Re: [PATCH v4] iio: light: Adding driver for ISL29018 ALS

[Jonathan Cameron <jic23-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org>]

On 10/06/10 22:25, rklein-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org wrote:
> From: Rhyland Klein <rklein-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> Adding support for the ISL 29018 ambient light and proximity sensor.
> 
> Addressed comments from reviews by Jonathan Cameron and Joe Perches
>   * Removed some excess dbg prints that only printed function name
>   * Renamed some properties to make them more descriptive
>   * Added a property to list available adc resolutions
>   * Defined arrays for resolutions/ranges as static const
>   * Change loops initialization to memset for extensibility.
>     * used sizeof() instead of ARRAY_SIZE() to be safer
>   * Added a property to list available adc ranges
One typo in the documentation you will want to fix.
Otherwise, I'm happy.
> 
> Signed-off-by: Rhyland Klein <rklein-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Acked-by: Jonathan Cameron <jic23-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org>

Please send a copy to Greg KH <greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org> for merging
> ---
>  .../staging/iio/Documentation/sysfs-bus-iio-light  |   64 +++
>  drivers/staging/iio/light/Kconfig                  |   11 +
>  drivers/staging/iio/light/Makefile                 |    1 +
>  drivers/staging/iio/light/isl29018.c               |  563 ++++++++++++++++++++
>  4 files changed, 639 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/staging/iio/Documentation/sysfs-bus-iio-light
>  create mode 100755 drivers/staging/iio/light/isl29018.c
> 
> diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-light b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> new file mode 100644
> index 0000000..2f7d9c5
> --- /dev/null
> +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> @@ -0,0 +1,64 @@
> +
> +What:		/sys/bus/iio/devices/device[n]/range
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Hardware dependent ADC Full Scale Range used for some ambient
> +		light sensors in calculating lux.
> +
> +What:		/sys/bus/iio/devices/device[n]/range_available
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Hardware dependent supported vales for ADC Full Scale Range.
> +
> +What:		/sys/bus/iio/devices/device[n]/adc_resolution
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Hardware dependent ADC resolution of the ambient light sensor
> +		used in calculating the lux.
> +
> +What:		/sys/bus/iio/devices/device[n]/adc_resolution_available
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Hardware dependent list of possible values supported for the
> +		adc_resolution of the given sensor.
> +
> +What:		/sys/bus/iio/devices/device[n]/illuminance0[_input|_raw]
> +KernelVersion:	2.6.35
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		This should return the calculated lux from the light sensor. If
> +		it comes back in SI units, it should also inclue _input else it
typo inclue -> include.
> +		should include _raw to signify it is not in SI units.
> +
> +What:		/sys/.../device[n]/proximity_on_chip_ambient_infrared_supression
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Hardware dependent mode for an ALS device to calculate the value
> +		in proximity mode. When this is enabled, then the device should
> +		use a infrared sensor reading to remove infrared noise from the
> +		proximity reading. If this is not enabled, the driver can still
> +		do this calculation manually by reading the infrared sensor
> +		value and doing the negation in sw.
> +
> +What:		/sys/bus/iio/devices/device[n]/proximity[_input|_raw]
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		This property is supported by proximity sensors and should be
> +		used to return the value of a reading by the sensor. If this
> +		value is returned in SI units, it should also include _input
> +		but if it is not, then it should include _raw.
> +
> +What:		/sys/bus/iio/devices/device[n]/intensity_infrared[_input|_raw]
> +KernelVersion:	2.6.37
> +Contact:	linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		This property is supported by sensors that have an infrared
> +		sensing mode. This value should be the output from a reading
> +		and if expressed in SI units, should include _input. If this
> +		value is not in SI units, then it should include _raw.
> diff --git a/drivers/staging/iio/light/Kconfig b/drivers/staging/iio/light/Kconfig
> index 80cb6e5..36d8bbe 100644
> --- a/drivers/staging/iio/light/Kconfig
> +++ b/drivers/staging/iio/light/Kconfig
> @@ -13,3 +13,14 @@ config SENSORS_TSL2563
>  	 This driver can also be built as a module.  If so, the module
>  	 will be called tsl2563.
