Re: [PATCH v5] iio: add LM3533 ambient-light-sensor driver

[Johan Hovold <jhovold@gmail.com>]

On Tue, May 22, 2012 at 10:19:15AM +0100, Jonathan Cameron wrote:
> On 5/21/2012 1:18 PM, Johan Hovold wrote:
> > Add sub-driver for the ambient-light-sensor interface on National
> > Semiconductor / TI LM3533 lighting power chips.
> >
> > The sensor interface can be used to control the LEDs and backlights of
> > the chip through defining five light zones and three sets of
> > corresponding output-current values.
> >
> > The driver provides raw and mean adc readings along with the current
> > light zone through sysfs. A threshold event can be generated on zone
> > changes. The ALS-control output values can be set per zone for the three
> > current output channels.
> There are a few bits of documentation I'd rather were in
> sysfs-bus-iio but we can move them any time.
> 
> I haven't compile tested as no machine availability till this evening.
> Please do one last sanity check against staging-next.

Tested against staging-next of today (c3c6cc91b0ae7b).

Greg, any chance you can pick this one up for 3.5?

Thanks,
Johan

> 
> Thanks,
> >
> > Signed-off-by: Johan Hovold<jhovold@gmail.com>
> Acked-by: Jonathan Cameron <jic23@kernel.org>
> > ---
> >
> > v2:
> >   - reimplement using iio
> >   - add sysfs-ABI documentation
> > v3
> >   - use indexed channel
> >   - fix sysfs-ABI documentation typo and style
> >   - replace gain attribute with in_illuminance0_calibscale
> >   - add calibscale to platform data
> >   - fix adc register definitions
> >   - replace to_lm3533_dev_attr macro with inline function
> >   - fix device used for error reporting at irq allocation
> >   - use iio device for error reporting during setup/enable
> >   - rebase on staging-next
> >     - fix header include paths
> >     - use dev_to_iio_dev
> >     - add IIO_CHAN_INFO_RAW to info mask
> >     - use iio_device_{alloc,free}
> > v4
> >   - move to driver/iio/light
> >   - add events/in_illuminance0_threshY_hysteresis attributes
> >   - fix device zone-boundary quirkiness
> >   - clean up attribute handling
> >   - replace calibscale with device-specific r_select attribute
> > v5
> >   - drop r_select from sysfs ABI
> >   - fix set_input_mode
> >   - minor style changes
> >   - register iio device last at probe
> >   - use dev_name for iio_dev and irq name
> >   - add out_currentY channels
> >
> >
> >   .../ABI/testing/sysfs-bus-iio-light-lm3533-als     |   62 ++
> >   drivers/iio/Kconfig                                |    1 +
> >   drivers/iio/Makefile                               |    1 +
> >   drivers/iio/light/Kconfig                          |   22 +
> >   drivers/iio/light/Makefile                         |    5 +
> >   drivers/iio/light/lm3533-als.c                     |  932 ++++++++++++++++++++
> >   6 files changed, 1023 insertions(+), 0 deletions(-)
> >   create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als
> >   create mode 100644 drivers/iio/light/Kconfig
> >   create mode 100644 drivers/iio/light/Makefile
> >   create mode 100644 drivers/iio/light/lm3533-als.c
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als b/Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als
> > new file mode 100644
> > index 0000000..694a52c
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als
> > @@ -0,0 +1,62 @@
> > +What:		/sys/.../events/in_illuminance0_thresh_either_en
> > +Date:		April 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Event generated when channel passes one of the four thresholds
> > +		in each direction (rising|falling) and a zone change occurs.
> > +		The corresponding light zone can be read from
> > +		in_illuminance0_zone.
> > +
> > +What:		/sys/.../events/in_illuminance0_threshY_hysteresis
> > +Date:		May 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Get the hysteresis for thresholds Y, that is,
> > +
> > +		threshY_hysteresis = threshY_raising - threshY_falling
> > +
> > +What:		/sys/.../events/illuminance_threshY_falling_value
> > +What:		/sys/.../events/illuminance_threshY_raising_value
> > +Date:		April 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Specifies the value of threshold that the device is comparing
> > +		against for the events enabled by
> > +		in_illuminance0_thresh_either_en (0..255), where Y in 0..3.
> > +
> > +		Note that threshY_falling must be less than or equal to
> > +		threshY_raising.
> > +
> > +		These thresholds correspond to the eight zone-boundary
> > +		registers (boundaryY_{low,high}) and defines the five light
> > +		zones.
> > +
> > +What:		/sys/bus/iio/devices/iio:deviceX/in_illuminance0_zone
> > +Date:		April 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Get the current light zone (0..4) as defined by the
> > +		in_illuminance0_threshY_{falling,rising} thresholds.
> > +
> > +What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_raw
> > +Date:		May 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Get output current for channel Y (0..255), that is,
> > +		out_currentY_currentZ_raw, where Z is the current zone.
