Date:	Mon, 09 Nov 2009 14:03:45 +0000
From:	Jonathan Cameron <jic23@....ac.uk>
To:	Amit Kucheria <amit.kucheria@...durent.com>
CC:	List Linux Kernel <linux-kernel@...r.kernel.org>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	linux-omap@...r.kernel.org, Zhang Rui <rui.zhang@...el.com>,
	Jean Delvare <khali@...ux-fr.org>
Subject: Re: [PATCH 1/2] staging: iio: tsl2563 ambient light sensor driver


> Hi Amit,
> 
> Normally I'd welcome this in IIO, except that all ambient light sensors are in the
> process of moving to the new ALS subsystem.  There are still some issues to resolve
> in that subsystem (mainly to do with naming conventions) but hopefully we will
> get them sorted out shortly.
Sorry, I meant to add some links to relevant threads but clean forgot!
http://lkml.org/lkml/2009/9/21/392 for als patches

http://lkml.org/lkml/2009/10/9/198 for the tsl2550 (with a bug - Jean is kindly
testing a fixed version so will repost after that.(

I also meant to copy some of the als and other similar sensors people
who might be interested. Have now done so.

> I'll take a close look at this sometime over the next few days though.  On a quick
> glance at the data sheet, it looks very similar to the tsl2561.  Perhaps we can merge
> the drivers? Yours is certainly more complete than the tsl2561 version in IIO so it
> would make sense to lift the functional elements in to the code I have for an ALS
> driver. I hadn't posted that previously as I hadn't quite worked out how to handle
> the various gain related settings. What you have done seems to make sense (from a very
> quick look.)
> 
> Thanks,
> 
> Jonathan
> 
> 
> 
> 
>> Add driver support for the tsl2563 TAOS ambient light sensor. After looking at
>> discussions on LKML, the driver was modified from a 'hwmon' driver to an 'iio'
>> driver. The sysfs interfaces have been tested on an RX51 (N900) to see if it
>> responds to changing light conditions.
>>
>> The only real reason for submitting this to staging is that it is dependent on
>> the IIO subsystem.
>>
>> Signed-off-by: Amit Kucheria <amit.kucheria@...durent.com>
>> Cc: Jonathan Cameron <jic23@....ac.uk>
>> Cc: Greg Kroah-Hartman <gregkh@...e.de>
>> Cc: linux-omap@...r.kernel.org
>> ---
>>  drivers/staging/iio/light/Kconfig   |   11 +
>>  drivers/staging/iio/light/Makefile  |    1 +
>>  drivers/staging/iio/light/tsl2563.c |  772 +++++++++++++++++++++++++++++++++++
>>  drivers/staging/iio/light/tsl2563.h |    9 +
>>  4 files changed, 793 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/staging/iio/light/tsl2563.c
>>  create mode 100644 drivers/staging/iio/light/tsl2563.h
>>
>> diff --git a/drivers/staging/iio/light/Kconfig b/drivers/staging/iio/light/Kconfig
>> index 12af0c4..cf0d0d6 100644
>> --- a/drivers/staging/iio/light/Kconfig
>> +++ b/drivers/staging/iio/light/Kconfig
>> @@ -11,3 +11,14 @@ config TSL2561
>>  	convertor.  This chip has two light sensors. One is broadband
>>  	including infrared whilst the other measures only infrared.
>>  	Provides direct access via sysfs.
>> +
>> +config SENSORS_TSL2563
>> +	tristate "TAOS TSL2563 ambient light sensor"
>> +	depends on I2C
>> +	help
>> +	 If you say yes here you get support for the Taos TSL2563
>> +	 ambient light sensor (found in N900).
>> +
>> +	 This driver can also be built as a module.  If so, the module
>> +	 will be called tsl2563.