>  
> +config SENSORS_ISL29018
> +        tristate "ISL 29018 light and proximity sensor"
> +        depends on I2C
> +        default n
> +        help
> +         If you say yes here you get support for ambient light sensing and
> +         proximity infrared sensing from Intersil ISL29018.
> +         This driver will provide the measurements of ambient light intensity
> +         in lux, proximity infrared sensing and normal infrared sensing.
> +         Data from sensor is accessible via sysfs.
> +
> diff --git a/drivers/staging/iio/light/Makefile b/drivers/staging/iio/light/Makefile
> index 30f3300..9142c0e 100644
> --- a/drivers/staging/iio/light/Makefile
> +++ b/drivers/staging/iio/light/Makefile
> @@ -3,3 +3,4 @@
>  #
>  
>  obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
> +obj-$(CONFIG_SENSORS_ISL29018)	+= isl29018.o
> diff --git a/drivers/staging/iio/light/isl29018.c b/drivers/staging/iio/light/isl29018.c
> new file mode 100755
> index 0000000..c83f39f
> --- /dev/null
> +++ b/drivers/staging/iio/light/isl29018.c
> @@ -0,0 +1,563 @@
> +/*
> + * A iio driver for the light sensor ISL 29018.
> + *
> + * IIO driver for monitoring ambient light intensity in luxi, proximity
> + * sensing and infrared sensing.
> + *
> + * Copyright (c) 2010, NVIDIA Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA	02110-1301, USA.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include "../iio.h"
> +
> +#define CONVERSION_TIME_MS		100
> +
> +#define ISL29018_REG_ADD_COMMAND1	0x00
> +#define COMMMAND1_OPMODE_SHIFT		5
> +#define COMMMAND1_OPMODE_MASK		(7 << COMMMAND1_OPMODE_SHIFT)
> +#define COMMMAND1_OPMODE_POWER_DOWN	0
> +#define COMMMAND1_OPMODE_ALS_ONCE	1
> +#define COMMMAND1_OPMODE_IR_ONCE	2
> +#define COMMMAND1_OPMODE_PROX_ONCE	3
> +
> +#define ISL29018_REG_ADD_COMMANDII	0x01
> +#define COMMANDII_RESOLUTION_SHIFT	2
> +#define COMMANDII_RESOLUTION_MASK	(0x3 << COMMANDII_RESOLUTION_SHIFT)
> +
> +#define COMMANDII_RANGE_SHIFT		0
> +#define COMMANDII_RANGE_MASK		(0x3 << COMMANDII_RANGE_SHIFT)
> +
> +#define COMMANDII_SCHEME_SHIFT		7
> +#define COMMANDII_SCHEME_MASK		(0x1 << COMMANDII_SCHEME_SHIFT)
> +
> +#define ISL29018_REG_ADD_DATA_LSB	0x02
> +#define ISL29018_REG_ADD_DATA_MSB	0x03
> +#define ISL29018_MAX_REGS		ISL29018_REG_ADD_DATA_MSB
> +
> +struct isl29018_chip {
> +	struct iio_dev		*indio_dev;
> +	struct i2c_client	*client;
> +	struct mutex		lock;
> +	unsigned int		range;
> +	unsigned int		adc_bit;
> +	int			prox_scheme;
> +	u8			reg_cache[ISL29018_MAX_REGS];
> +};
> +
> +static int isl29018_write_data(struct i2c_client *client, u8 reg,
> +			u8 val, u8 mask, u8 shift)
> +{
> +	u8 regval;
> +	int ret = 0;
> +	struct isl29018_chip *chip = i2c_get_clientdata(client);
> +
> +	regval = chip->reg_cache[reg];
> +	regval &= ~mask;
> +	regval |= val << shift;
> +
> +	ret = i2c_smbus_write_byte_data(client, reg, regval);
> +	if (ret) {
> +		dev_err(&client->dev, "Write to device fails status %x\n", ret);
> +		return ret;
> +	}
> +	chip->reg_cache[reg] = regval;
> +
> +	return 0;
> +}
> +