> Should be in core docs. Can fix that later though.
> > +
> > +What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_currentZ_raw
> > +Date:		May 2012
> > +KernelVersion:	3.5
> > +Contact:	Johan Hovold<jhovold@gmail.com>
> > +Description:
> > +		Set the output current for channel out_currentY when in zone
> > +		Z (0..255), where Y in 0..2 and Z in 0..4.
> > +
> > +		These values correspond to the ALS-mapper target registers for
> > +		ALS-mapper Y + 1.
> Hmm. tempted to move this to core docs too.
> > diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> > index 56eecef..cacc74d 100644
> > --- a/drivers/iio/Kconfig
> > +++ b/drivers/iio/Kconfig
> > @@ -50,5 +50,6 @@ config IIO_CONSUMERS_PER_TRIGGER
> >
> >   source "drivers/iio/adc/Kconfig"
> >   source "drivers/iio/amplifiers/Kconfig"
> > +source "drivers/iio/light/Kconfig"
> >
> >   endif # IIO
> > diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> > index e425afd..060b674 100644
> > --- a/drivers/iio/Makefile
> > +++ b/drivers/iio/Makefile
> > @@ -11,3 +11,4 @@ obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
> >
> >   obj-y += adc/
> >   obj-y += amplifiers/
> > +obj-y += light/
> > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> > new file mode 100644
> > index 0000000..db5618e
> > --- /dev/null
> > +++ b/drivers/iio/light/Kconfig
> > @@ -0,0 +1,22 @@
> > +#
> > +# Light sensors
> > +#
> > +menu "Light sensors"
> > +
> > +config SENSORS_LM3533
> > +	tristate "LM3533 ambient light sensor"
> > +	depends on MFD_LM3533
> > +	help
> > +	  If you say yes here you get support for the ambient light sensor
> > +	  interface on National Semiconductor / TI LM3533 Lighting Power
> > +	  chips.
> > +
> > +	  The sensor interface can be used to control the LEDs and backlights
> > +	  of the chip through defining five light zones and three sets of
> > +	  corresponding output-current values.
> > +
> > +	  The driver provides raw and mean adc readings along with the current
> > +	  light zone through sysfs. A threshold event can be generated on zone
> > +	  changes. The ALS-control output values can be set per zone for the
> > +	  three current output channels.
> > +endmenu
> > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> > new file mode 100644
> > index 0000000..c1c23a0
> > --- /dev/null
> > +++ b/drivers/iio/light/Makefile
> > @@ -0,0 +1,5 @@
> > +#
> > +# Makefile for IIO Light sensors
> > +#
> > +
> > +obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
> > diff --git a/drivers/iio/light/lm3533-als.c b/drivers/iio/light/lm3533-als.c
> > new file mode 100644
> > index 0000000..c3e7bac
> > --- /dev/null
> > +++ b/drivers/iio/light/lm3533-als.c
> > @@ -0,0 +1,932 @@
> > +/*
> > + * lm3533-als.c -- LM3533 Ambient Light Sensor driver
> > + *
> > + * Copyright (C) 2011-2012 Texas Instruments
> > + *
> > + * Author: Johan Hovold<jhovold@gmail.com>
> > + *
> > + * 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.
> > + */
> > +
> > +#include<linux/atomic.h>
> > +#include<linux/fs.h>
> > +#include<linux/interrupt.h>
> > +#include<linux/io.h>
> > +#include<linux/iio/events.h>
> > +#include<linux/iio/iio.h>
> > +#include<linux/module.h>
> > +#include<linux/mutex.h>
> > +#include<linux/mfd/core.h>
> > +#include<linux/platform_device.h>
> > +#include<linux/slab.h>
> > +#include<linux/uaccess.h>
> > +
> > +#include<linux/mfd/lm3533.h>
> > +
> > +
> > +#define LM3533_ALS_RESISTOR_MIN			1
> > +#define LM3533_ALS_RESISTOR_MAX			127
> > +#define LM3533_ALS_CHANNEL_CURRENT_MAX		2
> > +#define LM3533_ALS_THRESH_MAX			3
> > +#define LM3533_ALS_ZONE_MAX			4
> > +
> > +#define LM3533_REG_ALS_RESISTOR_SELECT		0x30
> > +#define LM3533_REG_ALS_CONF			0x31
> > +#define LM3533_REG_ALS_ZONE_INFO		0x34
> > +#define LM3533_REG_ALS_READ_ADC_RAW		0x37
> > +#define LM3533_REG_ALS_READ_ADC_AVERAGE		0x38
> > +#define LM3533_REG_ALS_BOUNDARY_BASE		0x50
> > +#define LM3533_REG_ALS_TARGET_BASE		0x60
> > +
> > +#define LM3533_ALS_ENABLE_MASK			0x01
