iio: magnetometer: add support for Melexis MLX90393

Add devicetree bindings for the Melexis MLX90393
3-axis magnetometer and temperature sensor.

The device supports magnetic field and temperature measurements over I2C and SPI interfaces.

This initial binding documents the I2C interface.

Signed-off-by Nikhil Gautam <[email protected]>

Add Industrial I/O subsystem support for the Melexis MLX90393 3-axis magnetometer and temperature sensor.

The driver currently supports:

raw magnetic field measurements
raw temperature measurements
configurable gain/scale selection
configurable oversampling ratio
direct mode operation

The MLX90393 supports both I2C and SPI interfaces. This initial implementation adds support for the I2C interface.

The device uses a command-based communication protocol rather than a conventional register-addressed interface. A small transport abstraction layer is therefore used instead of regmap to share the common sensor logic between the current I2C implementation and future SPI support without duplicating code.

Signed-off-by Nikhil Gautam <[email protected]>

---
 MAINTAINERS                              |   1 +
 drivers/iio/magnetometer/Kconfig         |  10 +
 drivers/iio/magnetometer/Makefile        |   2 +
 drivers/iio/magnetometer/mlx90393.h      |  73 +++
 drivers/iio/magnetometer/mlx90393_core.c | 701 +++++++++++++++++++++++
 drivers/iio/magnetometer/mlx90393_i2c.c  |  76 +++
 6 files changed, 863 insertions(+)
 create mode 100644 drivers/iio/magnetometer/mlx90393.h
 create mode 100644 drivers/iio/magnetometer/mlx90393_core.c
 create mode 100644 drivers/iio/magnetometer/mlx90393_i2c.c

MAINTAINERS +1 -0

index 469ae3f9aa0f..177dda261801 100644
@@ -15506,6 +15506,7 @@ M:	Nikhil Gautam <[email protected]>
 L:	[email protected]
 S:	Maintained
 F:	Documentation/devicetree/bindings/iio/magnetometer/melexis,mlx90393.yaml
+F:	drivers/iio/magnetometer/mlx90393*
 
 MELEXIS MLX90614 DRIVER
 M:	Crt Mori <[email protected]>

drivers/iio/magnetometer/Kconfig +10 -0

index 3debf1320ad1..e6b74e7e3317 100644
@@ -128,6 +128,16 @@ config HID_SENSOR_MAGNETOMETER_3D
 	  Say yes here to build support for the HID SENSOR
 	  Magnetometer 3D.
 
+config MLX90393
+	tristate "MELEXIS MLX90393 3-axis magnetometer sensor"
+	depends on I2C
+	help
+	  Say yes here to build support for the MELEXIS MLX90393 3-axis
+	  magnetometer.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called mlx90393.
+
 config MMC35240
 	tristate "MEMSIC MMC35240 3-axis magnetic sensor"
 	select REGMAP_I2C