>> +
>> diff --git a/drivers/staging/iio/light/Makefile b/drivers/staging/iio/light/Makefile
>> index ccff151..30dbfb1 100644
>> --- a/drivers/staging/iio/light/Makefile
>> +++ b/drivers/staging/iio/light/Makefile
>> @@ -3,3 +3,4 @@
>>  #
>>  
>>  obj-$(CONFIG_TSL2561)   += tsl2561.o
>> +obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
>> diff --git a/drivers/staging/iio/light/tsl2563.c b/drivers/staging/iio/light/tsl2563.c
>> new file mode 100644
>> index 0000000..3e812b2
>> --- /dev/null
>> +++ b/drivers/staging/iio/light/tsl2563.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * drivers/i2c/chips/tsl2563.c
>> + *
>> + * Copyright (C) 2008 Nokia Corporation
>> + *
>> + * Written by Timo O. Karjalainen <timo.o.karjalainen@...ia.com>
>> + * Contact: Amit Kucheria <amit.kucheria@...durent.com>
>> + *
>> + * Converted to IIO driver
>> + * Amit Kucheria <amit.kucheria@...durent.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 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.
>> + *
>> + * 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 St, Fifth Floor, Boston, MA
>> + * 02110-1301 USA
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/i2c.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/sched.h>
>> +#include <linux/mutex.h>
>> +#include <linux/delay.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/err.h>
>> +
>> +#include "../iio.h"
>> +#include "tsl2563.h"
>> +
>> +#define DRIVER_NAME  "tsl2563"
>> +
>> +/* Use this many bits for fraction part. */
>> +#define ADC_FRAC_BITS		(14)
>> +
>> +/* Given number of 1/10000's in ADC_FRAC_BITS precision. */
>> +#define FRAC10K(f)		(((f) * (1L << (ADC_FRAC_BITS))) / (10000))
>> +
>> +/* Bits used for fraction in calibration coefficients.*/
>> +#define CALIB_FRAC_BITS		(10)
>> +/* 0.5 in CALIB_FRAC_BITS precision */
>> +#define CALIB_FRAC_HALF		(1 << (CALIB_FRAC_BITS - 1))
>> +/* Make a fraction from a number n that was multiplied with b. */
>> +#define CALIB_FRAC(n, b)	(((n) << CALIB_FRAC_BITS) / (b))
>> +/* Decimal 10^(digits in sysfs presentation) */
>> +#define CALIB_BASE_SYSFS	(1000)
>> +
>> +#define TSL2563_CMD		(0x80)
>> +#define TSL2563_CLEARINT	(0x40)
>> +
>> +#define TSL2563_REG_CTRL	(0x00)
>> +#define TSL2563_REG_TIMING	(0x01)
>> +#define TSL2563_REG_LOWLOW	(0x02) /* data0 low threshold, 2 bytes */
>> +#define TSL2563_REG_LOWHIGH	(0x03)
>> +#define TSL2563_REG_HIGHLOW	(0x04) /* data0 high threshold, 2 bytes */
>> +#define TSL2563_REG_HIGHHIGH	(0x05)
>> +#define TSL2563_REG_INT		(0x06)
>> +#define TSL2563_REG_ID		(0x0a)
>> +#define TSL2563_REG_DATA0LOW	(0x0c) /* broadband sensor value, 2 bytes */
>> +#define TSL2563_REG_DATA0HIGH	(0x0d)
>> +#define TSL2563_REG_DATA1LOW	(0x0e) /* infrared sensor value, 2 bytes */
