diff --git a/boards/px4/raspberrypi/src/board_config.h b/boards/px4/raspberrypi/src/board_config.h
index 28d0665ca9..c8f3e257b1 100644
--- a/boards/px4/raspberrypi/src/board_config.h
+++ b/boards/px4/raspberrypi/src/board_config.h
@@ -53,6 +53,10 @@
 
 #define PX4_NUMBER_I2C_BUSES 2
 
+// SPI
+#define PX4_SPI_BUS_SENSORS		0
+#define PX4_SPIDEV_MPU			PX4_MK_SPI_SEL(PX4_SPI_BUS_SENSORS, 0)
+
 #define ADC_BATTERY_VOLTAGE_CHANNEL 0
 #define ADC_BATTERY_CURRENT_CHANNEL 1
 
diff --git a/src/drivers/imu/mpu9250/MPU9250_mag.cpp b/src/drivers/imu/mpu9250/MPU9250_mag.cpp
index b834908e7a..7d982aad37 100644
--- a/src/drivers/imu/mpu9250/MPU9250_mag.cpp
+++ b/src/drivers/imu/mpu9250/MPU9250_mag.cpp
@@ -158,32 +158,17 @@ MPU9250_mag::set_passthrough(uint8_t reg, uint8_t size, uint8_t *out)
 	}
 
 	_parent->write_reg(MPUREG_I2C_SLV0_ADDR, addr);
-	_parent->write_reg(MPUREG_I2C_SLV0_REG,  reg);
+	_parent->write_reg(MPUREG_I2C_SLV0_REG, reg);
 	_parent->write_reg(MPUREG_I2C_SLV0_CTRL, size | BIT_I2C_SLV0_EN);
 }
 
-void
-MPU9250_mag::read_block(uint8_t reg, uint8_t *val, uint8_t count)
-{
-	_parent->_interface->read(reg, val, count);
-}
-
-void
-MPU9250_mag::passthrough_read(uint8_t reg, uint8_t *buf, uint8_t size)
-{
-	set_passthrough(reg, size);
-	px4_usleep(25 + 25 * size); // wait for the value to be read from slave
-	read_block(MPUREG_EXT_SENS_DATA_00, buf, size);
-	_parent->write_reg(MPUREG_I2C_SLV0_CTRL, 0); // disable new reads
-}
-
 uint8_t
 MPU9250_mag::read_reg(unsigned int reg)
 {
 	uint8_t buf{};
 
 	if (_interface == nullptr) {
-		passthrough_read(reg, &buf, 0x01);
+		read_reg_through_mpu9250(reg, &buf);
 
 	} else {
 		_interface->read(reg, &buf, 1);
@@ -200,23 +185,12 @@ MPU9250_mag::ak8963_check_id(uint8_t &deviceid)
 	return (AK8963_DEVICE_ID == deviceid);
 }
 
-/*
- * 400kHz I2C bus speed = 2.5us per bit = 25us per byte
- */
-void
-MPU9250_mag::passthrough_write(uint8_t reg, uint8_t val)
-{
-	set_passthrough(reg, 1, &val);
-	px4_usleep(50); // wait for the value to be written to slave
-	_parent->write_reg(MPUREG_I2C_SLV0_CTRL, 0); // disable new writes
-}
-
 void
 MPU9250_mag::write_reg(unsigned reg, uint8_t value)
 {
 	// general register transfer at low clock speed
 	if (_interface == nullptr) {
-		passthrough_write(reg, value);
+		write_reg_through_mpu9250(reg, value);
 
 	} else {
 		_interface->write(MPU9250_LOW_SPEED_OP(reg), &value, 1);
@@ -246,17 +220,19 @@ MPU9250_mag::ak8963_read_adjustments()
 	uint8_t response[3];
 	float ak8963_ASA[3];
 
-	write_reg(AK8963REG_CNTL1, AK8963_FUZE_MODE | AK8963_16BIT_ADC);
-	px4_usleep(50);
+	write_reg_through_mpu9250(AK8963REG_CNTL1, AK8963_FUZE_MODE | AK8963_16BIT_ADC);
+	px4_usleep(200);
 
 	if (_interface != nullptr) {
 		_interface->read(AK8963REG_ASAX, response, 3);
 
