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Commit 94a9b7b1 authored by Andreas Dannenberg's avatar Andreas Dannenberg Committed by Jonathan Cameron
Browse files

iio: light: add support for TI's opt3001 light sensor 

TI's opt3001 light sensor is a simple and yet powerful
little device. The device provides 99% IR rejection,
automatic full-scale, very low power consumption and
measurements from 0.01 to 83k lux.

This patch adds support for that device using the IIO
framework.

See http://www.ti.com/product/opt3001

 for more information.

Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarAndreas Dannenberg <dannenberg@ti.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 081d9740

drivers/iio/light/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -209,6 +209,16 @@ config LTR501 
	 This driver can also be built as a module.  If so, the module

         will be called ltr501.



config OPT3001

	tristate "Texas Instruments OPT3001 Light Sensor"

	depends on I2C

	help

	  If you say Y or M here, you get support for Texas Instruments

	  OPT3001 Ambient Light Sensor.



	  If built as a dynamically linked module, it will be called

	  opt3001.



config STK3310

	tristate "STK3310 ALS and proximity sensor"

	depends on I2C

drivers/iio/light/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ obj-$(CONFIG_ISL29125) += isl29125.o 
obj-$(CONFIG_JSA1212)		+= jsa1212.o

obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o

obj-$(CONFIG_LTR501)		+= ltr501.o

obj-$(CONFIG_OPT3001)		+= opt3001.o

obj-$(CONFIG_RPR0521)		+= rpr0521.o

obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o

obj-$(CONFIG_STK3310)          += stk3310.o

drivers/iio/light/opt3001.c

0 → 100644
+804 −0
Original line number Diff line number Diff line 
/**

 * opt3001.c - Texas Instruments OPT3001 Light Sensor

 *

 * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com

 *

 * Author: Andreas Dannenberg <dannenberg@ti.com>

 * Based on previous work from: Felipe Balbi <balbi@ti.com>

 *

 * This program is free software: you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 of the License

 * as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 */



#include <linux/bitops.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/slab.h>

#include <linux/types.h>



#include <linux/iio/events.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>



#define OPT3001_RESULT		0x00

#define OPT3001_CONFIGURATION	0x01

#define OPT3001_LOW_LIMIT	0x02

#define OPT3001_HIGH_LIMIT	0x03

#define OPT3001_MANUFACTURER_ID	0x7e

#define OPT3001_DEVICE_ID	0x7f



#define OPT3001_CONFIGURATION_RN_MASK	(0xf << 12)

#define OPT3001_CONFIGURATION_RN_AUTO	(0xc << 12)



#define OPT3001_CONFIGURATION_CT	BIT(11)



#define OPT3001_CONFIGURATION_M_MASK	(3 << 9)

#define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9)

#define OPT3001_CONFIGURATION_M_SINGLE	(1 << 9)

#define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */



#define OPT3001_CONFIGURATION_OVF	BIT(8)

#define OPT3001_CONFIGURATION_CRF	BIT(7)

#define OPT3001_CONFIGURATION_FH	BIT(6)

#define OPT3001_CONFIGURATION_FL	BIT(5)

#define OPT3001_CONFIGURATION_L		BIT(4)

#define OPT3001_CONFIGURATION_POL	BIT(3)

#define OPT3001_CONFIGURATION_ME	BIT(2)



#define OPT3001_CONFIGURATION_FC_MASK	(3 << 0)



/* The end-of-conversion enable is located in the low-limit register */

#define OPT3001_LOW_LIMIT_EOC_ENABLE	0xc000



#define OPT3001_REG_EXPONENT(n)		((n) >> 12)

#define OPT3001_REG_MANTISSA(n)		((n) & 0xfff)



/*

 * Time to wait for conversion result to be ready. The device datasheet

 * worst-case max value is 880ms. Add some slack to be on the safe side.

