drivers/iio/light/ltr501.c - maze/linux - Git at Google

 /*
  * ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
  *
  * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
  *
  * 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.
  *
  * 7-bit I2C slave address 0x23
  *
  * TODO: interrupt, threshold, measurement rate, IR LED characteristics
  */

 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/delay.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>

 #define LTR501_DRV_NAME "ltr501"

 #define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
 #define LTR501_PS_CONTR 0x81 /* PS operation mode */
 #define LTR501_PART_ID 0x86
 #define LTR501_MANUFAC_ID 0x87
 #define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
 #define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
 #define LTR501_ALS_PS_STATUS 0x8c
 #define LTR501_PS_DATA 0x8d /* 16-bit, little endian */

 #define LTR501_ALS_CONTR_SW_RESET BIT(2)
 #define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
 #define LTR501_CONTR_PS_GAIN_SHIFT 2
 #define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
 #define LTR501_CONTR_ACTIVE BIT(1)

 #define LTR501_STATUS_ALS_RDY BIT(2)
 #define LTR501_STATUS_PS_RDY BIT(0)

 #define LTR501_PS_DATA_MASK 0x7ff

 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
 };

 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 {
 	int tries = 100;
 	int ret;

 	while (tries--) {
 		ret = i2c_smbus_read_byte_data(data->client,
 			LTR501_ALS_PS_STATUS);
 		if (ret < 0)
 			return ret;
 		if ((ret & drdy_mask) == drdy_mask)
 			return 0;
 		msleep(25);
 	}

 	dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
 	return -EIO;
 }

 static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 {
 	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
 	if (ret < 0)
 		return ret;
 	/* always read both ALS channels in given order */
 	return i2c_smbus_read_i2c_block_data(data->client,
 		LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);
 }

 static int ltr501_read_ps(struct ltr501_data *data)
 {
 	int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
 	if (ret < 0)
 		return ret;
 	return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
 }

 #define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
 	.type = IIO_INTENSITY, \
 	.modified = 1, \
 	.address = (_addr), \
 	.channel2 = (_mod), \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = (_shared), \
 	.scan_index = (_idx), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 16, \
 		.storagebits = 16, \
 		.endianness = IIO_CPU, \
 	} \
 }

 static const struct iio_chan_spec ltr501_channels[] = {
 	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
 		BIT(IIO_CHAN_INFO_SCALE)),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE),
 		.scan_index = 2,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 11,
 			.storagebits = 16,
 			.endianness = IIO_CPU,
 		},
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

 static const int ltr501_ps_gain[4][2] = {
 	{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
 };

 static int ltr501_read_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int *val, int *val2, long mask)
 {
 	struct ltr501_data *data = iio_priv(indio_dev);
 	__le16 buf[2];
 	int ret, i;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		if (iio_buffer_enabled(indio_dev))
 			return -EBUSY;

 		switch (chan->type) {
 		case IIO_INTENSITY:
 			mutex_lock(&data->lock_als);
 			ret = ltr501_read_als(data, buf);
 			mutex_unlock(&data->lock_als);
 			if (ret < 0)
 				return ret;
 			*val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
 				buf[0] : buf[1]);
 			return IIO_VAL_INT;
 		case IIO_PROXIMITY:
 			mutex_lock(&data->lock_ps);
 			ret = ltr501_read_ps(data);
 			mutex_unlock(&data->lock_ps);
 			if (ret < 0)
 				return ret;
 			*val = ret & LTR501_PS_DATA_MASK;
 			return IIO_VAL_INT;
 		default:
 			return -EINVAL;
 		}
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_INTENSITY:
 			if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
 				*val = 0;
 				*val2 = 5000;
 				return IIO_VAL_INT_PLUS_MICRO;
 			} else {
 				*val = 1;
 				*val2 = 0;
 				return IIO_VAL_INT;
 			}
 		case IIO_PROXIMITY:
 			i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
 				LTR501_CONTR_PS_GAIN_SHIFT;
 			*val = ltr501_ps_gain[i][0];
 			*val2 = ltr501_ps_gain[i][1];
 			return IIO_VAL_INT_PLUS_MICRO;
 		default:
 			return -EINVAL;
 		}
 	}
 	return -EINVAL;
 }

