// SPDX-License-Identifier: GPL-2.0-only
/*
 * apds9300.c - IIO driver for Avago APDS9300 ambient light sensor
 *
 * Copyright 2013 Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>

#define APDS9300_DRV_NAME "apds9300"

/* Command register bits */
#define APDS9300_CMD    BIT(7) /* Select command register. Must write as 1 */
#define APDS9300_WORD   BIT(5) /* I2C write/read: if 1 word, if 0 byte */
#define APDS9300_CLEAR  BIT(6) /* Interrupt clear. Clears pending interrupt */

/* Register set */
#define APDS9300_CONTROL        0x00 /* Control of basic functions */
#define APDS9300_THRESHLOWLOW   0x02 /* Low byte of low interrupt threshold */
#define APDS9300_THRESHHIGHLOW  0x04 /* Low byte of high interrupt threshold */
#define APDS9300_INTERRUPT      0x06 /* Interrupt control */
#define APDS9300_DATA0LOW       0x0c /* Low byte of ADC channel 0 */
#define APDS9300_DATA1LOW       0x0e /* Low byte of ADC channel 1 */

/* Power on/off value for APDS9300_CONTROL register */
#define APDS9300_POWER_ON       0x03
#define APDS9300_POWER_OFF      0x00

/* Interrupts */
#define APDS9300_INTR_ENABLE    0x10
/* Interrupt Persist Function: Any value outside of threshold range */
#define APDS9300_THRESH_INTR    0x01

#define APDS9300_THRESH_MAX     0xffff /* Max threshold value */

struct apds9300_data {
        struct i2c_client *client;
        struct mutex mutex;
        bool power_state;
        int thresh_low;
        int thresh_hi;
        bool intr_en;
};

/* Lux calculation */

/* Calculated values 1000 * (CH1/CH0)^1.4 for CH1/CH0 from 0 to 0.52 */
static const u16 apds9300_lux_ratio[] = {
        0, 2, 4, 7, 11, 15, 19, 24, 29, 34, 40, 45, 51, 57, 64, 70, 77, 84, 91,
        98, 105, 112, 120, 128, 136, 144, 152, 160, 168, 177, 185, 194, 203,
        212, 221, 230, 239, 249, 258, 268, 277, 287, 297, 307, 317, 327, 337,
        347, 358, 368, 379, 390, 400,
};

static unsigned long apds9300_calculate_lux(u16 ch0, u16 ch1)
{
        unsigned long lux, tmp;

        /* avoid division by zero */
        if (ch0 == 0)
                return 0;

        tmp = DIV_ROUND_UP(ch1 * 100, ch0);
        if (tmp <= 52) {
                lux = 3150 * ch0 - (unsigned long)DIV_ROUND_UP_ULL(ch0
                                * apds9300_lux_ratio[tmp] * 5930ull, 1000);
        } else if (tmp <= 65) {
                lux = 2290 * ch0 - 2910 * ch1;
        } else if (tmp <= 80) {
                lux = 1570 * ch0 - 1800 * ch1;
        } else if (tmp <= 130) {
                lux = 338 * ch0 - 260 * ch1;
        } else {
                lux = 0;
        }

        return lux / 100000;
}

static int apds9300_get_adc_val(struct apds9300_data *data, int adc_number)
{
        int ret;
        u8 flags = APDS9300_CMD | APDS9300_WORD;

        if (!data->power_state)
                return -EBUSY;

        /* Select ADC0 or ADC1 data register */
        flags |= adc_number ? APDS9300_DATA1LOW : APDS9300_DATA0LOW;

        ret = i2c_smbus_read_word_data(data->client, flags);
        if (ret < 0)
                dev_err(&data->client->dev,
                        "failed to read ADC%d value\n", adc_number);

        return ret;
}

static int apds9300_set_thresh_low(struct apds9300_data *data, int value)
{
        int ret;

        if (!data->power_state)
                return -EBUSY;

        if (value > APDS9300_THRESH_MAX)
                return -EINVAL;

        ret = i2c_smbus_write_word_data(data->client, APDS9300_THRESHLOWLOW
                        | APDS9300_CMD | APDS9300_WORD, value);
        if (ret) {
                dev_err(&data->client->dev, "failed to set thresh_low\n");
                return ret;
        }
        data->thresh_low = value;

        return 0;
}

static int apds9300_set_thresh_hi(struct apds9300_data *data, int value)
{
        int ret;

        if (!data->power_state)
                return -EBUSY;

        if (value > APDS9300_THRESH_MAX)
                return -EINVAL;

