7 files changed, 541 insertions, 91 deletions

diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index 05a364c543f8..b2dba9e506ab 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -17,6 +17,16 @@ config AK8975
 	  To compile this driver as a module, choose M here: the module
 	  will be called ak8975.
 
+config AK09911
+	tristate "Asahi Kasei AK09911 3-axis Compass"
+	depends on I2C
+	help
+	  Say yes here to build support for Asahi Kasei AK09911 3-Axis
+	  Magnetometer.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called ak09911.
+
 config MAG3110
 	tristate "Freescale MAG3110 3-Axis Magnetometer"
 	depends on I2C
diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
index 0f5d3c985799..b91315e0b826 100644
--- a/drivers/iio/magnetometer/Makefile
+++ b/drivers/iio/magnetometer/Makefile
@@ -3,6 +3,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AK09911)	+= ak09911.o
 obj-$(CONFIG_AK8975)	+= ak8975.o
 obj-$(CONFIG_MAG3110)	+= mag3110.o
 obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
diff --git a/drivers/iio/magnetometer/ak09911.c b/drivers/iio/magnetometer/ak09911.c
new file mode 100644
index 000000000000..b2bc942ff6b8
--- /dev/null
+++ b/drivers/iio/magnetometer/ak09911.c
@@ -0,0 +1,326 @@
+/*
+ * AK09911 3-axis compass driver
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/iio/iio.h>
+
+#define AK09911_REG_WIA1		0x00
+#define AK09911_REG_WIA2		0x01
+#define AK09911_WIA1_VALUE		0x48
+#define AK09911_WIA2_VALUE		0x05
+
+#define AK09911_REG_ST1			0x10
+#define AK09911_REG_HXL			0x11
+#define AK09911_REG_HXH			0x12
+#define AK09911_REG_HYL			0x13
+#define AK09911_REG_HYH			0x14
+#define AK09911_REG_HZL			0x15
+#define AK09911_REG_HZH			0x16
+
+#define AK09911_REG_ASAX		0x60
+#define AK09911_REG_ASAY		0x61
+#define AK09911_REG_ASAZ		0x62
+
+#define AK09911_REG_CNTL1		0x30
+#define AK09911_REG_CNTL2		0x31
+#define AK09911_REG_CNTL3		0x32
+
+#define AK09911_MODE_SNG_MEASURE	0x01
+#define AK09911_MODE_SELF_TEST		0x10
+#define AK09911_MODE_FUSE_ACCESS	0x1F
+#define AK09911_MODE_POWERDOWN		0x00
+#define AK09911_RESET_DATA		0x01
+
+#define AK09911_REG_CNTL1		0x30
+#define AK09911_REG_CNTL2		0x31
+#define AK09911_REG_CNTL3		0x32
+
+#define AK09911_RAW_TO_GAUSS(asa)	((((asa) + 128) * 6000) / 256)
+
+#define AK09911_MAX_CONVERSION_TIMEOUT_MS	500
+#define AK09911_CONVERSION_DONE_POLL_TIME_MS	10
+
+struct ak09911_data {
+	struct i2c_client	*client;
+	struct mutex		lock;
+	u8			asa[3];
+	long			raw_to_gauss[3];
+};
+
+static const int ak09911_index_to_reg[] = {
+	AK09911_REG_HXL, AK09911_REG_HYL, AK09911_REG_HZL,
+};
+
+static int ak09911_set_mode(struct i2c_client *client, u8 mode)
+{
+	int ret;
+
+	switch (mode) {
+	case AK09911_MODE_SNG_MEASURE:
+	case AK09911_MODE_SELF_TEST:
+	case AK09911_MODE_FUSE_ACCESS:
+	case AK09911_MODE_POWERDOWN:
+		ret = i2c_smbus_write_byte_data(client,
+						AK09911_REG_CNTL2, mode);
+		if (ret < 0) {
+			dev_err(&client->dev, "set_mode error\n");
+			return ret;
+		}
+		/* After mode change wait atleast 100us */
+		usleep_range(100, 500);
+		break;
+	default:
+		dev_err(&client->dev,
+			"%s: Unknown mode(%d).", __func__, mode);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/* Get Sensitivity Adjustment value */
+static int ak09911_get_asa(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ak09911_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = ak09911_set_mode(client, AK09911_MODE_FUSE_ACCESS);
+	if (ret < 0)
+		return ret;
+
+	/* Get asa data and store in the device data. */
+	ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_ASAX,
+					    3, data->asa);
+	if (ret < 0) {
+		dev_err(&client->dev, "Not able to read asa data\n");
+		return ret;
+	}
+
+	ret = ak09911_set_mode(client,  AK09911_MODE_POWERDOWN);
+	if (ret < 0)
+		return ret;
+
+	data->raw_to_gauss[0] = AK09911_RAW_TO_GAUSS(data->asa[0]);
+	data->raw_to_gauss[1] = AK09911_RAW_TO_GAUSS(data->asa[1]);
+	data->raw_to_gauss[2] = AK09911_RAW_TO_GAUSS(data->asa[2]);
+
+	return 0;
+}
+
+static int ak09911_verify_chip_id(struct i2c_client *client)
+{
+	u8 wia_val[2];
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_WIA1,
+					    2, wia_val);
+	if (ret < 0) {
+		dev_err(&client->dev, "Error reading WIA\n");
+		return ret;
+	}
+