>> +#define TSL2563_REG_DATA1HIGH	(0x0f)
>> +
>> +#define TSL2563_CMD_POWER_ON	(0x03)
>> +#define TSL2563_CMD_POWER_OFF	(0x00)
>> +#define TSL2563_CTRL_POWER_MASK	(0x03)
>> +
>> +#define TSL2563_TIMING_13MS	(0x00)
>> +#define TSL2563_TIMING_100MS	(0x01)
>> +#define TSL2563_TIMING_400MS	(0x02)
>> +#define TSL2563_TIMING_MASK	(0x03)
>> +#define TSL2563_TIMING_GAIN16	(0x10)
>> +#define TSL2563_TIMING_GAIN1	(0x00)
>> +
>> +#define TSL2563_INT_DISBLED	(0x00)
>> +#define TSL2563_INT_LEVEL	(0x10)
>> +#define TSL2563_INT_PERSIST(n)	((n) & 0x0F)
>> +
>> +struct tsl2563_gainlevel_coeff {
>> +	u8 gaintime;
>> +	u16 min;
>> +	u16 max;
>> +};
>> +
>> +static struct tsl2563_gainlevel_coeff tsl2563_gainlevel_table[] = {
>> +	{
>> +		.gaintime	= TSL2563_TIMING_400MS | TSL2563_TIMING_GAIN16,
>> +		.min		= 0,
>> +		.max		= 65534,
>> +	}, {
>> +		.gaintime	= TSL2563_TIMING_400MS | TSL2563_TIMING_GAIN1,
>> +		.min		= 2048,
>> +		.max		= 65534,
>> +	}, {
>> +		.gaintime	= TSL2563_TIMING_100MS | TSL2563_TIMING_GAIN1,
>> +		.min		= 4095,
>> +		.max		= 37177,
>> +	}, {
>> +		.gaintime	= TSL2563_TIMING_13MS | TSL2563_TIMING_GAIN1,
>> +		.min		= 3000,
>> +		.max		= 65535,
>> +	},
>> +};
>> +
>> +struct tsl2563_chip {
>> +	struct mutex		lock;
>> +	struct i2c_client	*client;
>> +	struct iio_dev		*indio_dev;
>> +	struct delayed_work	poweroff_work;
>> +
>> +	/* Remember state for suspend and resume functions */
>> +	pm_message_t		state;
>> +
>> +	struct tsl2563_gainlevel_coeff *gainlevel;
>> +
>> +	/* Thresholds are in lux */
>> +	u16			low_thres;
>> +	u16			high_thres;
>> +	u8			intr;
>> +
>> +	/* Calibration coefficients */
>> +	u32			calib0;
>> +	u32			calib1;
>> +	int			cover_comp_gain;
>> +
>> +	/* Cache current values, to be returned while suspended */
>> +	u32			data0;
>> +	u32			data1;
>> +};
>> +
>> +static int tsl2563_write(struct i2c_client *client, u8 reg, u8 value)
>> +{
>> +	int ret;
>> +	u8 buf[2];
>> +
>> +	buf[0] = TSL2563_CMD | reg;
>> +	buf[1] = value;
>> +
>> +	ret = i2c_master_send(client, buf, sizeof(buf));
>> +	return (ret == sizeof(buf)) ? 0 : ret;
>> +}
>> +
>> +static int tsl2563_read(struct i2c_client *client, u8 reg, void *buf, int len)
>> +{
>> +	int ret;
>> +	u8 cmd = TSL2563_CMD | reg;
>> +
>> +	ret = i2c_master_send(client, &cmd, sizeof(cmd));
>> +	if (ret != sizeof(cmd))
>> +		return ret;
>> +
>> +	return i2c_master_recv(client, buf, len);
>> +}
>> +
>> +static int tsl2563_set_power(struct tsl2563_chip *chip, int on)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +	u8 cmd;
>> +
>> +	cmd = on ? TSL2563_CMD_POWER_ON : TSL2563_CMD_POWER_OFF;
>> +	return tsl2563_write(client, TSL2563_REG_CTRL, cmd);
>> +}
>> +
>> +/*
>> + * Return value is 0 for off, 1 for on, or a negative error
>> + * code if reading failed.
