stm32_adc_v2.cpp

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/**
 * @file        stm32_adc_v2.cpp
 * @brief       Port implementation for the STM32 "v2" ADC found on the STM32F4 and STM32F7
 *
 * @date February 9, 2021
 * @author Matthew Kennedy, (c) 2021
 */
 
#include "pch.h"
 
#ifdef EFI_SOFTWARE_KNOCK
#include "knock_config.h"
#endif
 
#if HAL_USE_ADC
 
/* HW channels count per ADC */
constexpr size_t adcChannelCount = 16;
constexpr size_t adcAuxChannelCount = 2;
 
/* Depth of the conversion buffer, channels are sampled X times each.*/
#define SLOW_ADC_OVERSAMPLE      8
 
#ifndef EFI_INTERNAL_SLOW_ADC_BACKGROUND
#define EFI_INTERNAL_SLOW_ADC_BACKGROUND FALSE
#endif
 
#ifdef ADC_MUX_PIN
// https://github.com/rusefi/alphax-4chan is the reference board with ADC mux
static OutputPin muxControl;
#endif // ADC_MUX_PIN
 
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == TRUE)
static void slowAdcEndCB(ADCDriver *adcp);
#endif
static void slowAdcErrorCB(ADCDriver *, adcerror_t);
 
/*
 * ADC conversion group.
 */
static const ADCConversionGroup auxConvGroup = {
    .circular           = FALSE,
    .num_channels       = adcAuxChannelCount,
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == TRUE)
    .end_cb             = slowAdcEndCB,
#else
    .end_cb             = nullptr,
#endif
    .error_cb           = slowAdcErrorCB,
    /* HW dependent part below */
    .cr1                = 0,
    .cr2                = ADC_CR2_SWSTART,
    // sample times for channels 10...18
    .smpr1 =
        ADC_SMPR1_SMP_VBAT(ADC_SAMPLE_144) |    /* input18 - temperature and vbat input on some STM32F7xx */
        ADC_SMPR1_SMP_SENSOR(ADC_SAMPLE_144) |  /* input16 - temperature sensor input on STM32F4xx */
        ADC_SMPR1_SMP_VREF(ADC_SAMPLE_144),     /* input17 - Vrefint input */
    .smpr2 = 0,
    .htr = 0, .ltr = 0,
    .sqr1 = 0,
    .sqr2 = 0,
    .sqr3 =
#if defined(STM32F4XX)
        ADC_SQR3_SQ1_N(16) |
#endif
#if defined(STM32F7XX)
        ADC_SQR3_SQ1_N(18) |
#endif
        ADC_SQR3_SQ2_N(17),
};
 
// 4x oversample is plenty
static constexpr int auxSensorOversample = 4;
static volatile NO_CACHE adcsample_t auxSensorSamples[adcAuxChannelCount * auxSensorOversample];
 
float getMcuTemperature() {
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == FALSE)
    // Temperature sensor is only physically wired to ADC1
    adcConvert(&ADCD1, &auxConvGroup, (adcsample_t *)auxSensorSamples, auxSensorOversample);
#endif
 
    uint32_t sum = 0;
    for (size_t i = 0; i < auxSensorOversample; i++) {
        sum += auxSensorSamples[0 + adcAuxChannelCount * i];
    }
 
    float volts = (float)sum / (ADC_MAX_VALUE * auxSensorOversample);
    volts *= engineConfiguration->adcVcc;
 
    volts -= 0.760f; // Subtract the reference voltage at 25 deg C
    float degrees = volts / 0.0025f; // Divide by slope 2.5mV
 
    degrees += 25.0; // Add the 25 deg C
 
    return degrees;
}
 
float getMcuVrefVoltage() {
    uint32_t sum = 0;
    for (size_t i = 0; i < auxSensorOversample; i++) {
        sum += auxSensorSamples[1 + adcAuxChannelCount * i];
    }
 
