Commit fdadbce0 authored by Oleksandr Kravchenko's avatar Oleksandr Kravchenko Committed by Jonathan Cameron
Browse files

iio: add Bosch BMA180 acceleration sensor driver 

This patch adds IIO driver for Bosch BMA180 triaxial
acceleration sensor.
http://dlnmh9ip6v2uc.cloudfront.net/datasheets/


		Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf

Signed-off-by: default avatarOleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Acked-by: default avatarStephen Warren <swarren@nvidia.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 63fa65d3

Documentation/devicetree/bindings/iio/accel/bma180.txt

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* Bosch BMA180 triaxial acceleration sensor



http://omapworld.com/BMA180_111_1002839.pdf



Required properties:



  - compatible : should be "bosch,bma180"

  - reg : the I2C address of the sensor



Optional properties:



  - interrupt-parent : should be the phandle for the interrupt controller



  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with

		flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING



Example:



bma180@40 {

	compatible = "bosch,bma180";

	reg = <0x40>;

	interrupt-parent = <&gpio6>;

	interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;

};

drivers/iio/accel/Kconfig

+12 −0
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@@ -5,6 +5,18 @@ 


menu "Accelerometers"



config BMA180

	tristate "Bosch BMA180 3-Axis Accelerometer Driver"

	depends on I2C

	select IIO_BUFFER

	select IIO_TRIGGERED_BUFFER

	help

	  Say Y here if you want to build a driver for the Bosch BMA180

	  triaxial acceleration sensor.



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

	  module will be called bma180.



config HID_SENSOR_ACCEL_3D

	depends on HID_SENSOR_HUB

	select IIO_BUFFER

drivers/iio/accel/Makefile

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@@ -3,6 +3,7 @@ 
#



# When adding new entries keep the list in alphabetical order

obj-$(CONFIG_BMA180) += bma180.o

obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o

obj-$(CONFIG_KXSD9)	+= kxsd9.o

drivers/iio/accel/bma180.c

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/*

 * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor

 *

 * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>

 *

 * 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.

 */



#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/delay.h>

#include <linux/of.h>

#include <linux/bitops.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/buffer.h>

#include <linux/iio/trigger.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>



#define BMA180_DRV_NAME "bma180"

#define BMA180_IRQ_NAME "bma180_event"



/* Register set */

#define BMA180_CHIP_ID		0x00 /* Need to distinguish BMA180 from other */

#define BMA180_ACC_X_LSB	0x02 /* First of 6 registers of accel data */

#define BMA180_CTRL_REG0	0x0d

#define BMA180_RESET		0x10

#define BMA180_BW_TCS		0x20

#define BMA180_CTRL_REG3	0x21

#define BMA180_TCO_Z		0x30

#define BMA180_OFFSET_LSB1	0x35



/* BMA180_CTRL_REG0 bits */

#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */

#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */

#define BMA180_EE_W		BIT(4) /* Unlock writing to addr from 0x20 */

#define BMA180_RESET_INT	BIT(6) /* Reset pending interrupts */



/* BMA180_CTRL_REG3 bits */

#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */



/* BMA180_OFFSET_LSB1 skipping mode bit */

#define BMA180_SMP_SKIP		BIT(0)



/* Bit masks for registers bit fields */

#define BMA180_RANGE		0x0e /* Range of measured accel values*/

#define BMA180_BW		0xf0 /* Accel bandwidth */

#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */



/* We have to write this value in reset register to do soft reset */

#define BMA180_RESET_VAL	0xb6



#define BMA_180_ID_REG_VAL	0x03



/* Chip power modes */

#define BMA180_LOW_NOISE	0x00

#define BMA180_LOW_POWER	0x03



#define BMA180_LOW_NOISE_STR	"low_noise"

#define BMA180_LOW_POWER_STR	"low_power"



/* Defaults values */

#define BMA180_DEF_PMODE	0

#define BMA180_DEF_BW		20

#define BMA180_DEF_SCALE	250



/* Available values for sysfs */

#define BMA180_FLP_FREQ_AVAILABLE \

	"10 20 40 75 150 300"

#define BMA180_SCALE_AVAILABLE \

	"0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"



struct bma180_data {

	struct i2c_client *client;

	struct iio_trigger *trig;

	struct mutex mutex;

	int sleep_state;

	int scale;

	int bw;

	int pmode;

	char *buff;

};



enum bma180_axis {

	AXIS_X,

	AXIS_Y,

	AXIS_Z,

};



static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */

static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };



static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)

{

	u8 reg = BMA180_ACC_X_LSB + axis * 2;

	int ret;



	if (data->sleep_state)

		return -EBUSY;