> > +#define LM3533_ALS_INPUT_MODE_MASK		0x02
> > +#define LM3533_ALS_INT_ENABLE_MASK		0x01
> > +
> > +#define LM3533_ALS_ZONE_SHIFT			2
> > +#define LM3533_ALS_ZONE_MASK			0x1c
> > +
> > +#define LM3533_ALS_FLAG_INT_ENABLED		1
> > +
> > +
> > +struct lm3533_als {
> > +	struct lm3533 *lm3533;
> > +	struct platform_device *pdev;
> > +
> > +	unsigned long flags;
> > +	int irq;
> > +
> > +	atomic_t zone;
> > +	struct mutex thresh_mutex;
> > +};
> > +
> > +
> > +static int lm3533_als_get_adc(struct iio_dev *indio_dev, bool average,
> > +								int *adc)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 reg;
> > +	u8 val;
> > +	int ret;
> > +
> > +	if (average)
> > +		reg = LM3533_REG_ALS_READ_ADC_AVERAGE;
> > +	else
> > +		reg = LM3533_REG_ALS_READ_ADC_RAW;
> > +
> > +	ret = lm3533_read(als->lm3533, reg,&val);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to read adc\n");
> > +		return ret;
> > +	}
> > +
> > +	*adc = val;
> > +
> > +	return 0;
> > +}
> > +
> > +static int _lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 val;
> > +	int ret;
> > +
> > +	ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO,&val);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to read zone\n");
> > +		return ret;
> > +	}
> > +
> > +	val = (val&  LM3533_ALS_ZONE_MASK)>>  LM3533_ALS_ZONE_SHIFT;
> > +	*zone = min_t(u8, val, LM3533_ALS_ZONE_MAX);
> > +
> > +	return 0;
> > +}
> > +
> > +static int lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	int ret;
> > +
> > +	if (test_bit(LM3533_ALS_FLAG_INT_ENABLED,&als->flags)) {
> > +		*zone = atomic_read(&als->zone);
> > +	} else {
> > +		ret = _lm3533_als_get_zone(indio_dev, zone);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * channel	output channel 0..2
> > + * zone		zone 0..4
> > + */
> > +static inline u8 lm3533_als_get_target_reg(unsigned channel, unsigned zone)
> > +{
> > +	return LM3533_REG_ALS_TARGET_BASE + 5 * channel + zone;
> > +}
> > +
> > +static int lm3533_als_get_target(struct iio_dev *indio_dev, unsigned channel,
> > +							unsigned zone, u8 *val)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 reg;
> > +	int ret;
> > +
> > +	if (channel>  LM3533_ALS_CHANNEL_CURRENT_MAX)
> > +		return -EINVAL;
> > +
> > +	if (zone>  LM3533_ALS_ZONE_MAX)
> > +		return -EINVAL;
> > +
> > +	reg = lm3533_als_get_target_reg(channel, zone);
> > +	ret = lm3533_read(als->lm3533, reg, val);
> > +	if (ret)
> > +		dev_err(&indio_dev->dev, "failed to get target current\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int lm3533_als_set_target(struct iio_dev *indio_dev, unsigned channel,
> > +							unsigned zone, u8 val)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 reg;
> > +	int ret;
> > +
> > +	if (channel>  LM3533_ALS_CHANNEL_CURRENT_MAX)
> > +		return -EINVAL;
> > +
> > +	if (zone>  LM3533_ALS_ZONE_MAX)
> > +		return -EINVAL;
> > +
> > +	reg = lm3533_als_get_target_reg(channel, zone);
> > +	ret = lm3533_write(als->lm3533, reg, val);
> > +	if (ret)
> > +		dev_err(&indio_dev->dev, "failed to set target current\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int lm3533_als_get_current(struct iio_dev *indio_dev, unsigned channel,
> > +								int *val)
> > +{
> > +	u8 zone;
> > +	u8 target;
> > +	int ret;
> > +
> > +	ret = lm3533_als_get_zone(indio_dev,&zone);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = lm3533_als_get_target(indio_dev, channel, zone,&target);
> > +	if (ret)
> > +		return ret;
> > +
> > +	*val = target;
> > +
> > +	return 0;
> > +}
> > +
> > +static int lm3533_als_read_raw(struct iio_dev *indio_dev,
> > +				struct iio_chan_spec const *chan,
> > +				int *val, int *val2, long mask)
> > +{
> > +	int ret;
> > +
> > +	switch (mask) {
> > +	case 0:
> > +		switch (chan->type) {
> > +		case IIO_LIGHT:
> > +			ret = lm3533_als_get_adc(indio_dev, false, val);
> > +			break;
> > +		case IIO_CURRENT:
> > +			ret = lm3533_als_get_current(indio_dev, chan->channel,
> > +									val);
> > +			break;
