }
 
+void Timer::reset(efitick_t nowNt) {
+	m_lastReset = nowNt;
+}
+
 bool Timer::hasElapsedSec(float seconds) const {
 	return hasElapsedMs(seconds * 1e3);
 }
@@ -25,3 +29,15 @@ bool Timer::hasElapsedUs(float microseconds) const {
 
 	return delta32 > USF2NT(microseconds);
 }
+
+float Timer::getElapsedSeconds() const {
+	auto delta = getTimeNowNt() - m_lastReset;
+
+	if (delta > UINT32_MAX - 1) {
+		delta = UINT32_MAX - 1;
+	}
+
+	auto delta32 = (uint32_t)delta;
+
+	return NT2US(delta32);
+}

firmware/util/timer.h

@@ -5,10 +5,19 @@
 class Timer {
 public:
 	void reset();
+
+	// Reset the timer to a known timestamp (don't take a timestamp internally)
+	void reset(efitick_t nowNt);
+
 	bool hasElapsedSec(float seconds) const;
 	bool hasElapsedMs(float ms) const;
 	bool hasElapsedUs(float us) const;
 
+	// Return the elapsed time since the last reset.
+	// If the elapsed time is longer than 2^32 timer tick counts,
+	// then a time period representing 2^32 counts will be returned.
+	float getElapsedSeconds() const;
+
 private:
 	efitick_t m_lastReset = INT64_MIN;
 };