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

	if (ret < 0)

		dev_err(&data->client->dev,

			"failed to read accel_%c registers\n", 'x' + axis);



	return ret;

}



static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)

{

	int ret = i2c_smbus_read_byte_data(data->client, reg);

	u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));



	if (ret < 0)

		return ret;



	return i2c_smbus_write_byte_data(data->client, reg, reg_val);

}



static int bma180_reset_intr(struct bma180_data *data)

{

	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);



	if (ret)

		dev_err(&data->client->dev, "failed to reset interrupt\n");



	return ret;

}



static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)

{

	u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;

	int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,

			reg_val);



	if (ret)

		goto err;

	ret = bma180_reset_intr(data);

	if (ret)

		goto err;



	return 0;



err:

	dev_err(&data->client->dev,

		"failed to set new data interrupt state %d\n", state);

	return ret;

}



static int bma180_set_sleep_state(struct bma180_data *data, int state)

{

	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);



	if (ret) {

		dev_err(&data->client->dev,

			"failed to set sleep state %d\n", state);

		return ret;

	}

	data->sleep_state = state;



	return 0;

}



static int bma180_set_ee_writing_state(struct bma180_data *data, int state)

{

	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);



	if (ret)

		dev_err(&data->client->dev,

			"failed to set ee writing state %d\n", state);



	return ret;

}



static int bma180_set_bw(struct bma180_data *data, int val)

{

	int ret, i;



	if (data->sleep_state)

		return -EBUSY;



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

		if (bw_table[i] == val) {

			ret = bma180_set_bits(data,

					BMA180_BW_TCS, BMA180_BW, i);

			if (ret) {

				dev_err(&data->client->dev,

					"failed to set bandwidth\n");

				return ret;

			}

			data->bw = val;

			return 0;

		}

	}



	return -EINVAL;

}



static int bma180_set_scale(struct bma180_data *data, int val)

{

	int ret, i;



	if (data->sleep_state)

		return -EBUSY;



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

		if (scale_table[i] == val) {

			ret = bma180_set_bits(data,

					BMA180_OFFSET_LSB1, BMA180_RANGE, i);

			if (ret) {

				dev_err(&data->client->dev,

					"failed to set scale\n");

				return ret;

			}

			data->scale = val;

			return 0;

		}



	return -EINVAL;

}



static int bma180_set_pmode(struct bma180_data *data, int mode)

{

	u8 reg_val = mode ? BMA180_LOW_POWER : BMA180_LOW_NOISE;

	int ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG,

			reg_val);



	if (ret) {

		dev_err(&data->client->dev, "failed to set power mode\n");

		return ret;

	}

	data->pmode = mode;



	return 0;

}



static int bma180_soft_reset(struct bma180_data *data)

{

	int ret = i2c_smbus_write_byte_data(data->client,

			BMA180_RESET, BMA180_RESET_VAL);



	if (ret)

		dev_err(&data->client->dev, "failed to reset the chip\n");



	return ret;

}



static int bma180_chip_init(struct bma180_data *data)

{

	/* Try to read chip_id register. It must return 0x03. */

	int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);



	if (ret < 0)

		goto err;

	if (ret != BMA_180_ID_REG_VAL) {

		ret = -ENODEV;

		goto err;

	}



	ret = bma180_soft_reset(data);

	if (ret)

		goto err;

	/*

	 * No serial transaction should occur within minimum 10 us

	 * after soft_reset command

	 */

	msleep(20);



	ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);

	if (ret)

		goto err;

	ret = bma180_set_ee_writing_state(data, 1);

	if (ret)

		goto err;

	ret = bma180_set_new_data_intr_state(data, 0);

	if (ret)

		goto err;

	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);

	if (ret)

		goto err;

	ret = bma180_set_pmode(data, BMA180_DEF_PMODE);

	if (ret)

		goto err;

	ret = bma180_set_bw(data, BMA180_DEF_BW);

	if (ret)

		goto err;

	ret = bma180_set_scale(data, BMA180_DEF_SCALE);

	if (ret)

		goto err;



	return 0;



err:

	dev_err(&data->client->dev, "failed to init the chip\n");

	return ret;

}



static void bma180_chip_disable(struct bma180_data *data)

{

	if (bma180_set_new_data_intr_state(data, 0))

		goto err;

	if (bma180_set_ee_writing_state(data, 0))

		goto err;

	if (bma180_set_sleep_state(data, 1))

		goto err;



	return;



err:

	dev_err(&data->client->dev, "failed to disable the chip\n");