 static int ltr501_get_ps_gain_index(int val, int val2)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
 		if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
 			return i;

 	return -1;
 }

 static int ltr501_write_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask)
 {
 	struct ltr501_data *data = iio_priv(indio_dev);
 	int i;

 	if (iio_buffer_enabled(indio_dev))
 		return -EBUSY;

 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_INTENSITY:
 			if (val == 0 && val2 == 5000)
 				data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;
 			else if (val == 1 && val2 == 0)
 				data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
 			else
 				return -EINVAL;
 			return i2c_smbus_write_byte_data(data->client,
 				LTR501_ALS_CONTR, data->als_contr);
 		case IIO_PROXIMITY:
 			i = ltr501_get_ps_gain_index(val, val2);
 			if (i < 0)
 				return -EINVAL;
 			data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
 			data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
 			return i2c_smbus_write_byte_data(data->client,
 				LTR501_PS_CONTR, data->ps_contr);
 		default:
 			return -EINVAL;
 		}
 	}
 	return -EINVAL;
 }

 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");

 static struct attribute *ltr501_attributes[] = {
 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
 	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group ltr501_attribute_group = {
 	.attrs = ltr501_attributes,
 };

 static const struct iio_info ltr501_info = {
 	.read_raw = ltr501_read_raw,
 	.write_raw = ltr501_write_raw,
 	.attrs = &ltr501_attribute_group,
 	.driver_module = THIS_MODULE,
 };

 static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
 {
 	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
 	if (ret < 0)
 		return ret;

 	return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
 }

 static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct ltr501_data *data = iio_priv(indio_dev);
 	u16 buf[8];
 	__le16 als_buf[2];
 	u8 mask = 0;
 	int j = 0;
 	int ret;

 	memset(buf, 0, sizeof(buf));

 	/* figure out which data needs to be ready */
 	if (test_bit(0, indio_dev->active_scan_mask) ||
 		test_bit(1, indio_dev->active_scan_mask))
 		mask |= LTR501_STATUS_ALS_RDY;
 	if (test_bit(2, indio_dev->active_scan_mask))
 		mask |= LTR501_STATUS_PS_RDY;

 	ret = ltr501_drdy(data, mask);
 	if (ret < 0)
 		goto done;

 	if (mask & LTR501_STATUS_ALS_RDY) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,
 			LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);
 		if (ret < 0)
 			return ret;
 		if (test_bit(0, indio_dev->active_scan_mask))
 			buf[j++] = le16_to_cpu(als_buf[1]);
 		if (test_bit(1, indio_dev->active_scan_mask))
 			buf[j++] = le16_to_cpu(als_buf[0]);
 	}

 	if (mask & LTR501_STATUS_PS_RDY) {
 		ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
 		if (ret < 0)
 			goto done;
 		buf[j++] = ret & LTR501_PS_DATA_MASK;
 	}

 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
 		iio_get_time_ns());

 done:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int ltr501_init(struct ltr501_data *data)
 {
 	int ret;

 	ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
 	if (ret < 0)
 		return ret;
 	data->als_contr = ret | LTR501_CONTR_ACTIVE;

 	ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
 	if (ret < 0)
 		return ret;
 	data->ps_contr = ret | LTR501_CONTR_ACTIVE;

 	return ltr501_write_contr(data->client, data->als_contr,
 		data->ps_contr);
 }

 static int ltr501_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
 	struct ltr501_data *data;
 	struct iio_dev *indio_dev;
 	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;
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);

 	ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
 	if (ret < 0)
 		return ret;
 	if ((ret >> 4) != 0x8)
 		return -ENODEV;