> > +		default:
> > +			return -EINVAL;
> > +		}
> > +		break;
> > +	case IIO_CHAN_INFO_AVERAGE_RAW:
> > +		ret = lm3533_als_get_adc(indio_dev, true, val);
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (ret)
> > +		return ret;
> > +
> > +	return IIO_VAL_INT;
> > +}
> > +
> > +#define CHANNEL_CURRENT(_channel)					\
> > +	{								\
> > +		.type		= IIO_CURRENT,				\
> > +		.channel	= _channel,				\
> > +		.indexed	= true,					\
> > +		.output		= true,					\
> > +		.info_mask	= IIO_CHAN_INFO_RAW_SEPARATE_BIT,	\
> > +	}
> > +
> > +static const struct iio_chan_spec lm3533_als_channels[] = {
> > +	{
> > +		.type		= IIO_LIGHT,
> > +		.channel	= 0,
> > +		.indexed	= true,
> > +		.info_mask	= (IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT |
> > +				   IIO_CHAN_INFO_RAW_SEPARATE_BIT),
> > +	},
> > +	CHANNEL_CURRENT(0),
> > +	CHANNEL_CURRENT(1),
> > +	CHANNEL_CURRENT(2),
> > +};
> > +
> > +static irqreturn_t lm3533_als_isr(int irq, void *dev_id)
> > +{
> > +
> > +	struct iio_dev *indio_dev = dev_id;
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 zone;
> > +	int ret;
> > +
> > +	/* Clear interrupt by reading the ALS zone register. */
> > +	ret = _lm3533_als_get_zone(indio_dev,&zone);
> > +	if (ret)
> > +		goto out;
> > +
> > +	atomic_set(&als->zone, zone);
> > +
> > +	iio_push_event(indio_dev,
> > +		       IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
> > +					    0,
> > +					    IIO_EV_TYPE_THRESH,
> > +					    IIO_EV_DIR_EITHER),
> > +		       iio_get_time_ns());
> > +out:
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static int lm3533_als_set_int_mode(struct iio_dev *indio_dev, int enable)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 mask = LM3533_ALS_INT_ENABLE_MASK;
> > +	u8 val;
> > +	int ret;
> > +
> > +	if (enable)
> > +		val = mask;
> > +	else
> > +		val = 0;
> > +
> > +	ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, val, mask);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to set int mode %d\n",
> > +								enable);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int lm3533_als_get_int_mode(struct iio_dev *indio_dev, int *enable)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 mask = LM3533_ALS_INT_ENABLE_MASK;
> > +	u8 val;
> > +	int ret;
> > +
> > +	ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO,&val);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to get int mode\n");
> > +		return ret;
> > +	}
> > +
> > +	*enable = !!(val&  mask);
> > +
> > +	return 0;
> > +}
> > +
> > +static inline u8 lm3533_als_get_threshold_reg(unsigned nr, bool raising)
> > +{
> > +	u8 offset = !raising;
> > +
> > +	return LM3533_REG_ALS_BOUNDARY_BASE + 2 * nr + offset;
> > +}
> > +
> > +static int lm3533_als_get_threshold(struct iio_dev *indio_dev, unsigned nr,
> > +							bool raising, u8 *val)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 reg;
> > +	int ret;
> > +
> > +	if (nr>  LM3533_ALS_THRESH_MAX)
> > +		return -EINVAL;
> > +
> > +	reg = lm3533_als_get_threshold_reg(nr, raising);
> > +	ret = lm3533_read(als->lm3533, reg, val);
> > +	if (ret)
> > +		dev_err(&indio_dev->dev, "failed to get threshold\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int lm3533_als_set_threshold(struct iio_dev *indio_dev, unsigned nr,
> > +							bool raising, u8 val)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 val2;
> > +	u8 reg, reg2;
> > +	int ret;
> > +
> > +	if (nr>  LM3533_ALS_THRESH_MAX)
> > +		return -EINVAL;
> > +
> > +	reg = lm3533_als_get_threshold_reg(nr, raising);
> > +	reg2 = lm3533_als_get_threshold_reg(nr, !raising);
> > +
> > +	mutex_lock(&als->thresh_mutex);
> > +	ret = lm3533_read(als->lm3533, reg2,&val2);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to get threshold\n");
> > +		goto out;
> > +	}
> > +	/*
> > +	 * This device does not allow negative hysteresis (in fact, it uses
> > +	 * whichever value is smaller as the lower bound) so we need to make
> > +	 * sure that thresh_falling<= thresh_raising.
