drivers/iio/accel/mma7660.c - linux-imx - Git at Google

 /**
  * Freescale MMA7660FC 3-Axis Accelerometer
  *
  * Copyright (c) 2016, 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 Freescale MMA7660FC; 7-bit I2C address: 0x4c.
  */

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

 #define MMA7660_DRIVER_NAME	"mma7660"

 #define MMA7660_REG_XOUT	0x00
 #define MMA7660_REG_YOUT	0x01
 #define MMA7660_REG_ZOUT	0x02
 #define MMA7660_REG_OUT_BIT_ALERT	BIT(6)

 #define MMA7660_REG_MODE	0x07
 #define MMA7660_REG_MODE_BIT_MODE	BIT(0)
 #define MMA7660_REG_MODE_BIT_TON	BIT(2)

 #define MMA7660_I2C_READ_RETRIES	5

 /*
  * The accelerometer has one measurement range:
  *
  * -1.5g - +1.5g (6-bit, signed)
  *
  * scale = (1.5 + 1.5) * 9.81 / (2^6 - 1)	= 0.467142857
  */

 #define MMA7660_SCALE_AVAIL	"0.467142857"

 static const int mma7660_nscale = 467142857;

 #define MMA7660_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 mma7660_channels[] = {
 	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
 	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
 	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
 };

 enum mma7660_mode {
 	MMA7660_MODE_STANDBY,
 	MMA7660_MODE_ACTIVE
 };

 struct mma7660_data {
 	struct i2c_client *client;
 	struct mutex lock;
 	enum mma7660_mode mode;
 };

 static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);

 static struct attribute *mma7660_attributes[] = {
 	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group mma7660_attribute_group = {
 	.attrs = mma7660_attributes
 };

 static int mma7660_set_mode(struct mma7660_data *data,
 				enum mma7660_mode mode)
 {
 	int ret;
 	struct i2c_client *client = data->client;

 	if (mode == data->mode)
 		return 0;

 	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to read sensor mode\n");
 		return ret;
 	}

 	if (mode == MMA7660_MODE_ACTIVE) {
 		ret &= ~MMA7660_REG_MODE_BIT_TON;
 		ret |= MMA7660_REG_MODE_BIT_MODE;
 	} else {
 		ret &= ~MMA7660_REG_MODE_BIT_TON;
 		ret &= ~MMA7660_REG_MODE_BIT_MODE;
 	}

 	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to change sensor mode\n");
 		return ret;
 	}

 	data->mode = mode;

 	return ret;
 }

 static int mma7660_read_accel(struct mma7660_data *data, u8 address)
 {
 	int ret, retries = MMA7660_I2C_READ_RETRIES;
 	struct i2c_client *client = data->client;

 	/*
 	 * Read data. If the Alert bit is set, the register was read at
 	 * the same time as the device was attempting to update the content.
 	 * The solution is to read the register again. Do this only
 	 * MMA7660_I2C_READ_RETRIES times to avoid spending too much time
 	 * in the kernel.
 	 */
 	do {
 		ret = i2c_smbus_read_byte_data(client, address);
 		if (ret < 0) {
 			dev_err(&client->dev, "register read failed\n");
 			return ret;
 		}
 	} while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);

 	if (ret & MMA7660_REG_OUT_BIT_ALERT) {
 		dev_err(&client->dev, "all register read retries failed\n");
 		return -ETIMEDOUT;
 	}

 	return ret;
 }

 static int mma7660_read_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int *val, int *val2, long mask)
 {
 	struct mma7660_data *data = iio_priv(indio_dev);
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&data->lock);
 		ret = mma7660_read_accel(data, chan->address);
 		mutex_unlock(&data->lock);
 		if (ret < 0)
 			return ret;
 		*val = sign_extend32(ret, 5);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		*val2 = mma7660_nscale;
 		return IIO_VAL_INT_PLUS_NANO;
 	default:
 		return -EINVAL;
 	}

 	return -EINVAL;
 }

 static const struct iio_info mma7660_info = {
 	.driver_module	= THIS_MODULE,
 	.read_raw		= mma7660_read_raw,
 	.attrs			= &mma7660_attribute_group,
 };

 static int mma7660_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret;
 	struct iio_dev *indio_dev;
 	struct mma7660_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);
 	data->mode = MMA7660_MODE_STANDBY;

