/*
 * drivers/iio/light/tsl2563.c
 *
 * Copyright (C) 2008 Nokia Corporation
 *
 * Written by Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
 * Contact: Amit Kucheria <amit.kucheria@verdurent.com>
 *
 * Converted to IIO driver
 * Amit Kucheria <amit.kucheria@verdurent.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/irq.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/err.h>
#include <linux/slab.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/platform_data/tsl2563.h>

/* 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 const 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 delayed_work     poweroff_work;

        /* Remember state for suspend and resume functions */
        bool suspended;

        struct tsl2563_gainlevel_coeff const *gainlevel;

        u16                     low_thres;
        u16                     high_thres;
        u8                      intr;
        bool                    int_enabled;

        /* 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_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 i2c_smbus_write_byte_data(client,
                                         TSL2563_CMD | 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;

        ret = i2c_smbus_read_byte_data(client, TSL2563_CMD | TSL2563_REG_CTRL);
        if (ret < 0)
                return ret;

        return (ret & TSL2563_CTRL_POWER_MASK) == TSL2563_CMD_POWER_ON;
}

static int tsl2563_configure(struct tsl2563_chip *chip)
{
        int ret;

        ret = i2c_smbus_write_byte_data(chip->client,
                        TSL2563_CMD | TSL2563_REG_TIMING,
                        chip->gainlevel->gaintime);
        if (ret)
                goto error_ret;
        ret = i2c_smbus_write_byte_data(chip->client,
                        TSL2563_CMD | TSL2563_REG_HIGHLOW,
                        chip->high_thres & 0xFF);
        if (ret)
                goto error_ret;
        ret = i2c_smbus_write_byte_data(chip->client,
                        TSL2563_CMD | TSL2563_REG_HIGHHIGH,
                        (chip->high_thres >> 8) & 0xFF);
        if (ret)
                goto error_ret;
        ret = i2c_smbus_write_byte_data(chip->client,
                        TSL2563_CMD | TSL2563_REG_LOWLOW,
                        chip->low_thres & 0xFF);
        if (ret)
                goto error_ret;
        ret = i2c_smbus_write_byte_data(chip->client,
                        TSL2563_CMD | TSL2563_REG_LOWHIGH,
                        (chip->low_thres >> 8) & 0xFF);
/*
 * Interrupt register is automatically written anyway if it is relevant
 * so is not here.
 */
error_ret:
        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 = i2c_smbus_read_byte_data(client, TSL2563_CMD | TSL2563_REG_ID);
        if (ret < 0)
                return ret;

        *id = 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 tsl2563_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 tsl2563_normalize_adc(u16 adc, u8 timing)
{
        return adc << tsl2563_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--;

                i2c_smbus_write_byte_data(client,
                                          TSL2563_CMD | 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;
        u16 adc0, adc1;
        int retry = 1;
        int ret = 0;

        if (chip->suspended)
                goto out;

        if (!chip->int_enabled) {
                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 = i2c_smbus_read_word_data(client,
                                TSL2563_CMD | TSL2563_REG_DATA0LOW);
                if (ret < 0)
                        goto out;
                adc0 = ret;

                ret = i2c_smbus_read_word_data(client,
                                TSL2563_CMD | TSL2563_REG_DATA1LOW);
                if (ret < 0)
                        goto out;
                adc1 = ret;

                retry = tsl2563_adjust_gainlevel(chip, adc0);
        }

        chip->data0 = tsl2563_normalize_adc(adc0, chip->gainlevel->gaintime);
        chip->data1 = tsl2563_normalize_adc(adc1, chip->gainlevel->gaintime);

        if (!chip->int_enabled)
                schedule_delayed_work(&chip->poweroff_work, 5 * HZ);

        ret = 0;
out:
        return ret;
}

static inline int tsl2563_calib_to_sysfs(u32 calib)
{
        return (int) (((calib * CALIB_BASE_SYSFS) +
                       CALIB_FRAC_HALF) >> CALIB_FRAC_BITS);
}

static inline u32 tsl2563_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 tsl2563_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);
}

