atbetaflight/src/main/drivers/accgyro/accgyro_mpu.c

/*
 * This file is part of Cleanflight and Betaflight.
 *
 * Cleanflight and Betaflight are free software. You can redistribute
 * this software and/or modify this software under the terms of the
 * GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * Cleanflight and Betaflight are distributed in the hope that they
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software.
 *
 * If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "platform.h"

#include "build/atomic.h"
#include "build/build_config.h"
#include "build/debug.h"

#include "common/maths.h"
#include "common/utils.h"

#include "drivers/bus.h"
#include "drivers/bus_i2c.h"
#include "drivers/bus_spi.h"
#include "drivers/exti.h"
#include "drivers/io.h"
#include "drivers/nvic.h"
#include "drivers/sensor.h"
#include "drivers/system.h"
#include "drivers/time.h"

#include "drivers/accgyro/accgyro.h"
#include "drivers/accgyro/accgyro_mpu3050.h"
#include "drivers/accgyro/accgyro_mpu6050.h"
#include "drivers/accgyro/accgyro_mpu6500.h"
#include "drivers/accgyro/accgyro_spi_bmi160.h"
#include "drivers/accgyro/accgyro_spi_bmi270.h"
#include "drivers/accgyro/accgyro_spi_icm20649.h"
#include "drivers/accgyro/accgyro_spi_icm20689.h"
#include "drivers/accgyro/accgyro_spi_icm426xx.h"
#include "drivers/accgyro/accgyro_spi_lsm6ds3.h"
#include "drivers/accgyro/accgyro_spi_lsm6dsl.h"
#include "drivers/accgyro/accgyro_spi_lsm6dso.h"
#include "drivers/accgyro/accgyro_spi_mpu6000.h"
#include "drivers/accgyro/accgyro_spi_mpu6500.h"
#include "drivers/accgyro/accgyro_spi_mpu9250.h"
#include "drivers/accgyro/accgyro_spi_sh3001.h"
#include "drivers/accgyro/accgyro_spi_l3gd20.h"
#include "drivers/accgyro/accgyro_mpu.h"

#include "pg/pg.h"
#include "pg/gyrodev.h"

#ifndef MPU_ADDRESS
#define MPU_ADDRESS             0x68
#endif

// 1 MHz max SPI frequency during device detection
#define MPU_MAX_SPI_DETECT_CLK_HZ 1000000

#define MPU_INQUIRY_MASK   0x7E

// Allow 100ms before attempting to access SPI bus
#define GYRO_SPI_STARTUP_MS 100

// Need to see at least this many interrupts during initialisation to confirm EXTI connectivity
#define GYRO_EXTI_DETECT_THRESHOLD 1000

#ifdef USE_I2C_GYRO
static void mpu6050FindRevision(gyroDev_t *gyro)
{
    // There is a map of revision contained in the android source tree which is quite comprehensive and may help to understand this code
    // See https://android.googlesource.com/kernel/msm.git/+/eaf36994a3992b8f918c18e4f7411e8b2320a35f/drivers/misc/mpu6050/mldl_cfg.c

    // determine product ID and revision
    uint8_t readBuffer[6];
    bool ack = busReadRegisterBuffer(&gyro->dev, MPU_RA_XA_OFFS_H, readBuffer, 6);
    uint8_t revision = ((readBuffer[5] & 0x01) << 2) | ((readBuffer[3] & 0x01) << 1) | (readBuffer[1] & 0x01);
    if (ack && revision) {
        // Congrats, these parts are better
        if (revision == 1) {
            gyro->mpuDetectionResult.resolution = MPU_HALF_RESOLUTION;
        } else if (revision == 2) {
            gyro->mpuDetectionResult.resolution = MPU_FULL_RESOLUTION;
        } else if ((revision == 3) || (revision == 7)) {
            gyro->mpuDetectionResult.resolution = MPU_FULL_RESOLUTION;
        } else {
            failureMode(FAILURE_ACC_INCOMPATIBLE);
        }
    } else {
        uint8_t productId;
        ack = busReadRegisterBuffer(&gyro->dev, MPU_RA_PRODUCT_ID, &productId, 1);
        revision = productId & 0x0F;
        if (!ack || revision == 0) {
            failureMode(FAILURE_ACC_INCOMPATIBLE);
        } else if (revision == 4) {
            gyro->mpuDetectionResult.resolution = MPU_HALF_RESOLUTION;
        } else {
            gyro->mpuDetectionResult.resolution = MPU_FULL_RESOLUTION;
        }
    }
}
#endif