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->info = &ltr501_info;
 	indio_dev->channels = ltr501_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
 	indio_dev->name = LTR501_DRV_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	ret = ltr501_init(data);
 	if (ret < 0)
 		return ret;

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 		ltr501_trigger_handler, NULL);
 	if (ret)
 		return ret;

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_unreg_buffer;

 	return 0;

 error_unreg_buffer:
 	iio_triggered_buffer_cleanup(indio_dev);
 	return ret;
 }

 static int ltr501_powerdown(struct ltr501_data *data)
 {
 	return ltr501_write_contr(data->client,
 		data->als_contr & ~LTR501_CONTR_ACTIVE,
 		data->ps_contr & ~LTR501_CONTR_ACTIVE);
 }

 static int ltr501_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);

 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);
 	ltr501_powerdown(iio_priv(indio_dev));

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int ltr501_suspend(struct device *dev)
 {
 	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
 		to_i2c_client(dev)));
 	return ltr501_powerdown(data);
 }

 static int ltr501_resume(struct device *dev)
 {
 	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
 		to_i2c_client(dev)));

 	return ltr501_write_contr(data->client, data->als_contr,
 		data->ps_contr);
 }
 #endif

 static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);

 static const struct i2c_device_id ltr501_id[] = {
 	{ "ltr501", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ltr501_id);

 static struct i2c_driver ltr501_driver = {
 	.driver = {
 		.name   = LTR501_DRV_NAME,
 		.pm	= &ltr501_pm_ops,
 		.owner  = THIS_MODULE,
 	},
 	.probe  = ltr501_probe,
 	.remove	= ltr501_remove,
 	.id_table = ltr501_id,
 };

 module_i2c_driver(ltr501_driver);

 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
 MODULE_LICENSE("GPL");
	/*
	* ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
	*
	* Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
	*
	* 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.
	*
	* 7-bit I2C slave address 0x23
	*
	* TODO: interrupt, threshold, measurement rate, IR LED characteristics
	*/

	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/err.h>
	#include <linux/delay.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/triggered_buffer.h>

	#define LTR501_DRV_NAME "ltr501"

	#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
	#define LTR501_PS_CONTR 0x81 /* PS operation mode */
	#define LTR501_PART_ID 0x86
	#define LTR501_MANUFAC_ID 0x87
	#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
	#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
	#define LTR501_ALS_PS_STATUS 0x8c
	#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */

	#define LTR501_ALS_CONTR_SW_RESET BIT(2)
	#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) \| BIT(2))
	#define LTR501_CONTR_PS_GAIN_SHIFT 2
	#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
	#define LTR501_CONTR_ACTIVE BIT(1)

	#define LTR501_STATUS_ALS_RDY BIT(2)
	#define LTR501_STATUS_PS_RDY BIT(0)

	#define LTR501_PS_DATA_MASK 0x7ff

	struct ltr501_data {
	struct i2c_client *client;
	struct mutex lock_als, lock_ps;
	u8 als_contr, ps_contr;
	};

	static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
	{
	int tries = 100;
	int ret;

	while (tries--) {
	ret = i2c_smbus_read_byte_data(data->client,
	LTR501_ALS_PS_STATUS);
	if (ret < 0)
	return ret;
	if ((ret & drdy_mask) == drdy_mask)
	return 0;
	msleep(25);
	}

	dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
	return -EIO;
	}

	static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
	{
	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
	if (ret < 0)
	return ret;
	/* always read both ALS channels in given order */
	return i2c_smbus_read_i2c_block_data(data->client,
	LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);
	}

	static int ltr501_read_ps(struct ltr501_data *data)
	{
	int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
	if (ret < 0)
	return ret;
	return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
	}

