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Commit 20ffac27 authored by Daniel Baluta's avatar Daniel Baluta Committed by Jonathan Cameron
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iio: imu: Add support for Kionix KMX61 sensor 

Minimal implementation for KMX61 6-axis accelerometer/magnetometer. It exports
raw accel/magn readings together with scale and sampling frequency.

This driver uses two IIO devices one for accelerometer and one for magnetometer.

Datasheet will be available at:
http://www.kionix.com/6-axis-accelerometer-magnetometer/kmx61



Signed-off-by: default avatarDaniel Baluta <daniel.baluta@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 3909a071

drivers/iio/imu/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -25,6 +25,15 @@ config ADIS16480 
	  Say yes here to build support for Analog Devices ADIS16375, ADIS16480,

	  ADIS16485, ADIS16488 inertial sensors.



config KMX61

	tristate "Kionix KMX61 6-axis accelerometer and magnetometer"

	depends on I2C

	help

	  Say Y here if you want to build a driver for Kionix KMX61 6-axis

	  accelerometer and magnetometer.

	  To compile this driver as module, choose M here: the module will

	  be called kmx61.



source "drivers/iio/imu/inv_mpu6050/Kconfig"



endmenu

drivers/iio/imu/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -14,3 +14,5 @@ adis_lib-$(CONFIG_IIO_ADIS_LIB_BUFFER) += adis_buffer.o 
obj-$(CONFIG_IIO_ADIS_LIB) += adis_lib.o



obj-y += inv_mpu6050/



obj-$(CONFIG_KMX61) += kmx61.o

drivers/iio/imu/kmx61.c

0 → 100644
+691 −0
Original line number Diff line number Diff line 
/*

 * KMX61 - Kionix 6-axis Accelerometer/Magnetometer

 *

 * Copyright (c) 2014, Intel Corporation.

 *

 * This file is subject to the terms and conditions of version 2 of

 * the GNU General Public License.  See the file COPYING in the main

 * directory of this archive for more details.

 *

 * IIO driver for KMX61 (7-bit I2C slave address 0x0E or 0x0F).

 *

 */



#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>



#define KMX61_DRV_NAME "kmx61"



#define KMX61_REG_WHO_AM_I	0x00



/*

 * three 16-bit accelerometer output registers for X/Y/Z axis

 * we use only XOUT_L as a base register, all other addresses

 * can be obtained by applying an offset and are provided here

 * only for clarity.

 */

#define KMX61_ACC_XOUT_L	0x0A

#define KMX61_ACC_XOUT_H	0x0B

#define KMX61_ACC_YOUT_L	0x0C

#define KMX61_ACC_YOUT_H	0x0D

#define KMX61_ACC_ZOUT_L	0x0E

#define KMX61_ACC_ZOUT_H	0x0F



/*

 * one 16-bit temperature output register

 */

#define KMX61_TEMP_L		0x10

#define KMX61_TEMP_H		0x11



/*

 * three 16-bit magnetometer output registers for X/Y/Z axis

 */

#define KMX61_MAG_XOUT_L	0x12

#define KMX61_MAG_XOUT_H	0x13

#define KMX61_MAG_YOUT_L	0x14

#define KMX61_MAG_YOUT_H	0x15

#define KMX61_MAG_ZOUT_L	0x16

#define KMX61_MAG_ZOUT_H	0x17



#define KMX61_REG_STBY		0x29

#define KMX61_REG_CTRL1		0x2A

#define KMX61_REG_ODCNTL	0x2C



#define KMX61_ACC_STBY_BIT	BIT(0)

#define KMX61_MAG_STBY_BIT	BIT(1)

#define KMX61_ACT_STBY_BIT	BIT(7)



#define KMX61_ALL_STBY		(KMX61_ACC_STBY_BIT | KMX61_MAG_STBY_BIT)



#define KMX61_REG_CTRL1_GSEL_MASK	0x03



#define KMX61_ACC_ODR_SHIFT	0

#define KMX61_MAG_ODR_SHIFT	4

#define KMX61_ACC_ODR_MASK	0x0F

#define KMX61_MAG_ODR_MASK	0xF0



#define KMX61_CHIP_ID		0x12



/* KMX61 devices */

#define KMX61_ACC	0x01

#define KMX61_MAG	0x02



struct kmx61_data {

	struct i2c_client *client;