/*
 * Gyro interrupt service routine
 */
#ifdef USE_GYRO_EXTI
#ifdef USE_SPI_GYRO
// Called in ISR context
// Gyro read has just completed
busStatus_e mpuIntcallback(uint32_t arg)
{
    gyroDev_t *gyro = (gyroDev_t *)arg;
    int32_t gyroDmaDuration = cmpTimeCycles(getCycleCounter(), gyro->gyroLastEXTI);

    if (gyroDmaDuration > gyro->gyroDmaMaxDuration) {
        gyro->gyroDmaMaxDuration = gyroDmaDuration;
    }

    gyro->dataReady = true;

    return BUS_READY;
}

static void mpuIntExtiHandler(extiCallbackRec_t *cb)
{
    gyroDev_t *gyro = container_of(cb, gyroDev_t, exti);

    // Ideally we'd use a timer to capture such information, but unfortunately the port used for EXTI interrupt does
    // not have an associated timer
    uint32_t nowCycles = getCycleCounter();
    int32_t gyroLastPeriod = cmpTimeCycles(nowCycles, gyro->gyroLastEXTI);
    // This detects the short (~79us) EXTI interval of an MPU6xxx gyro
    if ((gyro->gyroShortPeriod == 0) || (gyroLastPeriod < gyro->gyroShortPeriod)) {
        gyro->gyroSyncEXTI = gyro->gyroLastEXTI + gyro->gyroDmaMaxDuration;
    }
    gyro->gyroLastEXTI = nowCycles;

    if (gyro->gyroModeSPI == GYRO_EXTI_INT_DMA) {
        spiSequence(&gyro->dev, gyro->segments);
    }

    gyro->detectedEXTI++;
}
#else
static void mpuIntExtiHandler(extiCallbackRec_t *cb)
{
    gyroDev_t *gyro = container_of(cb, gyroDev_t, exti);
    gyro->dataReady = true;
}
#endif

static void mpuIntExtiInit(gyroDev_t *gyro)
{
    if (gyro->mpuIntExtiTag == IO_TAG_NONE) {
        return;
    }

    const IO_t mpuIntIO = IOGetByTag(gyro->mpuIntExtiTag);

#ifdef ENSURE_MPU_DATA_READY_IS_LOW
    uint8_t status = IORead(mpuIntIO);
    if (status) {
        return;
    }
#endif

    IOInit(mpuIntIO, OWNER_GYRO_EXTI, 0);
    EXTIHandlerInit(&gyro->exti, mpuIntExtiHandler);
    EXTIConfig(mpuIntIO, &gyro->exti, NVIC_PRIO_MPU_INT_EXTI, IOCFG_IN_FLOATING, BETAFLIGHT_EXTI_TRIGGER_RISING);
    EXTIEnable(mpuIntIO);
}
#endif // USE_GYRO_EXTI

bool mpuAccRead(accDev_t *acc)
{
    uint8_t data[6];

    const bool ack = busReadRegisterBuffer(&acc->gyro->dev, acc->gyro->accDataReg, data, 6);
    if (!ack) {
        return false;
    }

    acc->ADCRaw[X] = (int16_t)((data[0] << 8) | data[1]);
    acc->ADCRaw[Y] = (int16_t)((data[2] << 8) | data[3]);
    acc->ADCRaw[Z] = (int16_t)((data[4] << 8) | data[5]);

    return true;
}

bool mpuGyroRead(gyroDev_t *gyro)
{
    uint8_t data[6];

    const bool ack = busReadRegisterBuffer(&gyro->dev, gyro->gyroDataReg, data, 6);
    if (!ack) {
        return false;
    }

    gyro->gyroADCRaw[X] = (int16_t)((data[0] << 8) | data[1]);
    gyro->gyroADCRaw[Y] = (int16_t)((data[2] << 8) | data[3]);
    gyro->gyroADCRaw[Z] = (int16_t)((data[4] << 8) | data[5]);