> > +	 */
> > +	if ((raising&&  (val<  val2)) || (!raising&&  (val>  val2))) {
> > +		ret = -EINVAL;
> > +		goto out;
> > +	}
> > +
> > +	ret = lm3533_write(als->lm3533, reg, val);
> > +	if (ret) {
> > +		dev_err(&indio_dev->dev, "failed to set threshold\n");
> > +		goto out;
> > +	}
> > +out:
> > +	mutex_unlock(&als->thresh_mutex);
> > +
> > +	return ret;
> > +}
> > +
> > +static int lm3533_als_get_hysteresis(struct iio_dev *indio_dev, unsigned nr,
> > +								u8 *val)
> > +{
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	u8 falling;
> > +	u8 raising;
> > +	int ret;
> > +
> > +	if (nr>  LM3533_ALS_THRESH_MAX)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&als->thresh_mutex);
> > +	ret = lm3533_als_get_threshold(indio_dev, nr, false,&falling);
> > +	if (ret)
> > +		goto out;
> > +	ret = lm3533_als_get_threshold(indio_dev, nr, true,&raising);
> > +	if (ret)
> > +		goto out;
> > +
> > +	*val = raising - falling;
> > +out:
> > +	mutex_unlock(&als->thresh_mutex);
> > +
> > +	return ret;
> > +}
> > +
> > +static int show_thresh_either_en(struct device *dev,
> > +					struct device_attribute *attr,
> > +					char *buf)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	int enable;
> > +	int ret;
> > +
> > +	if (als->irq) {
> > +		ret = lm3533_als_get_int_mode(indio_dev,&enable);
> > +		if (ret)
> > +			return ret;
> > +	} else {
> > +		enable = 0;
> > +	}
> > +
> > +	return scnprintf(buf, PAGE_SIZE, "%u\n", enable);
> > +}
> > +
> > +static int store_thresh_either_en(struct device *dev,
> > +					struct device_attribute *attr,
> > +					const char *buf, size_t len)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +	unsigned long enable;
> > +	bool int_enabled;
> > +	u8 zone;
> > +	int ret;
> > +
> > +	if (!als->irq)
> > +		return -EBUSY;
> > +
> > +	if (kstrtoul(buf, 0,&enable))
> > +		return -EINVAL;
> > +
> > +	int_enabled = test_bit(LM3533_ALS_FLAG_INT_ENABLED,&als->flags);
> > +
> > +	if (enable&&  !int_enabled) {
> > +		ret = lm3533_als_get_zone(indio_dev,&zone);
> > +		if (ret)
> > +			return ret;
> > +
> > +		atomic_set(&als->zone, zone);
> > +
> > +		set_bit(LM3533_ALS_FLAG_INT_ENABLED,&als->flags);
> > +	}
> > +
> > +	ret = lm3533_als_set_int_mode(indio_dev, enable);
> > +	if (ret) {
> > +		if (!int_enabled)
> > +			clear_bit(LM3533_ALS_FLAG_INT_ENABLED,&als->flags);
> > +
> > +		return ret;
> > +	}
> > +
> > +	if (!enable)
> > +		clear_bit(LM3533_ALS_FLAG_INT_ENABLED,&als->flags);
> > +
> > +	return len;
> > +}
> > +
> > +static ssize_t show_zone(struct device *dev,
> > +				struct device_attribute *attr, char *buf)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	u8 zone;
> > +	int ret;
> > +
> > +	ret = lm3533_als_get_zone(indio_dev,&zone);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return scnprintf(buf, PAGE_SIZE, "%u\n", zone);
> > +}
> > +
> > +enum lm3533_als_attribute_type {
> > +	LM3533_ATTR_TYPE_HYSTERESIS,
> > +	LM3533_ATTR_TYPE_TARGET,
> > +	LM3533_ATTR_TYPE_THRESH_FALLING,
> > +	LM3533_ATTR_TYPE_THRESH_RAISING,
> > +};
> > +
> > +struct lm3533_als_attribute {
> > +	struct device_attribute dev_attr;
> > +	enum lm3533_als_attribute_type type;
> > +	u8 val1;
> > +	u8 val2;
> > +};
> > +
> > +static inline struct lm3533_als_attribute *
> > +to_lm3533_als_attr(struct device_attribute *attr)
> > +{
> > +	return container_of(attr, struct lm3533_als_attribute, dev_attr);
> > +}
> > +
> > +static ssize_t show_als_attr(struct device *dev,
> > +					struct device_attribute *attr,
> > +					char *buf)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
> > +	u8 val;
> > +	int ret;
> > +
> > +	switch (als_attr->type) {
> > +	case LM3533_ATTR_TYPE_HYSTERESIS:
> > +		ret = lm3533_als_get_hysteresis(indio_dev, als_attr->val1,
> > +									&val);
> > +		break;
> > +	case LM3533_ATTR_TYPE_TARGET:
> > +		ret = lm3533_als_get_target(indio_dev, als_attr->val1,
> > +							als_attr->val2,&val);
> > +		break;
> > +	case LM3533_ATTR_TYPE_THRESH_FALLING:
> > +		ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
> > +								false,&val);
> > +		break;
> > +	case LM3533_ATTR_TYPE_THRESH_RAISING:
> > +		ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
> > +								true,&val);
> > +		break;
> > +	default:
> > +		ret = -ENXIO;