        ret = i2c_smbus_write_word_data(data->client, APDS9300_THRESHHIGHLOW
                        | APDS9300_CMD | APDS9300_WORD, value);
        if (ret) {
                dev_err(&data->client->dev, "failed to set thresh_hi\n");
                return ret;
        }
        data->thresh_hi = value;

        return 0;
}

static int apds9300_set_intr_state(struct apds9300_data *data, bool state)
{
        int ret;
        u8 cmd;

        if (!data->power_state)
                return -EBUSY;

        cmd = state ? APDS9300_INTR_ENABLE | APDS9300_THRESH_INTR : 0x00;
        ret = i2c_smbus_write_byte_data(data->client,
                        APDS9300_INTERRUPT | APDS9300_CMD, cmd);
        if (ret) {
                dev_err(&data->client->dev,
                        "failed to set interrupt state %d\n", state);
                return ret;
        }
        data->intr_en = state;

        return 0;
}

static int apds9300_set_power_state(struct apds9300_data *data, bool state)
{
        int ret;
        u8 cmd;

        cmd = state ? APDS9300_POWER_ON : APDS9300_POWER_OFF;
        ret = i2c_smbus_write_byte_data(data->client,
                        APDS9300_CONTROL | APDS9300_CMD, cmd);
        if (ret) {
                dev_err(&data->client->dev,
                        "failed to set power state %d\n", state);
                return ret;
        }
        data->power_state = state;

        return 0;
}

static void apds9300_clear_intr(struct apds9300_data *data)
{
        int ret;

        ret = i2c_smbus_write_byte(data->client, APDS9300_CLEAR | APDS9300_CMD);
        if (ret < 0)
                dev_err(&data->client->dev, "failed to clear interrupt\n");
}

static int apds9300_chip_init(struct apds9300_data *data)
{
        int ret;

        /* Need to set power off to ensure that the chip is off */
        ret = apds9300_set_power_state(data, 0);
        if (ret < 0)
                goto err;
        /*
         * Probe the chip. To do so we try to power up the device and then to
         * read back the 0x03 code
         */
        ret = apds9300_set_power_state(data, 1);
        if (ret < 0)
                goto err;
        ret = i2c_smbus_read_byte_data(data->client,
                        APDS9300_CONTROL | APDS9300_CMD);
        if (ret != APDS9300_POWER_ON) {
                ret = -ENODEV;
                goto err;
        }
        /*
         * Disable interrupt to ensure thai it is doesn't enable
         * i.e. after device soft reset
         */
        ret = apds9300_set_intr_state(data, false);
        if (ret < 0)
                goto err;

        return 0;

err:
        dev_err(&data->client->dev, "failed to init the chip\n");
        return ret;
}

static int apds9300_read_raw(struct iio_dev *indio_dev,
                struct iio_chan_spec const *chan, int *val, int *val2,
                long mask)
{
        int ch0, ch1, ret = -EINVAL;
        struct apds9300_data *data = iio_priv(indio_dev);

        mutex_lock(&data->mutex);
        switch (chan->type) {
        case IIO_LIGHT:
                ch0 = apds9300_get_adc_val(data, 0);
                if (ch0 < 0) {
                        ret = ch0;
                        break;
                }
                ch1 = apds9300_get_adc_val(data, 1);
                if (ch1 < 0) {
                        ret = ch1;
                        break;
                }
                *val = apds9300_calculate_lux(ch0, ch1);
                ret = IIO_VAL_INT;
                break;
        case IIO_INTENSITY:
                ret = apds9300_get_adc_val(data, chan->channel);
                if (ret < 0)
                        break;
                *val = ret;
                ret = IIO_VAL_INT;
                break;
        default:
                break;
        }
        mutex_unlock(&data->mutex);

        return ret;
}

static int apds9300_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 apds9300_data *data = iio_priv(indio_dev);

        switch (dir) {
        case IIO_EV_DIR_RISING:
                *val = data->thresh_hi;
                break;
        case IIO_EV_DIR_FALLING:
                *val = data->thresh_low;
                break;
        default:
                return -EINVAL;
        }

        return IIO_VAL_INT;
}

static int apds9300_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 apds9300_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        if (dir == IIO_EV_DIR_RISING)
                ret = apds9300_set_thresh_hi(data, val);
        else
                ret = apds9300_set_thresh_low(data, val);
        mutex_unlock(&data->mutex);

        return ret;
}

static int apds9300_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 apds9300_data *data = iio_priv(indio_dev);