/* Apply calibration coefficient to ADC count. */
static u32 tsl2563_calib_adc(u32 adc, u32 calib)
{
        unsigned long scaled = adc;

        scaled *= calib;
        scaled >>= CALIB_FRAC_BITS;

        return (u32) scaled;
}

static int tsl2563_write_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int val,
                               int val2,
                               long mask)
{
        struct tsl2563_chip *chip = iio_priv(indio_dev);

        if (mask != IIO_CHAN_INFO_CALIBSCALE)
                return -EINVAL;
        if (chan->channel2 == IIO_MOD_LIGHT_BOTH)
                chip->calib0 = tsl2563_calib_from_sysfs(val);
        else if (chan->channel2 == IIO_MOD_LIGHT_IR)
                chip->calib1 = tsl2563_calib_from_sysfs(val);
        else
                return -EINVAL;

        return 0;
}

static int tsl2563_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int *val,
                            int *val2,
                            long mask)
{
        int ret = -EINVAL;
        u32 calib0, calib1;
        struct tsl2563_chip *chip = iio_priv(indio_dev);

        mutex_lock(&chip->lock);
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
        case IIO_CHAN_INFO_PROCESSED:
                switch (chan->type) {
                case IIO_LIGHT:
                        ret = tsl2563_get_adc(chip);
                        if (ret)
                                goto error_ret;
                        calib0 = tsl2563_calib_adc(chip->data0, chip->calib0) *
                                chip->cover_comp_gain;
                        calib1 = tsl2563_calib_adc(chip->data1, chip->calib1) *
                                chip->cover_comp_gain;
                        *val = tsl2563_adc_to_lux(calib0, calib1);
                        ret = IIO_VAL_INT;
                        break;
                case IIO_INTENSITY:
                        ret = tsl2563_get_adc(chip);
                        if (ret)
                                goto error_ret;
                        if (chan->channel2 == IIO_MOD_LIGHT_BOTH)
                                *val = chip->data0;
                        else
                                *val = chip->data1;
                        ret = IIO_VAL_INT;
                        break;
                default:
                        break;
                }
                break;

        case IIO_CHAN_INFO_CALIBSCALE:
                if (chan->channel2 == IIO_MOD_LIGHT_BOTH)
                        *val = tsl2563_calib_to_sysfs(chip->calib0);
                else
                        *val = tsl2563_calib_to_sysfs(chip->calib1);
                ret = IIO_VAL_INT;
                break;
        default:
                ret = -EINVAL;
                goto error_ret;
        }

error_ret:
        mutex_unlock(&chip->lock);
        return ret;
}

static const struct iio_event_spec tsl2563_events[] = {
        {
                .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 tsl2563_channels[] = {
        {
                .type = IIO_LIGHT,
                .indexed = 1,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
                .channel = 0,
        }, {
                .type = IIO_INTENSITY,
                .modified = 1,
                .channel2 = IIO_MOD_LIGHT_BOTH,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                BIT(IIO_CHAN_INFO_CALIBSCALE),
                .event_spec = tsl2563_events,
                .num_event_specs = ARRAY_SIZE(tsl2563_events),
        }, {
                .type = IIO_INTENSITY,
                .modified = 1,
                .channel2 = IIO_MOD_LIGHT_IR,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                BIT(IIO_CHAN_INFO_CALIBSCALE),
        }
};

static int tsl2563_read_thresh(struct iio_dev *indio_dev,
        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 tsl2563_chip *chip = iio_priv(indio_dev);

        switch (dir) {
        case IIO_EV_DIR_RISING:
                *val = chip->high_thres;
                break;
        case IIO_EV_DIR_FALLING:
                *val = chip->low_thres;
                break;
        default:
                return -EINVAL;
        }

        return IIO_VAL_INT;
}

static int tsl2563_write_thresh(struct iio_dev *indio_dev,
        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 tsl2563_chip *chip = iio_priv(indio_dev);
        int ret;
        u8 address;

        if (dir == IIO_EV_DIR_RISING)
                address = TSL2563_REG_HIGHLOW;
        else
                address = TSL2563_REG_LOWLOW;
        mutex_lock(&chip->lock);
        ret = i2c_smbus_write_byte_data(chip->client, TSL2563_CMD | address,
                                        val & 0xFF);
        if (ret)
                goto error_ret;
        ret = i2c_smbus_write_byte_data(chip->client,
                                        TSL2563_CMD | (address + 1),
                                        (val >> 8) & 0xFF);
        if (dir == IIO_EV_DIR_RISING)
                chip->high_thres = val;
        else
                chip->low_thres = val;