> > +	}
> > +
> > +	if (ret)
> > +		return ret;
> > +
> > +	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
> > +}
> > +
> > +static ssize_t store_als_attr(struct device *dev,
> > +					struct device_attribute *attr,
> > +					const char *buf, size_t len)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
> > +	u8 val;
> > +	int ret;
> > +
> > +	if (kstrtou8(buf, 0,&val))
> > +		return -EINVAL;
> > +
> > +	switch (als_attr->type) {
> > +	case LM3533_ATTR_TYPE_TARGET:
> > +		ret = lm3533_als_set_target(indio_dev, als_attr->val1,
> > +							als_attr->val2, val);
> > +		break;
> > +	case LM3533_ATTR_TYPE_THRESH_FALLING:
> > +		ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
> > +								false, val);
> > +		break;
> > +	case LM3533_ATTR_TYPE_THRESH_RAISING:
> > +		ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
> > +								true, val);
> > +		break;
> > +	default:
> > +		ret = -ENXIO;
> > +	}
> > +
> > +	if (ret)
> > +		return ret;
> > +
> > +	return len;
> > +}
> > +
> > +#define ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)	\
> > +	{ .dev_attr	= __ATTR(_name, _mode, _show, _store),		\
> > +	  .type		= _type,					\
> > +	  .val1		= _val1,					\
> > +	  .val2		= _val2 }
> > +
> > +#define LM3533_ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2) \
> > +	struct lm3533_als_attribute lm3533_als_attr_##_name =		  \
> > +		ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)
> > +
> > +#define ALS_TARGET_ATTR_RW(_channel, _zone)				\
> > +	LM3533_ALS_ATTR(out_current##_channel##_current##_zone##_raw,	\
> > +				S_IRUGO | S_IWUSR,			\
> > +				show_als_attr, store_als_attr,		\
> > +				LM3533_ATTR_TYPE_TARGET, _channel, _zone)
> > +/*
> > + * ALS output current values (ALS mapper targets)
> > + *
> > + * out_current[0-2]_current[0-4]_raw		0-255
> > + */
> > +static ALS_TARGET_ATTR_RW(0, 0);
> > +static ALS_TARGET_ATTR_RW(0, 1);
> > +static ALS_TARGET_ATTR_RW(0, 2);
> > +static ALS_TARGET_ATTR_RW(0, 3);
> > +static ALS_TARGET_ATTR_RW(0, 4);
> > +
> > +static ALS_TARGET_ATTR_RW(1, 0);
> > +static ALS_TARGET_ATTR_RW(1, 1);
> > +static ALS_TARGET_ATTR_RW(1, 2);
> > +static ALS_TARGET_ATTR_RW(1, 3);
> > +static ALS_TARGET_ATTR_RW(1, 4);
> > +
> > +static ALS_TARGET_ATTR_RW(2, 0);
> > +static ALS_TARGET_ATTR_RW(2, 1);
> > +static ALS_TARGET_ATTR_RW(2, 2);
> > +static ALS_TARGET_ATTR_RW(2, 3);
> > +static ALS_TARGET_ATTR_RW(2, 4);
> > +
> > +#define ALS_THRESH_FALLING_ATTR_RW(_nr)					\
> > +	LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_falling_value,	\
> > +			S_IRUGO | S_IWUSR,				\
> > +			show_als_attr, store_als_attr,		\
> > +			LM3533_ATTR_TYPE_THRESH_FALLING, _nr, 0)
> > +
> > +#define ALS_THRESH_RAISING_ATTR_RW(_nr)					\
> > +	LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_raising_value,	\
> > +			S_IRUGO | S_IWUSR,				\
> > +			show_als_attr, store_als_attr,			\
> > +			LM3533_ATTR_TYPE_THRESH_RAISING, _nr, 0)
> > +/*
> > + * ALS Zone thresholds (boundaries)
> > + *
> > + * in_illuminance0_thresh[0-3]_falling_value	0-255
> > + * in_illuminance0_thresh[0-3]_raising_value	0-255
> > + */
> > +static ALS_THRESH_FALLING_ATTR_RW(0);
> > +static ALS_THRESH_FALLING_ATTR_RW(1);
> > +static ALS_THRESH_FALLING_ATTR_RW(2);
> > +static ALS_THRESH_FALLING_ATTR_RW(3);
> > +
> > +static ALS_THRESH_RAISING_ATTR_RW(0);
> > +static ALS_THRESH_RAISING_ATTR_RW(1);
> > +static ALS_THRESH_RAISING_ATTR_RW(2);
> > +static ALS_THRESH_RAISING_ATTR_RW(3);
> > +
> > +#define ALS_HYSTERESIS_ATTR_RO(_nr)					\
> > +	LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_hysteresis,	\
> > +			S_IRUGO, show_als_attr, NULL,			\
> > +			LM3533_ATTR_TYPE_HYSTERESIS, _nr, 0)
> > +/*
> > + * ALS Zone threshold hysteresis
> > + *
> > + * threshY_hysteresis = threshY_raising - threshY_falling
> > + *
> > + * in_illuminance0_thresh[0-3]_hysteresis	0-255
> > + * in_illuminance0_thresh[0-3]_hysteresis	0-255
> > + */
> > +static ALS_HYSTERESIS_ATTR_RO(0);
> > +static ALS_HYSTERESIS_ATTR_RO(1);
> > +static ALS_HYSTERESIS_ATTR_RO(2);
> > +static ALS_HYSTERESIS_ATTR_RO(3);
> > +
> > +#define ILLUMINANCE_ATTR_RO(_name) \
> > +	DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO, show_##_name, NULL)
> > +#define ILLUMINANCE_ATTR_RW(_name) \