    // TODO: apply calibration value from OTP (if exists)
    // vrefint should be 1.21V
    // Let's calculate external Vref+
    // sum / (ADC_MAX_VALUE * auxSensorOversample) * Vref+ = 1.21;
    float Vref = 1.21f * auxSensorOversample * ADC_MAX_VALUE / sum;
 
    return Vref;
}
 
// See https://github.com/rusefi/rusefi/issues/976 for discussion on these values
// ...  there is no reason to use a longer sampling time than 56 cycles with the current clock ...
#ifndef ADC_SAMPLING_SLOW
#define ADC_SAMPLING_SLOW ADC_SAMPLE_56
#endif
// see also ADC_SAMPLING_FAST in adc_inputs.cpp
// ADC clock is 21MHz on F4 and 27MHz on F7
// We want 500 Hz refresh rate for 16 (32) channels + MCU temperature
// 21 MHz / 500 = 42000 clocks for all channels including oversampling
// We want SLOW_ADC_OVERSAMPLE
// 42000 / 8 / 16 = 328.125 clocks / channel
// 42000 / 8 / 32 = 164 clocks / channel
// This ^ does not include additional MCU temperatur conversions
 
// Slow ADC has 16 channels we can sample, or 32 if ADC mux mode is enabled.
static volatile NO_CACHE adcsample_t slowSampleBuffer[SLOW_ADC_OVERSAMPLE * adcChannelCount];
#ifdef ADC_MUX_PIN
static volatile NO_CACHE adcsample_t slowSampleBufferMuxed[SLOW_ADC_OVERSAMPLE * adcChannelCount];
#endif
 
static void slowAdcErrorCB(ADCDriver *, adcerror_t err) {
    engine->outputChannels.slowAdcErrorCount++;
    if (err == ADC_ERR_OVERFLOW) {
        engine->outputChannels.slowAdcOverrunCount++;
    }
    // TODO: restart?
}
 
// Conversion group for slow channels
// This simply samples every channel in sequence
static /* constexpr */ ADCConversionGroup convGroupSlow = {
    .circular           = FALSE,
    .num_channels       = adcChannelCount,
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == TRUE)
    .end_cb             = slowAdcEndCB,
#else
    .end_cb             = nullptr,
#endif
    .error_cb           = slowAdcErrorCB,
    /* HW dependent part.*/
    .cr1                = 0,
    .cr2                = ADC_CR2_SWSTART,
    // Configure all channels to ADC_SAMPLING_SLOW sample time
    .smpr1 =
        ADC_SMPR1_SMP_AN10(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN11(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN12(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN13(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN14(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN15(ADC_SAMPLING_SLOW),
    .smpr2 =
        ADC_SMPR2_SMP_AN0(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN1(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN2(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN3(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN4(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN5(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN6(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN7(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN8(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN9(ADC_SAMPLING_SLOW),
    .htr    = 0,
    .ltr    = 0,
    // Simply sequence every channel in order
    .sqr1   = ADC_SQR1_SQ13_N(12) | ADC_SQR1_SQ14_N(13) | ADC_SQR1_SQ15_N(14) | ADC_SQR1_SQ16_N(15), // Conversion group sequence 13...16
    .sqr2   =   ADC_SQR2_SQ7_N(6) |   ADC_SQR2_SQ8_N(7) |   ADC_SQR2_SQ9_N(8) | ADC_SQR2_SQ10_N(9) | ADC_SQR2_SQ11_N(10) | ADC_SQR2_SQ12_N(11), // Conversion group sequence 7...12
    .sqr3   =   ADC_SQR3_SQ1_N(0) |   ADC_SQR3_SQ2_N(1) |   ADC_SQR3_SQ3_N(2) |  ADC_SQR3_SQ4_N(3) |   ADC_SQR3_SQ5_N(4) |   ADC_SQR3_SQ6_N(5), // Conversion group sequence 1...6
};
 
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == TRUE)
 
typedef enum {
    convertPrimary,
#ifdef ADC_MUX_PIN
    convertMuxed,
#endif
    convertAux,
} slowAdcState_t;
 
static slowAdcState_t slowAdcGetNextState(slowAdcState_t state)
{
    switch (state) {
    case convertPrimary:
        #ifdef ADC_MUX_PIN
        return convertMuxed;
        #else
        return convertAux;
        #endif
    break;
#ifdef ADC_MUX_PIN
    case convertMuxed:
        return convertAux;
    break;
#endif
    case convertAux:
        return convertPrimary;
    break;
    }
    return convertPrimary;
}
 
static slowAdcState_t slowAdcState = convertPrimary;
 