> +static int isl29018_set_range(struct i2c_client *client, unsigned long range,
> +		unsigned int *new_range)
> +{
> +	static const unsigned long supp_ranges[] = {1000, 4000, 16000, 64000};
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(supp_ranges); ++i) {
> +		if (range <= supp_ranges[i]) {
> +			*new_range = (unsigned int)supp_ranges[i];
> +			break;
> +		}
> +	}
> +
> +	if (i >= ARRAY_SIZE(supp_ranges))
> +		return -EINVAL;
> +
> +	return isl29018_write_data(client, ISL29018_REG_ADD_COMMANDII,
> +			i, COMMANDII_RANGE_MASK, COMMANDII_RANGE_SHIFT);
> +}
> +
> +static int isl29018_set_resolution(struct i2c_client *client,
> +			unsigned long adcbit, unsigned int *conf_adc_bit)
> +{
> +	static const unsigned long supp_adcbit[] = {16, 12, 8, 4};
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(supp_adcbit); ++i) {
> +		if (adcbit >= supp_adcbit[i]) {
> +			*conf_adc_bit = (unsigned int)supp_adcbit[i];
> +			break;
> +		}
> +	}
> +
> +	if (i >= ARRAY_SIZE(supp_adcbit))
> +		return -EINVAL;
> +
> +	return isl29018_write_data(client, ISL29018_REG_ADD_COMMANDII,
> +			i, COMMANDII_RESOLUTION_MASK,
> +			COMMANDII_RESOLUTION_SHIFT);
> +}
> +
> +static int isl29018_read_sensor_input(struct i2c_client *client, int mode)
> +{
> +	int status;
> +	int lsb;
> +	int msb;
> +
> +	/* Set mode */
> +	status = isl29018_write_data(client, ISL29018_REG_ADD_COMMAND1,
> +			mode, COMMMAND1_OPMODE_MASK, COMMMAND1_OPMODE_SHIFT);
> +	if (status) {
> +		dev_err(&client->dev, "Error in setting operating mode\n");
> +		return status;
> +	}
> +	msleep(CONVERSION_TIME_MS);
> +	lsb = i2c_smbus_read_byte_data(client, ISL29018_REG_ADD_DATA_LSB);
> +	if (lsb < 0) {
> +		dev_err(&client->dev, "Error in reading LSB DATA\n");
> +		return lsb;
> +	}
> +
> +	msb = i2c_smbus_read_byte_data(client, ISL29018_REG_ADD_DATA_MSB);
> +	if (msb < 0) {
> +		dev_err(&client->dev, "Error in reading MSB DATA\n");
> +		return msb;
> +	}
> +	dev_vdbg(&client->dev, "MSB 0x%x and LSB 0x%x\n", msb, lsb);
> +
> +	return (msb << 8) | lsb;
> +}
> +
> +static int isl29018_read_lux(struct i2c_client *client, int *lux)
> +{
> +	int lux_data;
> +	struct isl29018_chip *chip = i2c_get_clientdata(client);
> +
> +	lux_data = isl29018_read_sensor_input(client,
> +				COMMMAND1_OPMODE_ALS_ONCE);
> +
> +	if (lux_data < 0)
> +		return lux_data;
> +
> +	*lux = (lux_data * chip->range) >> chip->adc_bit;
> +
> +	return 0;
> +}
> +
> +static int isl29018_read_ir(struct i2c_client *client, int *ir)
> +{
> +	int ir_data;
> +
> +	ir_data = isl29018_read_sensor_input(client, COMMMAND1_OPMODE_IR_ONCE);
> +
> +	if (ir_data < 0)
> +		return ir_data;
> +
> +	*ir = ir_data;
> +
> +	return 0;
> +}
> +
> +static int isl29018_read_proximity_ir(struct i2c_client *client, int scheme,
> +		int *near_ir)
> +{
> +	int status;
> +	int prox_data = -1;
> +	int ir_data = -1;
> +
> +	/* Do proximity sensing with required scheme */
> +	status = isl29018_write_data(client, ISL29018_REG_ADD_COMMANDII,
> +			scheme, COMMANDII_SCHEME_MASK, COMMANDII_SCHEME_SHIFT);
> +	if (status) {
> +		dev_err(&client->dev, "Error in setting operating mode\n");