> > +	DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO | S_IWUSR , \
> > +						show_##_name, store_##_name)
> > +/*
> > + * ALS Zone threshold-event enable
> > + *
> > + * in_illuminance0_thresh_either_en		0,1
> > + */
> > +static ILLUMINANCE_ATTR_RW(thresh_either_en);
> > +
> > +/*
> > + * ALS Current Zone
> > + *
> > + * in_illuminance0_zone		0-4
> > + */
> > +static ILLUMINANCE_ATTR_RO(zone);
> > +
> > +static struct attribute *lm3533_als_event_attributes[] = {
> > +	&dev_attr_in_illuminance0_thresh_either_en.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh0_falling_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh0_hysteresis.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh0_raising_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh1_falling_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh1_hysteresis.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh1_raising_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh2_falling_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh2_hysteresis.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh2_raising_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh3_falling_value.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh3_hysteresis.dev_attr.attr,
> > +	&lm3533_als_attr_in_illuminance0_thresh3_raising_value.dev_attr.attr,
> > +	NULL
> > +};
> > +
> > +static struct attribute_group lm3533_als_event_attribute_group = {
> > +	.attrs = lm3533_als_event_attributes
> > +};
> > +
> > +static struct attribute *lm3533_als_attributes[] = {
> > +	&dev_attr_in_illuminance0_zone.attr,
> > +	&lm3533_als_attr_out_current0_current0_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current0_current1_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current0_current2_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current0_current3_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current0_current4_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current1_current0_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current1_current1_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current1_current2_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current1_current3_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current1_current4_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current2_current0_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current2_current1_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current2_current2_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current2_current3_raw.dev_attr.attr,
> > +	&lm3533_als_attr_out_current2_current4_raw.dev_attr.attr,
> > +	NULL
> > +};
> > +
> > +static struct attribute_group lm3533_als_attribute_group = {
> > +	.attrs = lm3533_als_attributes
> > +};
> > +
> > +static int __devinit lm3533_als_set_input_mode(struct lm3533_als *als,
> > +								bool pwm_mode)
> > +{
> > +	u8 mask = LM3533_ALS_INPUT_MODE_MASK;
> > +	u8 val;
> > +	int ret;
> > +
> > +	if (pwm_mode)
> > +		val = mask;	/* pwm input */
> > +	else
> > +		val = 0;	/* analog input */
> > +
> > +	ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, val, mask);
> > +	if (ret) {
> > +		dev_err(&als->pdev->dev, "failed to set input mode %d\n",
> > +								pwm_mode);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int __devinit lm3533_als_set_resistor(struct lm3533_als *als, u8 val)
> > +{
> > +	int ret;
> > +
> > +	if (val<  LM3533_ALS_RESISTOR_MIN || val>  LM3533_ALS_RESISTOR_MAX)
> > +		return -EINVAL;
> > +
> > +	ret = lm3533_write(als->lm3533, LM3533_REG_ALS_RESISTOR_SELECT, val);
> > +	if (ret) {
> > +		dev_err(&als->pdev->dev, "failed to set resistor\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int __devinit lm3533_als_setup(struct lm3533_als *als,
> > +					struct lm3533_als_platform_data *pdata)
> > +{
> > +	int ret;
> > +
> > +	ret = lm3533_als_set_input_mode(als, pdata->pwm_mode);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* ALS input is always high impedance in PWM-mode. */
> > +	if (!pdata->pwm_mode) {
> > +		ret = lm3533_als_set_resistor(als, pdata->r_select);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int __devinit lm3533_als_setup_irq(struct lm3533_als *als, void *dev)