	#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
	.type = IIO_INTENSITY, \
	.modified = 1, \
	.address = (_addr), \
	.channel2 = (_mod), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = (_shared), \
	.scan_index = (_idx), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 16, \
	.storagebits = 16, \
	.endianness = IIO_CPU, \
	} \
	}

	static const struct iio_chan_spec ltr501_channels[] = {
	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
	BIT(IIO_CHAN_INFO_SCALE)),
	{
	.type = IIO_PROXIMITY,
	.address = LTR501_PS_DATA,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
	BIT(IIO_CHAN_INFO_SCALE),
	.scan_index = 2,
	.scan_type = {
	.sign = 'u',
	.realbits = 11,
	.storagebits = 16,
	.endianness = IIO_CPU,
	},
	},
	IIO_CHAN_SOFT_TIMESTAMP(3),
	};

	static const int ltr501_ps_gain[4][2] = {
	{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
	};

	static int ltr501_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct ltr501_data *data = iio_priv(indio_dev);
	__le16 buf[2];
	int ret, i;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	if (iio_buffer_enabled(indio_dev))
	return -EBUSY;

	switch (chan->type) {
	case IIO_INTENSITY:
	mutex_lock(&data->lock_als);
	ret = ltr501_read_als(data, buf);
	mutex_unlock(&data->lock_als);
	if (ret < 0)
	return ret;
	*val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
	buf[0] : buf[1]);
	return IIO_VAL_INT;
	case IIO_PROXIMITY:
	mutex_lock(&data->lock_ps);
	ret = ltr501_read_ps(data);
	mutex_unlock(&data->lock_ps);
	if (ret < 0)
	return ret;
	*val = ret & LTR501_PS_DATA_MASK;
	return IIO_VAL_INT;
	default:
	return -EINVAL;
	}
	case IIO_CHAN_INFO_SCALE:
	switch (chan->type) {
	case IIO_INTENSITY:
	if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
	*val = 0;
	*val2 = 5000;
	return IIO_VAL_INT_PLUS_MICRO;
	} else {
	*val = 1;
	*val2 = 0;
	return IIO_VAL_INT;
	}
	case IIO_PROXIMITY:
	i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
	LTR501_CONTR_PS_GAIN_SHIFT;
	*val = ltr501_ps_gain[i][0];
	*val2 = ltr501_ps_gain[i][1];
	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	}
	return -EINVAL;
	}

	static int ltr501_get_ps_gain_index(int val, int val2)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
	if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
	return i;

	return -1;
	}

	static int ltr501_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct ltr501_data *data = iio_priv(indio_dev);
	int i;

	if (iio_buffer_enabled(indio_dev))
	return -EBUSY;

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
	switch (chan->type) {
	case IIO_INTENSITY:
	if (val == 0 && val2 == 5000)
	data->als_contr \|= LTR501_CONTR_ALS_GAIN_MASK;
	else if (val == 1 && val2 == 0)
	data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
	else
	return -EINVAL;
	return i2c_smbus_write_byte_data(data->client,
	LTR501_ALS_CONTR, data->als_contr);
	case IIO_PROXIMITY:
	i = ltr501_get_ps_gain_index(val, val2);
	if (i < 0)
	return -EINVAL;
	data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
	data->ps_contr \|= i << LTR501_CONTR_PS_GAIN_SHIFT;
	return i2c_smbus_write_byte_data(data->client,
	LTR501_PS_CONTR, data->ps_contr);
	default:
	return -EINVAL;
	}
	}
	return -EINVAL;
	}

	static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
	static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");

	static struct attribute *ltr501_attributes[] = {
	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
	NULL
	};

	static const struct attribute_group ltr501_attribute_group = {
	.attrs = ltr501_attributes,
	};

	static const struct iio_info ltr501_info = {
	.read_raw = ltr501_read_raw,
	.write_raw = ltr501_write_raw,
	.attrs = &ltr501_attribute_group,
	.driver_module = THIS_MODULE,
	};

	static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
	{
	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
	if (ret < 0)
	return ret;

	return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
	}

	static irqreturn_t ltr501_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ltr501_data *data = iio_priv(indio_dev);
	u16 buf[8];
	__le16 als_buf[2];
	u8 mask = 0;
	int j = 0;
	int ret;

	memset(buf, 0, sizeof(buf));