    return true;
}


#ifdef USE_SPI_GYRO
bool mpuAccReadSPI(accDev_t *acc)
{
    switch (acc->gyro->gyroModeSPI) {
    case GYRO_EXTI_INT:
    case GYRO_EXTI_NO_INT:
    {
        acc->gyro->dev.txBuf[0] = acc->gyro->accDataReg | 0x80;

        busSegment_t segments[] = {
                {.u.buffers = {NULL, NULL}, 7, true, NULL},
                {.u.link = {NULL, NULL}, 0, true, NULL},
        };
        segments[0].u.buffers.txData = acc->gyro->dev.txBuf;
        segments[0].u.buffers.rxData = &acc->gyro->dev.rxBuf[1];

        spiSequence(&acc->gyro->dev, &segments[0]);

        // Wait for completion
        spiWait(&acc->gyro->dev);

        // Fall through
        FALLTHROUGH;
    }

    case GYRO_EXTI_INT_DMA:
    {
        // If read was triggered in interrupt don't bother waiting. The worst that could happen is that we pick
        // up an old value.

        // This data was read from the gyro, which is the same SPI device as the acc
        int16_t *accData = (int16_t *)acc->gyro->dev.rxBuf;
        acc->ADCRaw[X] = __builtin_bswap16(accData[1]);
        acc->ADCRaw[Y] = __builtin_bswap16(accData[2]);
        acc->ADCRaw[Z] = __builtin_bswap16(accData[3]);
        break;
    }

    case GYRO_EXTI_INIT:
    default:
        break;
    }

    return true;
}

bool mpuGyroReadSPI(gyroDev_t *gyro)
{
    int16_t *gyroData = (int16_t *)gyro->dev.rxBuf;
    switch (gyro->gyroModeSPI) {
    case GYRO_EXTI_INIT:
    {
        // Initialise the tx buffer to all 0xff
        memset(gyro->dev.txBuf, 0xff, 16);
#ifdef USE_GYRO_EXTI
        // Check that minimum number of interrupts have been detected

        // We need some offset from the gyro interrupts to ensure sampling after the interrupt
        gyro->gyroDmaMaxDuration = 5;
        if (gyro->detectedEXTI > GYRO_EXTI_DETECT_THRESHOLD) {
            if (spiUseDMA(&gyro->dev)) {
                gyro->dev.callbackArg = (uint32_t)gyro;
                gyro->dev.txBuf[0] = gyro->accDataReg | 0x80;
                gyro->segments[0].len = gyro->gyroDataReg - gyro->accDataReg + 7;
                gyro->segments[0].callback = mpuIntcallback;
                gyro->segments[0].u.buffers.txData = gyro->dev.txBuf;
                gyro->segments[0].u.buffers.rxData = &gyro->dev.rxBuf[1];
                gyro->segments[0].negateCS = true;
                gyro->gyroModeSPI = GYRO_EXTI_INT_DMA;
            } else {
                // Interrupts are present, but no DMA
                gyro->gyroModeSPI = GYRO_EXTI_INT;
            }
        } else
#endif
        {
            gyro->gyroModeSPI = GYRO_EXTI_NO_INT;
        }
        break;
    }

    case GYRO_EXTI_INT:
    case GYRO_EXTI_NO_INT:
    {
        gyro->dev.txBuf[0] = gyro->gyroDataReg | 0x80;

        busSegment_t segments[] = {
                {.u.buffers = {NULL, NULL}, 7, true, NULL},
                {.u.link = {NULL, NULL}, 0, true, NULL},
        };
        segments[0].u.buffers.txData = gyro->dev.txBuf;
        segments[0].u.buffers.rxData = &gyro->dev.rxBuf[1];

        spiSequence(&gyro->dev, &segments[0]);

        // Wait for completion
        spiWait(&gyro->dev);

        gyro->gyroADCRaw[X] = __builtin_bswap16(gyroData[1]);
        gyro->gyroADCRaw[Y] = __builtin_bswap16(gyroData[2]);
        gyro->gyroADCRaw[Z] = __builtin_bswap16(gyroData[3]);
        break;
    }

    case GYRO_EXTI_INT_DMA:
    {
        // Acc and gyro data may not be continuous (MPU6xxx has temperature in between)
        const uint8_t gyroDataIndex = ((gyro->gyroDataReg - gyro->accDataReg) >> 1) + 1;

