iio: magnetometer: add support for Melexis MLX90393

Documentation/devicetree/bindings/iio/magnetometer/melexis,mlx90393.yaml new file +12 -0

+description:
+  Melexis MLX90393 3-axis magnetometer and temperature sensor.
+
+properties:
+  compatible:
+    const: melexis,mlx90393
+
+  reg:
+    maxItems: 1
+
+  vdd-supply: true
+  vddio-supply: true

Documentation/devicetree/bindings/iio/magnetometer/melexis,mlx90393.yaml new file +22 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        magnetometer@c {
+            compatible = "melexis,mlx90393";
+            reg = <0x0c>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <17 IRQ_TYPE_EDGE_RISING>;
+
+            trigger-gpios = <&gpio 18 GPIO_ACTIVE_HIGH>;
+        };
+    };

MAINTAINERS +0 -0

index a92290fffa16..e9ddcd12feb5 100644

MAINTAINERS +0 -0

 M:	Mark Greer <[email protected]>
 L:	[email protected]

Signature · 1 line

2.39.5

drivers/iio/magnetometer/mlx90393_i2c.c new file +5 -0

+};
+MODULE_DEVICE_TABLE(i2c, mlx90393_id);
+
+static const struct of_device_id mlx90393_of_match[] = {
+	{ .compatible = "melexis,mlx90393" },

Hello,

On Thu, Jun 18, 2026 at 09:31:41PM +0530, Nikhil Gautam wrote:
Please make that:

	{ .name = "mlx90393" },

I guess you want

	.id_table = mlx90393_id,

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 driver is structured around a shared sensor core with a small transport abstraction layer to simplify future SPI support without duplicating sensor logic.

drivers/iio/magnetometer/Kconfig +7 -0

+	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 +2 -0

index 9297723a97d8..542c89d38a59 100644
@@ -14,6 +14,8 @@ obj-$(CONFIG_BMC150_MAGN_SPI) += bmc150_magn_spi.o
 
 obj-$(CONFIG_MAG3110)	+= mag3110.o
 obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
+obj-$(CONFIG_MLX90393)		+= mlx90393_core.o
+obj-$(CONFIG_MLX90393)		+= mlx90393_i2c.o
 obj-$(CONFIG_MMC35240)	+= mmc35240.o

+#include <linux/types.h>

+#include <linux/delay.h>

drivers/iio/magnetometer/Makefile +23 -0

+	/* 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},
+		{ 605, 1210, 2420, 4840},
+		{ 484, 968, 1936, 3872},
+		{ 403, 807, 1613, 3227},
+		{ 323, 645, 1291, 2581},
+		{ 242, 484, 968, 1936},
+	}
+};

+/*
+ * Calculate total conversion time in microseconds.
+ *
+ * Formula derived from datasheet timing equations.

+ */

+

drivers/iio/magnetometer/Makefile +14 -0

+	 */
+	tconvm = 67 + (64 * BIT(osr) * (2 + BIT(df)));
+
+	/*
+	 * Datasheet:
+	 * TCONVT = 67 + 192 * 2^OSR2
+	 */
+	tconvt = 67 + (192 * BIT(osr2));
+	/*
+	 * Total conversion time:
+	 * TSTBY + TACTIVE + m * TCONVM + TCONVT + TCONV_END
+	 */
+	return 220 + 360 + (m * tconvm) + tconvt + 1100;
+}