drivers/iio/magnetometer/Makefile +0 -0

index 9297723a97d8..542c89d38a59 100644

drivers/iio/magnetometer/Makefile +0 -0

 obj-$(CONFIG_MMC35240)	+= mmc35240.o
 
 obj-$(CONFIG_IIO_ST_MAGN_3AXIS) += st_magn.o

drivers/iio/magnetometer/mlx90393.h new file +73 -0

new file mode 100644
index 000000000000..6a646ac05198
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * MLX90393 magnetometer & temperature sensor driver
+ *
+ * Copyright (c) 2026 Nikhil Gautam <[email protected]>
+ */
+
+#ifndef MLX90393_H
+#define MLX90393_H
+
+#include <linux/bits.h>
+#include <linux/types.h>
+
+#define MLX90393_AXIS_MAX		2
+#define MLX90393_GAIN_MAX		8
+#define MLX90393_RES_MAX		4
+#define MLX90393_OSR2_MAX		4
+#define MLX90393_OSR_MAX		4
+
+#define MLX90393_CMD_MASK        GENMASK(7, 4)
+
+/* Commands (datasheet, Table 11 - Command List) */
+#define MLX90393_CMD_SB        0x10	/* Start Burst Mode */
+#define MLX90393_CMD_SW        0x20	/* Start Wake-up on Change Mode */
+#define MLX90393_CMD_SM        0x30	/* Start Single Measurement Mode */
+#define MLX90393_CMD_RM        0x40	/* Read Measurement */
+#define MLX90393_CMD_RR        0x50	/* Read Register */
+#define MLX90393_CMD_WR        0x60	/* Write Register */
+#define MLX90393_CMD_EX        0x80	/* Exit Mode */
+#define MLX90393_CMD_HR        0xD0	/* Memory Recall */
+#define MLX90393_CMD_HS        0xE0	/* Memory Store */
+#define MLX90393_CMD_RT        0xF0	/* Reset Device */
+
+#define MLX90393_MEASURE_Z    BIT(0)
+#define MLX90393_MEASURE_Y    BIT(1)
+#define MLX90393_MEASURE_X    BIT(2)
+#define MLX90393_MEASURE_TEMP BIT(3)
+
+#define MLX90393_MEASURE_ALL	(MLX90393_MEASURE_TEMP | \
+		MLX90393_MEASURE_X | MLX90393_MEASURE_Y | MLX90393_MEASURE_Z)
+
+#define MLX90393_NUM_CHANNELS	4
+
+#define MLX90393_STATUS_RESP    GENMASK(1, 0)
+#define MLX90393_STATUS_RT	BIT(2)
+#define MLX90393_STATUS_ERROR   BIT(4)
+
+#define MLX90393_REG_CONF1          0x00
+#define MLX90393_REG_CONF2          0x01
+#define MLX90393_REG_CONF3          0x02
+#define MLX90393_REG_CONF4          0x03
+
+#define MLX90393_CONF1_GAIN_SEL     GENMASK(6, 4)
+#define MLX90393_CONF1_HALLCONF     GENMASK(3, 0)
+
+#define MLX90393_CONF3_OSR        GENMASK(1, 0)
+#define MLX90393_CONF3_DIG_FILT   GENMASK(4, 2)
+#define MLX90393_CONF3_RES_X      GENMASK(6, 5)
+#define MLX90393_CONF3_RES_Y      GENMASK(8, 7)
+#define MLX90393_CONF3_RES_Z      GENMASK(10, 9)
+#define MLX90393_CONF3_OSR2       GENMASK(12, 11)
+
+struct device;
+
+struct mlx90393_transfer_ops {
+	int (*xfer)(void *context, const u8 *tx, int tx_len, u8 *rx, int rx_len);
+};
+
+int mlx90393_core_probe(struct device *dev,
+			const struct mlx90393_transfer_ops *ops,
+			void *context);
+
+#endif

drivers/iio/magnetometer/mlx90393_core.c new file +45 -0

new file mode 100644
index 000000000000..78fcab8a2b56
@@ -0,0 +1,701 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MLX90393 magnetometer & temperature sensor driver
+ *
+ * Copyright (c) 2026 Nikhil Gautam <[email protected]>
+ *
+ * Datasheet: https://media.melexis.com/-/media/files/documents/datasheets/mlx90393-datasheet-melexis.pdf
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/time64.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
+
+#include <linux/iio/iio.h>
+
+#include "mlx90393.h"
+
+struct mlx90393_data {
+	/* Protects sensor configuration and measurement operations */
+	struct mutex lock;
+	struct device *dev;
+	void *bus_context;
+	const struct mlx90393_transfer_ops *ops;
+	u8 gain_sel;
+	u8 hallconf;
+
+	u8 res_xy;
+	u8 res_z;
+
+	u8 dig_filt;
+	u8 osr;
+	u8 osr2;
+};
+
+enum mlx90393_channels {
+	MLX90393_CHAN_X,
+	MLX90393_CHAN_Y,

