stm32_adc_v4.cpp

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/**
 * @file        stm32_adc_v4.cpp
 * @brief       Port implementation for the STM32 "v4" ADC found on the STM32H7
 *
 * @date February 25, 2021
 * @author Matthew Kennedy, (c) 2021
 */
 
#include "pch.h"
 
#if HAL_USE_ADC
 
#include "mpu_util.h"
#include "map_averaging.h"
 
#ifdef ADC_MUX_PIN
#error "ADC mux not yet supported on STM32H7"
#endif
 
#ifndef H7_ADC_SPEED
#define H7_ADC_SPEED (10000)
#endif
 
#ifndef H7_ADC_OVERSAMPLE
#define H7_ADC_OVERSAMPLE (4)
#endif
 
static_assert((H7_ADC_OVERSAMPLE & (H7_ADC_OVERSAMPLE - 1)) == 0, "H7_ADC_OVERSAMPLE must be a power of 2");
 
static constexpr size_t log2_int(size_t x) {
    size_t result = 0;
    while (x >>= 1) result++;
    return result;
}
 
// poor man's unit test
static_assert(log2_int(4) == 2);
static_assert(log2_int(16) == 4);
 
// Shift the result by log2(N) bits to divide by N
static constexpr int H7_ADC_SHIFT_BITS = log2_int(H7_ADC_OVERSAMPLE);
 
void portInitAdc() {
    // Init slow ADC
    adcStart(&ADCD1, NULL);
 
#if STM32_ADC_USE_ADC3
    // Knock/trigger scope ADC
    adcStart(&ADCD3, nullptr);
#endif // STM32_ADC_USE_ADC3
 
    // Connect the analog switches between {PA0_C, PA1_C, PC2_C, PC3_C} and their non-C counterparts
    // This lets us use normal (non-direct) analog on those channels
    SYSCFG->PMCR &= ~(SYSCFG_PMCR_PA0SO | SYSCFG_PMCR_PA1SO | SYSCFG_PMCR_PC2SO | SYSCFG_PMCR_PC3SO);
}
 
float getMcuTemperature() {
    // Ugh, internal temp sensor is wired to ADC3, which makes it nearly useless on the H7.
    return 0;
}
 
float getMcuVrefVoltage() {
    // TODO: implement me!
    return engineConfiguration->adcVcc;
}
 
float getMcuVbatVoltage() {
    // TODO: implement me!
    return 0;
}
 
adcsample_t* fastSampleBuffer;
 
static void adc_callback(ADCDriver *adcp) {
    // State may not be complete if we get a callback for "half done"
    if (adcIsBufferComplete(adcp)) {
      // here we invoke 'fast' from slow ADC due to https://github.com/rusefi/rusefi/issues/3301
        onFastAdcComplete(adcp->samples);
    }
 
    assertInterruptPriority(__func__, EFI_IRQ_ADC_PRIORITY);
}
 
// ADC Clock is 25MHz
// 16.5 sampling + 8.5 conversion = 25 cycles per sample total
// 16 channels * 4x oversample = 64 samples per batch
// (25 * 64) / 25MHz -> 64 microseconds to sample all channels
#define ADC_SAMPLING_SLOW ADC_SMPR_SMP_16P5
 
// Sample the 16 channels that line up with the STM32F4/F7
constexpr size_t slowChannelCount = 16;
 