 */

#define OPT3001_RESULT_READY_TIMEOUT	msecs_to_jiffies(1000)



struct opt3001 {

	struct i2c_client	*client;

	struct device		*dev;



	struct mutex		lock;

	u16			ok_to_ignore_lock:1;

	u16			result_ready:1;

	wait_queue_head_t	result_ready_queue;

	u16			result;



	u32			int_time;

	u32			mode;



	u16			high_thresh_mantissa;

	u16			low_thresh_mantissa;



	u8			high_thresh_exp;

	u8			low_thresh_exp;

};



struct opt3001_scale {

	int	val;

	int	val2;

};



static const struct opt3001_scale opt3001_scales[] = {

	{

		.val = 40,

		.val2 = 950000,

	},

	{

		.val = 81,

		.val2 = 900000,

	},

	{

		.val = 163,

		.val2 = 800000,

	},

	{

		.val = 327,

		.val2 = 600000,

	},

	{

		.val = 655,

		.val2 = 200000,

	},

	{

		.val = 1310,

		.val2 = 400000,

	},

	{

		.val = 2620,

		.val2 = 800000,

	},

	{

		.val = 5241,

		.val2 = 600000,

	},

	{

		.val = 10483,

		.val2 = 200000,

	},

	{

		.val = 20966,

		.val2 = 400000,

	},

	{

		.val = 83865,

		.val2 = 600000,

	},

};



static int opt3001_find_scale(const struct opt3001 *opt, int val,

		int val2, u8 *exponent)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(opt3001_scales); i++) {

		const struct opt3001_scale *scale = &opt3001_scales[i];



		/*

		 * Combine the integer and micro parts for comparison

		 * purposes. Use milli lux precision to avoid 32-bit integer

		 * overflows.

		 */

		if ((val * 1000 + val2 / 1000) <=

				(scale->val * 1000 + scale->val2 / 1000)) {

			*exponent = i;

			return 0;

		}

	}



	return -EINVAL;

}



static void opt3001_to_iio_ret(struct opt3001 *opt, u8 exponent,

		u16 mantissa, int *val, int *val2)

{

	int lux;



	lux = 10 * (mantissa << exponent);

	*val = lux / 1000;

	*val2 = (lux - (*val * 1000)) * 1000;

}



static void opt3001_set_mode(struct opt3001 *opt, u16 *reg, u16 mode)

{

	*reg &= ~OPT3001_CONFIGURATION_M_MASK;

	*reg |= mode;

	opt->mode = mode;

}



static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.8");



static struct attribute *opt3001_attributes[] = {

	&iio_const_attr_integration_time_available.dev_attr.attr,

	NULL

};



static const struct attribute_group opt3001_attribute_group = {

	.attrs = opt3001_attributes,

};



static const struct iio_event_spec opt3001_event_spec[] = {

	{

		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_RISING,

		.mask_separate = BIT(IIO_EV_INFO_VALUE) |

			BIT(IIO_EV_INFO_ENABLE),

	},

	{

		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_FALLING,

		.mask_separate = BIT(IIO_EV_INFO_VALUE) |

			BIT(IIO_EV_INFO_ENABLE),

	},

};



static const struct iio_chan_spec opt3001_channels[] = {

	{

		.type = IIO_LIGHT,

		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |

				BIT(IIO_CHAN_INFO_INT_TIME),

		.event_spec = opt3001_event_spec,

		.num_event_specs = ARRAY_SIZE(opt3001_event_spec),

	},

	IIO_CHAN_SOFT_TIMESTAMP(1),

};



static int opt3001_get_lux(struct opt3001 *opt, int *val, int *val2)

{

	int ret;

	u16 mantissa;

	u16 reg;

	u8 exponent;

	u16 value;



	/*

	 * Enable the end-of-conversion interrupt mechanism. Note that doing

	 * so will overwrite the low-level limit value however we will restore

	 * this value later on.