        return data->intr_en;
}

static int apds9300_write_interrupt_config(struct iio_dev *indio_dev,
                const struct iio_chan_spec *chan, enum iio_event_type type,
                enum iio_event_direction dir, bool state)
{
        struct apds9300_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        ret = apds9300_set_intr_state(data, state);
        mutex_unlock(&data->mutex);

        return ret;
}

static const struct iio_info apds9300_info_no_irq = {
        .read_raw       = apds9300_read_raw,
};

static const struct iio_info apds9300_info = {
        .read_raw               = apds9300_read_raw,
        .read_event_value       = apds9300_read_thresh,
        .write_event_value      = apds9300_write_thresh,
        .read_event_config      = apds9300_read_interrupt_config,
        .write_event_config     = apds9300_write_interrupt_config,
};

static const struct iio_event_spec apds9300_event_spec[] = {
        {
                .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 apds9300_channels[] = {
        {
                .type = IIO_LIGHT,
                .channel = 0,
                .indexed = true,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
        }, {
                .type = IIO_INTENSITY,
                .channel = 0,
                .channel2 = IIO_MOD_LIGHT_BOTH,
                .indexed = true,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .event_spec = apds9300_event_spec,
                .num_event_specs = ARRAY_SIZE(apds9300_event_spec),
        }, {
                .type = IIO_INTENSITY,
                .channel = 1,
                .channel2 = IIO_MOD_LIGHT_IR,
                .indexed = true,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
        },
};

static irqreturn_t apds9300_interrupt_handler(int irq, void *private)
{
        struct iio_dev *dev_info = private;
        struct apds9300_data *data = iio_priv(dev_info);

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

        apds9300_clear_intr(data);

        return IRQ_HANDLED;
}

static int apds9300_probe(struct i2c_client *client)
{
        struct apds9300_data *data;
        struct iio_dev *indio_dev;
        int ret;

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

        data = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        data->client = client;

        ret = apds9300_chip_init(data);
        if (ret < 0)
                goto err;

        mutex_init(&data->mutex);

        indio_dev->channels = apds9300_channels;
        indio_dev->num_channels = ARRAY_SIZE(apds9300_channels);
        indio_dev->name = APDS9300_DRV_NAME;
        indio_dev->modes = INDIO_DIRECT_MODE;

        if (client->irq)
                indio_dev->info = &apds9300_info;
        else
                indio_dev->info = &apds9300_info_no_irq;

        if (client->irq) {
                ret = devm_request_threaded_irq(&client->dev, client->irq,
                                NULL, apds9300_interrupt_handler,
                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                "apds9300_event", indio_dev);
                if (ret) {
                        dev_err(&client->dev, "irq request error %d\n", -ret);
                        goto err;
                }
        }

        ret = iio_device_register(indio_dev);
        if (ret < 0)
                goto err;

        return 0;

err:
        /* Ensure that power off in case of error */
        apds9300_set_power_state(data, 0);
        return ret;
}

static void apds9300_remove(struct i2c_client *client)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
        struct apds9300_data *data = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);

        /* Ensure that power off and interrupts are disabled */
        apds9300_set_intr_state(data, false);
        apds9300_set_power_state(data, false);
}

static int apds9300_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
        struct apds9300_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        ret = apds9300_set_power_state(data, false);
        mutex_unlock(&data->mutex);

        return ret;
}

static int apds9300_resume(struct device *dev)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
        struct apds9300_data *data = iio_priv(indio_dev);
        int ret;

        mutex_lock(&data->mutex);
        ret = apds9300_set_power_state(data, true);
        mutex_unlock(&data->mutex);

        return ret;
}

static DEFINE_SIMPLE_DEV_PM_OPS(apds9300_pm_ops, apds9300_suspend,
                                apds9300_resume);

static const struct i2c_device_id apds9300_id[] = {
        { .name = APDS9300_DRV_NAME },
        { }
};

MODULE_DEVICE_TABLE(i2c, apds9300_id);

static struct i2c_driver apds9300_driver = {
        .driver = {
                .name   = APDS9300_DRV_NAME,
                .pm     = pm_sleep_ptr(&apds9300_pm_ops),
        },
        .probe          = apds9300_probe,
        .remove         = apds9300_remove,
        .id_table       = apds9300_id,
};

module_i2c_driver(apds9300_driver);

MODULE_AUTHOR("Kravchenko Oleksandr <o.v.kravchenko@globallogic.com>");
MODULE_AUTHOR("GlobalLogic inc.");
MODULE_DESCRIPTION("APDS9300 ambient light photo sensor driver");
MODULE_LICENSE("GPL");