// Conversion group for slow channels
// This simply samples every channel in sequence
static constexpr ADCConversionGroup convGroupSlow = {
    .circular           = true,     // Continuous mode means we will auto re-trigger on every timer event
    .num_channels       = slowChannelCount,
    .end_cb             = adc_callback,
    .error_cb           = nullptr,
    .cfgr               = ADC_CFGR_EXTEN_0 | (4 << ADC_CFGR_EXTSEL_Pos),    // External trigger ch4, rising edge: TIM3 TRGO
    .cfgr2              =   (H7_ADC_OVERSAMPLE - 1) << ADC_CFGR2_OVSR_Pos | // Oversample by Nx (register contains N-1)
                            H7_ADC_SHIFT_BITS << ADC_CFGR2_OVSS_Pos |       // shift the result right log2(N) bits to make a 16 bit result out of the internal oversample sum
                            ADC_CFGR2_ROVSE,            // Enable oversampling
    .ccr                = 0,
    .pcsel              = 0xFFFFFFFF, // enable analog switches on all channels
    // Thresholds aren't used
    .ltr1 = 0, .htr1 = 0, .ltr2 = 0, .htr2 = 0, .ltr3 = 0, .htr3 = 0,
    .awd2cr = 0,
    .awd3cr = 0,
    .smpr = {
        // Configure all channels to use ADC_SAMPLING_SLOW time
        ADC_SMPR1_SMP_AN0(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN1(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN2(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN3(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN4(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN5(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN6(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN7(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN8(ADC_SAMPLING_SLOW) |
        ADC_SMPR1_SMP_AN9(ADC_SAMPLING_SLOW),
        ADC_SMPR2_SMP_AN10(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN11(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN12(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN13(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN14(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN15(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN16(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN17(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN18(ADC_SAMPLING_SLOW) |
        ADC_SMPR2_SMP_AN19(ADC_SAMPLING_SLOW)
    },
    .sqr = {
        // The seemingly insane values here exist to put the values
        // in the buffer in the same order as the ADCv2 (F4/F7) ADC
        ADC_SQR1_SQ1_N(16) |    // PA0 (aka PA0_C)
        ADC_SQR1_SQ2_N(17) |    // PA1 (aka PA1_C)
        ADC_SQR1_SQ3_N(14) |    // PA2
        ADC_SQR1_SQ4_N(15),     // PA3
        ADC_SQR2_SQ5_N(18) |    // PA4
        ADC_SQR2_SQ6_N(19) |    // PA5
        ADC_SQR2_SQ7_N(3) |     // PA6
        ADC_SQR2_SQ8_N(7) |     // PA7
        ADC_SQR2_SQ9_N(9),      // PB0
        ADC_SQR3_SQ10_N(5) |    // PB1
        ADC_SQR3_SQ11_N(10) |   // PC0
        ADC_SQR3_SQ12_N(11) |   // PC1
        ADC_SQR3_SQ13_N(12) |   // PC2 (aka PC2_C)
        ADC_SQR3_SQ14_N(13),    // PC3 (aka PC3_C)
        ADC_SQR4_SQ15_N(4) |    // PC4
        ADC_SQR4_SQ16_N(8)      // PC5
    },
};
 
static bool didStart = false;
 
bool readSlowAnalogInputs(adcsample_t* convertedSamples) {
    // This only needs to happen once, as the timer will continue firing the ADC and writing to the buffer without our help
    if (didStart) {
        return true;
    }
    didStart = true;
 
    fastSampleBuffer = convertedSamples;
 
    {
        chibios_rt::CriticalSectionLocker csl;
        // Oversampling and right-shift happen in hardware, so we can sample directly to the output buffer
        adcStartConversionI(&ADCD1, &convGroupSlow, convertedSamples, 1);
    }
 
    constexpr uint32_t samplingRate = H7_ADC_SPEED;
    constexpr uint32_t timerCountFrequency = samplingRate * 10;
    constexpr uint32_t timerPeriod = timerCountFrequency / samplingRate;
 
    static constexpr GPTConfig gptCfg = {
        timerCountFrequency,
        nullptr,
        TIM_CR2_MMS_1,  // TRGO on update event
        0
    };
 
    // Start timer
    gptStart(&GPTD3, &gptCfg);
    gptStartContinuous(&GPTD3, timerPeriod);
 
    // Return true if OK
    return true;
}
 
AdcToken enableFastAdcChannel(const char*, adc_channel_e channel) {
    if (!isAdcChannelValid(channel)) {
        return invalidAdcToken;
    }
 