+	dev_dbg(&client->dev, "WIA %02x %02x\n", wia_val[0], wia_val[1]);
+
+	if (wia_val[0] != AK09911_WIA1_VALUE ||
+		wia_val[1] != AK09911_WIA2_VALUE) {
+		dev_err(&client->dev, "Device ak09911 not found\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int wait_conversion_complete_polled(struct ak09911_data *data)
+{
+	struct i2c_client *client = data->client;
+	u8 read_status;
+	u32 timeout_ms = AK09911_MAX_CONVERSION_TIMEOUT_MS;
+	int ret;
+
+	/* Wait for the conversion to complete. */
+	while (timeout_ms) {
+		msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME_MS);
+		ret = i2c_smbus_read_byte_data(client, AK09911_REG_ST1);
+		if (ret < 0) {
+			dev_err(&client->dev, "Error in reading ST1\n");
+			return ret;
+		}
+		read_status = ret & 0x01;
+		if (read_status)
+			break;
+		timeout_ms -= AK09911_CONVERSION_DONE_POLL_TIME_MS;
+	}
+	if (!timeout_ms) {
+		dev_err(&client->dev, "Conversion timeout happened\n");
+		return -EIO;
+	}
+
+	return read_status;
+}
+
+static int ak09911_read_axis(struct iio_dev *indio_dev, int index, int *val)
+{
+	struct ak09911_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	int ret;
+
+	mutex_lock(&data->lock);
+
+	ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE);
+	if (ret < 0)
+		goto fn_exit;
+
+	ret = wait_conversion_complete_polled(data);
+	if (ret < 0)
+		goto fn_exit;
+
+	/* Read data */
+	ret = i2c_smbus_read_word_data(client, ak09911_index_to_reg[index]);
+	if (ret < 0) {
+		dev_err(&client->dev, "Read axis data fails\n");
+		goto fn_exit;
+	}
+
+	mutex_unlock(&data->lock);
+
+	/* Clamp to valid range. */
+	*val = sign_extend32(clamp_t(s16, ret, -8192, 8191), 13);
+
+	return IIO_VAL_INT;
+
+fn_exit:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int ak09911_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2,
+			    long mask)
+{
+	struct ak09911_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		return ak09911_read_axis(indio_dev, chan->address, val);
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = data->raw_to_gauss[chan->address];
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	return -EINVAL;
+}
+
+#define AK09911_CHANNEL(axis, index)					\
+	{								\
+		.type = IIO_MAGN,					\
+		.modified = 1,						\
+		.channel2 = IIO_MOD_##axis,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+			     BIT(IIO_CHAN_INFO_SCALE),			\
+		.address = index,					\
+	}
+
+static const struct iio_chan_spec ak09911_channels[] = {
+	AK09911_CHANNEL(X, 0), AK09911_CHANNEL(Y, 1), AK09911_CHANNEL(Z, 2),
+};
+
+static const struct iio_info ak09911_info = {
+	.read_raw = &ak09911_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct acpi_device_id ak_acpi_match[] = {
+	{"AK009911", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
+
+static int ak09911_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct ak09911_data *data;
+	const char *name;
+	int ret;
+
+	ret = ak09911_verify_chip_id(client);
+	if (ret) {
+		dev_err(&client->dev, "AK00911 not detected\n");
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+
+	data->client = client;
+	mutex_init(&data->lock);
+
+	ret = ak09911_get_asa(client);
+	if (ret)
+		return ret;
+
+	if (id)
+		name = id->name;
+	else if (ACPI_HANDLE(&client->dev))
+		name = dev_name(&client->dev);
+	else
+		return -ENODEV;
+
+	dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->channels = ak09911_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ak09911_channels);
+	indio_dev->info = &ak09911_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->name = name;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ak09911_id[] = {
+	{"ak09911", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, ak09911_id);
+
+static struct i2c_driver ak09911_driver = {
+	.driver = {
+		.name	= "ak09911",
+		.acpi_match_table = ACPI_PTR(ak_acpi_match),
+	},
+	.probe		= ak09911_probe,
+	.id_table	= ak09911_id,
+};
+module_i2c_driver(ak09911_driver);
+
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("AK09911 Compass driver");
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index ea08313af0d2..a2357921d761 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -165,7 +165,7 @@ static int ak8975_setup_irq(struct ak8975_data *data)
 	else
 		irq = gpio_to_irq(data->eoc_gpio);
 