drivers/iio/magnetometer/mlx90393_core.c new file +18 -0

+static const int mlx90393_scale_table[MLX90393_AXIS_MAX][MLX90393_GAIN_MAX]
+				      [MLX90393_RES_MAX] = {
+	/* XY axis */
+	{
+		{ 751, 1502, 3004, 6009},
+		{ 601, 1202, 2403, 4840},
+		{ 451, 901, 1803, 3605},
+		{ 376, 751, 1502, 3004},
+		{ 300, 601, 1202, 2403},
+		{ 250, 501, 1001, 2003},
+		{ 200, 401, 801, 1602},
+		{ 150, 300, 601, 1202},
+	},
+	/* Z axis */
+	{
+		{ 1210, 2420, 4840, 9680},
+		{ 968, 1936, 3872, 7744},
+		{ 726, 1452, 2904, 5808},

drivers/iio/magnetometer/mlx90393_core.c new file +24 -0

+};
+
+static const int mlx90393_osr_avail[MLX90393_OSR_MAX] = {
+	1, 2, 4, 8,
+};
+
+#define MLX90393_CHAN(idx, axis, addr) { \
+	.type = IIO_MAGN, \
+	.modified = 1, \
+	.channel = idx, \
+	.address = addr, \
+	.channel2 = IIO_MOD_##axis, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+		BIT(IIO_CHAN_INFO_SCALE), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),\
+	.info_mask_separate_available = \
+		BIT(IIO_CHAN_INFO_SCALE),  \
+	.info_mask_shared_by_type_available = \
+		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+}
+
+static const struct iio_chan_spec mlx90393_channels[] = {
+	MLX90393_CHAN(0, X, MLX90393_CHAN_X),
+	MLX90393_CHAN(1, Y, MLX90393_CHAN_Y),

drivers/iio/magnetometer/mlx90393_core.c new file +16 -0

+	},
+};
+
+/*
+ * Calculate total conversion time in microseconds.
+ *
+ * Formula derived from datasheet timing equations.
+ * Datasheet: Table 8, Page no. 12
+ *
+ * Abbreviations:
+ * TCONVM	-> Single Magnetic axis conversion time
+ * TCONVT	-> Temperature conversion time
+ * TSTBY	-> Time from IDLE to STANDBY
+ * TACTIVE	-> Time from STBY to ACTIVE
+ * TCONV_END	-> Time to end analog active mode
+ */

drivers/iio/magnetometer/mlx90393_core.c new file +15 -0

+}
+
+static int mlx90393_xfer(struct mlx90393_data *data,
+			 const u8 *tx, int tx_len,
+			 u8 *rx, int rx_len)
+{
+	return data->ops->xfer(data->bus_context, tx, tx_len, rx, rx_len);
+}
+
+static int mlx90393_check_status(u8 cmd, u8 status)
+{
+	/* Datasheet: Table 12: Status byte definition */
+
+	/* Always validate error bit */
+	if (status & MLX90393_STATUS_ERROR)