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->info = &mma7660_info;
 	indio_dev->name = MMA7660_DRIVER_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = mma7660_channels;
 	indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);

 	ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
 	if (ret < 0)
 		return ret;

 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "device_register failed\n");
 		mma7660_set_mode(data, MMA7660_MODE_STANDBY);
 	}

 	return ret;
 }

 static int mma7660_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);

 	iio_device_unregister(indio_dev);

 	return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
 }

 #ifdef CONFIG_PM_SLEEP
 static int mma7660_suspend(struct device *dev)
 {
 	struct mma7660_data *data;

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

 	return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
 }

 static int mma7660_resume(struct device *dev)
 {
 	struct mma7660_data *data;

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

 	return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
 }

 static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);

 #define MMA7660_PM_OPS (&mma7660_pm_ops)
 #else
 #define MMA7660_PM_OPS NULL
 #endif

 static const struct i2c_device_id mma7660_i2c_id[] = {
 	{"mma7660", 0},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);

 static const struct of_device_id mma7660_of_match[] = {
 	{ .compatible = "fsl,mma7660" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, mma7660_of_match);

 static const struct acpi_device_id mma7660_acpi_id[] = {
 	{"MMA7660", 0},
 	{}
 };

 MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);

 static struct i2c_driver mma7660_driver = {
 	.driver = {
 		.name = "mma7660",
 		.pm = MMA7660_PM_OPS,
 		.of_match_table = mma7660_of_match,
 		.acpi_match_table = ACPI_PTR(mma7660_acpi_id),
 	},
 	.probe		= mma7660_probe,
 	.remove		= mma7660_remove,
 	.id_table	= mma7660_i2c_id,
 };

 module_i2c_driver(mma7660_driver);

 MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
 MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
 MODULE_LICENSE("GPL v2");
	/**
	* Freescale MMA7660FC 3-Axis Accelerometer
	*
	* Copyright (c) 2016, 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 Freescale MMA7660FC; 7-bit I2C address: 0x4c.
	*/

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

	#define MMA7660_DRIVER_NAME "mma7660"

	#define MMA7660_REG_XOUT 0x00
	#define MMA7660_REG_YOUT 0x01
	#define MMA7660_REG_ZOUT 0x02
	#define MMA7660_REG_OUT_BIT_ALERT BIT(6)

	#define MMA7660_REG_MODE 0x07
	#define MMA7660_REG_MODE_BIT_MODE BIT(0)
	#define MMA7660_REG_MODE_BIT_TON BIT(2)

	#define MMA7660_I2C_READ_RETRIES 5

	/*
	* The accelerometer has one measurement range:
	*
	* -1.5g - +1.5g (6-bit, signed)
	*
	* scale = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857
	*/

	#define MMA7660_SCALE_AVAIL "0.467142857"

	static const int mma7660_nscale = 467142857;

	#define MMA7660_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 mma7660_channels[] = {
	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
	};

	enum mma7660_mode {
	MMA7660_MODE_STANDBY,
	MMA7660_MODE_ACTIVE
	};

	struct mma7660_data {
	struct i2c_client *client;
	struct mutex lock;
	enum mma7660_mode mode;
	};

	static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);

	static struct attribute *mma7660_attributes[] = {
	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group mma7660_attribute_group = {
	.attrs = mma7660_attributes
	};

	static int mma7660_set_mode(struct mma7660_data *data,
	enum mma7660_mode mode)
	{
	int ret;
	struct i2c_client *client = data->client;

	if (mode == data->mode)
	return 0;

