// SPDX-License-Identifier: GPL-2.0-only
/*
 * IIO driver for the light sensor ISL29028.
 * ISL29028 is Concurrent Ambient Light and Proximity Sensor
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 * Copyright (c) 2016-2017 Brian Masney <masneyb@onstation.org>
 *
 * Datasheets:
 *  - http://www.intersil.com/content/dam/Intersil/documents/isl2/isl29028.pdf
 *  - http://www.intersil.com/content/dam/Intersil/documents/isl2/isl29030.pdf
 */

#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 <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/pm_runtime.h>

#define ISL29028_CONV_TIME_MS                   100

#define ISL29028_REG_CONFIGURE                  0x01

#define ISL29028_CONF_ALS_IR_MODE_ALS           0
#define ISL29028_CONF_ALS_IR_MODE_IR            BIT(0)
#define ISL29028_CONF_ALS_IR_MODE_MASK          BIT(0)

#define ISL29028_CONF_ALS_RANGE_LOW_LUX         0
#define ISL29028_CONF_ALS_RANGE_HIGH_LUX        BIT(1)
#define ISL29028_CONF_ALS_RANGE_MASK            BIT(1)

#define ISL29028_CONF_ALS_DIS                   0
#define ISL29028_CONF_ALS_EN                    BIT(2)
#define ISL29028_CONF_ALS_EN_MASK               BIT(2)

#define ISL29028_CONF_PROX_SLP_SH               4
#define ISL29028_CONF_PROX_SLP_MASK             (7 << ISL29028_CONF_PROX_SLP_SH)

#define ISL29028_CONF_PROX_EN                   BIT(7)
#define ISL29028_CONF_PROX_EN_MASK              BIT(7)

#define ISL29028_REG_INTERRUPT                  0x02

#define ISL29028_REG_PROX_DATA                  0x08
#define ISL29028_REG_ALSIR_L                    0x09
#define ISL29028_REG_ALSIR_U                    0x0A

#define ISL29028_REG_TEST1_MODE                 0x0E
#define ISL29028_REG_TEST2_MODE                 0x0F

#define ISL29028_NUM_REGS                       (ISL29028_REG_TEST2_MODE + 1)

#define ISL29028_POWER_OFF_DELAY_MS             2000

struct isl29028_prox_data {
        int sampling_int;
        int sampling_fract;
        int sleep_time;
};

static const struct isl29028_prox_data isl29028_prox_data[] = {
        {   1, 250000, 800 },
        {   2, 500000, 400 },
        {   5,      0, 200 },
        {  10,      0, 100 },
        {  13, 300000,  75 },
        {  20,      0,  50 },
        {  80,      0,  13 }, /*
                               * Note: Data sheet lists 12.5 ms sleep time.
                               * Round up a half millisecond for msleep().
                               */
        { 100,  0,   0 }
};

enum isl29028_als_ir_mode {
        ISL29028_MODE_NONE = 0,
        ISL29028_MODE_ALS,
        ISL29028_MODE_IR,
};

struct isl29028_chip {
        struct mutex                    lock;
        struct regmap                   *regmap;
        int                             prox_sampling_int;
        int                             prox_sampling_frac;
        bool                            enable_prox;
        int                             lux_scale;
        enum isl29028_als_ir_mode       als_ir_mode;
};

static int isl29028_find_prox_sleep_index(int sampling_int, int sampling_fract)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(isl29028_prox_data); ++i) {
                if (isl29028_prox_data[i].sampling_int == sampling_int &&
                    isl29028_prox_data[i].sampling_fract == sampling_fract)
                        return i;
        }

        return -EINVAL;
}

static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
                                        int sampling_int, int sampling_fract)
{
        struct device *dev = regmap_get_device(chip->regmap);
        int sleep_index, ret;

        sleep_index = isl29028_find_prox_sleep_index(sampling_int,
                                                     sampling_fract);
        if (sleep_index < 0)
                return sleep_index;

        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                 ISL29028_CONF_PROX_SLP_MASK,
                                 sleep_index << ISL29028_CONF_PROX_SLP_SH);

        if (ret < 0) {
                dev_err(dev, "%s(): Error %d setting the proximity sampling\n",
                        __func__, ret);
                return ret;
        }

        chip->prox_sampling_int = sampling_int;
        chip->prox_sampling_frac = sampling_fract;

        return ret;
}

static int isl29028_enable_proximity(struct isl29028_chip *chip)
{
        int prox_index, ret;

        ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling_int,
                                           chip->prox_sampling_frac);
        if (ret < 0)
                return ret;

        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                 ISL29028_CONF_PROX_EN_MASK,
                                 ISL29028_CONF_PROX_EN);
        if (ret < 0)
                return ret;