> +		return status;
> +	}
> +
> +	prox_data = isl29018_read_sensor_input(client,
> +					COMMMAND1_OPMODE_PROX_ONCE);
> +	if (prox_data < 0)
> +		return prox_data;
> +
> +	if (scheme == 1) {
> +		*near_ir = prox_data;
> +		return 0;
> +	}
> +
> +	ir_data = isl29018_read_sensor_input(client,
> +				COMMMAND1_OPMODE_IR_ONCE);
> +
> +	if (ir_data < 0)
> +		return ir_data;
> +
> +	if (prox_data >= ir_data)
> +		*near_ir = prox_data - ir_data;
> +	else
> +		*near_ir = 0;
> +
> +	return 0;
> +}
> +
> +static ssize_t get_sensor_data(struct device *dev, char *buf, int mode)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +	struct i2c_client *client = chip->client;
> +	int value = 0;
> +	int status;
> +
> +	mutex_lock(&chip->lock);
> +	switch (mode) {
> +	case COMMMAND1_OPMODE_PROX_ONCE:
> +		status = isl29018_read_proximity_ir(client,
> +				chip->prox_scheme, &value);
> +		break;
> +
> +	case COMMMAND1_OPMODE_ALS_ONCE:
> +		status = isl29018_read_lux(client, &value);
> +		break;
> +
> +	case COMMMAND1_OPMODE_IR_ONCE:
> +		status = isl29018_read_ir(client, &value);
> +		break;
> +
> +	default:
> +		dev_err(&client->dev, "Mode %d is not supported\n", mode);
> +		mutex_unlock(&chip->lock);
> +		return -EBUSY;
> +	}
> +	if (status < 0) {
> +		dev_err(&client->dev, "Error in Reading data");
> +		mutex_unlock(&chip->lock);
> +		return status;
> +	}
> +
> +	mutex_unlock(&chip->lock);
> +
> +	return sprintf(buf, "%d\n", value);
> +}
> +
> +/* Sysfs interface */
> +/* range */
> +static ssize_t show_range(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +
> +	return sprintf(buf, "%u\n", chip->range);
> +}
> +
> +static ssize_t store_range(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +	struct i2c_client *client = chip->client;
> +	int status;
> +	unsigned long lval;
> +	unsigned int new_range;
> +
> +	if (strict_strtoul(buf, 10, &lval))
> +		return -EINVAL;
> +
> +	if (!(lval == 1000UL || lval == 4000UL ||
> +			lval == 16000UL || lval == 64000UL)) {
> +		dev_err(dev, "The range is not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	mutex_lock(&chip->lock);
> +	status = isl29018_set_range(client, lval, &new_range);
> +	if (status < 0) {
> +		mutex_unlock(&chip->lock);
> +		dev_err(dev, "Error in setting max range\n");
> +		return status;
> +	}
> +	chip->range = new_range;
> +	mutex_unlock(&chip->lock);
> +
> +	return count;
> +}
> +
> +/* resolution */
> +static ssize_t show_resolution(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +
> +	return sprintf(buf, "%u\n", chip->adc_bit);
> +}
> +
> +static ssize_t store_resolution(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +	struct i2c_client *client = chip->client;
> +	int status;
> +	unsigned long lval;
> +	unsigned int new_adc_bit;
> +
> +	if (strict_strtoul(buf, 10, &lval))
> +		return -EINVAL;
> +	if (!(lval == 4 || lval == 8 || lval == 12 || lval == 16)) {
> +		dev_err(dev, "The resolution is not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	mutex_lock(&chip->lock);
> +	status = isl29018_set_resolution(client, lval, &new_adc_bit);