drivers/iio/magnetometer/mlx90393_core.c new file +73 -0

+		return 0;
+	default:
+		return 0;
+	}
+}
+
+static int mlx90393_write_cmd(struct mlx90393_data *data, u8 cmd)
+{
+	u8 status;
+	int ret;
+
+	ret = mlx90393_xfer(data, &cmd, 1, &status, 1);
+	if (ret)
+		return ret;
+
+	return mlx90393_check_status(cmd, status);
+}
+
+static int mlx90393_read_cmd(struct mlx90393_data *data, u8 cmd, u8 *rx,
+			     int rx_len)
+{
+	int ret;
+
+	ret = mlx90393_xfer(data, &cmd, 1, rx, rx_len);
+	if (ret)
+		return ret;
+
+	return mlx90393_check_status(cmd, rx[0]);
+}
+
+static int mlx90393_read_reg(struct mlx90393_data *data, u8 reg, u16 *val)
+{
+	u8 tx[2];
+	u8 rx[3];
+	int ret;
+
+	tx[0] = MLX90393_CMD_RR;
+	/* Register address is encoded in bits [7:2] */
+	tx[1] = reg << 2;
+
+	ret = mlx90393_xfer(data, tx, sizeof(tx), rx, sizeof(rx));
+	if (ret)
+		return ret;
+
+	ret = mlx90393_check_status(tx[0], rx[0]);
+	if (ret)
+		return ret;
+
+	*val = get_unaligned_be16(&rx[1]);
+
+	return 0;
+}
+
+static int mlx90393_write_reg(struct mlx90393_data *data, u8 reg, u16 val)
+{
+	u8 tx[4];
+	u8 status;
+	int ret;
+
+	tx[0] = MLX90393_CMD_WR;
+	put_unaligned_be16(val, &tx[1]);
+	/* Register address is encoded in bits [7:2] */
+	tx[3] = reg << 2;
+
+	ret = mlx90393_xfer(data, tx, sizeof(tx), &status, 1);
+	if (ret)
+		return ret;
+
+	return mlx90393_check_status(tx[0], status);
+}
+
+static int mlx90393_update_bits(struct mlx90393_data *data, u8 reg,
+				u16 mask, u16 val)

drivers/iio/magnetometer/mlx90393_core.c new file +13 -0

+
+static int mlx90393_read_measurement(struct mlx90393_data *data,
+				     enum mlx90393_channels chan, int *val)
+{
+	u8 rx[9];
+	int ret;
+
+	/* Start measurement */
+	ret = mlx90393_write_cmd(data, MLX90393_CMD_SM | MLX90393_MEASURE_ALL);
+	if (ret)
+		return ret;
+
+	/* Wait conversion */

drivers/iio/magnetometer/mlx90393_core.c new file +15 -0

+	 */
+
+	switch (chan) {
+	case MLX90393_CHAN_TEMP:
+		*val = get_unaligned_be16(&rx[1]);
+		return 0;
+
+	case MLX90393_CHAN_X:
+		*val = sign_extend32(get_unaligned_be16(&rx[3]), 15);
+		return 0;
+
+	case MLX90393_CHAN_Y:
+		*val = sign_extend32(get_unaligned_be16(&rx[5]), 15);
+		return 0;
+

drivers/iio/magnetometer/mlx90393_core.c new file +11 -0

+			      const struct iio_chan_spec *chan,
+			      int *val, int *val2)
+{
+	enum mlx90393_axis_type axis;
+	u8 res;
+
+	if (chan->channel2 == IIO_MOD_Z) {
+		axis = MLX90393_AXIS_TYPE_Z;
+		res = data->res_z;
+	} else {
+		axis = MLX90393_AXIS_TYPE_XY;

drivers/iio/magnetometer/mlx90393_core.c new file +52 -0

+
+	if (z_axis) {
+		axis = MLX90393_AXIS_TYPE_Z;
+		res = data->res_z;
+	} else {
+		axis = MLX90393_AXIS_TYPE_XY;
+		res = data->res_xy;
+	}
+
+	if (val != 0)
+		return -EINVAL;
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(mlx90393_scale_table[0]); i++) {
+		if (mlx90393_scale_table[axis][i][res] == val2) {
+			*gain = i;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int mlx90393_set_scale(struct mlx90393_data *data,
+			      const struct iio_chan_spec *chan,
+			      int val, int val2)
+{
+	bool z_axis;
+	int gain;
+	int ret;
+
+	z_axis = chan->channel2 == IIO_MOD_Z;
+
+	ret = mlx90393_find_scale(data, z_axis, val, val2, &gain);
+	if (ret)
+		return ret;
+
+	ret = mlx90393_update_bits(data, MLX90393_REG_CONF1, MLX90393_CONF1_GAIN_SEL,
+				   gain);
+	if (ret)
+		return ret;
+
+	data->gain_sel = gain;
+	return 0;
+}
+
+static int mlx90393_get_osr(struct mlx90393_data *data, int *val)
+{
+	*val = mlx90393_osr_avail[data->osr];
+	return IIO_VAL_INT;
+}
+
+static int mlx90393_find_osr(int val, int *osr)