	/* serialize access to non-atomic ops, e.g set_mode */

	struct mutex lock;



	/* standby state */

	bool acc_stby;

	bool mag_stby;



	/* config bits */

	u8 range;

	u8 odr_bits;



	/* accelerometer specific data */

	struct iio_dev *acc_indio_dev;



	/* magnetometer specific data */

	struct iio_dev *mag_indio_dev;

};



enum kmx61_range {

	KMX61_RANGE_2G,

	KMX61_RANGE_4G,

	KMX61_RANGE_8G,

};



enum kmx61_axis {

	KMX61_AXIS_X,

	KMX61_AXIS_Y,

	KMX61_AXIS_Z,

};



static const u16 kmx61_uscale_table[] = {9582, 19163, 38326};



static const struct {

	int val;

	int val2;

	u8 odr_bits;

} kmx61_samp_freq_table[] = { {12, 500000, 0x00},

			{25, 0, 0x01},

			{50, 0, 0x02},

			{100, 0, 0x03},

			{200, 0, 0x04},

			{400, 0, 0x05},

			{800, 0, 0x06},

			{1600, 0, 0x07},

			{0, 781000, 0x08},

			{1, 563000, 0x09},

			{3, 125000, 0x0A},

			{6, 250000, 0x0B} };



static IIO_CONST_ATTR(accel_scale_available, "0.009582 0.019163 0.038326");

static IIO_CONST_ATTR(magn_scale_available, "0.001465");

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(

	"0.781000 1.563000 3.125000 6.250000 12.500000 25 50 100 200 400 800");



static struct attribute *kmx61_acc_attributes[] = {

	&iio_const_attr_accel_scale_available.dev_attr.attr,

	&iio_const_attr_sampling_frequency_available.dev_attr.attr,

	NULL,

};



static struct attribute *kmx61_mag_attributes[] = {

	&iio_const_attr_magn_scale_available.dev_attr.attr,

	&iio_const_attr_sampling_frequency_available.dev_attr.attr,

	NULL,

};



static const struct attribute_group kmx61_acc_attribute_group = {

	.attrs = kmx61_acc_attributes,

};



static const struct attribute_group kmx61_mag_attribute_group = {

	.attrs = kmx61_mag_attributes,

};



#define KMX61_ACC_CHAN(_axis) { \

	.type = IIO_ACCEL, \

	.modified = 1, \

	.channel2 = IIO_MOD_ ## _axis, \

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \

				BIT(IIO_CHAN_INFO_SAMP_FREQ), \

	.address = KMX61_ACC, \

	.scan_index = KMX61_AXIS_ ## _axis, \

	.scan_type = { \

		.sign = 's', \

		.realbits = 12, \

		.storagebits = 16, \

		.shift = 4, \

		.endianness = IIO_LE, \

	}, \

}



#define KMX61_MAG_CHAN(_axis) { \

	.type = IIO_MAGN, \

	.modified = 1, \

	.channel2 = IIO_MOD_ ## _axis, \

	.address = KMX61_MAG, \

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \

				BIT(IIO_CHAN_INFO_SAMP_FREQ), \

	.scan_index = KMX61_AXIS_ ## _axis, \

	.scan_type = { \

		.sign = 's', \

		.realbits = 14, \

		.storagebits = 16, \

		.shift = 2, \

		.endianness = IIO_LE, \

	}, \

}



static const struct iio_chan_spec kmx61_acc_channels[] = {

	KMX61_ACC_CHAN(X),

	KMX61_ACC_CHAN(Y),

	KMX61_ACC_CHAN(Z),

};



static const struct iio_chan_spec kmx61_mag_channels[] = {

	KMX61_MAG_CHAN(X),

	KMX61_MAG_CHAN(Y),

	KMX61_MAG_CHAN(Z),

};



static void kmx61_set_data(struct iio_dev *indio_dev, struct kmx61_data *data)

{

	struct kmx61_data **priv = iio_priv(indio_dev);



	*priv = data;

}



static struct kmx61_data *kmx61_get_data(struct iio_dev *indio_dev)

{

	return *(struct kmx61_data **)iio_priv(indio_dev);

}



static int kmx61_convert_freq_to_bit(int val, int val2)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)

		if (val == kmx61_samp_freq_table[i].val &&

		    val2 == kmx61_samp_freq_table[i].val2)

			return kmx61_samp_freq_table[i].odr_bits;

	return -EINVAL;

}



/**

 * kmx61_set_mode() - set KMX61 device operating mode

 * @data - kmx61 device private data pointer

 * @mode - bitmask, indicating operating mode for @device

 * @device - bitmask, indicating device for which @mode needs to be set

 * @update - update stby bits stored in device's private  @data

 *

 * For each sensor (accelerometer/magnetometer) there are two operating modes

 * STANDBY and OPERATION. Neither accel nor magn can be disabled independently

 * if they are both enabled. Internal sensors state is saved in acc_stby and

 * mag_stby members of driver's private @data.