-	rc = request_irq(irq, ak8975_irq_handler,
+	rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
 			 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 			 dev_name(&client->dev), data);
 	if (rc < 0) {
@@ -513,21 +513,21 @@ static int ak8975_probe(struct i2c_client *client,
 	/* We may not have a GPIO based IRQ to scan, that is fine, we will
 	   poll if so */
 	if (gpio_is_valid(eoc_gpio)) {
-		err = gpio_request_one(eoc_gpio, GPIOF_IN, "ak_8975");
+		err = devm_gpio_request_one(&client->dev, eoc_gpio,
+							GPIOF_IN, "ak_8975");
 		if (err < 0) {
 			dev_err(&client->dev,
 				"failed to request GPIO %d, error %d\n",
 							eoc_gpio, err);
-			goto exit;
+			return err;
 		}
 	}
 
 	/* Register with IIO */
-	indio_dev = iio_device_alloc(sizeof(*data));
-	if (indio_dev == NULL) {
-		err = -ENOMEM;
-		goto exit_gpio;
-	}
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 
@@ -542,17 +542,16 @@ static int ak8975_probe(struct i2c_client *client,
 		name = (char *) id->name;
 	} else if (ACPI_HANDLE(&client->dev))
 		name = ak8975_match_acpi_device(&client->dev, &data->chipset);
-	else {
-		err = -ENOSYS;
-		goto exit_free_iio;
-	}
+	else
+		return -ENOSYS;
+
 	dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
 
 	/* Perform some basic start-of-day setup of the device. */
 	err = ak8975_setup(client);
 	if (err < 0) {
 		dev_err(&client->dev, "AK8975 initialization fails\n");
-		goto exit_free_iio;
+		return err;
 	}
 
 	data->client = client;
@@ -564,37 +563,9 @@ static int ak8975_probe(struct i2c_client *client,
 	indio_dev->info = &ak8975_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->name = name;
-	err = iio_device_register(indio_dev);
+	err = devm_iio_device_register(&client->dev, indio_dev);
 	if (err < 0)
-		goto exit_free_iio;
-
-	return 0;
-
-exit_free_iio:
-	iio_device_free(indio_dev);
-	if (data->eoc_irq)
-		free_irq(data->eoc_irq, data);
-exit_gpio:
-	if (gpio_is_valid(eoc_gpio))
-		gpio_free(eoc_gpio);
-exit:
-	return err;
-}
-
-static int ak8975_remove(struct i2c_client *client)
-{
-	struct iio_dev *indio_dev = i2c_get_clientdata(client);
-	struct ak8975_data *data = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-
-	if (data->eoc_irq)
-		free_irq(data->eoc_irq, data);
-
-	if (gpio_is_valid(data->eoc_gpio))
-		gpio_free(data->eoc_gpio);
-
-	iio_device_free(indio_dev);
+		return err;
 