        // If read was triggered in interrupt don't bother waiting. The worst that could happen is that we pick
        // up an old value.
        gyro->gyroADCRaw[X] = __builtin_bswap16(gyroData[gyroDataIndex]);
        gyro->gyroADCRaw[Y] = __builtin_bswap16(gyroData[gyroDataIndex + 1]);
        gyro->gyroADCRaw[Z] = __builtin_bswap16(gyroData[gyroDataIndex + 2]);
        break;
    }

    default:
        break;
    }

    return true;
}

typedef uint8_t (*gyroSpiDetectFn_t)(const extDevice_t *dev);

static gyroSpiDetectFn_t gyroSpiDetectFnTable[] = {
#ifdef USE_GYRO_SPI_MPU6000
    mpu6000SpiDetect,
#endif
#ifdef USE_GYRO_SPI_MPU6500
    mpu6500SpiDetect,   // some targets using MPU_9250_SPI, ICM_20608_SPI or ICM_20602_SPI state sensor is MPU_65xx_SPI
#endif
#ifdef  USE_GYRO_SPI_MPU9250
    mpu9250SpiDetect,
#endif
#ifdef USE_GYRO_SPI_ICM20689
    icm20689SpiDetect,  // icm20689SpiDetect detects ICM20602 and ICM20689
#endif
#ifdef USE_ACCGYRO_LSM6DS3
    lsm6ds3Detect,
#endif
#ifdef USE_ACCGYRO_LSM6DSL
    lsm6dslDetect,
#endif
#ifdef USE_ACCGYRO_LSM6DSO
    lsm6dsoDetect,
#endif
#ifdef USE_ACCGYRO_SH3001
    sh3001Detect,
#endif
#ifdef USE_ACCGYRO_BMI160
    bmi160Detect,
#endif
#ifdef USE_ACCGYRO_BMI270
    bmi270Detect,
#endif
#if defined(USE_GYRO_SPI_ICM42605) || defined(USE_GYRO_SPI_ICM42688P)
    icm426xxSpiDetect,
#endif
#ifdef USE_GYRO_SPI_ICM20649
    icm20649SpiDetect,
#endif
#ifdef USE_GYRO_L3GD20
    l3gd20Detect,
#endif
    NULL // Avoid an empty array
};

static bool detectSPISensorsAndUpdateDetectionResult(gyroDev_t *gyro, const gyroDeviceConfig_t *config)
{
    if (!config->csnTag || !spiSetBusInstance(&gyro->dev, config->spiBus)) {
        return false;
    }

    gyro->dev.busType_u.spi.csnPin = IOGetByTag(config->csnTag);

    IOInit(gyro->dev.busType_u.spi.csnPin, OWNER_GYRO_CS, RESOURCE_INDEX(config->index));
    IOConfigGPIO(gyro->dev.busType_u.spi.csnPin, SPI_IO_CS_CFG);
    IOHi(gyro->dev.busType_u.spi.csnPin); // Ensure device is disabled, important when two devices are on the same bus.

    uint8_t sensor = MPU_NONE;

    // Allow 100ms before attempting to access gyro's SPI bus
    // Do this once here rather than in each detection routine to speed boot
    while (millis() < GYRO_SPI_STARTUP_MS);

    // Set a slow SPI clock that all potential devices can handle during gyro detection
    spiSetClkDivisor(&gyro->dev, spiCalculateDivider(MPU_MAX_SPI_DETECT_CLK_HZ));

    // It is hard to use hardware to optimize the detection loop here,
    // as hardware type and detection function name doesn't match.
    // May need a bitmap of hardware to detection function to do it right?

    for (size_t index = 0 ; gyroSpiDetectFnTable[index] ; index++) {
        sensor = (gyroSpiDetectFnTable[index])(&gyro->dev);
        if (sensor != MPU_NONE) {
            gyro->mpuDetectionResult.sensor = sensor;
            busDeviceRegister(&gyro->dev);
            return true;
        }
    }