>> + */
>> +static int tsl2563_get_power(struct tsl2563_chip *chip)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +	int ret;
>> +	u8 val;
>> +
>> +	ret = tsl2563_read(client, TSL2563_REG_CTRL, &val, sizeof(val));
>> +	if (ret != sizeof(val))
>> +		return ret;
>> +
>> +	return (val & TSL2563_CTRL_POWER_MASK) == TSL2563_CMD_POWER_ON;
>> +}
>> +
>> +static int tsl2563_configure(struct tsl2563_chip *chip)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +	int ret;
>> +
>> +	ret = tsl2563_write(client, TSL2563_REG_TIMING,
>> +			chip->gainlevel->gaintime);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = tsl2563_write(client, TSL2563_REG_INT, chip->intr);
>> +
>> +out:
>> +	return ret;
>> +}
>> +
>> +static void tsl2563_poweroff_work(struct work_struct *work)
>> +{
>> +	struct tsl2563_chip *chip =
>> +		container_of(work, struct tsl2563_chip, poweroff_work.work);
>> +	tsl2563_set_power(chip, 0);
>> +}
>> +
>> +static int tsl2563_detect(struct tsl2563_chip *chip)
>> +{
>> +	int ret;
>> +
>> +	ret = tsl2563_set_power(chip, 1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = tsl2563_get_power(chip);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return ret ? 0 : -ENODEV;
>> +}
>> +
>> +static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +	int ret;
>> +
>> +	ret = tsl2563_read(client, TSL2563_REG_ID, id, sizeof(*id));
>> +	if (ret != sizeof(*id))
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>> +/*
>> + * "Normalized" ADC value is one obtained with 400ms of integration time and
>> + * 16x gain. This function returns the number of bits of shift needed to
>> + * convert between normalized values and HW values obtained using given
>> + * timing and gain settings.
>> + */
>> +static int adc_shiftbits(u8 timing)
>> +{
>> +	int shift = 0;
>> +
>> +	switch (timing & TSL2563_TIMING_MASK) {
>> +	case TSL2563_TIMING_13MS:
>> +		shift += 5;
>> +		break;
>> +	case TSL2563_TIMING_100MS:
>> +		shift += 2;
>> +		break;
>> +	case TSL2563_TIMING_400MS:
>> +		/* no-op */
>> +		break;
>> +	}
>> +
>> +	if (!(timing & TSL2563_TIMING_GAIN16))
>> +		shift += 4;
>> +
>> +	return shift;
>> +}
>> +
>> +/* Convert a HW ADC value to normalized scale. */
>> +static u32 normalize_adc(u16 adc, u8 timing)
>> +{
>> +	return adc << adc_shiftbits(timing);
>> +}
>> +
>> +static void tsl2563_wait_adc(struct tsl2563_chip *chip)
>> +{
>> +	unsigned int delay;
>> +
>> +	switch (chip->gainlevel->gaintime & TSL2563_TIMING_MASK) {
>> +	case TSL2563_TIMING_13MS:
>> +		delay = 14;
>> +		break;
>> +	case TSL2563_TIMING_100MS:
>> +		delay = 101;
>> +		break;
>> +	default:
>> +		delay = 402;
>> +	}
>> +	/*
>> +	 * TODO: Make sure that we wait at least required delay but why we
>> +	 * have to extend it one tick more?
>> +	 */
>> +	schedule_timeout_interruptible(msecs_to_jiffies(delay) + 2);
>> +}
>> +
>> +static int tsl2563_adjust_gainlevel(struct tsl2563_chip *chip, u16 adc)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +
>> +	if (adc > chip->gainlevel->max || adc < chip->gainlevel->min) {
>> +
>> +		(adc > chip->gainlevel->max) ?