 	return 0;
 }
@@ -621,7 +592,6 @@ static struct i2c_driver ak8975_driver = {
 		.acpi_match_table = ACPI_PTR(ak_acpi_match),
 	},
 	.probe		= ak8975_probe,
-	.remove		= ak8975_remove,
 	.id_table	= ak8975_id,
 };
 module_i2c_driver(ak8975_driver);
diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
index b2b0937d5133..3ec777a8f64e 100644
--- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
+++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
@@ -35,6 +35,10 @@ enum magn_3d_channel {
 	CHANNEL_SCAN_INDEX_X,
 	CHANNEL_SCAN_INDEX_Y,
 	CHANNEL_SCAN_INDEX_Z,
+	CHANNEL_SCAN_INDEX_NORTH_MAGN_TILT_COMP,
+	CHANNEL_SCAN_INDEX_NORTH_TRUE_TILT_COMP,
+	CHANNEL_SCAN_INDEX_NORTH_MAGN,
+	CHANNEL_SCAN_INDEX_NORTH_TRUE,
 	MAGN_3D_CHANNEL_MAX,
 };
 
@@ -42,7 +46,12 @@ struct magn_3d_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info magn[MAGN_3D_CHANNEL_MAX];
-	u32 magn_val[MAGN_3D_CHANNEL_MAX];
+
+	/* dynamically sized array to hold sensor values */
+	u32 *iio_vals;
+	/* array of pointers to sensor value */
+	u32 *magn_val_addr[MAGN_3D_CHANNEL_MAX];
+
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
@@ -52,7 +61,11 @@ struct magn_3d_state {
 static const u32 magn_3d_addresses[MAGN_3D_CHANNEL_MAX] = {
 	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS,
 	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS,
-	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS
+	HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS,
+	HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH,
+	HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH,
+	HID_USAGE_SENSOR_ORIENT_MAGN_NORTH,
+	HID_USAGE_SENSOR_ORIENT_TRUE_NORTH,
 };
 
 /* Channel definitions */
@@ -66,7 +79,6 @@ static const struct iio_chan_spec magn_3d_channels[] = {
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_X,
 	}, {
 		.type = IIO_MAGN,
 		.modified = 1,
@@ -76,7 +88,6 @@ static const struct iio_chan_spec magn_3d_channels[] = {
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_Y,
 	}, {
 		.type = IIO_MAGN,
 		.modified = 1,
@@ -86,7 +97,42 @@ static const struct iio_chan_spec magn_3d_channels[] = {
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
-		.scan_index = CHANNEL_SCAN_INDEX_Z,
+	}, {
+		.type = IIO_ROT,
+		.modified = 1,
+		.channel2 = IIO_MOD_NORTH_MAGN_TILT_COMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS),
+	}, {
+		.type = IIO_ROT,
+		.modified = 1,
+		.channel2 = IIO_MOD_NORTH_TRUE_TILT_COMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS),
+	}, {
+		.type = IIO_ROT,
+		.modified = 1,
+		.channel2 = IIO_MOD_NORTH_MAGN,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS),
+	}, {
+		.type = IIO_ROT,
+		.modified = 1,
+		.channel2 = IIO_MOD_NORTH_TRUE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS),
 	}
 };
 