 	} else {
-		passthrough_read(AK8963REG_ASAX, response, 3);
+		for (int i = 0; i < 3; ++i) {
+			read_reg_through_mpu9250(AK8963REG_ASAX + i, response + i);
+		}
 	}
 
-	write_reg(AK8963REG_CNTL1, AK8963_POWERDOWN_MODE);
+	write_reg_through_mpu9250(AK8963REG_CNTL1, AK8963_POWERDOWN_MODE);
 
 	for (int i = 0; i < 3; i++) {
 		if (0 != response[i] && 0xff != response[i]) {
@@ -291,6 +267,7 @@ MPU9250_mag::ak8963_setup_master_i2c()
 
 	return OK;
 }
+
 int
 MPU9250_mag::ak8963_setup()
 {
@@ -299,6 +276,7 @@ MPU9250_mag::ak8963_setup()
 	do {
 		ak8963_setup_master_i2c();
 		write_reg(AK8963REG_CNTL2, AK8963_RESET);
+		px4_usleep(100);
 
 		uint8_t id = 0;
 
@@ -347,3 +325,107 @@ MPU9250_mag::ak8963_setup()
 
 	return OK;
 }
+
+void MPU9250_mag::write_imu_reg_verified(int reg, uint8_t val, uint8_t mask)
+{
+	uint8_t b;
+	int retry = 5;
+
+	while (retry) { // should not reach any retries in normal condition
+		--retry;
+		_parent->write_reg(reg, val);
+
+		b = _parent->read_reg(reg);
+
+		if ((b & mask) != val) {
+			PX4_DEBUG("MPU9250_mag::write_imu_reg_verified failed. retrying...");
+			continue;
+
+		} else {
+			return;
+		}
+	}
+}
+
+void MPU9250_mag::read_reg_through_mpu9250(uint8_t reg, uint8_t *val)
+{
+	uint8_t b = 0;
+
+	// Read operation on the mag using the slave 4 registers.
+	write_imu_reg_verified(MPUREG_I2C_SLV4_ADDR,
+			       AK8963_I2C_ADDR | BIT_I2C_READ_FLAG, 0xff);
+
+	// Set the mag register to read from.
+	write_imu_reg_verified(MPUREG_I2C_SLV4_REG, reg, 0xff);
+
+	// Read the existing value of the SLV4 control register.
+	b = _parent->read_reg(MPUREG_I2C_SLV4_CTRL);
+
+	// Set the I2C_SLV4_EN bit in I2C_SL4_CTRL register without overwriting other
+	// bits. Enable data transfer, a read transfer as configured above.
+	b |= 0x80;
+	// Trigger the data transfer
+	_parent->write_reg(MPUREG_I2C_SLV4_CTRL, b);
+
+	// Continuously check I2C_MST_STATUS register value for the completion
+	// of I2C transfer until timeout
+
+	int loop_ctrl = 1000; // wait up to 1000 * 1ms for completion
+
+	do {
+		px4_usleep(1000);
+		b = _parent->read_reg(MPUREG_I2C_MST_STATUS);
+	} while (((b & 0x40) == 0x00) && (--loop_ctrl));
+
+	if (loop_ctrl == 0) {
+		PX4_ERR("I2C transfer timed out");
+
+	} else {
+		PX4_DEBUG("mpu9250 SPI2IIC read delay: %dms", loop_ctrl);
+	}
+
+	// Read the value received from the mag, and copy to the caller's out parameter.
+	*val = _parent->read_reg(MPUREG_I2C_SLV4_DI);
+}
+
+void MPU9250_mag::write_reg_through_mpu9250(uint8_t reg, uint8_t val)
+{
+	uint8_t b = 0;
+
+	// Configure a write operation to the mag using Slave 4.
+	write_imu_reg_verified(MPUREG_I2C_SLV4_ADDR,
+			       AK8963_I2C_ADDR, 0xff);
+
+	// Set the mag register address to write to using Slave 4.
+	write_imu_reg_verified(MPUREG_I2C_SLV4_REG, reg, 0xff);
+
+	// Set the value to write in the I2C_SLV4_DO register.
+	write_imu_reg_verified(MPUREG_I2C_SLV4_DO, val, 0xff);
+
+	// Read the current value of the Slave 4 control register.
+	b = _parent->read_reg(MPUREG_I2C_SLV4_CTRL);
+
+	// Set I2C_SLV4_EN bit in I2C_SL4_CTRL register without overwriting other
+	// bits.
+	b |= 0x80;
+	// Trigger the data transfer from the byte now stored in the SLV4_DO register.
+	_parent->write_reg(MPUREG_I2C_SLV4_CTRL, b);
+
+	// Continuously check I2C_MST_STATUS regsiter value for the completion
+	// of I2C transfer until timeout.
+
+	int loop_ctrl = 1000; // wait up to 1000 * 1ms for completion
+
+	do {
+		px4_usleep(1000);
+		b = _parent->read_reg(MPUREG_I2C_MST_STATUS);
+
+	} while (((b & 0x40) == 0x00) && (--loop_ctrl));
+
+	if (loop_ctrl == 0) {
+		PX4_ERR("I2C transfer to mag timed out");
+
+	} else {
+		PX4_DEBUG("mpu9250 SPI2IIC write delay: %dms", loop_ctrl);
+	}
+}
diff --git a/src/drivers/imu/mpu9250/MPU9250_mag.h b/src/drivers/imu/mpu9250/MPU9250_mag.h
index 05c1ad8ce3..7ab330ab13 100644
--- a/src/drivers/imu/mpu9250/MPU9250_mag.h
+++ b/src/drivers/imu/mpu9250/MPU9250_mag.h
@@ -115,10 +115,7 @@ public:
 	MPU9250_mag(MPU9250 *parent, device::Device *interface, enum Rotation rotation);
 	~MPU9250_mag();
 