> +	if (status < 0) {
> +		mutex_unlock(&chip->lock);
> +		dev_err(dev, "Error in setting resolution\n");
> +		return status;
> +	}
> +	chip->adc_bit = new_adc_bit;
> +	mutex_unlock(&chip->lock);
> +
> +	return count;
> +}
> +
> +/* proximity scheme */
> +static ssize_t show_prox_infrared_supression(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +
> +	/* return the "proximity scheme" i.e. if the chip does on chip
> +	infrared supression (1 means perform on chip supression) */
> +	return sprintf(buf, "%d\n", chip->prox_scheme);
> +}
> +
> +static ssize_t store_prox_infrared_supression(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +	unsigned long lval;
> +
> +	if (strict_strtoul(buf, 10, &lval))
> +		return -EINVAL;
> +	if (!(lval == 0UL || lval == 1UL)) {
> +		dev_err(dev, "The mode is not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	/* get the  "proximity scheme" i.e. if the chip does on chip
> +	infrared supression (1 means perform on chip supression) */
> +	mutex_lock(&chip->lock);
> +	chip->prox_scheme = (int)lval;
> +	mutex_unlock(&chip->lock);
> +
> +	return count;
> +}
> +
> +/* Read lux */
> +static ssize_t show_lux(struct device *dev,
> +		struct device_attribute *devattr, char *buf)
> +{
> +	return get_sensor_data(dev, buf, COMMMAND1_OPMODE_ALS_ONCE);
> +}
> +
> +/* Read ir */
> +static ssize_t show_ir(struct device *dev,
> +		struct device_attribute *devattr, char *buf)
> +{
> +	return get_sensor_data(dev, buf, COMMMAND1_OPMODE_IR_ONCE);
> +}
> +
> +/* Read nearest ir */
> +static ssize_t show_proxim_ir(struct device *dev,
> +		struct device_attribute *devattr, char *buf)
> +{
> +	return get_sensor_data(dev, buf, COMMMAND1_OPMODE_PROX_ONCE);
> +}
> +
> +/* Read name */
> +static ssize_t show_name(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +
> +	return sprintf(buf, "%s\n", chip->client->name);
> +}
> +
> +static IIO_DEVICE_ATTR(range, S_IRUGO | S_IWUSR, show_range, store_range, 0);
> +static IIO_CONST_ATTR(range_available, "1000 4000 16000 64000");
> +static IIO_CONST_ATTR(adc_resolution_available, "4 8 12 16");
> +static IIO_DEVICE_ATTR(adc_resolution, S_IRUGO | S_IWUSR,
> +					show_resolution, store_resolution, 0);
> +static IIO_DEVICE_ATTR(proximity_on_chip_ambient_infrared_supression,
> +					S_IRUGO | S_IWUSR,
> +					show_prox_infrared_suppression,
> +					store_prox_infrared_supression, 0);
> +static IIO_DEVICE_ATTR(illuminance0_input, S_IRUGO, show_lux, NULL, 0);
> +static IIO_DEVICE_ATTR(intensity_infrared_raw, S_IRUGO, show_ir, NULL, 0);
> +static IIO_DEVICE_ATTR(proximity_raw, S_IRUGO, show_proxim_ir, NULL, 0);
> +static IIO_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
> +
> +#define ISL29018_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
> +static struct attribute *isl29018_attributes[] = {
> +	ISL29018_DEV_ATTR(name),
> +	ISL29018_DEV_ATTR(range),
> +	ISL29018_DEV_ATTR(range_available),
> +	ISL29018_DEV_ATTR(adc_resolution),
> +	ISL29018_DEV_ATTR(adc_resolution_available),
> +	ISL29018_DEV_ATTR(proximity_on_chip_ambient_infrared_supression),