}



static IIO_CONST_ATTR(in_accel_filter_low_pass_3db_frequency_available,

		BMA180_FLP_FREQ_AVAILABLE);

static IIO_CONST_ATTR(in_accel_scale_available, BMA180_SCALE_AVAILABLE);



static struct attribute *bma180_attributes[] = {

	&iio_const_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,

	&iio_const_attr_in_accel_scale_available.dev_attr.attr,

	NULL,

};



static const struct attribute_group bma180_attrs_group = {

	.attrs = bma180_attributes,

};



static int bma180_read_raw(struct iio_dev *indio_dev,

		struct iio_chan_spec const *chan, int *val, int *val2,

		long mask)

{

	struct bma180_data *data = iio_priv(indio_dev);

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		mutex_lock(&data->mutex);

		if (iio_buffer_enabled(indio_dev))

			ret = -EBUSY;

		else

			ret = bma180_get_acc_reg(data, chan->scan_index);

		mutex_unlock(&data->mutex);

		if (ret < 0)

			return ret;

		*val = (s16)ret >> chan->scan_type.shift;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:

		*val = data->bw;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		*val = 0;

		*val2 = data->scale;

		return IIO_VAL_INT_PLUS_MICRO;

	default:

		return -EINVAL;

	}

}



static int bma180_write_raw(struct iio_dev *indio_dev,

		struct iio_chan_spec const *chan, int val, int val2, long mask)

{

	struct bma180_data *data = iio_priv(indio_dev);

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_SCALE:

		if (val)

			return -EINVAL;

		mutex_lock(&data->mutex);

		ret = bma180_set_scale(data, val2);

		mutex_unlock(&data->mutex);

		return ret;

	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:

		mutex_lock(&data->mutex);

		ret = bma180_set_bw(data, val);

		mutex_unlock(&data->mutex);

		return ret;

	default:

		return -EINVAL;

	}

}



static int bma180_update_scan_mode(struct iio_dev *indio_dev,

		const unsigned long *scan_mask)

{

	struct bma180_data *data = iio_priv(indio_dev);



	if (data->buff)

		devm_kfree(&indio_dev->dev, data->buff);

	data->buff = devm_kzalloc(&indio_dev->dev,

			indio_dev->scan_bytes, GFP_KERNEL);

	if (!data->buff)

		return -ENOMEM;



	return 0;

}



static const struct iio_info bma180_info = {

	.attrs			= &bma180_attrs_group,

	.read_raw		= bma180_read_raw,

	.write_raw		= bma180_write_raw,

	.update_scan_mode	= bma180_update_scan_mode,

	.driver_module		= THIS_MODULE,

};



static const char * const bma180_power_modes[] = {

	BMA180_LOW_NOISE_STR,

	BMA180_LOW_POWER_STR,

};



static int bma180_get_power_mode(struct iio_dev *indio_dev,

		const struct iio_chan_spec *chan)

{

	struct bma180_data *data = iio_priv(indio_dev);



	return data->pmode;

}



static int bma180_set_power_mode(struct iio_dev *indio_dev,

		const struct iio_chan_spec *chan, unsigned int mode)

{

	struct bma180_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	ret = bma180_set_pmode(data, mode);

	mutex_unlock(&data->mutex);



	return ret;

}



static const struct iio_enum bma180_power_mode_enum = {

	.items = bma180_power_modes,

	.num_items = ARRAY_SIZE(bma180_power_modes),

	.get = bma180_get_power_mode,

	.set = bma180_set_power_mode,

};



static const struct iio_chan_spec_ext_info bma180_ext_info[] = {

	IIO_ENUM("power_mode", true, &bma180_power_mode_enum),

	IIO_ENUM_AVAILABLE("power_mode", &bma180_power_mode_enum),

	{ },

};



#define BMA180_CHANNEL(_index) {					\

	.type = IIO_ACCEL,						\

	.indexed = 1,							\

	.channel = (_index),						\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\

		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\

	.scan_index = (_index),						\

	.scan_type = IIO_ST('s', 14, 16, 2),				\

	.ext_info = bma180_ext_info,					\

}



static const struct iio_chan_spec bma180_channels[] = {

	BMA180_CHANNEL(AXIS_X),

	BMA180_CHANNEL(AXIS_Y),

	BMA180_CHANNEL(AXIS_Z),

	IIO_CHAN_SOFT_TIMESTAMP(4),

};



static irqreturn_t bma180_trigger_handler(int irq, void *p)

{

	struct iio_poll_func *pf = p;

	struct iio_dev *indio_dev = pf->indio_dev;

	struct bma180_data *data = iio_priv(indio_dev);

	int bit, ret, i = 0;



	mutex_lock(&data->mutex);

	if (indio_dev->scan_timestamp) {

		ret = indio_dev->scan_bytes / sizeof(s64) - 1;

		((s64 *)data->buff)[ret] = iio_get_time_ns();