 */

static int kmx61_set_mode(struct kmx61_data *data, u8 mode, u8 device,

			  bool update)

{

	int ret;

	int acc_stby = -1, mag_stby = -1;



	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_STBY);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error reading reg_stby\n");

		return ret;

	}

	if (device & KMX61_ACC) {

		if (mode & KMX61_ACC_STBY_BIT) {

			ret |= KMX61_ACC_STBY_BIT;

			acc_stby = 1;

		} else {

			ret &= ~KMX61_ACC_STBY_BIT;

			acc_stby = 0;

		}

	}



	if (device & KMX61_MAG) {

		if (mode & KMX61_MAG_STBY_BIT) {

			ret |= KMX61_MAG_STBY_BIT;

			mag_stby = 1;

		} else {

			ret &= ~KMX61_MAG_STBY_BIT;

			mag_stby = 0;

		}

	}



	if (mode & KMX61_ACT_STBY_BIT)

		ret |= KMX61_ACT_STBY_BIT;



	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_STBY, ret);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error writing reg_stby\n");

		return ret;

	}



	if (acc_stby != -1 && update)

		data->acc_stby = acc_stby;

	if (mag_stby != -1 && update)

		data->mag_stby = mag_stby;



	return 0;

}



static int kmx61_get_mode(struct kmx61_data *data, u8 *mode, u8 device)

{

	int ret;



	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_STBY);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error reading reg_stby\n");

		return ret;

	}

	*mode = 0;



	if (device & KMX61_ACC) {

		if (ret & KMX61_ACC_STBY_BIT)

			*mode |= KMX61_ACC_STBY_BIT;

		else

			*mode &= ~KMX61_ACC_STBY_BIT;

	}



	if (device & KMX61_MAG) {

		if (ret & KMX61_MAG_STBY_BIT)

			*mode |= KMX61_MAG_STBY_BIT;

		else

			*mode &= ~KMX61_MAG_STBY_BIT;

	}



	return 0;

}



static int kmx61_set_odr(struct kmx61_data *data, int val, int val2, u8 device)

{

	int ret;

	u8 mode;

	int lodr_bits, odr_bits;



	ret = kmx61_get_mode(data, &mode, KMX61_ACC | KMX61_MAG);

	if (ret < 0)

		return ret;



	lodr_bits = kmx61_convert_freq_to_bit(val, val2);

	if (lodr_bits < 0)

		return lodr_bits;



	/* To change ODR, accel and magn must be in STDBY */

	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG,

			     true);

	if (ret < 0)

		return ret;



	odr_bits = 0;

	if (device & KMX61_ACC)

		odr_bits |= lodr_bits << KMX61_ACC_ODR_SHIFT;

	if (device & KMX61_MAG)

		odr_bits |= lodr_bits << KMX61_MAG_ODR_SHIFT;



	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_ODCNTL,

					odr_bits);

	if (ret < 0)

		return ret;



	return kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);

}



static int kmx61_get_odr(struct kmx61_data *data, int *val, int *val2,

			 u8 device)

{	int i;

	u8 lodr_bits;



	if (device & KMX61_ACC)

		lodr_bits = (data->odr_bits >> KMX61_ACC_ODR_SHIFT) &

			     KMX61_ACC_ODR_MASK;

	else if (device & KMX61_MAG)

		lodr_bits = (data->odr_bits >> KMX61_MAG_ODR_SHIFT) &

			     KMX61_MAG_ODR_MASK;

	else

		return -EINVAL;



	for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)

		if (lodr_bits == kmx61_samp_freq_table[i].odr_bits) {

			*val = kmx61_samp_freq_table[i].val;

			*val2 = kmx61_samp_freq_table[i].val2;

			return 0;

		}

	return -EINVAL;