drivers/iio/magnetometer/mlx90393_core.c new file +16 -0

+{
+	int osr;
+	int ret;
+
+	ret = mlx90393_find_osr(val, &osr);
+	if (ret)
+		return ret;
+
+	if (osr == data->osr)
+		return 0;
+
+	ret = mlx90393_update_bits(data, MLX90393_REG_CONF3, MLX90393_CONF3_OSR,
+				   osr);
+	if (ret)
+		return ret;
+

drivers/iio/magnetometer/mlx90393_core.c new file +67 -0

+
+	if (val == data->osr2)
+		return 0;
+
+	ret = mlx90393_update_bits(data, MLX90393_REG_CONF3, MLX90393_CONF3_OSR2,
+				   val);
+	if (ret)
+		return ret;
+
+	data->osr2 = val;
+
+	return 0;
+}
+
+static int mlx90393_write_raw_get_fmt(struct iio_dev *indio_dev,
+				      struct iio_chan_spec const *chan,
+				      long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		return IIO_VAL_INT_PLUS_NANO;
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mlx90393_write_raw(struct iio_dev *indio_dev,
+			      const struct iio_chan_spec *chan,
+			      int val, int val2,
+			      long mask)
+{
+	struct mlx90393_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE: {
+		guard(mutex)(&data->lock);
+		return mlx90393_set_scale(data, chan, val, val2);
+	}
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO: {
+		guard(mutex)(&data->lock);
+		switch (chan->type) {
+		case IIO_TEMP:
+			return mlx90393_set_temp_osr2(data, val);
+
+		case IIO_MAGN:
+			return mlx90393_set_osr(data, val);
+
+		default:
+			return -EINVAL;
+		}
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mlx90393_read_raw(struct iio_dev *indio_dev,
+			     const struct iio_chan_spec *chan,
+			     int *val, int *val2, long mask)
+{
+	struct mlx90393_data *data = iio_priv(indio_dev);
+	int ret;

drivers/iio/magnetometer/mlx90393_core.c new file +47 -0

+			return IIO_VAL_INT_PLUS_MICRO;
+
+		default:
+			return -EINVAL;
+		}
+
+	case IIO_CHAN_INFO_OFFSET:
+		if (chan->type != IIO_TEMP)
+			return -EINVAL;
+		/*
+		 * Datasheet Table 7: Thermal Specification
+		 */
+
+		*val = -45114;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return mlx90393_get_temp_osr2(data, val);
+		case IIO_MAGN:
+			return mlx90393_get_osr(data, val);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mlx90393_read_avail(struct iio_dev *indio_dev,
+			       const struct iio_chan_spec *chan,
+			       const int **vals,
+			       int *type,
+			       int *length,
+			       long mask)
+{
+	struct mlx90393_data *data = iio_priv(indio_dev);
+	static int scale_avail[MLX90393_GAIN_MAX][MLX90393_AXIS_MAX];
+	enum mlx90393_axis_type axis;
+	u8 res;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE: {
+		guard(mutex)(&data->lock);
+		axis = chan->channel2 == IIO_MOD_Z;
+		res = axis ? data->res_z : data->res_xy;