>> +			chip->gainlevel++ : chip->gainlevel--;
>> +
>> +		tsl2563_write(client, TSL2563_REG_TIMING,
>> +			      chip->gainlevel->gaintime);
>> +
>> +		tsl2563_wait_adc(chip);
>> +		tsl2563_wait_adc(chip);
>> +
>> +		return 1;
>> +	} else
>> +		return 0;
>> +}
>> +
>> +static int tsl2563_get_adc(struct tsl2563_chip *chip)
>> +{
>> +	struct i2c_client *client = chip->client;
>> +	u8 buf0[2], buf1[2];
>> +	u16 adc0, adc1;
>> +	int retry = 1;
>> +	int ret = 0;
>> +
>> +	if (chip->state.event != PM_EVENT_ON)
>> +		goto out;
>> +
>> +	cancel_delayed_work(&chip->poweroff_work);
>> +
>> +	if (!tsl2563_get_power(chip)) {
>> +		ret = tsl2563_set_power(chip, 1);
>> +		if (ret)
>> +			goto out;
>> +		ret = tsl2563_configure(chip);
>> +		if (ret)
>> +			goto out;
>> +		tsl2563_wait_adc(chip);
>> +	}
>> +
>> +	while (retry) {
>> +		ret = tsl2563_read(client,
>> +				   TSL2563_REG_DATA0LOW | TSL2563_CLEARINT,
>> +				   buf0, sizeof(buf0));
>> +		if (ret != sizeof(buf0))
>> +			goto out;
>> +
>> +		ret = tsl2563_read(client, TSL2563_REG_DATA1LOW,
>> +				   buf1, sizeof(buf1));
>> +		if (ret != sizeof(buf1))
>> +			goto out;
>> +
>> +		adc0 = (buf0[1] << 8) + buf0[0];
>> +		adc1 = (buf1[1] << 8) + buf1[0];
>> +
>> +		retry = tsl2563_adjust_gainlevel(chip, adc0);
>> +	}
>> +
>> +	chip->data0 = normalize_adc(adc0, chip->gainlevel->gaintime);
>> +	chip->data1 = normalize_adc(adc1, chip->gainlevel->gaintime);
>> +
>> +	schedule_delayed_work(&chip->poweroff_work, 5 * HZ);
>> +
>> +	ret = 0;
>> +out:
>> +	return ret;
>> +}
>> +
>> +static inline int calib_to_sysfs(u32 calib)
>> +{
>> +	return (int) (((calib * CALIB_BASE_SYSFS) +
>> +		       CALIB_FRAC_HALF) >> CALIB_FRAC_BITS);
>> +}
>> +
>> +static inline u32 calib_from_sysfs(int value)
>> +{
>> +	return (((u32) value) << CALIB_FRAC_BITS) / CALIB_BASE_SYSFS;
>> +}
>> +
>> +/*
>> + * Conversions between lux and ADC values.
>> + *
>> + * The basic formula is lux = c0 * adc0 - c1 * adc1, where c0 and c1 are
>> + * appropriate constants. Different constants are needed for different
>> + * kinds of light, determined by the ratio adc1/adc0 (basically the ratio
>> + * of the intensities in infrared and visible wavelengths). lux_table below
>> + * lists the upper threshold of the adc1/adc0 ratio and the corresponding
>> + * constants.
>> + */
>> +
>> +struct tsl2563_lux_coeff {
>> +	unsigned long ch_ratio;
>> +	unsigned long ch0_coeff;
>> +	unsigned long ch1_coeff;
>> +};
>> +
>> +static const struct tsl2563_lux_coeff lux_table[] = {
>> +	{
>> +		.ch_ratio	= FRAC10K(1300),
>> +		.ch0_coeff	= FRAC10K(315),
>> +		.ch1_coeff	= FRAC10K(262),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(2600),
>> +		.ch0_coeff	= FRAC10K(337),
>> +		.ch1_coeff	= FRAC10K(430),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(3900),
>> +		.ch0_coeff	= FRAC10K(363),
>> +		.ch1_coeff	= FRAC10K(529),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(5200),
>> +		.ch0_coeff	= FRAC10K(392),
>> +		.ch1_coeff	= FRAC10K(605),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(6500),
>> +		.ch0_coeff	= FRAC10K(229),
>> +		.ch1_coeff	= FRAC10K(291),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(8000),
>> +		.ch0_coeff	= FRAC10K(157),
>> +		.ch1_coeff	= FRAC10K(180),
>> +	}, {
>> +		.ch_ratio	= FRAC10K(13000),
>> +		.ch0_coeff	= FRAC10K(34),
>> +		.ch1_coeff	= FRAC10K(26),
>> +	}, {
>> +		.ch_ratio	= ULONG_MAX,
>> +		.ch0_coeff	= 0,
>> +		.ch1_coeff	= 0,
>> +	},
>> +};
>> +
>> +/*
>> + * Convert normalized, scaled ADC values to lux.
