drivers/iio/accel/stk8312.c - kernel/msm-4.9 - Gitiles

 /**
  * Sensortek STK8312 3-Axis Accelerometer
  *
  * Copyright (c) 2015, 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 STK8312; 7-bit I2C address: 0x3D.
  */

 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>

 #define STK8312_REG_XOUT		0x00
 #define STK8312_REG_YOUT		0x01
 #define STK8312_REG_ZOUT		0x02
 #define STK8312_REG_MODE		0x07
 #define STK8312_REG_STH			0x13
 #define STK8312_REG_RESET		0x20
 #define STK8312_REG_AFECTRL		0x24
 #define STK8312_REG_OTPADDR		0x3D
 #define STK8312_REG_OTPDATA		0x3E
 #define STK8312_REG_OTPCTRL		0x3F

 #define STK8312_MODE_ACTIVE		1
 #define STK8312_MODE_STANDBY		0
 #define STK8312_MODE_MASK		0x01
 #define STK8312_RNG_MASK		0xC0
 #define STK8312_RNG_SHIFT		6
 #define STK8312_READ_RETRIES		16

 #define STK8312_DRIVER_NAME		"stk8312"

 /*
  * The accelerometer has two measurement ranges:
  *
  * -6g - +6g (8-bit, signed)
  * -16g - +16g (8-bit, signed)
  *
  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
  */
 #define STK8312_SCALE_AVAIL		"0.4616 1.2311"

 static const int stk8312_scale_table[][2] = {
 	{0, 461600}, {1, 231100}
 };

 #define STK8312_ACCEL_CHANNEL(reg, axis) {			\
 	.type = IIO_ACCEL,					\
 	.address = reg,						\
 	.modified = 1,						\
 	.channel2 = IIO_MOD_##axis,				\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 }

 static const struct iio_chan_spec stk8312_channels[] = {
 	STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
 	STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
 	STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
 };

 struct stk8312_data {
 	struct i2c_client *client;
 	struct mutex lock;
 	int range;
 	u8 mode;
 };

 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);

 static struct attribute *stk8312_attributes[] = {
 	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group stk8312_attribute_group = {
 	.attrs = stk8312_attributes
 };

 static int stk8312_otp_init(struct stk8312_data *data)
 {
 	int ret;
 	int count = 10;
 	struct i2c_client *client = data->client;

 	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
 	if (ret < 0)
 		goto exit_err;
 	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
 	if (ret < 0)
 		goto exit_err;

 	do {
 		usleep_range(1000, 5000);
 		ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
 		if (ret < 0)
 			goto exit_err;
 		count--;
 	} while (!(ret & 0x80) && count > 0);

 	if (count == 0)
 		goto exit_err;

 	ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
 	if (ret < 0)
 		goto exit_err;

 	ret = i2c_smbus_write_byte_data(data->client,
 			STK8312_REG_AFECTRL, ret);
 	if (ret < 0)
 		goto exit_err;
 	msleep(150);

 	return ret;

 exit_err:
 	dev_err(&client->dev, "failed to initialize sensor\n");
 	return ret;
 }

 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
 {
 	int ret;
 	u8 masked_reg;
 	struct i2c_client *client = data->client;

 	if (mode > 1)
 		return -EINVAL;
 	else if (mode == data->mode)
 		return 0;

 	ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to change sensor mode\n");
 		return ret;
 	}
 	masked_reg = ret & (~STK8312_MODE_MASK);
 	masked_reg |= mode;

 	ret = i2c_smbus_write_byte_data(client,
 			STK8312_REG_MODE, masked_reg);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to change sensor mode\n");
 		return ret;
 	}

 	data->mode = mode;
 	if (mode == STK8312_MODE_ACTIVE) {
 		/* Need to run OTP sequence before entering active mode */
 		usleep_range(1000, 5000);
 		ret = stk8312_otp_init(data);
 	}

 	return ret;
 }

 static int stk8312_set_range(struct stk8312_data *data, u8 range)
 {
 	int ret;
 	u8 masked_reg;
 	u8 mode;
 	struct i2c_client *client = data->client;

 	if (range != 1 && range != 2)
 		return -EINVAL;
 	else if (range == data->range)
 		return 0;

 	mode = data->mode;
 	/* We need to go in standby mode to modify registers */
 	ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to change sensor range\n");
 		return ret;
 	}

 	masked_reg = ret & (~STK8312_RNG_MASK);
 	masked_reg |= range << STK8312_RNG_SHIFT;

