LSM9DS1_MAG.cpp 7.51 KB
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#include "LSM9DS1_MAG.hpp"

using namespace time_literals;

static constexpr int16_t combine(uint8_t msb, uint8_t lsb)
{
	return (msb << 8u) | lsb;
}

LSM9DS1_MAG::LSM9DS1_MAG(I2CSPIBusOption bus_option, int bus, uint32_t device, enum Rotation rotation,
			 int bus_frequency, spi_mode_e spi_mode) :
	SPI(DRV_MAG_DEVTYPE_ST_LSM9DS1_M, MODULE_NAME, bus, device, spi_mode, bus_frequency),
	I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus),
	_px4_mag(get_device_id(), rotation)
{
	_px4_mag.set_external(external());
}

LSM9DS1_MAG::~LSM9DS1_MAG()
{
	perf_free(_bad_register_perf);
	perf_free(_bad_transfer_perf);
}

int LSM9DS1_MAG::init()
{
	int ret = SPI::init();

	if (ret != PX4_OK) {
		DEVICE_DEBUG("SPI::init failed (%i)", ret);
		return ret;
	}

	return Reset() ? 0 : -1;
}

bool LSM9DS1_MAG::Reset()
{
	_state = STATE::RESET;
	ScheduleClear();
	ScheduleNow();
	return true;
}

void LSM9DS1_MAG::print_status()
{
	I2CSPIDriverBase::print_status();

	perf_print_counter(_bad_register_perf);
	perf_print_counter(_bad_transfer_perf);
}

int LSM9DS1_MAG::probe()
{
	const uint8_t WHO_AM_I_M = RegisterRead(Register::WHO_AM_I_M);

	if (WHO_AM_I_M != Device_identification) {
		DEVICE_DEBUG("unexpected WHO_AM_I_M 0x%02x", WHO_AM_I_M);
		return PX4_ERROR;
	}

	return PX4_OK;
}

void LSM9DS1_MAG::RunImpl()
{
	const hrt_abstime now = hrt_absolute_time();

	switch (_state) {
	case STATE::RESET:
		// CTRL_REG2_M: SOFT_RST
		RegisterWrite(Register::CTRL_REG2_M, CTRL_REG2_M_BIT::SOFT_RST);
		_reset_timestamp = now;
		_failure_count = 0;
		_state = STATE::WAIT_FOR_RESET;
		ScheduleDelayed(100_ms);
		break;

	case STATE::WAIT_FOR_RESET:
		if (RegisterRead(Register::WHO_AM_I_M) == Device_identification) {
			// if reset succeeded then configure
			_state = STATE::CONFIGURE;
			ScheduleDelayed(10_ms);

		} else {
			// RESET not complete
			if (hrt_elapsed_time(&_reset_timestamp) > 1000_ms) {
				PX4_DEBUG("Reset failed, retrying");
				_state = STATE::RESET;
				ScheduleDelayed(100_ms);

			} else {
				PX4_DEBUG("Reset not complete, check again in 100 ms");
				ScheduleDelayed(100_ms);
			}
		}

		break;

	case STATE::CONFIGURE:
		if (Configure()) {
			// if configure succeeded then start reading
			_state = STATE::READ;
			ScheduleOnInterval(1000000 / ST_LSM9DS1_MAG::M_ODR);

		} else {
			// CONFIGURE not complete
			if (hrt_elapsed_time(&_reset_timestamp) > 1000_ms) {
				PX4_DEBUG("Configure failed, resetting");
				_state = STATE::RESET;