	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
	if (ret < 0) {
	dev_err(&client->dev, "failed to read sensor mode\n");
	return ret;
	}

	if (mode == MMA7660_MODE_ACTIVE) {
	ret &= ~MMA7660_REG_MODE_BIT_TON;
	ret \|= MMA7660_REG_MODE_BIT_MODE;
	} else {
	ret &= ~MMA7660_REG_MODE_BIT_TON;
	ret &= ~MMA7660_REG_MODE_BIT_MODE;
	}

	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
	if (ret < 0) {
	dev_err(&client->dev, "failed to change sensor mode\n");
	return ret;
	}

	data->mode = mode;

	return ret;
	}

	static int mma7660_read_accel(struct mma7660_data *data, u8 address)
	{
	int ret, retries = MMA7660_I2C_READ_RETRIES;
	struct i2c_client *client = data->client;

	/*
	* Read data. If the Alert bit is set, the register was read at
	* the same time as the device was attempting to update the content.
	* The solution is to read the register again. Do this only
	* MMA7660_I2C_READ_RETRIES times to avoid spending too much time
	* in the kernel.
	*/
	do {
	ret = i2c_smbus_read_byte_data(client, address);
	if (ret < 0) {
	dev_err(&client->dev, "register read failed\n");
	return ret;
	}
	} while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);

	if (ret & MMA7660_REG_OUT_BIT_ALERT) {
	dev_err(&client->dev, "all register read retries failed\n");
	return -ETIMEDOUT;
	}

	return ret;
	}

	static int mma7660_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct mma7660_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	mutex_lock(&data->lock);
	ret = mma7660_read_accel(data, chan->address);
	mutex_unlock(&data->lock);
	if (ret < 0)
	return ret;
	*val = sign_extend32(ret, 5);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	*val2 = mma7660_nscale;
	return IIO_VAL_INT_PLUS_NANO;
	default:
	return -EINVAL;
	}

	return -EINVAL;
	}

	static const struct iio_info mma7660_info = {
	.driver_module = THIS_MODULE,
	.read_raw = mma7660_read_raw,
	.attrs = &mma7660_attribute_group,
	};

	static int mma7660_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct iio_dev *indio_dev;
	struct mma7660_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);
	data->mode = MMA7660_MODE_STANDBY;

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &mma7660_info;
	indio_dev->name = MMA7660_DRIVER_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mma7660_channels;
	indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);

	ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
	if (ret < 0)
	return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
	dev_err(&client->dev, "device_register failed\n");
	mma7660_set_mode(data, MMA7660_MODE_STANDBY);
	}

	return ret;
	}

	static int mma7660_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);

	return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
	}

	#ifdef CONFIG_PM_SLEEP
	static int mma7660_suspend(struct device *dev)
	{
	struct mma7660_data *data;

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

	return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
	}

	static int mma7660_resume(struct device *dev)
	{
	struct mma7660_data *data;

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

	return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
	}

	static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);

	#define MMA7660_PM_OPS (&mma7660_pm_ops)
	#else
	#define MMA7660_PM_OPS NULL
	#endif

	static const struct i2c_device_id mma7660_i2c_id[] = {
	{"mma7660", 0},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);

	static const struct of_device_id mma7660_of_match[] = {
	{ .compatible = "fsl,mma7660" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, mma7660_of_match);

	static const struct acpi_device_id mma7660_acpi_id[] = {
	{"MMA7660", 0},
	{}
	};

	MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);

	static struct i2c_driver mma7660_driver = {
	.driver = {
	.name = "mma7660",
	.pm = MMA7660_PM_OPS,
	.of_match_table = mma7660_of_match,
	.acpi_match_table = ACPI_PTR(mma7660_acpi_id),
	},
	.probe = mma7660_probe,
	.remove = mma7660_remove,
	.id_table = mma7660_i2c_id,
	};

	module_i2c_driver(mma7660_driver);

	MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
	MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
	MODULE_LICENSE("GPL v2");