 	ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
 	if (ret < 0)
 		dev_err(&client->dev, "failed to change sensor range\n");
 	else
 		data->range = range;

 	return stk8312_set_mode(data, mode);
 }

 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
 {
 	int ret;
 	struct i2c_client *client = data->client;

 	if (address > 2)
 		return -EINVAL;

 	ret = i2c_smbus_read_byte_data(client, address);
 	if (ret < 0) {
 		dev_err(&client->dev, "register read failed\n");
 		return ret;
 	}

 	return sign_extend32(ret, 7);
 }

 static int stk8312_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct stk8312_data *data = iio_priv(indio_dev);

 	if (chan->type != IIO_ACCEL)
 		return -EINVAL;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&data->lock);
 		*val = stk8312_read_accel(data, chan->address);
 		mutex_unlock(&data->lock);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = stk8312_scale_table[data->range - 1][0];
 		*val2 = stk8312_scale_table[data->range - 1][1];
 		return IIO_VAL_INT_PLUS_MICRO;
 	}

 	return -EINVAL;
 }

 static int stk8312_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	int i;
 	int index = -1;
 	int ret;
 	struct stk8312_data *data = iio_priv(indio_dev);

 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
 			if (val == stk8312_scale_table[i][0] &&
 			    val2 == stk8312_scale_table[i][1]) {
 				index = i + 1;
 				break;
 			}
 		if (index < 0)
 			return -EINVAL;

 		mutex_lock(&data->lock);
 		ret = stk8312_set_range(data, index);
 		mutex_unlock(&data->lock);

 		return ret;
 	}

 	return -EINVAL;
 }

 static const struct iio_info stk8312_info = {
 	.driver_module		= THIS_MODULE,
 	.read_raw		= stk8312_read_raw,
 	.write_raw		= stk8312_write_raw,
 	.attrs			= &stk8312_attribute_group,
 };

 static int stk8312_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	int ret;
 	struct iio_dev *indio_dev;
 	struct stk8312_data *data;

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev) {
 		dev_err(&client->dev, "iio allocation failed!\n");
 		return -ENOMEM;
 	}

 	data = iio_priv(indio_dev);
 	data->client = client;
 	i2c_set_clientdata(client, indio_dev);
 	mutex_init(&data->lock);

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->info = &stk8312_info;
 	indio_dev->name = STK8312_DRIVER_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = stk8312_channels;
 	indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);

 	/* A software reset is recommended at power-on */
 	ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to reset sensor\n");
 		return ret;
 	}
 	ret = stk8312_set_range(data, 1);
 	if (ret < 0)
 		return ret;

 	ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
 	if (ret < 0)
 		return ret;

 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "device_register failed\n");
 		stk8312_set_mode(data, STK8312_MODE_STANDBY);
 	}

 	return ret;
 }

 static int stk8312_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);

 	iio_device_unregister(indio_dev);

 	return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
 }

 #ifdef CONFIG_PM_SLEEP
 static int stk8312_suspend(struct device *dev)
 {
 	struct stk8312_data *data;

 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

 	return stk8312_set_mode(data, STK8312_MODE_STANDBY);
 }

 static int stk8312_resume(struct device *dev)
 {
 	struct stk8312_data *data;

 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

 	return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
 }

 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);

 #define STK8312_PM_OPS (&stk8312_pm_ops)
 #else
 #define STK8312_PM_OPS NULL
 #endif

 static const struct i2c_device_id stk8312_i2c_id[] = {
 	{"STK8312", 0},
 	{}
 };

 static const struct acpi_device_id stk8312_acpi_id[] = {
 	{"STK8312", 0},
 	{}
 };

 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);

 static struct i2c_driver stk8312_driver = {
 	.driver = {
 		.name = "stk8312",
 		.pm = STK8312_PM_OPS,
 		.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
 	},
 	.probe =            stk8312_probe,
 	.remove =           stk8312_remove,
 	.id_table =         stk8312_i2c_id,
 };

 module_i2c_driver(stk8312_driver);