        /* Wait for conversion to be complete for first sample */
        prox_index = isl29028_find_prox_sleep_index(chip->prox_sampling_int,
                                                    chip->prox_sampling_frac);
        if (prox_index < 0)
                return prox_index;

        msleep(isl29028_prox_data[prox_index].sleep_time);

        return 0;
}

static int isl29028_set_als_scale(struct isl29028_chip *chip, int lux_scale)
{
        struct device *dev = regmap_get_device(chip->regmap);
        int val = (lux_scale == 2000) ? ISL29028_CONF_ALS_RANGE_HIGH_LUX :
                                        ISL29028_CONF_ALS_RANGE_LOW_LUX;
        int ret;

        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                 ISL29028_CONF_ALS_RANGE_MASK, val);
        if (ret < 0) {
                dev_err(dev, "%s(): Error %d setting the ALS scale\n", __func__,
                        ret);
                return ret;
        }

        chip->lux_scale = lux_scale;

        return ret;
}

static int isl29028_set_als_ir_mode(struct isl29028_chip *chip,
                                    enum isl29028_als_ir_mode mode)
{
        int ret;

        if (chip->als_ir_mode == mode)
                return 0;

        ret = isl29028_set_als_scale(chip, chip->lux_scale);
        if (ret < 0)
                return ret;

        switch (mode) {
        case ISL29028_MODE_ALS:
                ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                         ISL29028_CONF_ALS_IR_MODE_MASK,
                                         ISL29028_CONF_ALS_IR_MODE_ALS);
                if (ret < 0)
                        return ret;

                ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                         ISL29028_CONF_ALS_RANGE_MASK,
                                         ISL29028_CONF_ALS_RANGE_HIGH_LUX);
                break;
        case ISL29028_MODE_IR:
                ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                         ISL29028_CONF_ALS_IR_MODE_MASK,
                                         ISL29028_CONF_ALS_IR_MODE_IR);
                break;
        case ISL29028_MODE_NONE:
                return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                          ISL29028_CONF_ALS_EN_MASK,
                                          ISL29028_CONF_ALS_DIS);
        }

        if (ret < 0)
                return ret;

        /* Enable the ALS/IR */
        ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
                                 ISL29028_CONF_ALS_EN_MASK,
                                 ISL29028_CONF_ALS_EN);
        if (ret < 0)
                return ret;

        /* Need to wait for conversion time if ALS/IR mode enabled */
        msleep(ISL29028_CONV_TIME_MS);

        chip->als_ir_mode = mode;

        return 0;
}

static int isl29028_read_als_ir(struct isl29028_chip *chip, int *als_ir)
{
        struct device *dev = regmap_get_device(chip->regmap);
        unsigned int lsb;
        unsigned int msb;
        int ret;

        ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_L, &lsb);
        if (ret < 0) {
                dev_err(dev,
                        "%s(): Error %d reading register ALSIR_L\n",
                        __func__, ret);
                return ret;
        }

        ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_U, &msb);
        if (ret < 0) {
                dev_err(dev,
                        "%s(): Error %d reading register ALSIR_U\n",
                        __func__, ret);
                return ret;
        }

        *als_ir = ((msb & 0xF) << 8) | (lsb & 0xFF);

        return 0;
}

static int isl29028_read_proxim(struct isl29028_chip *chip, int *prox)
{
        struct device *dev = regmap_get_device(chip->regmap);
        unsigned int data;
        int ret;

        if (!chip->enable_prox) {
                ret = isl29028_enable_proximity(chip);
                if (ret < 0)
                        return ret;

                chip->enable_prox = true;
        }

        ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
        if (ret < 0) {
                dev_err(dev, "%s(): Error %d reading register PROX_DATA\n",
                        __func__, ret);
                return ret;
        }

        *prox = data;

        return 0;
}

static int isl29028_als_get(struct isl29028_chip *chip, int *als_data)
{
        struct device *dev = regmap_get_device(chip->regmap);
        int ret;
        int als_ir_data;

        ret = isl29028_set_als_ir_mode(chip, ISL29028_MODE_ALS);
        if (ret < 0) {
                dev_err(dev, "%s(): Error %d enabling ALS mode\n", __func__,
                        ret);
                return ret;
        }

        ret = isl29028_read_als_ir(chip, &als_ir_data);
        if (ret < 0)
                return ret;

        /*
         * convert als data count to lux.
         * if lux_scale = 125,  lux = count * 0.031
         * if lux_scale = 2000, lux = count * 0.49
         */
        if (chip->lux_scale == 125)
                als_ir_data = (als_ir_data * 31) / 1000;
        else
                als_ir_data = (als_ir_data * 49) / 100;