>> + */
>> +static unsigned int adc_to_lux(u32 adc0, u32 adc1)
>> +{
>> +	const struct tsl2563_lux_coeff *lp = lux_table;
>> +	unsigned long ratio, lux, ch0 = adc0, ch1 = adc1;
>> +
>> +	ratio = ch0 ? ((ch1 << ADC_FRAC_BITS) / ch0) : ULONG_MAX;
>> +
>> +	while (lp->ch_ratio < ratio)
>> +		lp++;
>> +
>> +	lux = ch0 * lp->ch0_coeff - ch1 * lp->ch1_coeff;
>> +
>> +	return (unsigned int) (lux >> ADC_FRAC_BITS);
>> +}
>> +
>> +/*--------------------------------------------------------------*/
>> +/*                      Sysfs interface                         */
>> +/*--------------------------------------------------------------*/
>> +
>> +static ssize_t tsl2563_adc0_show(struct device *dev,
>> +				struct device_attribute *attr, char *buf)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +
>> +	ret = tsl2563_get_adc(chip);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = snprintf(buf, PAGE_SIZE, "%d\n", chip->data0);
>> +out:
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static ssize_t tsl2563_adc1_show(struct device *dev,
>> +				struct device_attribute *attr, char *buf)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +
>> +	ret = tsl2563_get_adc(chip);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = snprintf(buf, PAGE_SIZE, "%d\n", chip->data1);
>> +out:
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +/* Apply calibration coefficient to ADC count. */
>> +static u32 calib_adc(u32 adc, u32 calib)
>> +{
>> +	unsigned long scaled = adc;
>> +
>> +	scaled *= calib;
>> +	scaled >>= CALIB_FRAC_BITS;
>> +
>> +	return (u32) scaled;
>> +}
>> +
>> +static ssize_t tsl2563_lux_show(struct device *dev,
>> +				struct device_attribute *attr, char *buf)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	u32 calib0, calib1;
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +
>> +	ret = tsl2563_get_adc(chip);
>> +	if (ret)
>> +		goto out;
>> +
>> +	calib0 = calib_adc(chip->data0, chip->calib0) * chip->cover_comp_gain;
>> +	calib1 = calib_adc(chip->data1, chip->calib1) * chip->cover_comp_gain;
>> +
>> +	ret = snprintf(buf, PAGE_SIZE, "%d\n", adc_to_lux(calib0, calib1));
>> +
>> +out:
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static ssize_t format_calib(char *buf, int len, u32 calib)
>> +{
>> +	return snprintf(buf, PAGE_SIZE, "%d\n", calib_to_sysfs(calib));
>> +}
>> +
>> +static ssize_t tsl2563_calib0_show(struct device *dev,
>> +				   struct device_attribute *attr, char *buf)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +	ret = format_calib(buf, PAGE_SIZE, chip->calib0);
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static ssize_t tsl2563_calib1_show(struct device *dev,
>> +				   struct device_attribute *attr, char *buf)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +	ret = format_calib(buf, PAGE_SIZE, chip->calib1);
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static int do_calib_store(struct device *dev, const char *buf, size_t len,
>> +			  int ch)
>> +{
>> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +	struct tsl2563_chip *chip = indio_dev->dev_data;
>> +	int value;
>> +	u32 calib;
>> +
>> +	if (1 != sscanf(buf, "%d", &value))
>> +		return -EINVAL;
>> +
>> +	calib = calib_from_sysfs(value);
>> +
>> +	if (ch)
>> +		chip->calib1 = calib;
>> +	else
>> +		chip->calib0 = calib;
>> +
>> +	return len;
>> +}
>> +
>> +static ssize_t tsl2563_calib0_store(struct device *dev,
>> +				    struct device_attribute *attr,
>> +				    const char *buf, size_t len)
>> +{
>> +	return do_calib_store(dev, buf, len, 0);
>> +}
>> +
>> +static ssize_t tsl2563_calib1_store(struct device *dev,
>> +				    struct device_attribute *attr,
>> +				    const char *buf, size_t len)
>> +{
>> +	return do_calib_store(dev, buf, len, 1);
>> +}
>> +
>> +/* AmitXXXX: Convert to IIO_DEV_ATTR_LIGHT* as in tsl2561
>> + * once I understand what they mean */
>> +static DEVICE_ATTR(adc0, S_IRUGO, tsl2563_adc0_show, NULL);
>> +static DEVICE_ATTR(adc1, S_IRUGO, tsl2563_adc1_show, NULL);
>> +static DEVICE_ATTR(lux, S_IRUGO, tsl2563_lux_show, NULL);
>> +static DEVICE_ATTR(calib0, S_IRUGO | S_IWUSR,
>> +		   tsl2563_calib0_show, tsl2563_calib0_store);
>> +static DEVICE_ATTR(calib1, S_IRUGO | S_IWUSR,
>> +		   tsl2563_calib1_show, tsl2563_calib1_store);
>> +
>> +static struct attribute *tsl2563_attributes[] = {
>> +	&dev_attr_adc0.attr,
>> +	&dev_attr_adc1.attr,
>> +	&dev_attr_lux.attr,
>> +	&dev_attr_calib0.attr,
>> +	&dev_attr_calib1.attr,
>> +	NULL
>> +};
>> +
>> +static const struct attribute_group tsl2563_group = {
>> +	.attrs = tsl2563_attributes,
>> +};
>> +
>> +/*--------------------------------------------------------------*/
>> +/*                      Probe, Attach, Remove                   */
>> +/*--------------------------------------------------------------*/
>> +static struct i2c_driver tsl2563_i2c_driver;
>> +
>> +static int __devinit tsl2563_probe(struct i2c_client *client,
>> +				const struct i2c_device_id *device_id)
>> +{
>> +	struct tsl2563_chip *chip;
>> +	struct tsl2563_platform_data *pdata = client->dev.platform_data;
>> +	int err = 0;
>> +	int ret;
>> +	u8 id;
>> +
>> +	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
>> +	if (!chip)
>> +		return -ENOMEM;
>> +
>> +	i2c_set_clientdata(client, chip);
>> +	chip->client = client;
>> +
>> +	err = tsl2563_detect(chip);
>> +	if (err) {
>> +		dev_err(&client->dev, "device not found, error %d \n", -err);
>> +		goto fail1;
>> +	}
>> +
>> +	err = tsl2563_read_id(chip, &id);
>> +	if (err)
>> +		goto fail1;
>> +
>> +	mutex_init(&chip->lock);
>> +
>> +	/* Default values used until userspace says otherwise */
>> +	chip->low_thres = 0x0;
>> +	chip->high_thres = 0xffff;
>> +	chip->gainlevel = tsl2563_gainlevel_table;
>> +	chip->intr = TSL2563_INT_PERSIST(4);
>> +	chip->calib0 = calib_from_sysfs(CALIB_BASE_SYSFS);
>> +	chip->calib1 = calib_from_sysfs(CALIB_BASE_SYSFS);
>> +
>> +	if (pdata)
>> +		chip->cover_comp_gain = pdata->cover_comp_gain;
>> +	else
>> +		chip->cover_comp_gain = 1;
>> +