> +	ISL29018_DEV_ATTR(illuminance0_input),
> +	ISL29018_DEV_ATTR(intensity_infrared_raw),
> +	ISL29018_DEV_ATTR(proximity_raw),
> +	NULL
> +};
> +
> +static const struct attribute_group isl29108_group = {
> +	.attrs = isl29018_attributes,
> +};
> +
> +static int isl29018_chip_init(struct i2c_client *client)
> +{
> +	struct isl29018_chip *chip = i2c_get_clientdata(client);
> +	int status;
> +	int i;
> +	int new_adc_bit;
> +	unsigned int new_range;
> +
> +	memset(chip->reg_cache, 0, sizeof(chip->reg_cache));
> +
> +	/* set defaults */
> +	status = isl29018_set_range(client, chip->range, &new_range);
> +	if (status < 0) {
> +		dev_err(&client->dev, "Init of isl29018 fails\n");
> +		return status;
> +	}
> +
> +	status = isl29018_set_resolution(client, chip->adc_bit,
> +						&new_adc_bit);
> +
> +	return 0;
> +}
> +
> +static int __devinit isl29018_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct isl29018_chip *chip;
> +	int err;
> +
> +	chip = kzalloc(sizeof(struct isl29018_chip), GFP_KERNEL);
> +	if (!chip) {
> +		dev_err(&client->dev, "Memory allocation fails\n");
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	i2c_set_clientdata(client, chip);
> +	chip->client = client;
> +
> +	mutex_init(&chip->lock);
> +
> +	chip->range = 1000;
> +	chip->adc_bit = 16;
> +
> +	err = isl29018_chip_init(client);
> +	if (err)
> +		goto exit_free;
> +
> +	chip->indio_dev = iio_allocate_device();
> +	if (!chip->indio_dev) {
> +		dev_err(&client->dev, "iio allocation fails\n");
> +		goto exit_free;
> +	}
> +	chip->indio_dev->attrs = &isl29108_group;
> +	chip->indio_dev->dev.parent = &client->dev;
> +	chip->indio_dev->dev_data = (void *)(chip);
> +	chip->indio_dev->driver_module = THIS_MODULE;
> +	chip->indio_dev->modes = INDIO_DIRECT_MODE;
> +	err = iio_device_register(chip->indio_dev);
> +	if (err) {
> +		dev_err(&client->dev, "iio registration fails\n");
> +		goto exit_iio_free;
> +	}
> +
> +	return 0;
> +exit_iio_free:
> +	iio_free_device(chip->indio_dev);
> +exit_free:
> +	kfree(chip);
> +exit:
> +	return err;
> +}
> +
> +static int __devexit isl29018_remove(struct i2c_client *client)
> +{
> +	struct isl29018_chip *chip = i2c_get_clientdata(client);
> +
> +	dev_dbg(&client->dev, "%s()\n", __func__);
> +	iio_device_unregister(chip->indio_dev);
> +	kfree(chip);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id isl29018_id[] = {
> +	{"isl29018", 0},
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, isl29018_id);
> +
> +static struct i2c_driver isl29018_driver = {
> +	.class	= I2C_CLASS_HWMON,
> +	.driver	 = {
> +			.name = "isl29018",
> +			.owner = THIS_MODULE,
> +		    },
> +	.probe	 = isl29018_probe,
> +	.remove	 = __devexit_p(isl29018_remove),
> +	.id_table = isl29018_id,
> +};
> +
> +static int __init isl29018_init(void)
> +{
> +	return i2c_add_driver(&isl29018_driver);
> +}
> +
> +static void __exit isl29018_exit(void)
> +{
> +	i2c_del_driver(&isl29018_driver);
> +}
> +
> +module_init(isl29018_init);
> +module_exit(isl29018_exit);
> +
> +MODULE_DESCRIPTION("ISL29018 Ambient Light Sensor driver");
> +MODULE_LICENSE("GPL");