    // H7 always samples all fast channels, nothing to do here but compute index
    return channel - EFI_ADC_0;
}
 
adcsample_t getFastAdc(AdcToken token) {
    if (token == invalidAdcToken) {
        return 0;
    }
 
    return fastSampleBuffer[token];
}
 
#ifdef EFI_SOFTWARE_KNOCK
#include "knock_config.h"
 
static_assert((H7_KNOCK_OVERSAMPLE & (H7_KNOCK_OVERSAMPLE - 1)) == 0, "H7_ADC_OVERSAMPLE must be a power of 2");
static constexpr int H7_KNOCK_ADC_SHIFT_BITS = log2_int(H7_KNOCK_OVERSAMPLE);
 
static void knockCompletionCallback(ADCDriver* adcp) {
    if (adcIsBufferComplete(adcp)) {
        onKnockSamplingComplete();
    }
 
    assertInterruptPriority(__func__, EFI_IRQ_ADC_PRIORITY);
}
 
static void knockErrorCallback(ADCDriver*, adcerror_t) {
}
 
static const uint32_t smpr1 =
    ADC_SMPR1_SMP_AN0(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN1(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN2(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN3(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN4(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN5(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN6(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN7(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN8(KNOCK_SAMPLE_TIME) |
    ADC_SMPR1_SMP_AN9(KNOCK_SAMPLE_TIME);
 
static const uint32_t smpr2 =
    ADC_SMPR2_SMP_AN10(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN11(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN12(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN13(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN14(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN15(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN16(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN17(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN18(KNOCK_SAMPLE_TIME) |
    ADC_SMPR2_SMP_AN19(KNOCK_SAMPLE_TIME);
 
static const ADCConversionGroup adcConvGroupCh1 = {
    .circular = FALSE,
    .num_channels = 1,
    .end_cb = &knockCompletionCallback,
    .error_cb = &knockErrorCallback,
    .cfgr               = 0,
    .cfgr2              =   (H7_KNOCK_OVERSAMPLE - 1) << ADC_CFGR2_OVSR_Pos |   // Oversample by Nx (register contains N-1)
                            H7_KNOCK_ADC_SHIFT_BITS << ADC_CFGR2_OVSS_Pos |     // shift the result right log2(N) bits to make a 16 bit result out of the internal oversample sum
                            ADC_CFGR2_ROVSE,            // Enable oversampling
    .ccr                = 0,
    .pcsel              = 0xFFFFFFFF, // enable analog switches on all channels
    // Thresholds aren't used
    .ltr1 = 0, .htr1 = 0, .ltr2 = 0, .htr2 = 0, .ltr3 = 0, .htr3 = 0,
    .awd2cr = 0,
    .awd3cr = 0,
    .smpr = {smpr1, smpr2},
    .sqr = {
        ADC_SQR1_SQ1_N(KNOCK_ADC_CH1),
        0,
        0
    },
};
 
// 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,
    .cfgr               = 0,
    .cfgr2              =   (H7_ADC_OVERSAMPLE - 1) << ADC_CFGR2_OVSR_Pos | // Oversample by Nx (register contains N-1)
                            H7_ADC_SHIFT_BITS << ADC_CFGR2_OVSS_Pos |       // shift the result right log2(N) bits to make a 16 bit result out of the internal oversample sum
                            ADC_CFGR2_ROVSE,            // Enable oversampling
    .ccr                = 0,
    .pcsel              = 0xFFFFFFFF, // enable analog switches on all channels
    // Thresholds aren't used
    .ltr1 = 0, .htr1 = 0, .ltr2 = 0, .htr2 = 0, .ltr3 = 0, .htr3 = 0,
    .awd2cr = 0,
    .awd3cr = 0,
    .smpr = {smpr1, smpr2},
    .sqr = {
        ADC_SQR1_SQ1_N(KNOCK_ADC_CH2),
        0,
        0
    },
};
#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
 
#endif // HAL_USE_ADC