error_ret:
        mutex_unlock(&chip->lock);

        return ret;
}

static irqreturn_t tsl2563_event_handler(int irq, void *private)
{
        struct iio_dev *dev_info = private;
        struct tsl2563_chip *chip = iio_priv(dev_info);

        iio_push_event(dev_info,
                       IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
                                            0,
                                            IIO_EV_TYPE_THRESH,
                                            IIO_EV_DIR_EITHER),
                       iio_get_time_ns());

        /* clear the interrupt and push the event */
        i2c_smbus_write_byte(chip->client, TSL2563_CMD | TSL2563_CLEARINT);
        return IRQ_HANDLED;
}

static int tsl2563_write_interrupt_config(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan, enum iio_event_type type,
        enum iio_event_direction dir, int state)
{
        struct tsl2563_chip *chip = iio_priv(indio_dev);
        int ret = 0;

        mutex_lock(&chip->lock);
        if (state && !(chip->intr & 0x30)) {
                chip->intr &= ~0x30;
                chip->intr |= 0x10;
                /* ensure the chip is actually on */
                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;
                }
                ret = i2c_smbus_write_byte_data(chip->client,
                                                TSL2563_CMD | TSL2563_REG_INT,
                                                chip->intr);
                chip->int_enabled = true;
        }

        if (!state && (chip->intr & 0x30)) {
                chip->intr &= ~0x30;
                ret = i2c_smbus_write_byte_data(chip->client,
                                                TSL2563_CMD | TSL2563_REG_INT,
                                                chip->intr);
                chip->int_enabled = false;
                /* now the interrupt is not enabled, we can go to sleep */
                schedule_delayed_work(&chip->poweroff_work, 5 * HZ);
        }
out:
        mutex_unlock(&chip->lock);

        return ret;
}

static int tsl2563_read_interrupt_config(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan, enum iio_event_type type,
        enum iio_event_direction dir)
{
        struct tsl2563_chip *chip = iio_priv(indio_dev);
        int ret;

        mutex_lock(&chip->lock);
        ret = i2c_smbus_read_byte_data(chip->client,
                                       TSL2563_CMD | TSL2563_REG_INT);
        mutex_unlock(&chip->lock);
        if (ret < 0)
                return ret;

        return !!(ret & 0x30);
}

static const struct iio_info tsl2563_info_no_irq = {
        .driver_module = THIS_MODULE,
        .read_raw = &tsl2563_read_raw,
        .write_raw = &tsl2563_write_raw,
};

static const struct iio_info tsl2563_info = {
        .driver_module = THIS_MODULE,
        .read_raw = &tsl2563_read_raw,
        .write_raw = &tsl2563_write_raw,
        .read_event_value = &tsl2563_read_thresh,
        .write_event_value = &tsl2563_write_thresh,
        .read_event_config = &tsl2563_read_interrupt_config,
        .write_event_config = &tsl2563_write_interrupt_config,
};

static int tsl2563_probe(struct i2c_client *client,
                                const struct i2c_device_id *device_id)
{
        struct iio_dev *indio_dev;
        struct tsl2563_chip *chip;
        struct tsl2563_platform_data *pdata = client->dev.platform_data;
        struct device_node *np = client->dev.of_node;
        int err = 0;
        u8 id = 0;

        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
        if (!indio_dev)
                return -ENOMEM;

        chip = iio_priv(indio_dev);

        i2c_set_clientdata(client, chip);
        chip->client = client;

        err = tsl2563_detect(chip);
        if (err) {
                dev_err(&client->dev, "detect error %d\n", -err);
                return err;
        }

        err = tsl2563_read_id(chip, &id);
        if (err) {
                dev_err(&client->dev, "read id error %d\n", -err);
                return err;
        }