@@ -126,8 +172,8 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
 		msleep_interruptible(poll_value * 2);
 
 		report_id =
-			magn_state->magn[chan->scan_index].report_id;
-		address = magn_3d_addresses[chan->scan_index];
+			magn_state->magn[chan->address].report_id;
+		address = magn_3d_addresses[chan->address];
 		if (report_id >= 0)
 			*val = sensor_hub_input_attr_get_raw_value(
 				magn_state->common_attributes.hsdev,
@@ -218,8 +264,8 @@ static int magn_3d_proc_event(struct hid_sensor_hub_device *hsdev,
 	dev_dbg(&indio_dev->dev, "magn_3d_proc_event\n");
 	if (atomic_read(&magn_state->common_attributes.data_ready))
 		hid_sensor_push_data(indio_dev,
-				magn_state->magn_val,
-				sizeof(magn_state->magn_val));
+				magn_state->iio_vals,
+				sizeof(magn_state->iio_vals));
 
 	return 0;
 }
@@ -233,52 +279,126 @@ static int magn_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
 	struct magn_3d_state *magn_state = iio_priv(indio_dev);
 	int offset;
-	int ret = -EINVAL;
+	int ret = 0;
+	u32 *iio_val = NULL;
 
 	switch (usage_id) {
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS:
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Y_AXIS:
 	case HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_Z_AXIS:
-		offset = usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS;
-		magn_state->magn_val[CHANNEL_SCAN_INDEX_X + offset] =
-						*(u32 *)raw_data;
-		ret = 0;
+		offset = (usage_id - HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS)
+				+ CHANNEL_SCAN_INDEX_X;
+	break;
+	case HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH:
+	case HID_USAGE_SENSOR_ORIENT_COMP_TRUE_NORTH:
+	case HID_USAGE_SENSOR_ORIENT_MAGN_NORTH:
+	case HID_USAGE_SENSOR_ORIENT_TRUE_NORTH:
+		offset = (usage_id - HID_USAGE_SENSOR_ORIENT_COMP_MAGN_NORTH)
+				+ CHANNEL_SCAN_INDEX_NORTH_MAGN_TILT_COMP;
 	break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
+	iio_val = magn_state->magn_val_addr[offset];
+
+	if (iio_val != NULL)
+		*iio_val = *((u32 *)raw_data);
+	else
+		ret = -EINVAL;
+
 	return ret;
 }
 
 /* Parse report which is specific to an usage id*/
 static int magn_3d_parse_report(struct platform_device *pdev,
 				struct hid_sensor_hub_device *hsdev,
-				struct iio_chan_spec *channels,
+				struct iio_chan_spec **channels,
+				int *chan_count,
 				unsigned usage_id,
 				struct magn_3d_state *st)
 {
-	int ret;
 	int i;
+	int attr_count = 0;
+	struct iio_chan_spec *_channels;
+
+	/* Scan for each usage attribute supported */
+	for (i = 0; i < MAGN_3D_CHANNEL_MAX; i++) {
+		int status;
+		u32 address = magn_3d_addresses[i];
+
+		/* Check if usage attribute exists in the sensor hub device */
+		status = sensor_hub_input_get_attribute_info(hsdev,
+			HID_INPUT_REPORT,
+			usage_id,
+			address,
+			&(st->magn[i]));
+		if (!status)
+			attr_count++;
+	}
 
-	for (i = 0; i <= CHANNEL_SCAN_INDEX_Z; ++i) {
-		ret = sensor_hub_input_get_attribute_info(hsdev,
-				HID_INPUT_REPORT,
-				usage_id,
-				HID_USAGE_SENSOR_ORIENT_MAGN_FLUX_X_AXIS + i,
-				&st->magn[CHANNEL_SCAN_INDEX_X + i]);
-		if (ret < 0)
-			break;
-		magn_3d_adjust_channel_bit_mask(channels,
-				CHANNEL_SCAN_INDEX_X + i,
-				st->magn[CHANNEL_SCAN_INDEX_X + i].size);
+	if (attr_count <= 0) {
+		dev_err(&pdev->dev,
+			"failed to find any supported usage attributes in report\n");
+		return  -EINVAL;
 	}
-	dev_dbg(&pdev->dev, "magn_3d %x:%x, %x:%x, %x:%x\n",
+
+	dev_dbg(&pdev->dev, "magn_3d Found %d usage attributes\n",
+			attr_count);
+	dev_dbg(&pdev->dev, "magn_3d X: %x:%x Y: %x:%x Z: %x:%x\n",
 			st->magn[0].index,
 			st->magn[0].report_id,
 			st->magn[1].index, st->magn[1].report_id,
 			st->magn[2].index, st->magn[2].report_id);
 