	 */

	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,

			OPT3001_LOW_LIMIT_EOC_ENABLE);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_LOW_LIMIT);

		return ret;

	}



	/* Reset data-ready indicator flag (will be set in the IRQ routine) */

	opt->result_ready = false;



	/* Allow IRQ to access the device despite lock being set */

	opt->ok_to_ignore_lock = true;



	/* Configure for single-conversion mode and start a new conversion */

	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		goto err;

	}



	reg = ret;

	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SINGLE);



	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,

			reg);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_CONFIGURATION);

		goto err;

	}



	/* Wait for the IRQ to indicate the conversion is complete */

	ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready,

			OPT3001_RESULT_READY_TIMEOUT);



err:

	/* Disallow IRQ to access the device while lock is active */

	opt->ok_to_ignore_lock = false;



	if (ret == 0)

		return -ETIMEDOUT;

	else if (ret < 0)

		return ret;



	/*

	 * Disable the end-of-conversion interrupt mechanism by restoring the

	 * low-level limit value (clearing OPT3001_LOW_LIMIT_EOC_ENABLE). Note

	 * that selectively clearing those enable bits would affect the actual

	 * limit value due to bit-overlap and therefore can't be done.

	 */

	value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa;

	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,

			value);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_LOW_LIMIT);

		return ret;

	}



	exponent = OPT3001_REG_EXPONENT(opt->result);

	mantissa = OPT3001_REG_MANTISSA(opt->result);



	opt3001_to_iio_ret(opt, exponent, mantissa, val, val2);



	return IIO_VAL_INT_PLUS_MICRO;

}



static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2)

{

	*val = 0;

	*val2 = opt->int_time;



	return IIO_VAL_INT_PLUS_MICRO;

}



static int opt3001_set_int_time(struct opt3001 *opt, int time)

{

	int ret;

	u16 reg;



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		return ret;

	}



	reg = ret;



	switch (time) {

	case 100000:

		reg &= ~OPT3001_CONFIGURATION_CT;

		opt->int_time = 100000;

		break;

	case 800000:

		reg |= OPT3001_CONFIGURATION_CT;

		opt->int_time = 800000;

		break;

	default:

		return -EINVAL;

	}



	return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,

			reg);

}



static int opt3001_read_raw(struct iio_dev *iio,

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

		long mask)

{

	struct opt3001 *opt = iio_priv(iio);

	int ret;



	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)

		return -EBUSY;



	if (chan->type != IIO_LIGHT)

		return -EINVAL;



	mutex_lock(&opt->lock);



	switch (mask) {

	case IIO_CHAN_INFO_PROCESSED:

		ret = opt3001_get_lux(opt, val, val2);

		break;

	case IIO_CHAN_INFO_INT_TIME:

		ret = opt3001_get_int_time(opt, val, val2);

		break;

	default:

		ret = -EINVAL;

	}



	mutex_unlock(&opt->lock);



	return ret;

}



static int opt3001_write_raw(struct iio_dev *iio,

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

		long mask)

{

	struct opt3001 *opt = iio_priv(iio);

	int ret;



	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)

		return -EBUSY;



	if (chan->type != IIO_LIGHT)

		return -EINVAL;



	if (mask != IIO_CHAN_INFO_INT_TIME)

		return -EINVAL;



	if (val != 0)

		return -EINVAL;



	mutex_lock(&opt->lock);

	ret = opt3001_set_int_time(opt, val2);

	mutex_unlock(&opt->lock);



	return ret;

}



static int opt3001_read_event_value(struct iio_dev *iio,

		const struct iio_chan_spec *chan, enum iio_event_type type,

		enum iio_event_direction dir, enum iio_event_info info,

		int *val, int *val2)

{

	struct opt3001 *opt = iio_priv(iio);

	int ret = IIO_VAL_INT_PLUS_MICRO;



	mutex_lock(&opt->lock);



	switch (dir) {

	case IIO_EV_DIR_RISING:

		opt3001_to_iio_ret(opt, opt->high_thresh_exp,

				opt->high_thresh_mantissa, val, val2);

		break;

	case IIO_EV_DIR_FALLING:

		opt3001_to_iio_ret(opt, opt->low_thresh_exp,

				opt->low_thresh_mantissa, val, val2);

		break;

	default:

		ret = -EINVAL;

	}



	mutex_unlock(&opt->lock);



	return ret;

}



static int opt3001_write_event_value(struct iio_dev *iio,

		const struct iio_chan_spec *chan, enum iio_event_type type,

		enum iio_event_direction dir, enum iio_event_info info,

		int val, int val2)