			} else {
				PX4_DEBUG("Configure failed, retrying");
			}

			ScheduleDelayed(100_ms);
		}

		break;

	case STATE::READ: {
			struct TransferBuffer {
				uint8_t cmd;
				uint8_t STATUS_REG_M;
				uint8_t OUT_X_L_M;
				uint8_t OUT_X_H_M;
				uint8_t OUT_Y_L_M;
				uint8_t OUT_Y_H_M;
				uint8_t OUT_Z_L_M;
				uint8_t OUT_Z_H_M;
			} buffer{};

			buffer.cmd = static_cast<uint8_t>(Register::STATUS_REG_M) | RW_BIT_READ | MS_BIT_AUTO_INCREMENT;

			bool success = false;

			if (transfer((uint8_t *)&buffer, (uint8_t *)&buffer, sizeof(buffer)) == PX4_OK) {
				if (buffer.STATUS_REG_M & STATUS_REG_M_BIT::ZYXDA) {
					// X, Y and Z-axis new data available.
					int16_t x = combine(buffer.OUT_X_H_M, buffer.OUT_X_L_M);
					int16_t y = combine(buffer.OUT_Y_H_M, buffer.OUT_Y_L_M);
					int16_t z = combine(buffer.OUT_Z_H_M, buffer.OUT_Z_L_M);

					// sensor Z is up (RHC), flip z for publication
					// sensor X is aligned with -X of lsm9ds1 accel/gyro
					x = (x == INT16_MIN) ? INT16_MAX : -x;
					y = y;
					z = (z == INT16_MIN) ? INT16_MAX : -z;

					_px4_mag.update(now, x, y, z);

					success = true;

					if (_failure_count > 0) {
						_failure_count--;
					}
				}
			}

			if (!success) {
				_failure_count++;

				// full reset if things are failing consistently
				if (_failure_count > 10) {
					Reset();
					return;
				}
			}

			if (!success || hrt_elapsed_time(&_last_config_check_timestamp) > 100_ms) {
				// check configuration registers periodically or immediately following any failure
				if (RegisterCheck(_register_cfg[_checked_register])) {
					_last_config_check_timestamp = now;
					_checked_register = (_checked_register + 1) % size_register_cfg;

				} else {
					// register check failed, force reset
					perf_count(_bad_register_perf);
					Reset();
				}
			}
		}

		break;
	}
}

bool LSM9DS1_MAG::Configure()
{
	// first set and clear all configured register bits
	for (const auto &reg_cfg : _register_cfg) {
		RegisterSetAndClearBits(reg_cfg.reg, reg_cfg.set_bits, reg_cfg.clear_bits);
	}

	// now check that all are configured
	bool success = true;

	for (const auto &reg_cfg : _register_cfg) {
		if (!RegisterCheck(reg_cfg)) {
			success = false;
		}
	}

	// Magnetic FS = ±16 gauss 0.58 mgauss/LSB
	_px4_mag.set_scale(0.58f / 1000.0f);

	return success;
}

bool LSM9DS1_MAG::RegisterCheck(const register_config_t &reg_cfg)
{
	bool success = true;

	const uint8_t reg_value = RegisterRead(reg_cfg.reg);

	if (reg_cfg.set_bits && ((reg_value & reg_cfg.set_bits) != reg_cfg.set_bits)) {
		PX4_DEBUG("0x%02hhX: 0x%02hhX (0x%02hhX not set)", (uint8_t)reg_cfg.reg, reg_value, reg_cfg.set_bits);
		success = false;
	}

	if (reg_cfg.clear_bits && ((reg_value & reg_cfg.clear_bits) != 0)) {
		PX4_DEBUG("0x%02hhX: 0x%02hhX (0x%02hhX not cleared)", (uint8_t)reg_cfg.reg, reg_value, reg_cfg.clear_bits);
		success = false;
	}

	return success;
}

uint8_t LSM9DS1_MAG::RegisterRead(Register reg)
{
	uint8_t cmd[2] {};
	cmd[0] = static_cast<uint8_t>(reg) | RW_BIT_READ;
	transfer(cmd, cmd, sizeof(cmd));
	return cmd[1];
}

void LSM9DS1_MAG::RegisterWrite(Register reg, uint8_t value)
{
	uint8_t cmd[2] { (uint8_t)reg, value };
	transfer(cmd, cmd, sizeof(cmd));
}

void LSM9DS1_MAG::RegisterSetAndClearBits(Register reg, uint8_t setbits, uint8_t clearbits)
{
	const uint8_t orig_val = RegisterRead(reg);

	uint8_t val = (orig_val & ~clearbits) | setbits;

	if (orig_val != val) {
		RegisterWrite(reg, val);
	}
}