+	/* Setup IIO channel array */
+	_channels = devm_kcalloc(&pdev->dev, attr_count,
+				sizeof(struct iio_chan_spec),
+				GFP_KERNEL);
+	if (!_channels) {
+		dev_err(&pdev->dev,
+			"failed to allocate space for iio channels\n");
+		return -ENOMEM;
+	}
+
+	st->iio_vals = devm_kcalloc(&pdev->dev, attr_count,
+				sizeof(u32),
+				GFP_KERNEL);
+	if (!st->iio_vals) {
+		dev_err(&pdev->dev,
+			"failed to allocate space for iio values array\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0, *chan_count = 0;
+	i < MAGN_3D_CHANNEL_MAX && *chan_count < attr_count;
+	i++){
+		if (st->magn[i].index >= 0) {
+			/* Setup IIO channel struct */
+			(_channels[*chan_count]) = magn_3d_channels[i];
+			(_channels[*chan_count]).scan_index = *chan_count;
+			(_channels[*chan_count]).address = i;
+
+			/* Set magn_val_addr to iio value address */
+			st->magn_val_addr[i] = &(st->iio_vals[*chan_count]);
+			magn_3d_adjust_channel_bit_mask(_channels,
+							*chan_count,
+							st->magn[i].size);
+			(*chan_count)++;
+		}
+	}
+
+	if (*chan_count <= 0) {
+		dev_err(&pdev->dev,
+			"failed to find any magnetic channels setup\n");
+		return -EINVAL;
+	}
+
+	*channels = _channels;
+
+	dev_dbg(&pdev->dev, "magn_3d Setup %d IIO channels\n",
+			*chan_count);
+
 	st->scale_precision = hid_sensor_format_scale(
 				HID_USAGE_SENSOR_COMPASS_3D,
 				&st->magn[CHANNEL_SCAN_INDEX_X],
@@ -296,7 +416,7 @@ static int magn_3d_parse_report(struct platform_device *pdev,
 			st->common_attributes.sensitivity.report_id);
 	}
 
-	return ret;
+	return 0;
 }
 
 /* Function to initialize the processing for usage id */
@@ -308,6 +428,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
 	struct magn_3d_state *magn_state;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 	struct iio_chan_spec *channels;
+	int chan_count = 0;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev,
 					  sizeof(struct magn_3d_state));
@@ -328,22 +449,16 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	channels = kmemdup(magn_3d_channels, sizeof(magn_3d_channels),
-			   GFP_KERNEL);
-	if (!channels) {
-		dev_err(&pdev->dev, "failed to duplicate channels\n");
-		return -ENOMEM;
-	}
-
-	ret = magn_3d_parse_report(pdev, hsdev, channels,
+	ret = magn_3d_parse_report(pdev, hsdev,
+				&channels, &chan_count,
 				HID_USAGE_SENSOR_COMPASS_3D, magn_state);
 	if (ret) {
-		dev_err(&pdev->dev, "failed to setup attributes\n");
-		goto error_free_dev_mem;
+		dev_err(&pdev->dev, "failed to parse report\n");
+		return ret;
 	}
 
 	indio_dev->channels = channels;
-	indio_dev->num_channels = ARRAY_SIZE(magn_3d_channels);
+	indio_dev->num_channels = chan_count;
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &magn_3d_info;
 	indio_dev->name = name;
@@ -353,7 +468,7 @@ static int hid_magn_3d_probe(struct platform_device *pdev)
 		NULL, NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
-		goto error_free_dev_mem;
+		return ret;
 	}
 	atomic_set(&magn_state->common_attributes.data_ready, 0);
 	ret = hid_sensor_setup_trigger(indio_dev, name,
@@ -387,8 +502,6 @@ error_remove_trigger:
 	hid_sensor_remove_trigger(&magn_state->common_attributes);
 error_unreg_buffer_funcs:
 	iio_triggered_buffer_cleanup(indio_dev);
-error_free_dev_mem:
-	kfree(indio_dev->channels);
 	return ret;
 }
 