{

	struct opt3001 *opt = iio_priv(iio);

	int ret;



	u16 mantissa;

	u16 value;

	u16 reg;



	u8 exponent;



	if (val < 0)

		return -EINVAL;



	mutex_lock(&opt->lock);



	ret = opt3001_find_scale(opt, val, val2, &exponent);

	if (ret < 0) {

		dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2);

		goto err;

	}



	mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent;

	value = (exponent << 12) | mantissa;



	switch (dir) {

	case IIO_EV_DIR_RISING:

		reg = OPT3001_HIGH_LIMIT;

		opt->high_thresh_mantissa = mantissa;

		opt->high_thresh_exp = exponent;

		break;

	case IIO_EV_DIR_FALLING:

		reg = OPT3001_LOW_LIMIT;

		opt->low_thresh_mantissa = mantissa;

		opt->low_thresh_exp = exponent;

		break;

	default:

		ret = -EINVAL;

		goto err;

	}



	ret = i2c_smbus_write_word_swapped(opt->client, reg, value);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n", reg);

		goto err;

	}



err:

	mutex_unlock(&opt->lock);



	return ret;

}



static int opt3001_read_event_config(struct iio_dev *iio,

		const struct iio_chan_spec *chan, enum iio_event_type type,

		enum iio_event_direction dir)

{

	struct opt3001 *opt = iio_priv(iio);



	return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS;

}



static int opt3001_write_event_config(struct iio_dev *iio,

		const struct iio_chan_spec *chan, enum iio_event_type type,

		enum iio_event_direction dir, int state)

{

	struct opt3001 *opt = iio_priv(iio);

	int ret;

	u16 mode;

	u16 reg;



	if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)

		return 0;



	if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)

		return 0;



	mutex_lock(&opt->lock);



	mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS

		: OPT3001_CONFIGURATION_M_SHUTDOWN;



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		goto err;

	}



	reg = ret;

	opt3001_set_mode(opt, &reg, mode);



	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,

			reg);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_CONFIGURATION);

		goto err;

	}



err:

	mutex_unlock(&opt->lock);



	return ret;

}



static const struct iio_info opt3001_info = {

	.driver_module = THIS_MODULE,

	.attrs = &opt3001_attribute_group,

	.read_raw = opt3001_read_raw,

	.write_raw = opt3001_write_raw,

	.read_event_value = opt3001_read_event_value,

	.write_event_value = opt3001_write_event_value,

	.read_event_config = opt3001_read_event_config,

	.write_event_config = opt3001_write_event_config,

};



static int opt3001_read_id(struct opt3001 *opt)

{

	char manufacturer[2];

	u16 device_id;

	int ret;



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_MANUFACTURER_ID);

		return ret;

	}



	manufacturer[0] = ret >> 8;

	manufacturer[1] = ret & 0xff;



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_DEVICE_ID);

		return ret;

	}



	device_id = ret;



	dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0],

			manufacturer[1], device_id);



	return 0;

}



static int opt3001_configure(struct opt3001 *opt)

{

	int ret;

	u16 reg;



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		return ret;

	}



	reg = ret;



	/* Enable automatic full-scale setting mode */

	reg &= ~OPT3001_CONFIGURATION_RN_MASK;

	reg |= OPT3001_CONFIGURATION_RN_AUTO;



	/* Reflect status of the device's integration time setting */

	if (reg & OPT3001_CONFIGURATION_CT)

		opt->int_time = 800000;

	else

		opt->int_time = 100000;



	/* Ensure device is in shutdown initially */

	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);



	/* Configure for latched window-style comparison operation */

	reg |= OPT3001_CONFIGURATION_L;

	reg &= ~OPT3001_CONFIGURATION_POL;

	reg &= ~OPT3001_CONFIGURATION_ME;

	reg &= ~OPT3001_CONFIGURATION_FC_MASK;



	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,

			reg);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_CONFIGURATION);

		return ret;

	}



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_LOW_LIMIT);

		return ret;

	}



	opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret);

	opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret);



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_HIGH_LIMIT);

		return ret;

	}



	opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret);

	opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret);



	return 0;