	}



	for_each_set_bit(bit, indio_dev->buffer->scan_mask,

			 indio_dev->masklength) {

		ret = bma180_get_acc_reg(data, bit);

		if (ret < 0) {

			mutex_unlock(&data->mutex);

			goto err;

		}

		((s16 *)data->buff)[i++] = ret;

	}

	mutex_unlock(&data->mutex);



	iio_push_to_buffers(indio_dev, (u8 *)data->buff);

err:

	iio_trigger_notify_done(indio_dev->trig);



	return IRQ_HANDLED;

}



static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,

		bool state)

{

	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);

	struct bma180_data *data = iio_priv(indio_dev);



	return bma180_set_new_data_intr_state(data, state);

}



static int bma180_trig_try_reen(struct iio_trigger *trig)

{

	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);

	struct bma180_data *data = iio_priv(indio_dev);



	return bma180_reset_intr(data);

}



static const struct iio_trigger_ops bma180_trigger_ops = {

	.set_trigger_state = bma180_data_rdy_trigger_set_state,

	.try_reenable = bma180_trig_try_reen,

	.owner = THIS_MODULE,

};



static int bma180_probe(struct i2c_client *client,

		const struct i2c_device_id *id)

{

	struct bma180_data *data;

	struct iio_dev *indio_dev;

	struct iio_trigger *trig;

	int ret;



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

	if (!indio_dev)

		return -ENOMEM;



	data = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);

	data->client = client;



	ret = bma180_chip_init(data);

	if (ret < 0)

		goto err_chip_disable;



	mutex_init(&data->mutex);



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

	indio_dev->channels = bma180_channels;

	indio_dev->num_channels = ARRAY_SIZE(bma180_channels);

	indio_dev->name = BMA180_DRV_NAME;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = &bma180_info;



	trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);

	if (!trig) {

		ret = -ENOMEM;

		goto err_chip_disable;

	}



	ret = devm_request_irq(&client->dev, client->irq,

			iio_trigger_generic_data_rdy_poll,

			IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);

	if (ret) {

		dev_err(&client->dev, "unable to request IRQ\n");

		goto err_trigger_free;

	}



	trig->dev.parent = &client->dev;

	trig->ops = &bma180_trigger_ops;

	iio_trigger_set_drvdata(trig, indio_dev);

	data->trig = trig;

	indio_dev->trig = trig;



	ret = iio_trigger_register(trig);

	if (ret)

		goto err_trigger_free;



	ret = iio_triggered_buffer_setup(indio_dev, NULL,

			bma180_trigger_handler, NULL);

	if (ret < 0) {

		dev_err(&client->dev, "unable to setup iio triggered buffer\n");

		goto err_trigger_unregister;

	}



	ret = iio_device_register(indio_dev);

	if (ret < 0) {

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

		goto err_buffer_cleanup;

	}



	return 0;



err_buffer_cleanup:

	iio_triggered_buffer_cleanup(indio_dev);

err_trigger_unregister:

	iio_trigger_unregister(trig);

err_trigger_free:

	iio_trigger_free(trig);

err_chip_disable:

	bma180_chip_disable(data);



	return ret;

}



static int bma180_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct bma180_data *data = iio_priv(indio_dev);



	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	iio_trigger_unregister(data->trig);

	iio_trigger_free(data->trig);



	mutex_lock(&data->mutex);

	bma180_chip_disable(data);

	mutex_unlock(&data->mutex);



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int bma180_suspend(struct device *dev)

{

	struct iio_dev *indio_dev = dev_to_iio_dev(dev);

	struct bma180_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	ret = bma180_set_sleep_state(data, 1);

	mutex_unlock(&data->mutex);



	return ret;

}



static int bma180_resume(struct device *dev)

{

	struct iio_dev *indio_dev = dev_to_iio_dev(dev);

	struct bma180_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	ret = bma180_set_sleep_state(data, 0);

	mutex_unlock(&data->mutex);



	return ret;

}



static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);

#define BMA180_PM_OPS (&bma180_pm_ops)

#else

#define BMA180_PM_OPS NULL

#endif



static struct i2c_device_id bma180_id[] = {

	{ BMA180_DRV_NAME, 0 },

	{ }

};



MODULE_DEVICE_TABLE(i2c, bma180_id);



static struct i2c_driver bma180_driver = {

	.driver = {

		.name	= BMA180_DRV_NAME,

		.owner	= THIS_MODULE,

		.pm	= BMA180_PM_OPS,

	},

	.probe		= bma180_probe,

	.remove		= bma180_remove,

	.id_table	= bma180_id,

};



module_i2c_driver(bma180_driver);



MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");

MODULE_AUTHOR("Texas Instruments, Inc.");

MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");

MODULE_LICENSE("GPL");