static void slowAdcEndCB(ADCDriver *adcp) {
    if (adcIsBufferComplete(adcp)) {
        chSysLockFromISR();
        // Switch state to ready to allow starting new conversion from here
        adcp->state = ADC_READY;
        // get next state
        slowAdcState = slowAdcGetNextState(slowAdcState);
        switch (slowAdcState) {
        case convertPrimary:
            #ifdef ADC_MUX_PIN
            muxControl.setValue(0, /*force*/true);
            #endif
            adcStartConversionI(adcp, &convGroupSlow, (adcsample_t *)slowSampleBuffer, SLOW_ADC_OVERSAMPLE);
            break;
        #ifdef ADC_MUX_PIN
        case convertMuxed:
            muxControl.setValue(1, /*force*/true);
            // convert second half
            adcStartConversionI(adcp, &convGroupSlow, (adcsample_t *)slowSampleBufferMuxed, SLOW_ADC_OVERSAMPLE);
            break;
        #endif
        case convertAux:
            adcStartConversionI(adcp, &auxConvGroup, (adcsample_t *)auxSensorSamples, auxSensorOversample);
            break;
        }
        chSysUnlockFromISR();
    }
}
#endif
 
static bool readBatch(adcsample_t* convertedSamples, adcsample_t* b) {
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == FALSE)
    msg_t result = adcConvert(&ADCD1, &convGroupSlow, b, SLOW_ADC_OVERSAMPLE);
 
    // If something went wrong - try again later
    if (result != MSG_OK) {
        return false;
    }
#endif
 
    // Average samples to get some noise filtering and oversampling
    for (size_t i = 0; i < adcChannelCount; i++) {
        uint32_t sum = 0;
        size_t index = i;
        for (size_t j = 0; j < SLOW_ADC_OVERSAMPLE; j++) {
            sum += b[index];
            index += adcChannelCount;
        }
 
        adcsample_t value = static_cast<adcsample_t>(sum / SLOW_ADC_OVERSAMPLE);
        convertedSamples[i] = value;
    }
 
    return true;
}
 
bool readSlowAnalogInputs(adcsample_t* convertedSamples) {
    bool result = true;
 
    result &= readBatch(convertedSamples, (adcsample_t *)slowSampleBuffer);
 
#ifdef ADC_MUX_PIN
    #if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == FALSE)
        muxControl.setValue(1, /*force*/true);
    #endif
        // read the second batch, starting where we left off
        result &= readBatch(&convertedSamples[adcChannelCount], (adcsample_t *)slowSampleBufferMuxed);
    #if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == FALSE)
        muxControl.setValue(0, /*force*/true);
    #endif
#endif
 
    return result;
}
 
#if EFI_USE_FAST_ADC
 
#include "adc_device.h"
#include "adc_onchip.h"
 
extern AdcDevice fastAdc;
 
// See: https://github.com/rusefi/rusefi/issues/8445
// We need to disable Slow ADC access to pins that are handled by fast ADC to avoid additional noise
static void slowAdcEnableDisableChannel(adc_channel_e hwChannel, bool en)
{
    if (!isAdcChannelValid(hwChannel)) {
        return;
    }
 
    /* TODO: following is correct for STM32 ADC1/2.
     * ADC3 has another input to gpio mapping
     * and should be handled separately */
    uint32_t channelAdcIndex = hwChannel - EFI_ADC_0;
    // Switch disabled channel to internal Vrefint channel
    adcConversionGroupSetSeqInput(&convGroupSlow, channelAdcIndex, en ? channelAdcIndex : 17);
}
 
AdcToken enableFastAdcChannel(const char*, adc_channel_e hwChannel) {
    if (!isAdcChannelValid(hwChannel)) {
        return invalidAdcToken;
    }
 