+}

drivers/iio/magnetometer/Makefile +8 -0

+static int mlx90393_check_status(u8 cmd, u8 status)
+{
+	/* Always validate error bit */
+	if (status & MLX90393_STATUS_ERROR)
+		return -EIO;
+
+	switch (cmd & MLX90393_CMD_MASK) {
+	case MLX90393_CMD_RM:

drivers/iio/magnetometer/Makefile +6 -0

+			return -EIO;
+		return 0;
+	default:
+		return 0;
+	}
+}

+static int mlx90393_write_reg(struct mlx90393_data *data, u8 reg, u16 val)

drivers/iio/magnetometer/Makefile +19 -0

+{
+	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_addr,
+				u16 mask, u16 val)

drivers/iio/magnetometer/Makefile +2 -0

+	return mlx90393_write_reg(data, reg_addr, reg);
+}

drivers/iio/magnetometer/Makefile +2 -0

+	return -EINVAL;
+}

drivers/iio/magnetometer/Makefile +2 -0

+	return IIO_VAL_INT;
+}

drivers/iio/magnetometer/Makefile +24 -0

+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE: {
+		guard(mutex)(&data->lock);
+		ret = mlx90393_set_scale(data, chan, val, val2);
+		return ret;
+	}
+	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;
+	}
+}

drivers/iio/magnetometer/Makefile +35 -0

+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;
+
+		for (unsigned int i = 0; i < MLX90393_GAIN_MAX; i++) {
+			scale_avail[i][0] = 0;
+			scale_avail[i][1] = mlx90393_scale_table[axis][i][res];
+		}
+
+		*vals = &scale_avail[0][0];
+		*type = IIO_VAL_INT_PLUS_NANO;
+		*length = MLX90393_GAIN_MAX * MLX90393_AXIS_MAX;
+		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;

+}

drivers/iio/magnetometer/Makefile +19 -0

+	ret = mlx90393_read_reg(data, MLX90393_REG_CONF1, &reg);
+	if (ret)
+		return ret;
+
+	data->gain_sel = FIELD_GET(MLX90393_CONF1_GAIN_SEL, reg);
+	data->hallconf = FIELD_GET(MLX90393_CONF1_HALLCONF, reg);
+
+	ret = mlx90393_read_reg(data, MLX90393_REG_CONF3, &reg);
+	if (ret)
+		return ret;
+
+	data->res_xy = FIELD_GET(MLX90393_CONF3_RES_X, reg);
+	data->res_z = FIELD_GET(MLX90393_CONF3_RES_Z, reg);
+	data->dig_filt = FIELD_GET(MLX90393_CONF3_DIG_FILT, reg);
+	data->osr = FIELD_GET(MLX90393_CONF3_OSR, reg);
+	data->osr2 = FIELD_GET(MLX90393_CONF3_OSR2, reg);
+
+	return 0;
+}

drivers/iio/magnetometer/Makefile +4 -0

+int mlx90393_core_probe(struct device *dev,
+			const struct mlx90393_transfer_ops *ops,
+			void *context)
+{

drivers/iio/magnetometer/Makefile +7 -0

+	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;

drivers/iio/magnetometer/Makefile +17 -0

+/*
+ * 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] = {

drivers/iio/magnetometer/Makefile +2 -0

+	return 0;
+}

+module_i2c_driver(mlx90393_i2c_driver);

On Thu, Jun 18, 2026 at 09:31:41PM +0530, Nikhil Gautam wrote:

drivers/iio/magnetometer/Kconfig config HID_SENSOR_MAGNETOMETER_3D · line 133

Quoted 3 lines

drivers/iio/magnetometer/Kconfig +3 -0

+config MLX90393
+	tristate "MELEXIS MLX90393 3-axis magnetometer sensor"
+	depends on I2C

Why not a regmap?

drivers/iio/magnetometer/mlx90393.h line 12

Quoted 5 lines

drivers/iio/magnetometer/mlx90393.h new file +4 -0

+#ifndef MLX90393_H
+#define MLX90393_H
 
+#include <linux/bitops.h>
+#include <linux/bits.h>

Not required, it's covered by bitops.h.

Quoted 1 line

+#include <linux/types.h>

...

drivers/iio/magnetometer/mlx90393.h line 42

Quoted 3 lines

drivers/iio/magnetometer/mlx90393.h new file +3 -0

+#define MLX90393_MEASURE_ALL \
+	(MLX90393_MEASURE_TEMP | MLX90393_MEASURE_X | \
+	MLX90393_MEASURE_Y | MLX90393_MEASURE_Z)

Split logically.