 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
 MODULE_LICENSE("GPL v2");
	/**
	* Sensortek STK8312 3-Axis Accelerometer
	*
	* Copyright (c) 2015, 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 STK8312; 7-bit I2C address: 0x3D.
	*/

	#include <linux/acpi.h>
	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>

	#define STK8312_REG_XOUT 0x00
	#define STK8312_REG_YOUT 0x01
	#define STK8312_REG_ZOUT 0x02
	#define STK8312_REG_MODE 0x07
	#define STK8312_REG_STH 0x13
	#define STK8312_REG_RESET 0x20
	#define STK8312_REG_AFECTRL 0x24
	#define STK8312_REG_OTPADDR 0x3D
	#define STK8312_REG_OTPDATA 0x3E
	#define STK8312_REG_OTPCTRL 0x3F

	#define STK8312_MODE_ACTIVE 1
	#define STK8312_MODE_STANDBY 0
	#define STK8312_MODE_MASK 0x01
	#define STK8312_RNG_MASK 0xC0
	#define STK8312_RNG_SHIFT 6
	#define STK8312_READ_RETRIES 16

	#define STK8312_DRIVER_NAME "stk8312"

	/*
	* The accelerometer has two measurement ranges:
	*
	* -6g - +6g (8-bit, signed)
	* -16g - +16g (8-bit, signed)
	*
	* scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
	* scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
	*/
	#define STK8312_SCALE_AVAIL "0.4616 1.2311"

	static const int stk8312_scale_table[][2] = {
	{0, 461600}, {1, 231100}
	};

	#define STK8312_ACCEL_CHANNEL(reg, axis) { \
	.type = IIO_ACCEL, \
	.address = reg, \
	.modified = 1, \
	.channel2 = IIO_MOD_##axis, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	}

	static const struct iio_chan_spec stk8312_channels[] = {
	STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
	STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
	STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
	};

	struct stk8312_data {
	struct i2c_client *client;
	struct mutex lock;
	int range;
	u8 mode;
	};

	static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);

	static struct attribute *stk8312_attributes[] = {
	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group stk8312_attribute_group = {
	.attrs = stk8312_attributes
	};

	static int stk8312_otp_init(struct stk8312_data *data)
	{
	int ret;
	int count = 10;
	struct i2c_client *client = data->client;

	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
	if (ret < 0)
	goto exit_err;
	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
	if (ret < 0)
	goto exit_err;

	do {
	usleep_range(1000, 5000);
	ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
	if (ret < 0)
	goto exit_err;
	count--;
	} while (!(ret & 0x80) && count > 0);

	if (count == 0)
	goto exit_err;

	ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
	if (ret < 0)
	goto exit_err;

	ret = i2c_smbus_write_byte_data(data->client,
	STK8312_REG_AFECTRL, ret);
	if (ret < 0)
	goto exit_err;
	msleep(150);

	return ret;

	exit_err:
	dev_err(&client->dev, "failed to initialize sensor\n");
	return ret;
	}

	static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
	{
	int ret;
	u8 masked_reg;
	struct i2c_client *client = data->client;

	if (mode > 1)
	return -EINVAL;
	else if (mode == data->mode)
	return 0;

	ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
	if (ret < 0) {
	dev_err(&client->dev, "failed to change sensor mode\n");
	return ret;
	}
	masked_reg = ret & (~STK8312_MODE_MASK);
	masked_reg \|= mode;

	ret = i2c_smbus_write_byte_data(client,
	STK8312_REG_MODE, masked_reg);
	if (ret < 0) {
	dev_err(&client->dev, "failed to change sensor mode\n");
	return ret;
	}

	data->mode = mode;
	if (mode == STK8312_MODE_ACTIVE) {
	/* Need to run OTP sequence before entering active mode */
	usleep_range(1000, 5000);
	ret = stk8312_otp_init(data);
	}

	return ret;
	}

	static int stk8312_set_range(struct stk8312_data *data, u8 range)
	{
	int ret;
	u8 masked_reg;
	u8 mode;
	struct i2c_client *client = data->client;

	if (range != 1 && range != 2)
	return -EINVAL;
	else if (range == data->range)
	return 0;

	mode = data->mode;
	/* We need to go in standby mode to modify registers */
	ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
	if (ret < 0) {
	dev_err(&client->dev, "failed to change sensor range\n");
	return ret;
	}

	masked_reg = ret & (~STK8312_RNG_MASK);
	masked_reg \|= range << STK8312_RNG_SHIFT;

	ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
	if (ret < 0)
	dev_err(&client->dev, "failed to change sensor range\n");
	else
	data->range = range;

	return stk8312_set_mode(data, mode);
	}

	static int stk8312_read_accel(struct stk8312_data *data, u8 address)
	{
	int ret;
	struct i2c_client *client = data->client;

	if (address > 2)
	return -EINVAL;

	ret = i2c_smbus_read_byte_data(client, address);
	if (ret < 0) {
	dev_err(&client->dev, "register read failed\n");
	return ret;
	}

	return sign_extend32(ret, 7);
	}

	static int stk8312_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct stk8312_data *data = iio_priv(indio_dev);

	if (chan->type != IIO_ACCEL)
	return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	mutex_lock(&data->lock);
	*val = stk8312_read_accel(data, chan->address);
	mutex_unlock(&data->lock);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = stk8312_scale_table[data->range - 1][0];
	*val2 = stk8312_scale_table[data->range - 1][1];
	return IIO_VAL_INT_PLUS_MICRO;
	}

	return -EINVAL;
	}

	static int stk8312_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	int i;
	int index = -1;
	int ret;
	struct stk8312_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
	for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
	if (val == stk8312_scale_table[i][0] &&
	val2 == stk8312_scale_table[i][1]) {
	index = i + 1;
	break;
	}
	if (index < 0)
	return -EINVAL;

	mutex_lock(&data->lock);
	ret = stk8312_set_range(data, index);
	mutex_unlock(&data->lock);

	return ret;
	}

	return -EINVAL;
	}

	static const struct iio_info stk8312_info = {
	.driver_module = THIS_MODULE,
	.read_raw = stk8312_read_raw,
	.write_raw = stk8312_write_raw,
	.attrs = &stk8312_attribute_group,
	};

	static int stk8312_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct iio_dev *indio_dev;
	struct stk8312_data *data;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev) {
	dev_err(&client->dev, "iio allocation failed!\n");
	return -ENOMEM;
	}

	data = iio_priv(indio_dev);
	data->client = client;
	i2c_set_clientdata(client, indio_dev);
	mutex_init(&data->lock);

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &stk8312_info;
	indio_dev->name = STK8312_DRIVER_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = stk8312_channels;
	indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);

	/* A software reset is recommended at power-on */
	ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
	if (ret < 0) {
	dev_err(&client->dev, "failed to reset sensor\n");
	return ret;
	}
	ret = stk8312_set_range(data, 1);
	if (ret < 0)
	return ret;

	ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
	if (ret < 0)
	return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
	dev_err(&client->dev, "device_register failed\n");
	stk8312_set_mode(data, STK8312_MODE_STANDBY);
	}

	return ret;
	}

	static int stk8312_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);

	return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
	}

	#ifdef CONFIG_PM_SLEEP
	static int stk8312_suspend(struct device *dev)
	{
	struct stk8312_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return stk8312_set_mode(data, STK8312_MODE_STANDBY);
	}

	static int stk8312_resume(struct device *dev)
	{
	struct stk8312_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
	}

	static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);

	#define STK8312_PM_OPS (&stk8312_pm_ops)
	#else
	#define STK8312_PM_OPS NULL
	#endif

	static const struct i2c_device_id stk8312_i2c_id[] = {
	{"STK8312", 0},
	{}
	};

	static const struct acpi_device_id stk8312_acpi_id[] = {
	{"STK8312", 0},
	{}
	};

	MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);

	static struct i2c_driver stk8312_driver = {
	.driver = {
	.name = "stk8312",
	.pm = STK8312_PM_OPS,
	.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
	},
	.probe = stk8312_probe,
	.remove = stk8312_remove,
	.id_table = stk8312_i2c_id,
	};

	module_i2c_driver(stk8312_driver);

	MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
	MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
	MODULE_LICENSE("GPL v2");