> > +{
> > +	u8 mask = LM3533_ALS_INT_ENABLE_MASK;
> > +	int ret;
> > +
> > +	/* Make sure interrupts are disabled. */
> > +	ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, 0, mask);
> > +	if (ret) {
> > +		dev_err(&als->pdev->dev, "failed to disable interrupts\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = request_threaded_irq(als->irq, NULL, lm3533_als_isr,
> > +					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> > +					dev_name(&als->pdev->dev), dev);
> > +	if (ret) {
> > +		dev_err(&als->pdev->dev, "failed to request irq %d\n",
> > +								als->irq);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int __devinit lm3533_als_enable(struct lm3533_als *als)
> > +{
> > +	u8 mask = LM3533_ALS_ENABLE_MASK;
> > +	int ret;
> > +
> > +	ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, mask, mask);
> > +	if (ret)
> > +		dev_err(&als->pdev->dev, "failed to enable ALS\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int lm3533_als_disable(struct lm3533_als *als)
> > +{
> > +	u8 mask = LM3533_ALS_ENABLE_MASK;
> > +	int ret;
> > +
> > +	ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, 0, mask);
> > +	if (ret)
> > +		dev_err(&als->pdev->dev, "failed to disable ALS\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct iio_info lm3533_als_info = {
> > +	.attrs		=&lm3533_als_attribute_group,
> > +	.event_attrs	=&lm3533_als_event_attribute_group,
> > +	.driver_module	= THIS_MODULE,
> > +	.read_raw	=&lm3533_als_read_raw,
> > +};
> > +
> > +static int __devinit lm3533_als_probe(struct platform_device *pdev)
> > +{
> > +	struct lm3533 *lm3533;
> > +	struct lm3533_als_platform_data *pdata;
> > +	struct lm3533_als *als;
> > +	struct iio_dev *indio_dev;
> > +	int ret;
> > +
> > +	lm3533 = dev_get_drvdata(pdev->dev.parent);
> > +	if (!lm3533)
> > +		return -EINVAL;
> > +
> > +	pdata = pdev->dev.platform_data;
> > +	if (!pdata) {
> > +		dev_err(&pdev->dev, "no platform data\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	indio_dev = iio_device_alloc(sizeof(*als));
> > +	if (!indio_dev)
> > +		return -ENOMEM;
> > +
> > +	indio_dev->info =&lm3533_als_info;
> > +	indio_dev->channels = lm3533_als_channels;
> > +	indio_dev->num_channels = ARRAY_SIZE(lm3533_als_channels);
> > +	indio_dev->name = dev_name(&pdev->dev);
> > +	indio_dev->dev.parent = pdev->dev.parent;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > +	als = iio_priv(indio_dev);
> > +	als->lm3533 = lm3533;
> > +	als->pdev = pdev;
> > +	als->irq = lm3533->irq;
> > +	atomic_set(&als->zone, 0);
> > +	mutex_init(&als->thresh_mutex);
> > +
> > +	platform_set_drvdata(pdev, indio_dev);
> > +
> > +	if (als->irq) {
> > +		ret = lm3533_als_setup_irq(als, indio_dev);
> > +		if (ret)
> > +			goto err_free_dev;
> > +	}
> > +
> > +	ret = lm3533_als_setup(als, pdata);
> > +	if (ret)
> > +		goto err_free_irq;
> > +
> > +	ret = lm3533_als_enable(als);
> > +	if (ret)
> > +		goto err_free_irq;
> > +
> > +	ret = iio_device_register(indio_dev);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to register ALS\n");
> > +		goto err_disable;
> > +	}
> > +
> > +	return 0;
> > +
> > +err_disable:
> > +	lm3533_als_disable(als);
> > +err_free_irq:
> > +	if (als->irq)
> > +		free_irq(als->irq, indio_dev);
> > +err_free_dev:
> > +	iio_device_free(indio_dev);
> > +
> > +	return ret;
> > +}
> > +
> > +static int __devexit lm3533_als_remove(struct platform_device *pdev)
> > +{
> > +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > +	struct lm3533_als *als = iio_priv(indio_dev);
> > +
> > +	lm3533_als_set_int_mode(indio_dev, false);
> > +	iio_device_unregister(indio_dev);
> > +	lm3533_als_disable(als);
> > +	if (als->irq)
> > +		free_irq(als->irq, indio_dev);
> > +	iio_device_free(indio_dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver lm3533_als_driver = {
> > +	.driver	= {
> > +		.name	= "lm3533-als",
> > +		.owner	= THIS_MODULE,
> > +	},
> > +	.probe		= lm3533_als_probe,
> > +	.remove		= __devexit_p(lm3533_als_remove),
> > +};
> > +module_platform_driver(lm3533_als_driver);
> > +
> > +MODULE_AUTHOR("Johan Hovold<jhovold@gmail.com>");
> > +MODULE_DESCRIPTION("LM3533 Ambient Light Sensor driver");
> > +MODULE_LICENSE("GPL");
> > +MODULE_ALIAS("platform:lm3533-als");
>