        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 = tsl2563_calib_from_sysfs(CALIB_BASE_SYSFS);
        chip->calib1 = tsl2563_calib_from_sysfs(CALIB_BASE_SYSFS);

        if (pdata)
                chip->cover_comp_gain = pdata->cover_comp_gain;
        else if (np)
                of_property_read_u32(np, "amstaos,cover-comp-gain",
                                     &chip->cover_comp_gain);
        else
                chip->cover_comp_gain = 1;

        dev_info(&client->dev, "model %d, rev. %d\n", id >> 4, id & 0x0f);
        indio_dev->name = client->name;
        indio_dev->channels = tsl2563_channels;
        indio_dev->num_channels = ARRAY_SIZE(tsl2563_channels);
        indio_dev->dev.parent = &client->dev;
        indio_dev->modes = INDIO_DIRECT_MODE;

        if (client->irq)
                indio_dev->info = &tsl2563_info;
        else
                indio_dev->info = &tsl2563_info_no_irq;

        if (client->irq) {
                err = devm_request_threaded_irq(&client->dev, client->irq,
                                           NULL,
                                           &tsl2563_event_handler,
                                           IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                                           "tsl2563_event",
                                           indio_dev);
                if (err) {
                        dev_err(&client->dev, "irq request error %d\n", -err);
                        return err;
                }
        }

        err = tsl2563_configure(chip);
        if (err) {
                dev_err(&client->dev, "configure error %d\n", -err);
                return err;
        }

        INIT_DELAYED_WORK(&chip->poweroff_work, tsl2563_poweroff_work);

        /* The interrupt cannot yet be enabled so this is fine without lock */
        schedule_delayed_work(&chip->poweroff_work, 5 * HZ);

        err = iio_device_register(indio_dev);
        if (err) {
                dev_err(&client->dev, "iio registration error %d\n", -err);
                goto fail;
        }

        return 0;

fail:
        cancel_delayed_work(&chip->poweroff_work);
        flush_scheduled_work();
        return err;
}

static int tsl2563_remove(struct i2c_client *client)
{
        struct tsl2563_chip *chip = i2c_get_clientdata(client);
        struct iio_dev *indio_dev = iio_priv_to_dev(chip);

        iio_device_unregister(indio_dev);
        if (!chip->int_enabled)
                cancel_delayed_work(&chip->poweroff_work);
        /* Ensure that interrupts are disabled - then flush any bottom halves */
        chip->intr &= ~0x30;
        i2c_smbus_write_byte_data(chip->client, TSL2563_CMD | TSL2563_REG_INT,
                                  chip->intr);
        flush_scheduled_work();
        tsl2563_set_power(chip, 0);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tsl2563_suspend(struct device *dev)
{
        struct tsl2563_chip *chip = i2c_get_clientdata(to_i2c_client(dev));
        int ret;

        mutex_lock(&chip->lock);

        ret = tsl2563_set_power(chip, 0);
        if (ret)
                goto out;

        chip->suspended = true;

out:
        mutex_unlock(&chip->lock);
        return ret;
}

static int tsl2563_resume(struct device *dev)
{
        struct tsl2563_chip *chip = i2c_get_clientdata(to_i2c_client(dev));
        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->suspended = false;

out:
        mutex_unlock(&chip->lock);
        return ret;
}

static SIMPLE_DEV_PM_OPS(tsl2563_pm_ops, tsl2563_suspend, tsl2563_resume);
#define TSL2563_PM_OPS (&tsl2563_pm_ops)
#else
#define TSL2563_PM_OPS NULL
#endif

static const struct i2c_device_id tsl2563_id[] = {
        { "tsl2560", 0 },
        { "tsl2561", 1 },
        { "tsl2562", 2 },
        { "tsl2563", 3 },
        {}
};
MODULE_DEVICE_TABLE(i2c, tsl2563_id);

static struct i2c_driver tsl2563_i2c_driver = {
        .driver = {
                .name    = "tsl2563",
                .pm     = TSL2563_PM_OPS,
        },
        .probe          = tsl2563_probe,
        .remove         = tsl2563_remove,
        .id_table       = tsl2563_id,
};
module_i2c_driver(tsl2563_i2c_driver);

MODULE_AUTHOR("Nokia Corporation");
MODULE_DESCRIPTION("tsl2563 light sensor driver");
MODULE_LICENSE("GPL");