#define MLX90393_MEASURE_ALL \
	(MLX90393_MEASURE_TEMP | \
	 MLX90393_MEASURE_X | MLX90393_MEASURE_Y | MLX90393_MEASURE_Z)

Or just a (long) single line.

drivers/iio/magnetometer/mlx90393.h line 67

Quoted 2 lines

drivers/iio/magnetometer/mlx90393.h new file +2 -0

+	int (*xfer)(void *context, const u8 *tx, int tx_len,
+		    u8 *rx, int rx_len);

One line, it's only 81 characters.

drivers/iio/magnetometer/mlx90393.h line 70

Quoted 3 lines

drivers/iio/magnetometer/mlx90393.h new file +3 -0

+};
+
+int mlx90393_core_probe(struct device *dev,

You want forward declaration for struct device.

+ array_size.h
+ bitfield.h // FIELD_GET()

Quoted 1 line

+#include <linux/delay.h>

+ errno.h // -Exxx

drivers/iio/magnetometer/mlx90393_core.c line 10

Quoted 2 lines

drivers/iio/magnetometer/mlx90393_core.c new file +2 -0

+#include <linux/module.h>
+#include <linux/mutex.h>

+ types.h // uXX

drivers/iio/magnetometer/mlx90393_core.c line 12

Quoted 2 lines

drivers/iio/magnetometer/mlx90393_core.c new file +2 -0

+#include <linux/unaligned.h>
+#include <linux/units.h>

IWYU, please (just pointed out a few missing above, there are more).

drivers/iio/magnetometer/mlx90393_core.c line 50

Quoted 4 lines

drivers/iio/magnetometer/mlx90393_core.c new file +4 -0

+/* Datasheet: Table no.17 */
+static const int mlx90393_scale_table[MLX90393_AXIS_MAX]
+				[MLX90393_GAIN_MAX]
+				[MLX90393_RES_MAX] = {

This is broken indentation.

Quoted 4 lines

+/*
+ * Calculate total conversion time in microseconds.
+ *
+ * Formula derived from datasheet timing equations.

Which formula? Where is datasheet? What if I have no access to it? Always repeat the important details in the comment in the code.

Quoted 2 lines

+ */
+

Unneeded blank line.

Quoted 6 lines

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

+static int mlx90393_get_tconv_us(struct mlx90393_data *data)
+{
+	const int osr = data->osr;
+	const int osr2 = data->osr2;
+	const int df = data->dig_filt;
+

drivers/iio/magnetometer/mlx90393_core.c line 132

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+	int tconvm;
+	int tconvt;
+
+	int m = 3; /* X,Y,Z */
+
+	/*
+	 * Datasheet:

What chapter/section/table name? Page number?

drivers/iio/magnetometer/mlx90393_core.c line 133

Quoted 1 line

drivers/iio/magnetometer/mlx90393_core.c new file +1 -0

+	 * TCONVM = 67 + 64 * 2^OSR * (2 + 2^DIG_FILT)

What does this cryptic message mean? Please, accompany this with more English plain text.

drivers/iio/magnetometer/mlx90393_core.c line 155

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -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);

It's perfectly one line.

Also you might want to have

	if (!...->xfer)
		return -E...;

Quoted 1 line

+}

Quoted 11 lines

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

+static int mlx90393_check_status(u8 cmd, u8 status)
+{
+	/* Always validate error bit */
+	if (status & MLX90393_STATUS_ERROR)
+		return -EIO;
+
+	switch (cmd & MLX90393_CMD_MASK) {
+	case MLX90393_CMD_RM:
+		/*
+		 * D1:D0 indicates response availability
+		 * 00 means invalid/no measurement

drivers/iio/magnetometer/mlx90393_core.c line 175

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+		 */
+		if ((status & MLX90393_STATUS_RESP) == 0)
+			return -EIO;
+		return 0;
+	case MLX90393_CMD_RT:
+		/* Reset acknowledge */
+		if (!(status & MLX90393_STATUS_RT))

For sake of consistency you might want to also compare to 0 here.