    // Detection failed, disable CS pin again

    spiPreinitByTag(config->csnTag);

    return false;
}
#endif

void mpuPreInit(const struct gyroDeviceConfig_s *config)
{
#ifdef USE_SPI_GYRO
    spiPreinitRegister(config->csnTag, IOCFG_IPU, 1);
#else
    UNUSED(config);
#endif
}

bool mpuDetect(gyroDev_t *gyro, const gyroDeviceConfig_t *config)
{
    static busDevice_t bus;
    gyro->dev.bus = &bus;

    // MPU datasheet specifies 30ms.
    delay(35);

    if (config->busType == BUS_TYPE_NONE) {
        return false;
    }

    if (config->busType == BUS_TYPE_GYRO_AUTO) {
        gyro->dev.bus->busType = BUS_TYPE_I2C;
    } else {
        gyro->dev.bus->busType = config->busType;
    }

#ifdef USE_I2C_GYRO
    if (gyro->dev.bus->busType == BUS_TYPE_I2C) {
        gyro->dev.bus->busType_u.i2c.device = I2C_CFG_TO_DEV(config->i2cBus);
        gyro->dev.busType_u.i2c.address = config->i2cAddress ? config->i2cAddress : MPU_ADDRESS;

        uint8_t sig = 0;
        bool ack = busReadRegisterBuffer(&gyro->dev, MPU_RA_WHO_AM_I, &sig, 1);

        if (ack) {
            busDeviceRegister(&gyro->dev);
            // If an MPU3050 is connected sig will contain 0.
            uint8_t inquiryResult;
            ack = busReadRegisterBuffer(&gyro->dev, MPU_RA_WHO_AM_I_LEGACY, &inquiryResult, 1);
            inquiryResult &= MPU_INQUIRY_MASK;
            if (ack && inquiryResult == MPUx0x0_WHO_AM_I_CONST) {
                gyro->mpuDetectionResult.sensor = MPU_3050;
                return true;
            }

            sig &= MPU_INQUIRY_MASK;
            if (sig == MPUx0x0_WHO_AM_I_CONST) {
                gyro->mpuDetectionResult.sensor = MPU_60x0;
                mpu6050FindRevision(gyro);
            } else if (sig == MPU6500_WHO_AM_I_CONST) {
                gyro->mpuDetectionResult.sensor = MPU_65xx_I2C;
            }
            return true;
        }
    }
#endif

#ifdef USE_SPI_GYRO
    gyro->dev.bus->busType = BUS_TYPE_SPI;

    return detectSPISensorsAndUpdateDetectionResult(gyro, config);
#else
    return false;
#endif
}

void mpuGyroInit(gyroDev_t *gyro)
{
    gyro->accDataReg = MPU_RA_ACCEL_XOUT_H;
    gyro->gyroDataReg = MPU_RA_GYRO_XOUT_H;
#ifdef USE_GYRO_EXTI
    mpuIntExtiInit(gyro);
#else
    UNUSED(gyro);
#endif
}

uint8_t mpuGyroDLPF(gyroDev_t *gyro)
{
    uint8_t ret = 0;

    // If gyro is in 32KHz mode then the DLPF bits aren't used
    if (gyro->gyroRateKHz <= GYRO_RATE_8_kHz) {
        switch (gyro->hardware_lpf) {
#ifdef USE_GYRO_DLPF_EXPERIMENTAL
            case GYRO_HARDWARE_LPF_EXPERIMENTAL:
                // experimental mode not supported for MPU60x0 family
                if ((gyro->gyroHardware != GYRO_MPU6050) && (gyro->gyroHardware != GYRO_MPU6000)) {
                    ret = 7;
                } else {
                    ret = 0;
                }
                break;
#endif

            case GYRO_HARDWARE_LPF_NORMAL:
            default:
                ret = 0;
                break;
        }
    }
    return ret;
}

#ifdef USE_GYRO_REGISTER_DUMP
uint8_t mpuGyroReadRegister(const extDevice_t *dev, uint8_t reg)
{
    uint8_t data;
    const bool ack = busReadRegisterBuffer(dev, reg, &data, 1);
    if (ack) {
        return data;
    } else {
        return 0;
    }

}
#endif