}



static int kmx61_set_range(struct kmx61_data *data, u8 range)

{

	int ret;



	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_CTRL1);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");

		return ret;

	}



	ret &= ~KMX61_REG_CTRL1_GSEL_MASK;

	ret |= range & KMX61_REG_CTRL1_GSEL_MASK;



	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error writing reg_ctrl1\n");

		return ret;

	}



	data->range = range;



	return 0;

}



static int kmx61_set_scale(struct kmx61_data *data, u16 uscale)

{

	int ret, i;

	u8  mode;



	for (i = 0; i < ARRAY_SIZE(kmx61_uscale_table); i++) {

		if (kmx61_uscale_table[i] == uscale) {

			ret = kmx61_get_mode(data, &mode,

					     KMX61_ACC | KMX61_MAG);

			if (ret < 0)

				return ret;



			ret = kmx61_set_mode(data, KMX61_ALL_STBY,

					     KMX61_ACC | KMX61_MAG, true);

			if (ret < 0)

				return ret;



			ret = kmx61_set_range(data, i);

			if (ret < 0)

				return ret;



			return  kmx61_set_mode(data, mode,

					       KMX61_ACC | KMX61_MAG, true);

		}

	}

	return -EINVAL;

}



static int kmx61_chip_init(struct kmx61_data *data)

{

	int ret;



	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_WHO_AM_I);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error reading who_am_i\n");

		return ret;

	}



	if (ret != KMX61_CHIP_ID) {

		dev_err(&data->client->dev,

			"Wrong chip id, got %x expected %x\n",

			 ret, KMX61_CHIP_ID);

		return -EINVAL;

	}



	/* set accel 12bit, 4g range */

	ret = kmx61_set_range(data, KMX61_RANGE_4G);

	if (ret < 0)

		return ret;



	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_ODCNTL);

	if (ret < 0) {

		dev_err(&data->client->dev, "Error reading reg_odcntl\n");

		return ret;

	}

	data->odr_bits = ret;



	/* set acc/magn to OPERATION mode */

	ret = kmx61_set_mode(data, 0, KMX61_ACC | KMX61_MAG, true);

	if (ret < 0)

		return ret;



	return 0;

}



static int kmx61_read_measurement(struct kmx61_data *data, u8 base, u8 offset)

{

	int ret;

	u8 reg = base + offset * 2;



	ret = i2c_smbus_read_word_data(data->client, reg);

	if (ret < 0)

		dev_err(&data->client->dev, "failed to read reg at %x\n", reg);



	return ret;

}



static int kmx61_read_raw(struct iio_dev *indio_dev,

			  struct iio_chan_spec const *chan, int *val,

			  int *val2, long mask)

{

	int ret;

	u8 base_reg;

	struct kmx61_data *data = kmx61_get_data(indio_dev);



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		switch (chan->type) {

		case IIO_ACCEL:

			base_reg = KMX61_ACC_XOUT_L;

			break;

		case IIO_MAGN:

			base_reg = KMX61_MAG_XOUT_L;

			break;

		default:

			return -EINVAL;

		}

		mutex_lock(&data->lock);



		ret = kmx61_read_measurement(data, base_reg, chan->scan_index);

		if (ret < 0) {

			mutex_unlock(&data->lock);

			return ret;

		}

		*val = sign_extend32(ret >> chan->scan_type.shift,

				     chan->scan_type.realbits - 1);



		mutex_unlock(&data->lock);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		switch (chan->type) {

		case IIO_ACCEL:

			*val = 0;

			*val2 = kmx61_uscale_table[data->range];

			return IIO_VAL_INT_PLUS_MICRO;

		case IIO_MAGN:

			/* 14 bits res, 1465 microGauss per magn count */

			*val = 0;

			*val2 = 1465;

			return IIO_VAL_INT_PLUS_MICRO;

		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_SAMP_FREQ:

		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)

			return -EINVAL;



		mutex_lock(&data->lock);

		ret = kmx61_get_odr(data, val, val2, chan->address);

		mutex_unlock(&data->lock);

		if (ret)

			return -EINVAL;

		return IIO_VAL_INT_PLUS_MICRO;

	}

	return -EINVAL;

}



static int kmx61_write_raw(struct iio_dev *indio_dev,

			   struct iio_chan_spec const *chan, int val,

			   int val2, long mask)

