Function start

Drivers/bmi270-module/source/bmi270.cpp:91–131

// region Driver lifecycle

static error_t start(Device* device) {
    auto* i2c_controller = device_get_parent(device);
    if (device_get_type(i2c_controller) != &I2C_CONTROLLER_TYPE) {
        LOG_E(TAG, "Parent is not an I2C controller");
        return ERROR_RESOURCE;
    }

    auto address = GET_CONFIG(device)->address;

    // Verify chip ID
    uint8_t chip_id= 0;
    if (i2c_controller_register8_get(i2c_controller, address, REG_CHIP_ID, &chip_id, I2C_TIMEOUT_TICKS) != ERROR_NONE || chip_id != 0x24) {
        return ERROR_RESOURCE;
    }

    // Soft reset — clears all registers; datasheet specifies 2 ms startup time.
    // Use 20 ms to be safe and allow the chip to fully re-initialise before
    // any further I2C traffic (a second chip-ID read immediately after reset
    // is unreliable and not part of the Bosch SensorAPI init flow).
    if (i2c_controller_register8_set(i2c_controller, address, REG_CMD, 0xB6, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;
    vTaskDelay(pdMS_TO_TICKS(20));

    // Upload 8KB configuration (enables internal feature engine)
    if (!configure(i2c_controller, address)) {
        return ERROR_RESOURCE;
    }

    // Configure accelerometer: ODR=100Hz, normal filter, ±8g
    if (i2c_controller_register8_set(i2c_controller, address, REG_ACC_CONF,  ACC_CONF_VAL, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;
    if (i2c_controller_register8_set(i2c_controller, address, REG_ACC_RANGE, ACC_RANGE_VAL, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;

    // Configure gyroscope: ODR=100Hz, normal filter, ±2000°/s
    if (i2c_controller_register8_set(i2c_controller, address, REG_GYR_CONF,  GYR_CONF_VAL, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;
    if (i2c_controller_register8_set(i2c_controller, address, REG_GYR_RANGE, GYR_RANGE_VAL, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;

    // Enable accelerometer and gyroscope (bit1=gyr_en, bit2=acc_en)
    if (i2c_controller_register8_set(i2c_controller, address, REG_PWR_CTRL, 0x06, I2C_TIMEOUT_TICKS) != ERROR_NONE) return ERROR_RESOURCE;
    vTaskDelay(pdMS_TO_TICKS(2));

    return ERROR_NONE;
}

static error_t stop(Device* device) {
    auto* i2c_controller = device_get_parent(device);