Quoted 1 line

+static int mlx90393_write_reg(struct mlx90393_data *data, u8 reg, u16 val)

Here the variable is named 'reg' there is 'reg_addr'. As I can see the code is full of inconsistencies (like 2+ people with different style guidelines wrote it). Please. take your time and check the code and make it consistent.

Quoted 27 lines

drivers/iio/magnetometer/mlx90393_core.c new file +26 -0

+{
+	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_addr,
+				u16 mask, u16 val)
+{
+	u16 reg;
+	int ret;
+
+	ret = mlx90393_read_reg(data, reg_addr, &reg);
+	if (ret)
+		return ret;

drivers/iio/magnetometer/mlx90393_core.c line 259

Quoted 2 lines

drivers/iio/magnetometer/mlx90393_core.c new file +2 -0

+	reg &= ~mask;
+	reg |= (val << __ffs(mask)) & mask;

bitfield.h has macros for this.

drivers/iio/magnetometer/mlx90393_core.c line 399

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+static int mlx90393_find_osr(int val, int *osr)
+{
+	for (unsigned int i = 0; i < MLX90393_OSR_MAX;  i++)
+		if (mlx90393_osr_avail[i] == val) {
+			*osr = i;
+			return 0;
+		}

Missing {}.

drivers/iio/magnetometer/mlx90393_core.c line 406

Quoted 3 lines

drivers/iio/magnetometer/mlx90393_core.c new file +3 -0

+static int mlx90393_get_temp_osr2(struct mlx90393_data *data, int *val)
+{
+	*val = mlx90393_osr2_avail[data->osr2];

Missing blank line.

drivers/iio/magnetometer/mlx90393_core.c line 473

Quoted 7 lines

int mlx90393_write_raw(struct iio_dev *indio_dev,

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

+			      const struct iio_chan_spec *chan,
+			      int val, int val2,
+			      long mask)
+{
+	struct mlx90393_data *data = iio_priv(indio_dev);
+	int ret;

Not needed, return directly.

drivers/iio/magnetometer/mlx90393_core.c line 534

Quoted 2 lines

drivers/iio/magnetometer/mlx90393_core.c new file +2 -0

+			/* Datasheet: 22124 millidegC/LSB */
+		/* Datasheet: temperature offset */

Again, at least put a page, better to have Section/Table/et cetera title.

drivers/iio/magnetometer/mlx90393_core.c new file +9 -0

+			*vals = mlx90393_osr_avail;
+			*type = IIO_VAL_INT;
+			*length = MLX90393_OSR_MAX;
+		}
+		return IIO_AVAIL_LIST;
+
+	default:
+		return -EINVAL;
+	}

Review

Quoted 1 line

(quoted diff) +1 -0

+	return -EINVAL;

Besides missing blank line, this is actually a dead code.

Quoted 4 lines

drivers/iio/magnetometer/mlx90393_core.c new file +4 -0

+static int mlx90393_init(struct mlx90393_data *data)
+{
+	int ret;
+	u16 reg;

drivers/iio/magnetometer/mlx90393_core.c line 615

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+
+	/* Exit mode */
+	ret = mlx90393_write_cmd(data, MLX90393_CMD_EX);
+	if (ret)
+		return ret;
+
+	/* Wait for device comes out of reset */

Datasheet? Empirical?

drivers/iio/magnetometer/mlx90393_core.c line 616

Quoted 1 line

drivers/iio/magnetometer/mlx90393_core.c new file +1 -0

+	fsleep(1000);

1 * USEC_PER_MSEC
(will require time.h to be included).

drivers/iio/magnetometer/mlx90393_core.c line 624

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+	/* Reset device */
+	ret = mlx90393_write_cmd(data, MLX90393_CMD_RT);
+	if (ret)
+		return ret;
+
+	/* Wait for device to reset */
+	fsleep(6000);

As per above.