drivers/iio/magnetometer/mlx90393_core.c new file +50 -0

+		return IIO_AVAIL_LIST;
+	}
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		if (chan->type == IIO_TEMP) {
+			*vals = mlx90393_osr2_avail;
+			*type = IIO_VAL_INT;
+			*length = MLX90393_OSR2_MAX;
+		} else {
+			*vals = mlx90393_osr_avail;
+			*type = IIO_VAL_INT;
+			*length = MLX90393_OSR_MAX;
+		}
+		return IIO_AVAIL_LIST;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info mlx90393_info = {
+	.read_raw = mlx90393_read_raw,
+	.write_raw = mlx90393_write_raw,
+	.read_avail = mlx90393_read_avail,
+	.write_raw_get_fmt = mlx90393_write_raw_get_fmt,
+};
+
+static int mlx90393_init(struct mlx90393_data *data)
+{
+	int ret;
+	u16 reg;
+
+	/* Exit mode */
+	ret = mlx90393_write_cmd(data, MLX90393_CMD_EX);
+	if (ret)
+		return ret;
+
+	/*
+	 * Datasheet section 15.4.1.2 (RT command), Figure 16:
+	 * Wait 1 ms after EX command before issuing RT.
+	 */
+	fsleep(1 * USEC_PER_MSEC);
+
+	/* Reset device */
+	ret = mlx90393_write_cmd(data, MLX90393_CMD_RT);
+	if (ret)
+		return ret;
+
+	/*
+	 * Datasheet section 15.4.1.2 (RT command), Figure 16:

drivers/iio/magnetometer/mlx90393_core.c new file +42 -0

+
+	return 0;
+}
+
+int mlx90393_core_probe(struct device *dev,
+			const struct mlx90393_transfer_ops *ops,
+			void *context)
+{
+	struct iio_dev *indio_dev;
+	struct mlx90393_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	ret = devm_mutex_init(dev, &data->lock);
+	if (ret)
+		return ret;
+
+	data->dev = dev;
+	data->ops = ops;
+	data->bus_context = context;
+
+	indio_dev->name = "mlx90393";
+	indio_dev->info = &mlx90393_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = mlx90393_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mlx90393_channels);
+
+	ret = mlx90393_init(data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to initialize device\n");
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(mlx90393_core_probe, "IIO_MLX90393");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nikhil Gautam <[email protected]>");
+MODULE_DESCRIPTION("MLX90393 magnetometer sensor driver");

drivers/iio/magnetometer/mlx90393_i2c.c new file +76 -0

new file mode 100644
index 000000000000..a9f0a40d15e8
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/array_size.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+
+#include "mlx90393.h"
+
+/*
+ * MLX90393 commands use repeated-start transfers where
+ * every command is followed by a status/data response.
+ */
+static int mlx90393_i2c_xfer(void *context,
+			     const u8 *tx, int tx_len,
+			     u8 *rx, int rx_len)
+{
+	struct i2c_client *client = context;
+	int ret;
+	struct i2c_msg msgs[2] = {
+		[0] = {
+			.addr = client->addr,
+			.len = tx_len,
+			.buf = (u8 *)tx,
+		},
+		[1] = {
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = rx_len,
+			.buf = rx,
+		},
+	};
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret != ARRAY_SIZE(msgs))
+		return ret < 0 ? ret : -EIO;
+
+	return 0;
+}
+
+static const struct mlx90393_transfer_ops mlx90393_i2c_ops = {
+	.xfer = mlx90393_i2c_xfer,
+};
+
+static int mlx90393_i2c_probe(struct i2c_client *client)
+{
+	return mlx90393_core_probe(&client->dev, &mlx90393_i2c_ops, client);
+}
+
+static const struct i2c_device_id mlx90393_id[] = {
+	{ .name = "mlx90393" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mlx90393_id);
+
+static const struct of_device_id mlx90393_of_match[] = {
+	{ .compatible = "melexis,mlx90393" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mlx90393_of_match);
+
+static struct i2c_driver mlx90393_i2c_driver = {
+	.driver = {
+		.name = "mlx90393",
+		.of_match_table = mlx90393_of_match,
+	},
+	.probe = mlx90393_i2c_probe,
+	.id_table = mlx90393_id,
+};
+
+module_i2c_driver(mlx90393_i2c_driver);
+
+MODULE_IMPORT_NS("IIO_MLX90393");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nikhil Gautam <[email protected]>");
+MODULE_DESCRIPTION("MLX90393 magnetometer sensor driver");

Add Industrial I/O subsystem support for the Melexis MLX90393 3-axis magnetometer and temperature sensor.

