rusefi-full/firmware/hw_layer/debounce.cpp

/**
 * @file        debounce.cpp
 * @brief       Generic button debounce class
 *
 * @date Aug 31, 2020
 * @author David Holdeman, (c) 2020
 */
#include "pch.h"

#include "debounce.h"
#include "hardware.h"

ButtonDebounce* ButtonDebounce::s_firstDebounce = nullptr;

ButtonDebounce::ButtonDebounce(const char *name)
	: m_name(name)
{
}

/**
We need to have a separate init function because we do not have the pin or mode in the context in which the class is originally created
*/
void ButtonDebounce::init (efitimems_t threshold, brain_pin_e &pin, pin_input_mode_e &mode) {
   // we need to keep track of whether we have already been initialized due to the way unit tests run.
    if (!isInstanceRegisteredInGlobalList) {
	// Link us to the list that is used to track ButtonDebounce instances, so that when the configuration changes,
	//  they can be looped through and updated.
        nextDebounce = s_firstDebounce;
        s_firstDebounce = this;
    }
    m_threshold = MS2NT(threshold);
    timeLast = 0;
    m_pin = &pin;
    m_mode = &mode;
    startConfiguration();
    isInstanceRegisteredInGlobalList = true;
}

void ButtonDebounce::stopConfigurationList () {
    ButtonDebounce *listItem = s_firstDebounce;
    while (listItem != nullptr) {
        listItem->stopConfiguration();
        listItem = listItem->nextDebounce;
    }
}

void ButtonDebounce::startConfigurationList () {
    ButtonDebounce *listItem = s_firstDebounce;
    while (listItem != nullptr) {
        listItem->startConfiguration();
        listItem = listItem->nextDebounce;
    }
}

void ButtonDebounce::stopConfiguration () {
    // If the configuration has changed
#if ! EFI_ACTIVE_CONFIGURATION_IN_FLASH
    if (*m_pin != active_pin || *m_mode != active_mode) {
#else
    if (*m_pin != active_pin || *m_mode != active_mode || (isActiveConfigurationVoid && ((int)(*m_pin) != 0 || (int)(*m_mode) != 0))) {
#endif /* EFI_ACTIVE_CONFIGURATION_IN_FLASH */
#if EFI_PROD_CODE
    	efiSetPadUnused(active_pin);
#endif /* EFI_UNIT_TEST */
    	needsPinInitialization = true;
    }
}

void ButtonDebounce::startConfiguration () {
#if EFI_PROD_CODE
    if (needsPinInitialization) {
        efiSetPadMode(m_name, *m_pin, getInputMode(*m_mode));
        needsPinInitialization = false;
    }
#endif
    active_pin = *m_pin;
    active_mode = *m_mode;
}

/**
@returns true if the button is pressed, and will not return true again within the set timeout
*/
bool ButtonDebounce::readPinEvent() {
    storedValue = false;
    return readPinState();
}

bool ButtonDebounce::readPinState() {
    if (!isBrainPinValid(*m_pin)) {
        return false;
    }
    efitick_t timeNow = getTimeNowNt();
    // If it's been less than the threshold since we were last called
    if ((timeNow - timeLast) < m_threshold) {
        return storedValue;
    }
    // storedValue is a class variable, so it needs to be reset.
    // We don't actually need it to be a class variable in this method,
    //  but when a method is implemented to actually get the pin's state,
    //  for example to implement long button presses, it will be needed.
#if EFI_PROD_CODE || EFI_UNIT_TEST
    storedValue = efiReadPin(active_pin);
#else
    storedValue = false;
#endif
    // Invert
    if (active_mode == PI_PULLUP) {
        storedValue = !storedValue;
    }
    if (storedValue) {
        timeLast = timeNow;
    }
    return storedValue;
}

void ButtonDebounce::debug() {
    ButtonDebounce *listItem = s_firstDebounce;
    while (listItem != nullptr) {
#if EFI_PROD_CODE || EFI_UNIT_TEST
        efiPrintf("%s timeLast %d", listItem->m_name, listItem->timeLast);
        efiPrintf("physical state %d value %d", efiReadPin(listItem->active_pin), listItem->storedValue);
#endif

        listItem = listItem->nextDebounce;
    }
}

void initButtonDebounce() {
#if !EFI_UNIT_TEST
	addConsoleAction("debounce", ButtonDebounce::debug);
#endif /* EFI_UNIT_TEST */
}