>> +	dev_info(&client->dev, "model %d, rev. %d\n", id >> 4, id & 0x0f);
>> +
>> +	chip->indio_dev = iio_allocate_device();
>> +	if (!chip->indio_dev)
>> +		goto fail1;
>> +	chip->indio_dev->attrs = &tsl2563_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;
>> +	ret = iio_device_register(chip->indio_dev);
>> +	if (ret)
>> +		goto fail1;
>> +
>> +	err = tsl2563_configure(chip);
>> +	if (err)
>> +		goto fail2;
>> +
>> +	INIT_DELAYED_WORK(&chip->poweroff_work, tsl2563_poweroff_work);
>> +	schedule_delayed_work(&chip->poweroff_work, 5 * HZ);
>> +
>> +	return 0;
>> +fail2:
>> +	iio_device_unregister(chip->indio_dev);
>> +fail1:
>> +	kfree(chip);
>> +	return err;
>> +}
>> +
>> +static int tsl2563_remove(struct i2c_client *client)
>> +{
>> +	struct tsl2563_chip *chip = i2c_get_clientdata(client);
>> +
>> +	iio_device_unregister(chip->indio_dev);
>> +
>> +	kfree(chip);
>> +	return 0;
>> +}
>> +
>> +static int tsl2563_suspend(struct i2c_client *client, pm_message_t state)
>> +{
>> +	struct tsl2563_chip *chip = i2c_get_clientdata(client);
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +
>> +	ret = tsl2563_set_power(chip, 0);
>> +	if (ret)
>> +		goto out;
>> +
>> +	chip->state = state;
>> +
>> +out:
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static int tsl2563_resume(struct i2c_client *client)
>> +{
>> +	struct tsl2563_chip *chip = i2c_get_clientdata(client);
>> +	int ret;
>> +
>> +	mutex_lock(&chip->lock);
>> +
>> +	ret = tsl2563_set_power(chip, 1);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = tsl2563_configure(chip);
>> +	if (ret)
>> +		goto out;
>> +
>> +	chip->state.event = PM_EVENT_ON;
>> +
>> +out:
>> +	mutex_unlock(&chip->lock);
>> +	return ret;
>> +}
>> +
>> +static const struct i2c_device_id tsl2563_id[] = {
>> +	{ DRIVER_NAME, 0 },
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(i2c, tsl2563_id);
>> +
>> +static struct i2c_driver tsl2563_i2c_driver = {
>> +	.driver = {
>> +		.name	 = DRIVER_NAME,
>> +	},
>> +	.suspend	= tsl2563_suspend,
>> +	.resume		= tsl2563_resume,
>> +	.probe		= tsl2563_probe,
>> +	.remove		= __devexit_p(tsl2563_remove),
>> +	.id_table	= tsl2563_id,
>> +};
>> +
>> +static int __init tsl2563_init(void)
>> +{
>> +	return i2c_add_driver(&tsl2563_i2c_driver);
>> +}
>> +
>> +static void __exit tsl2563_exit(void)
>> +{
>> +	i2c_del_driver(&tsl2563_i2c_driver);
>> +}
>> +
>> +MODULE_AUTHOR("Nokia Corporation");
>> +MODULE_DESCRIPTION("tsl2563 light sensor driver");
>> +MODULE_LICENSE("GPL");
>> +
>> +module_init(tsl2563_init);
>> +module_exit(tsl2563_exit);
>> diff --git a/drivers/staging/iio/light/tsl2563.h b/drivers/staging/iio/light/tsl2563.h
>> new file mode 100644
>> index 0000000..b97368b
>> --- /dev/null
>> +++ b/drivers/staging/iio/light/tsl2563.h
>> @@ -0,0 +1,9 @@
>> +#ifndef __LINUX_TSL2563_H
>> +#define __LINUX_TSL2563_H
>> +
>> +struct tsl2563_platform_data {
>> +	int cover_comp_gain;
>> +};
>> +
>> +#endif /* __LINUX_TSL2563_H */
>> +
> 
> 

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