	/* figure out which data needs to be ready */
	if (test_bit(0, indio_dev->active_scan_mask) \|\|
	test_bit(1, indio_dev->active_scan_mask))
	mask \|= LTR501_STATUS_ALS_RDY;
	if (test_bit(2, indio_dev->active_scan_mask))
	mask \|= LTR501_STATUS_PS_RDY;

	ret = ltr501_drdy(data, mask);
	if (ret < 0)
	goto done;

	if (mask & LTR501_STATUS_ALS_RDY) {
	ret = i2c_smbus_read_i2c_block_data(data->client,
	LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);
	if (ret < 0)
	return ret;
	if (test_bit(0, indio_dev->active_scan_mask))
	buf[j++] = le16_to_cpu(als_buf[1]);
	if (test_bit(1, indio_dev->active_scan_mask))
	buf[j++] = le16_to_cpu(als_buf[0]);
	}

	if (mask & LTR501_STATUS_PS_RDY) {
	ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
	if (ret < 0)
	goto done;
	buf[j++] = ret & LTR501_PS_DATA_MASK;
	}

	iio_push_to_buffers_with_timestamp(indio_dev, buf,
	iio_get_time_ns());

	done:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int ltr501_init(struct ltr501_data *data)
	{
	int ret;

	ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
	if (ret < 0)
	return ret;
	data->als_contr = ret \| LTR501_CONTR_ACTIVE;

	ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
	if (ret < 0)
	return ret;
	data->ps_contr = ret \| LTR501_CONTR_ACTIVE;

	return ltr501_write_contr(data->client, data->als_contr,
	data->ps_contr);
	}

	static int ltr501_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct ltr501_data *data;
	struct iio_dev *indio_dev;
	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;
	mutex_init(&data->lock_als);
	mutex_init(&data->lock_ps);

	ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
	if (ret < 0)
	return ret;
	if ((ret >> 4) != 0x8)
	return -ENODEV;

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &ltr501_info;
	indio_dev->channels = ltr501_channels;
	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
	indio_dev->name = LTR501_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = ltr501_init(data);
	if (ret < 0)
	return ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	ltr501_trigger_handler, NULL);
	if (ret)
	return ret;

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_unreg_buffer;

	return 0;

	error_unreg_buffer:
	iio_triggered_buffer_cleanup(indio_dev);
	return ret;
	}

	static int ltr501_powerdown(struct ltr501_data *data)
	{
	return ltr501_write_contr(data->client,
	data->als_contr & ~LTR501_CONTR_ACTIVE,
	data->ps_contr & ~LTR501_CONTR_ACTIVE);
	}

	static int ltr501_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	ltr501_powerdown(iio_priv(indio_dev));

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int ltr501_suspend(struct device *dev)
	{
	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
	to_i2c_client(dev)));
	return ltr501_powerdown(data);
	}

	static int ltr501_resume(struct device *dev)
	{
	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
	to_i2c_client(dev)));

	return ltr501_write_contr(data->client, data->als_contr,
	data->ps_contr);
	}
	#endif

	static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);

	static const struct i2c_device_id ltr501_id[] = {
	{ "ltr501", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, ltr501_id);

	static struct i2c_driver ltr501_driver = {
	.driver = {
	.name = LTR501_DRV_NAME,
	.pm = &ltr501_pm_ops,
	.owner = THIS_MODULE,
	},
	.probe = ltr501_probe,
	.remove = ltr501_remove,
	.id_table = ltr501_id,
	};

	module_i2c_driver(ltr501_driver);

	MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
	MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
	MODULE_LICENSE("GPL");