-	void set_passthrough(uint8_t reg, uint8_t size, uint8_t *out = NULL);
-	void passthrough_read(uint8_t reg, uint8_t *buf, uint8_t size);
-	void passthrough_write(uint8_t reg, uint8_t val);
-	void read_block(uint8_t reg, uint8_t *val, uint8_t count);
+	void set_passthrough(uint8_t reg, uint8_t size, uint8_t *out = nullptr);
 
 	int ak8963_reset();
 	int ak8963_setup();
@@ -138,6 +135,9 @@ protected:
 
 	uint8_t read_reg(unsigned reg);
 	void write_reg(unsigned reg, uint8_t value);
+	void write_imu_reg_verified(int reg, uint8_t val, uint8_t mask);
+	void read_reg_through_mpu9250(uint8_t reg, uint8_t *val);
+	void write_reg_through_mpu9250(uint8_t reg, uint8_t val);
 
 	bool is_passthrough() { return _interface == nullptr; }
 
diff --git a/src/drivers/imu/mpu9250/mpu9250.cpp b/src/drivers/imu/mpu9250/mpu9250.cpp
index cbe5df77f5..20a3504a72 100644
--- a/src/drivers/imu/mpu9250/mpu9250.cpp
+++ b/src/drivers/imu/mpu9250/mpu9250.cpp
@@ -398,17 +398,6 @@ MPU9250::read_reg_range(unsigned start_reg, uint32_t speed, uint8_t *buf, uint16
 	return _interface->read(MPU9250_SET_SPEED(start_reg, speed), buf, count);
 }
 
-uint16_t
-MPU9250::read_reg16(unsigned reg)
-{
-	uint8_t buf[2] {};
-
-	// general register transfer at low clock speed
-	_interface->read(MPU9250_LOW_SPEED_OP(reg), &buf, arraySize(buf));
-
-	return (uint16_t)(buf[0] << 8) | buf[1];
-}
-
 void
 MPU9250::write_reg(unsigned reg, uint8_t value)
 {
diff --git a/src/drivers/imu/mpu9250/mpu9250.h b/src/drivers/imu/mpu9250/mpu9250.h
index f6f461216e..59988af297 100644
--- a/src/drivers/imu/mpu9250/mpu9250.h
+++ b/src/drivers/imu/mpu9250/mpu9250.h
@@ -316,7 +316,6 @@ private:
 	 * @return		The value that was read.
 	 */
 	uint8_t			read_reg(unsigned reg, uint32_t speed = MPU9250_LOW_BUS_SPEED);
-	uint16_t		read_reg16(unsigned reg);
 
 
 	/**