        *als_data = als_ir_data;

        return 0;
}

static int isl29028_ir_get(struct isl29028_chip *chip, int *ir_data)
{
        struct device *dev = regmap_get_device(chip->regmap);
        int ret;

        ret = isl29028_set_als_ir_mode(chip, ISL29028_MODE_IR);
        if (ret < 0) {
                dev_err(dev, "%s(): Error %d enabling IR mode\n", __func__,
                        ret);
                return ret;
        }

        return isl29028_read_als_ir(chip, ir_data);
}

static int isl29028_set_pm_runtime_busy(struct isl29028_chip *chip, bool on)
{
        struct device *dev = regmap_get_device(chip->regmap);

        if (on)
                return pm_runtime_resume_and_get(dev);

        return pm_runtime_put_autosuspend(dev);
}

/* Channel IO */
static int isl29028_write_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int val, int val2, long mask)
{
        struct isl29028_chip *chip = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(chip->regmap);
        int ret;

        ret = isl29028_set_pm_runtime_busy(chip, true);
        if (ret < 0)
                return ret;

        mutex_lock(&chip->lock);

        ret = -EINVAL;
        switch (chan->type) {
        case IIO_PROXIMITY:
                if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
                        dev_err(dev,
                                "%s(): proximity: Mask value 0x%08lx is not supported\n",
                                __func__, mask);
                        break;
                }

                if (val < 1 || val > 100) {
                        dev_err(dev,
                                "%s(): proximity: Sampling frequency %d is not in the range [1:100]\n",
                                __func__, val);
                        break;
                }

                ret = isl29028_set_proxim_sampling(chip, val, val2);
                break;
        case IIO_LIGHT:
                if (mask != IIO_CHAN_INFO_SCALE) {
                        dev_err(dev,
                                "%s(): light: Mask value 0x%08lx is not supported\n",
                                __func__, mask);
                        break;
                }

                if (val != 125 && val != 2000) {
                        dev_err(dev,
                                "%s(): light: Lux scale %d is not in the set {125, 2000}\n",
                                __func__, val);
                        break;
                }

                ret = isl29028_set_als_scale(chip, val);
                break;
        default:
                dev_err(dev, "%s(): Unsupported channel type %x\n",
                        __func__, chan->type);
                break;
        }

        mutex_unlock(&chip->lock);

        if (ret < 0)
                return ret;

        ret = isl29028_set_pm_runtime_busy(chip, false);
        if (ret < 0)
                return ret;

        return ret;
}

static int isl29028_read_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             int *val, int *val2, long mask)
{
        struct isl29028_chip *chip = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(chip->regmap);
        int ret, pm_ret;

        ret = isl29028_set_pm_runtime_busy(chip, true);
        if (ret < 0)
                return ret;

        mutex_lock(&chip->lock);

        ret = -EINVAL;
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
        case IIO_CHAN_INFO_PROCESSED:
                switch (chan->type) {
                case IIO_LIGHT:
                        ret = isl29028_als_get(chip, val);
                        break;
                case IIO_INTENSITY:
                        ret = isl29028_ir_get(chip, val);
                        break;
                case IIO_PROXIMITY:
                        ret = isl29028_read_proxim(chip, val);
                        break;
                default:
                        break;
                }

                if (ret < 0)
                        break;

                ret = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_SAMP_FREQ:
                if (chan->type != IIO_PROXIMITY)
                        break;

                *val = chip->prox_sampling_int;
                *val2 = chip->prox_sampling_frac;
                ret = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_SCALE:
                if (chan->type != IIO_LIGHT)
                        break;
                *val = chip->lux_scale;
                ret = IIO_VAL_INT;
                break;
        default:
                dev_err(dev, "%s(): mask value 0x%08lx is not supported\n",
                        __func__, mask);
                break;
        }

        mutex_unlock(&chip->lock);

        if (ret < 0)
                return ret;

        /**
         * Preserve the ret variable if the call to
         * isl29028_set_pm_runtime_busy() is successful so the reading
         * (if applicable) is returned to user space.
         */
        pm_ret = isl29028_set_pm_runtime_busy(chip, false);
        if (pm_ret < 0)
                return pm_ret;

        return ret;
}

static IIO_CONST_ATTR(in_proximity_sampling_frequency_available,
                                "1.25 2.5 5 10 13.3 20 80 100");
static IIO_CONST_ATTR(in_illuminance_scale_available, "125 2000");

#define ISL29028_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
static struct attribute *isl29028_attributes[] = {
        ISL29028_CONST_ATTR(in_proximity_sampling_frequency_available),
        ISL29028_CONST_ATTR(in_illuminance_scale_available),
        NULL,
};

static const struct attribute_group isl29108_group = {
        .attrs = isl29028_attributes,
};

static const struct iio_chan_spec isl29028_channels[] = {
        {
                .type = IIO_LIGHT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
                BIT(IIO_CHAN_INFO_SCALE),
        }, {
                .type = IIO_INTENSITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
        }, {
                .type = IIO_PROXIMITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }
};

static const struct iio_info isl29028_info = {
        .attrs = &isl29108_group,
        .read_raw = isl29028_read_raw,
        .write_raw = isl29028_write_raw,
};

static int isl29028_clear_configure_reg(struct isl29028_chip *chip)
{
        struct device *dev = regmap_get_device(chip->regmap);
        int ret;

        ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
        if (ret < 0)
                dev_err(dev, "%s(): Error %d clearing the CONFIGURE register\n",
                        __func__, ret);

        chip->als_ir_mode = ISL29028_MODE_NONE;
        chip->enable_prox = false;

        return ret;
}

static bool isl29028_is_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case ISL29028_REG_INTERRUPT:
        case ISL29028_REG_PROX_DATA:
        case ISL29028_REG_ALSIR_L:
        case ISL29028_REG_ALSIR_U:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config isl29028_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .volatile_reg = isl29028_is_volatile_reg,
        .max_register = ISL29028_NUM_REGS - 1,
        .num_reg_defaults_raw = ISL29028_NUM_REGS,
        .cache_type = REGCACHE_MAPLE,
};

static int isl29028_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct isl29028_chip *chip;
        struct iio_dev *indio_dev;
        int ret;

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

        chip = iio_priv(indio_dev);

        i2c_set_clientdata(client, indio_dev);
        mutex_init(&chip->lock);

        chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
        if (IS_ERR(chip->regmap)) {
                ret = PTR_ERR(chip->regmap);
                dev_err(&client->dev, "%s: Error %d initializing regmap\n",
                        __func__, ret);
                return ret;
        }

        chip->enable_prox  = false;
        chip->prox_sampling_int = 20;
        chip->prox_sampling_frac = 0;
        chip->lux_scale = 2000;

        ret = regmap_write(chip->regmap, ISL29028_REG_TEST1_MODE, 0x0);
        if (ret < 0) {
                dev_err(&client->dev,
                        "%s(): Error %d writing to TEST1_MODE register\n",
                        __func__, ret);
                return ret;
        }

        ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
        if (ret < 0) {
                dev_err(&client->dev,
                        "%s(): Error %d writing to TEST2_MODE register\n",
                        __func__, ret);
                return ret;
        }

        ret = isl29028_clear_configure_reg(chip);
        if (ret < 0)
                return ret;

        indio_dev->info = &isl29028_info;
        indio_dev->channels = isl29028_channels;
        indio_dev->num_channels = ARRAY_SIZE(isl29028_channels);
        indio_dev->name = id->name;
        indio_dev->modes = INDIO_DIRECT_MODE;

        pm_runtime_enable(&client->dev);
        pm_runtime_set_autosuspend_delay(&client->dev,
                                         ISL29028_POWER_OFF_DELAY_MS);
        pm_runtime_use_autosuspend(&client->dev);

        ret = iio_device_register(indio_dev);
        if (ret < 0) {
                dev_err(&client->dev,
                        "%s(): iio registration failed with error %d\n",
                        __func__, ret);
                return ret;
        }

        return 0;
}

static void isl29028_remove(struct i2c_client *client)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
        struct isl29028_chip *chip = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);

        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);

        isl29028_clear_configure_reg(chip);
}

static int isl29028_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
        struct isl29028_chip *chip = iio_priv(indio_dev);
        int ret;

        mutex_lock(&chip->lock);

        ret = isl29028_clear_configure_reg(chip);

        mutex_unlock(&chip->lock);

        return ret;
}

static int isl29028_resume(struct device *dev)
{
        /**
         * The specific component (ALS/IR or proximity) will enable itself as
         * needed the next time that the user requests a reading. This is done
         * above in isl29028_set_als_ir_mode() and isl29028_enable_proximity().
         */
        return 0;
}

static DEFINE_RUNTIME_DEV_PM_OPS(isl29028_pm_ops, isl29028_suspend,
                                 isl29028_resume, NULL);

static const struct i2c_device_id isl29028_id[] = {
        { "isl29028" },
        { "isl29030" },
        { }
};
MODULE_DEVICE_TABLE(i2c, isl29028_id);

static const struct of_device_id isl29028_of_match[] = {
        { .compatible = "isl,isl29028", }, /* for backward compat., don't use */
        { .compatible = "isil,isl29028", },
        { .compatible = "isil,isl29030", },
        { }
};
MODULE_DEVICE_TABLE(of, isl29028_of_match);

static struct i2c_driver isl29028_driver = {
        .driver  = {
                .name = "isl29028",
                .pm = pm_ptr(&isl29028_pm_ops),
                .of_match_table = isl29028_of_match,
        },
        .probe = isl29028_probe,
        .remove  = isl29028_remove,
        .id_table = isl29028_id,
};

module_i2c_driver(isl29028_driver);

MODULE_DESCRIPTION("ISL29028 Ambient Light and Proximity Sensor driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");