{

	int ret;

	struct kmx61_data *data = kmx61_get_data(indio_dev);



	switch (mask) {

	case IIO_CHAN_INFO_SAMP_FREQ:

		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)

			return -EINVAL;



		mutex_lock(&data->lock);

		ret = kmx61_set_odr(data, val, val2, chan->address);

		mutex_unlock(&data->lock);

		return ret;

	case IIO_CHAN_INFO_SCALE:

		switch (chan->type) {

		case IIO_ACCEL:

			if (val != 0)

				return -EINVAL;

			mutex_lock(&data->lock);

			ret = kmx61_set_scale(data, val2);

			mutex_unlock(&data->lock);

			return ret;

		default:

			return -EINVAL;

		}

	default:

		return -EINVAL;

	}

}



static const struct iio_info kmx61_acc_info = {

	.driver_module		= THIS_MODULE,

	.read_raw		= kmx61_read_raw,

	.write_raw		= kmx61_write_raw,

	.attrs			= &kmx61_acc_attribute_group,

};



static const struct iio_info kmx61_mag_info = {

	.driver_module		= THIS_MODULE,

	.read_raw		= kmx61_read_raw,

	.write_raw		= kmx61_write_raw,

	.attrs			= &kmx61_mag_attribute_group,

};



static struct iio_dev *kmx61_indiodev_setup(struct kmx61_data *data,

					    const struct iio_info *info,

					    const struct iio_chan_spec *chan,

					    int num_channels,

					    const char *name)

{

	struct iio_dev *indio_dev;



	indio_dev = devm_iio_device_alloc(&data->client->dev, sizeof(data));

	if (!indio_dev)

		return ERR_PTR(-ENOMEM);



	kmx61_set_data(indio_dev, data);



	indio_dev->dev.parent = &data->client->dev;

	indio_dev->channels = chan;

	indio_dev->num_channels = num_channels;

	indio_dev->name = name;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = info;



	return indio_dev;

}



static int kmx61_probe(struct i2c_client *client,

		       const struct i2c_device_id *id)

{

	int ret;

	struct kmx61_data *data;

	const char *name = NULL;



	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	i2c_set_clientdata(client, data);

	data->client = client;



	mutex_init(&data->lock);



	data->acc_indio_dev =

		kmx61_indiodev_setup(data, &kmx61_acc_info,

				     kmx61_acc_channels,

				     ARRAY_SIZE(kmx61_acc_channels),

				     name);

	if (IS_ERR(data->acc_indio_dev))

		return PTR_ERR(data->acc_indio_dev);



	data->mag_indio_dev =

		kmx61_indiodev_setup(data, &kmx61_mag_info,

				     kmx61_mag_channels,

				     ARRAY_SIZE(kmx61_mag_channels),

				     name);

	if (IS_ERR(data->mag_indio_dev))

		return PTR_ERR(data->mag_indio_dev);



	ret = kmx61_chip_init(data);

	if (ret < 0)

		return ret;



	ret = iio_device_register(data->acc_indio_dev);

	if (ret < 0) {

		dev_err(&client->dev, "Failed to register acc iio device\n");

		goto err_chip_uninit;

	}



	ret = iio_device_register(data->mag_indio_dev);

	if (ret < 0) {

		dev_err(&client->dev, "Failed to register mag iio device\n");

		goto err_iio_unregister;

	}



	return 0;



err_iio_unregister:

	iio_device_unregister(data->acc_indio_dev);

err_chip_uninit:

	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);

	return ret;

}



static int kmx61_remove(struct i2c_client *client)

{

	struct kmx61_data *data = i2c_get_clientdata(client);



	iio_device_unregister(data->acc_indio_dev);

	iio_device_unregister(data->mag_indio_dev);



	mutex_lock(&data->lock);

	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);

	mutex_unlock(&data->lock);



	return 0;

}



static const struct i2c_device_id kmx61_id[] = {

	{"kmx611021", 0},

	{}

};



MODULE_DEVICE_TABLE(i2c, kmx61_id);



static struct i2c_driver kmx61_driver = {

	.driver = {

		.name = KMX61_DRV_NAME,

	},

	.probe		= kmx61_probe,

	.remove		= kmx61_remove,

	.id_table	= kmx61_id,

};



module_i2c_driver(kmx61_driver);



MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");

MODULE_DESCRIPTION("KMX61 accelerometer/magnetometer driver");

MODULE_LICENSE("GPL v2");