Quoted 9 lines

drivers/iio/magnetometer/mlx90393_core.c new file +9 -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));

drivers/iio/magnetometer/mlx90393_core.c line 659

Quoted 5 lines

drivers/iio/magnetometer/mlx90393_core.c new file +5 -0

+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	devm_mutex_init(dev, &data->lock);

Nonsense. If we don't check the return code of devm_*(), there is a little reason to use it in the first place. But then one should not use devm further. Easy fix: check for returned errors.

Quoted 10 lines

drivers/iio/magnetometer/mlx90393_core.c new file +10 -0

+	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);
+

drivers/iio/magnetometer/mlx90393_core.c line 677

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_core.c new file +7 -0

+	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_GPL(mlx90393_core_probe);

Make it namespaces.

+ array_size.h
+ errno.h

drivers/iio/magnetometer/mlx90393_i2c.c line 4

Quoted 3 lines

drivers/iio/magnetometer/mlx90393_i2c.c new file +3 -0

+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>

...and so on.

Same, follow the IWYU principle.

Quoted 17 lines

drivers/iio/magnetometer/mlx90393_i2c.c new file +17 -0

+/*
+ * 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] = {

drivers/iio/magnetometer/mlx90393_i2c.c line 34

Quoted 10 lines

drivers/iio/magnetometer/mlx90393_i2c.c new file +10 -0

+			.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;

Please, make this to be the regular pattern

	if (ret < 0)
		return ret;
	if (ret != ARRAY_SIZE(msgs))
		return -EIO;

Review

Quoted 2 lines

(quoted diff) +2 -0

+	return 0;
+}

drivers/iio/magnetometer/mlx90393_i2c.c line 66

Quoted 7 lines

drivers/iio/magnetometer/mlx90393_i2c.c new file +7 -0

+static struct i2c_driver mlx90393_i2c_driver = {
+	.driver = {
+		.name = "mlx90393",
+		.of_match_table = mlx90393_of_match,
+	},
+	.probe = mlx90393_i2c_probe,
+};

Remove this blank line.

Quoted 2 lines

+module_i2c_driver(mlx90393_i2c_driver);

Quoted 1 line · Andy Shevchenko

On Thu, Jun 18, 2026 at 09:31:41PM +0530, Nikhil Gautam wrote:

Thank you very much for taking the time to do such a thorough review of this patch series.

Your detailed comments and suggestions are very helpful. I'll address the issues you've pointed out, update the cover letter to better explain the design decisions,
and incorporate the requested coding style and API changes in the next revision.

I appreciate your review and feedback.

Quoted 4 lines

drivers/iio/magnetometer/Kconfig config HID_SENSOR_MAGNETOMETER_3D · line 133

Quoted 3 lines

drivers/iio/magnetometer/Kconfig +3 -0

+config MLX90393
+	tristate "MELEXIS MLX90393 3-axis magnetometer sensor"
+	depends on I2C

Why not a regmap?

The MLX90393 uses both register-based and command-based transactions. Since regmap does not naturally model the command-based interface, using it would require workarounds such as virtual registers or bypass paths.
A custom transport abstraction is therefore simpler and better suited for this device.

I already discussed this on thread, Link :
https://lore.kernel.org/linux-iio/[email protected]/

Quoted 6 lines

drivers/iio/magnetometer/mlx90393_core.c line 399

Quoted 5 lines

drivers/iio/magnetometer/mlx90393_core.c new file +5 -0

+	for (unsigned int i = 0; i < MLX90393_OSR_MAX;  i++)
+		if (mlx90393_osr_avail[i] == val) {
+			*osr = i;
+			return 0;
+		}

Missing {}.

Agreed, removed intentionally as single statement, will add as per guidelines all the places
where needed

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.

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.

Quoted 18 lines · Nikhil Gautam

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.

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

Quoted 3 lines

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.

This doesn't answer to two important questions:
- why do we need a brand new driver?
Can't one of the existing be updated to cover this HW?

- where to find the datasheet? Any Links or other means to get it?