}



static irqreturn_t opt3001_irq(int irq, void *_iio)

{

	struct iio_dev *iio = _iio;

	struct opt3001 *opt = iio_priv(iio);

	int ret;



	if (!opt->ok_to_ignore_lock)

		mutex_lock(&opt->lock);



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		goto out;

	}



	if ((ret & OPT3001_CONFIGURATION_M_MASK) ==

			OPT3001_CONFIGURATION_M_CONTINUOUS) {

		if (ret & OPT3001_CONFIGURATION_FH)

			iio_push_event(iio,

					IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,

							IIO_EV_TYPE_THRESH,

							IIO_EV_DIR_RISING),

					iio_get_time_ns());

		if (ret & OPT3001_CONFIGURATION_FL)

			iio_push_event(iio,

					IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,

							IIO_EV_TYPE_THRESH,

							IIO_EV_DIR_FALLING),

					iio_get_time_ns());

	} else if (ret & OPT3001_CONFIGURATION_CRF) {

		ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);

		if (ret < 0) {

			dev_err(opt->dev, "failed to read register %02x\n",

					OPT3001_RESULT);

			goto out;

		}

		opt->result = ret;

		opt->result_ready = true;

		wake_up(&opt->result_ready_queue);

	}



out:

	if (!opt->ok_to_ignore_lock)

		mutex_unlock(&opt->lock);



	return IRQ_HANDLED;

}



static int opt3001_probe(struct i2c_client *client,

		const struct i2c_device_id *id)

{

	struct device *dev = &client->dev;



	struct iio_dev *iio;

	struct opt3001 *opt;

	int irq = client->irq;

	int ret;



	iio = devm_iio_device_alloc(dev, sizeof(*opt));

	if (!iio)

		return -ENOMEM;



	opt = iio_priv(iio);

	opt->client = client;

	opt->dev = dev;



	mutex_init(&opt->lock);

	init_waitqueue_head(&opt->result_ready_queue);

	i2c_set_clientdata(client, iio);



	ret = opt3001_read_id(opt);

	if (ret)

		return ret;



	ret = opt3001_configure(opt);

	if (ret)

		return ret;



	iio->name = client->name;

	iio->channels = opt3001_channels;

	iio->num_channels = ARRAY_SIZE(opt3001_channels);

	iio->dev.parent = dev;

	iio->modes = INDIO_DIRECT_MODE;

	iio->info = &opt3001_info;



	ret = devm_iio_device_register(dev, iio);

	if (ret) {

		dev_err(dev, "failed to register IIO device\n");

		return ret;

	}



	ret = request_threaded_irq(irq, NULL, opt3001_irq,

			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,

			"opt3001", iio);

	if (ret) {

		dev_err(dev, "failed to request IRQ #%d\n", irq);

		return ret;

	}



	return 0;

}



static int opt3001_remove(struct i2c_client *client)

{

	struct iio_dev *iio = i2c_get_clientdata(client);

	struct opt3001 *opt = iio_priv(iio);

	int ret;

	u16 reg;



	free_irq(client->irq, iio);



	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);

	if (ret < 0) {

		dev_err(opt->dev, "failed to read register %02x\n",

				OPT3001_CONFIGURATION);

		return ret;

	}



	reg = ret;

	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);



	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,

			reg);

	if (ret < 0) {

		dev_err(opt->dev, "failed to write register %02x\n",

				OPT3001_CONFIGURATION);

		return ret;

	}



	return 0;

}



static const struct i2c_device_id opt3001_id[] = {

	{ "opt3001", 0 },

	{ } /* Terminating Entry */

};

MODULE_DEVICE_TABLE(i2c, opt3001_id);



static const struct of_device_id opt3001_of_match[] = {

	{ .compatible = "ti,opt3001" },

	{ }

};



static struct i2c_driver opt3001_driver = {

	.probe = opt3001_probe,

	.remove = opt3001_remove,

	.id_table = opt3001_id,



	.driver = {

		.name = "opt3001",

		.of_match_table = of_match_ptr(opt3001_of_match),

		.owner = THIS_MODULE,

	},

};



module_i2c_driver(opt3001_driver);



MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");

MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");