    // Do not run slow ADC for fast ADC inputs
    slowAdcEnableDisableChannel(hwChannel, false);
 
    return fastAdc.getAdcChannelToken(hwChannel);
}
 
adcsample_t getFastAdc(AdcToken token) {
    if (token == invalidAdcToken) {
        return 0;
    }
 
    return fastAdc.getAdcValueByToken(token);
}
 
#endif // EFI_USE_FAST_ADC
 
#ifdef EFI_SOFTWARE_KNOCK
 
static void knockCompletionCallback(ADCDriver* adcp) {
    if (adcIsBufferComplete(adcp)) {
        onKnockSamplingComplete();
    }
}
 
static void knockErrorCallback(ADCDriver*, adcerror_t) {
}
 
static const uint32_t smpr1 =
    ADC_SMPR1_SMP_AN10(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN11(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN12(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN13(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN14(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN15(KNOCK_SAMPLE_TIME);
 
static const uint32_t smpr2 =
    ADC_SMPR2_SMP_AN0(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN1(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN2(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN3(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN4(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN5(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN6(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN7(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN8(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN9(KNOCK_SAMPLE_TIME);
 
static const ADCConversionGroup adcConvGroupCh1 = {
    .circular = FALSE,
    .num_channels = 1,
    .end_cb = &knockCompletionCallback,
    .error_cb = &knockErrorCallback,
    .cr1 = 0,
    .cr2 = ADC_CR2_SWSTART,
    // sample times for channels 10...18
    .smpr1 = smpr1,
    // sample times for channels 0...9
    .smpr2 = smpr2,
 
    .htr = 0,
    .ltr = 0,
 
    .sqr1 = 0,
    .sqr2 = 0,
    .sqr3 = ADC_SQR3_SQ1_N(KNOCK_ADC_CH1)
};
 
// Not all boards have a second channel - configure it if it exists
#if KNOCK_HAS_CH2
static const ADCConversionGroup adcConvGroupCh2 = {
    .circular = FALSE,
    .num_channels = 1,
    .end_cb = &knockCompletionCallback,
    .error_cb = &knockErrorCallback,
    .cr1 = 0,
    .cr2 = ADC_CR2_SWSTART,
    // sample times for channels 10...18
    .smpr1 = smpr1,
    // sample times for channels 0...9
    .smpr2 = smpr2,
 
    .htr = 0,
    .ltr = 0,
 
    .sqr1 = 0,
    .sqr2 = 0,
    .sqr3 = ADC_SQR3_SQ1_N(KNOCK_ADC_CH2)
};
#endif // KNOCK_HAS_CH2
 
const ADCConversionGroup* getKnockConversionGroup(uint8_t channelIdx) {
#if KNOCK_HAS_CH2
    if (channelIdx == 1) {
        return &adcConvGroupCh2;
    }
#else
    (void)channelIdx;
#endif // KNOCK_HAS_CH2
 
    return &adcConvGroupCh1;
}
 
#endif // EFI_SOFTWARE_KNOCK
 
void portInitAdc() {
#ifdef ADC_MUX_PIN
    muxControl.initPin("ADC Mux", ADC_MUX_PIN);
#endif //ADC_MUX_PIN
 
    // Init slow ADC
    adcStart(&ADCD1, NULL);
 
    // Enable internal temperature reference
    adcSTM32EnableTSVREFE(); // Internal temperature sensor
 
#if (EFI_INTERNAL_SLOW_ADC_BACKGROUND == TRUE)
    adcStartConversion(&ADCD1, &convGroupSlow, (adcsample_t *)slowSampleBuffer, SLOW_ADC_OVERSAMPLE);
#endif
 
#if EFI_USE_FAST_ADC
    // Init fast ADC (MAP sensor)
    adcStart(&ADCD2, NULL);
#endif
 
#if defined(STM32F7XX)
    /* the temperature sensor is internally
     * connected to the same input channel as VBAT. Only one conversion,
     * temperature sensor or VBAT, must be selected at a time. */
    adcSTM32DisableVBATE();
#endif
 
    /* Enable this code only when you absolutly sure
     * that there is no possible errors from ADC */
#if 0
    /* All ADC use DMA and DMA calls end_cb from its IRQ
     * If none of ADC users need error callback - we can disable
     * shared ADC IRQ and save some CPU ticks */
    if ((adcgrpcfgSlow.error_cb == NULL) &&
        (adcgrpcfgFast.error_cb == NULL)
        /* TODO: Add ADC3? */) {
        nvicDisableVector(STM32_ADC_NUMBER);
    }
#endif
 
#ifdef EFI_SOFTWARE_KNOCK
    adcStart(&KNOCK_ADC, nullptr);
#endif // EFI_SOFTWARE_KNOCK
}
 
#endif // HAL_USE_ADC