@@ -403,7 +516,6 @@ static int hid_magn_3d_remove(struct platform_device *pdev)
 	iio_device_unregister(indio_dev);
 	hid_sensor_remove_trigger(&magn_state->common_attributes);
 	iio_triggered_buffer_cleanup(indio_dev);
-	kfree(indio_dev->channels);
 
 	return 0;
 }
diff --git a/drivers/iio/magnetometer/st_magn_core.c b/drivers/iio/magnetometer/st_magn_core.c
index 240a21dd0c61..a4b64130ac2f 100644
--- a/drivers/iio/magnetometer/st_magn_core.c
+++ b/drivers/iio/magnetometer/st_magn_core.c
@@ -299,6 +299,9 @@ static int st_magn_read_raw(struct iio_dev *indio_dev,
 		else
 			*val2 = mdata->current_fullscale->gain;
 		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = mdata->odr;
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
@@ -316,6 +319,13 @@ static int st_magn_write_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		err = st_sensors_set_fullscale_by_gain(indio_dev, val2);
 		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val2)
+			return -EINVAL;
+		mutex_lock(&indio_dev->mlock);
+		err = st_sensors_set_odr(indio_dev, val);
+		mutex_unlock(&indio_dev->mlock);
+		return err;
 	default:
 		err = -EINVAL;
 	}
@@ -323,14 +333,12 @@ static int st_magn_write_raw(struct iio_dev *indio_dev,
 	return err;
 }
 
-static ST_SENSOR_DEV_ATTR_SAMP_FREQ();
 static ST_SENSORS_DEV_ATTR_SAMP_FREQ_AVAIL();
 static ST_SENSORS_DEV_ATTR_SCALE_AVAIL(in_magn_scale_available);
 
 static struct attribute *st_magn_attributes[] = {
 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
 	&iio_dev_attr_in_magn_scale_available.dev_attr.attr,
-	&iio_dev_attr_sampling_frequency.dev_attr.attr,
 	NULL,
 };
 
diff --git a/drivers/iio/magnetometer/st_magn_i2c.c b/drivers/iio/magnetometer/st_magn_i2c.c
index 892e0feeb5c1..689250058442 100644
--- a/drivers/iio/magnetometer/st_magn_i2c.c
+++ b/drivers/iio/magnetometer/st_magn_i2c.c
@@ -18,6 +18,27 @@
 #include <linux/iio/common/st_sensors_i2c.h>
 #include "st_magn.h"
 
+#ifdef CONFIG_OF
+static const struct of_device_id st_magn_of_match[] = {
+	{
+		.compatible = "st,lsm303dlhc-magn",
+		.data = LSM303DLHC_MAGN_DEV_NAME,
+	},
+	{
+		.compatible = "st,lsm303dlm-magn",
+		.data = LSM303DLM_MAGN_DEV_NAME,
+	},
+	{
+		.compatible = "st,lis3mdl-magn",
+		.data = LIS3MDL_MAGN_DEV_NAME,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_magn_of_match);
+#else
+#define st_magn_of_match NULL
+#endif
+
 static int st_magn_i2c_probe(struct i2c_client *client,
 						const struct i2c_device_id *id)
 {
@@ -31,6 +52,7 @@ static int st_magn_i2c_probe(struct i2c_client *client,
 
 	mdata = iio_priv(indio_dev);
 	mdata->dev = &client->dev;
+	st_sensors_of_i2c_probe(client, st_magn_of_match);
 
 	st_sensors_i2c_configure(indio_dev, client, mdata);
 
@@ -61,6 +83,7 @@ static struct i2c_driver st_magn_driver = {
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = "st-magn-i2c",
+		.of_match_table = of_match_ptr(st_magn_of_match),
 	},
 	.probe = st_magn_i2c_probe,
 	.remove = st_magn_i2c_remove,