The driver currently supports:

raw magnetic field measurements
raw temperature measurements
configurable gain/scale selection
configurable oversampling ratio
direct mode operation

The MLX90393 supports both I2C and SPI interfaces. This initial implementation adds support for the I2C interface.

The device uses a command-based communication protocol rather than a conventional register-addressed interface. A small transport abstraction layer is therefore used instead of regmap to share the common sensor logic between the current I2C implementation and future SPI support without duplicating code.

Signed-off-by Nikhil Gautam <[email protected]>

drivers/iio/magnetometer/mlx90393_core.c new file +6 -0

new file mode 100644
index 000000000000..78fcab8a2b56
 
+static const int mlx90393_scale_table[MLX90393_AXIS_MAX][MLX90393_GAIN_MAX]
+				      [MLX90393_RES_MAX] = {
+	/* XY axis */
+	{
+		{ 751, 1502, 3004, 6009},
+		{ 601, 1202, 2403, 4840},

drivers/iio/magnetometer/mlx90393_core.c new file +28 -0

+		{ 968, 1936, 3872, 7744},
+		{ 726, 1452, 2904, 5808},
+		{ 605, 1210, 2420, 4840},
+		{ 484, 968, 1936, 3872},
+		{ 403, 807, 1613, 3227},
+		{ 323, 645, 1291, 2581},
+		{ 242, 484, 968, 1936},
+	}
+};
+
+static const int mlx90393_osr2_avail[MLX90393_OSR2_MAX] = {
+	0, 1, 2, 3,
+};
 
+static int mlx90393_read_raw(struct iio_dev *indio_dev,
+			     const struct iio_chan_spec *chan,
+			     int *val, int *val2, long mask)
+{
+	struct mlx90393_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		guard(mutex)(&data->lock);
+		ret = mlx90393_read_measurement(data, chan->address, val);
+		if (ret)
+			return ret;
+
+		return IIO_VAL_INT;

drivers/iio/magnetometer/mlx90393_core.c new file +18 -0

+		 */
+
+		*val = -45114;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return mlx90393_get_temp_osr2(data, val);
+		case IIO_MAGN:
+			return mlx90393_get_osr(data, val);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}

drivers/iio/magnetometer/mlx90393_i2c.c new file +0 -0

new file mode 100644
index 000000000000..a9f0a40d15e8

drivers/iio/magnetometer/mlx90393_i2c.c new file +6 -0

+module_i2c_driver(mlx90393_i2c_driver);
+
+MODULE_IMPORT_NS("IIO_MLX90393");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nikhil Gautam <[email protected]>");
+MODULE_DESCRIPTION("MLX90393 magnetometer sensor driver");

Hi,

This series adds initial Industrial I/O subsystem support for the Melexis MLX90393 3-axis magnetometer and temperature sensor.

The MLX90393 supports both I2C and SPI interfaces. This series implements support for the I2C interface while keeping the driver structure transport-independent to simplify future SPI support.

The device uses a command-based communication protocol rather than a conventional register-addressed interface. A small transport abstraction layer is therefore used instead of regmap to share the common sensor logic between the current I2C implementation and future SPI support.

Currently supported features:

* Raw magnetic field measurements for X/Y/Z axes
* Raw temperature measurements
* Configurable gain/scale selection
* Configurable oversampling ratio
* Direct mode operation through the IIO subsystem
* I2C interface support

The driver has been tested on Raspberry Pi 5 hardware using an MLX90393 sensor connected over I2C. Magnetic field and temperature measurements were verified through the IIO sysfs interface.

v3: https://lore.kernel.org/linux-iio/[email protected]/T/#u
v2: https://lore.kernel.org/linux-iio/[email protected]/T/#t
v1: https://lore.kernel.org/linux-iio/[email protected]/