// SPDX-License-Identifier: GPL-2.0-only
/*
 * vcnl4000.c - Support for Vishay VCNL4000/4010/4020/4040/4200 combined ambient
 * light and proximity sensor
 *
 * Copyright 2012 Peter Meerwald <pmeerw@pmeerw.net>
 * Copyright 2019 Pursim SPC
 *
 * IIO driver for:
 *   VCNL4000/10/20 (7-bit I2C slave address 0x13)
 *   VCNL4040 (7-bit I2C slave address 0x60)
 *   VCNL4200 (7-bit I2C slave address 0x51)
 *
 * TODO:
 *   allow to adjust IR current
 *   proximity threshold and event handling
 *   periodic ALS/proximity measurement (VCNL4010/20)
 *   interrupts (VCNL4010/20/40, VCNL4200)
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>

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

#define VCNL4000_DRV_NAME "vcnl4000"
#define VCNL4000_PROD_ID        0x01
#define VCNL4010_PROD_ID        0x02 /* for VCNL4020, VCNL4010 */
#define VCNL4040_PROD_ID        0x86
#define VCNL4200_PROD_ID        0x58

#define VCNL4000_COMMAND        0x80 /* Command register */
#define VCNL4000_PROD_REV       0x81 /* Product ID and Revision ID */
#define VCNL4000_LED_CURRENT    0x83 /* IR LED current for proximity mode */
#define VCNL4000_AL_PARAM       0x84 /* Ambient light parameter register */
#define VCNL4000_AL_RESULT_HI   0x85 /* Ambient light result register, MSB */
#define VCNL4000_AL_RESULT_LO   0x86 /* Ambient light result register, LSB */
#define VCNL4000_PS_RESULT_HI   0x87 /* Proximity result register, MSB */
#define VCNL4000_PS_RESULT_LO   0x88 /* Proximity result register, LSB */
#define VCNL4000_PS_MEAS_FREQ   0x89 /* Proximity test signal frequency */
#define VCNL4000_PS_MOD_ADJ     0x8a /* Proximity modulator timing adjustment */

#define VCNL4200_AL_CONF        0x00 /* Ambient light configuration */
#define VCNL4200_PS_CONF1       0x03 /* Proximity configuration */
#define VCNL4200_PS_DATA        0x08 /* Proximity data */
#define VCNL4200_AL_DATA        0x09 /* Ambient light data */
#define VCNL4200_DEV_ID         0x0e /* Device ID, slave address and version */

#define VCNL4040_DEV_ID         0x0c /* Device ID and version */

/* Bit masks for COMMAND register */
#define VCNL4000_AL_RDY         BIT(6) /* ALS data ready? */
#define VCNL4000_PS_RDY         BIT(5) /* proximity data ready? */
#define VCNL4000_AL_OD          BIT(4) /* start on-demand ALS measurement */
#define VCNL4000_PS_OD          BIT(3) /* start on-demand proximity measurement */

enum vcnl4000_device_ids {
        VCNL4000,
        VCNL4010,
        VCNL4040,
        VCNL4200,
};

struct vcnl4200_channel {
        u8 reg;
        ktime_t last_measurement;
        ktime_t sampling_rate;
        struct mutex lock;
};

struct vcnl4000_data {
        struct i2c_client *client;
        enum vcnl4000_device_ids id;
        int rev;
        int al_scale;
        const struct vcnl4000_chip_spec *chip_spec;
        struct mutex vcnl4000_lock;
        struct vcnl4200_channel vcnl4200_al;
        struct vcnl4200_channel vcnl4200_ps;
};

struct vcnl4000_chip_spec {
        const char *prod;
        int (*init)(struct vcnl4000_data *data);
        int (*measure_light)(struct vcnl4000_data *data, int *val);
        int (*measure_proximity)(struct vcnl4000_data *data, int *val);
};

static const struct i2c_device_id vcnl4000_id[] = {
        { "vcnl4000", VCNL4000 },
        { "vcnl4010", VCNL4010 },
        { "vcnl4020", VCNL4010 },
        { "vcnl4040", VCNL4040 },
        { "vcnl4200", VCNL4200 },
        { }
};
MODULE_DEVICE_TABLE(i2c, vcnl4000_id);

static int vcnl4000_init(struct vcnl4000_data *data)
{
        int ret, prod_id;

        ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
        if (ret < 0)
                return ret;

        prod_id = ret >> 4;
        switch (prod_id) {
        case VCNL4000_PROD_ID:
                if (data->id != VCNL4000)
                        dev_warn(&data->client->dev,
                                        "wrong device id, use vcnl4000");
                break;
        case VCNL4010_PROD_ID:
                if (data->id != VCNL4010)
                        dev_warn(&data->client->dev,
                                        "wrong device id, use vcnl4010/4020");
                break;
        default:
                return -ENODEV;
        }

        data->rev = ret & 0xf;
        data->al_scale = 250000;
        mutex_init(&data->vcnl4000_lock);

        return 0;
};

static int vcnl4200_init(struct vcnl4000_data *data)
{
        int ret, id;

        ret = i2c_smbus_read_word_data(data->client, VCNL4200_DEV_ID);
        if (ret < 0)
                return ret;

        id = ret & 0xff;

        if (id != VCNL4200_PROD_ID) {
                ret = i2c_smbus_read_word_data(data->client, VCNL4040_DEV_ID);
                if (ret < 0)
                        return ret;

                id = ret & 0xff;

                if (id != VCNL4040_PROD_ID)
                        return -ENODEV;
        }

        dev_dbg(&data->client->dev, "device id 0x%x", id);

        data->rev = (ret >> 8) & 0xf;

        /* Set defaults and enable both channels */
        ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, 0);
        if (ret < 0)
                return ret;
        ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, 0);
        if (ret < 0)
                return ret;

        data->vcnl4200_al.reg = VCNL4200_AL_DATA;
        data->vcnl4200_ps.reg = VCNL4200_PS_DATA;
        switch (id) {
        case VCNL4200_PROD_ID:
                /* Integration time is 50ms, but the experiments */
                /* show 54ms in total. */
                data->vcnl4200_al.sampling_rate = ktime_set(0, 54000 * 1000);
                data->vcnl4200_ps.sampling_rate = ktime_set(0, 4200 * 1000);
                data->al_scale = 24000;
                break;
        case VCNL4040_PROD_ID:
                /* Integration time is 80ms, add 10ms. */
                data->vcnl4200_al.sampling_rate = ktime_set(0, 100000 * 1000);
                data->vcnl4200_ps.sampling_rate = ktime_set(0, 100000 * 1000);
                data->al_scale = 120000;
                break;
        }
        data->vcnl4200_al.last_measurement = ktime_set(0, 0);
        data->vcnl4200_ps.last_measurement = ktime_set(0, 0);
        mutex_init(&data->vcnl4200_al.lock);
        mutex_init(&data->vcnl4200_ps.lock);

        return 0;
};

static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
                                u8 rdy_mask, u8 data_reg, int *val)
{
        int tries = 20;
        __be16 buf;
        int ret;

        mutex_lock(&data->vcnl4000_lock);

        ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
                                        req_mask);
        if (ret < 0)
                goto fail;

        /* wait for data to become ready */
        while (tries--) {
                ret = i2c_smbus_read_byte_data(data->client, VCNL4000_COMMAND);
                if (ret < 0)
                        goto fail;
                if (ret & rdy_mask)
                        break;
                msleep(20); /* measurement takes up to 100 ms */
        }

        if (tries < 0) {
                dev_err(&data->client->dev,
                        "vcnl4000_measure() failed, data not ready\n");
                ret = -EIO;
                goto fail;
        }

        ret = i2c_smbus_read_i2c_block_data(data->client,
                data_reg, sizeof(buf), (u8 *) &buf);
        if (ret < 0)
                goto fail;

        mutex_unlock(&data->vcnl4000_lock);
        *val = be16_to_cpu(buf);

        return 0;

fail:
        mutex_unlock(&data->vcnl4000_lock);
        return ret;
}

static int vcnl4200_measure(struct vcnl4000_data *data,
                struct vcnl4200_channel *chan, int *val)
{
        int ret;
        s64 delta;
        ktime_t next_measurement;

        mutex_lock(&chan->lock);

        next_measurement = ktime_add(chan->last_measurement,
                        chan->sampling_rate);
        delta = ktime_us_delta(next_measurement, ktime_get());
        if (delta > 0)
                usleep_range(delta, delta + 500);
        chan->last_measurement = ktime_get();

        mutex_unlock(&chan->lock);

        ret = i2c_smbus_read_word_data(data->client, chan->reg);
        if (ret < 0)
                return ret;

        *val = ret;

        return 0;
}

static int vcnl4000_measure_light(struct vcnl4000_data *data, int *val)
{
        return vcnl4000_measure(data,
                        VCNL4000_AL_OD, VCNL4000_AL_RDY,
                        VCNL4000_AL_RESULT_HI, val);
}

static int vcnl4200_measure_light(struct vcnl4000_data *data, int *val)
{
        return vcnl4200_measure(data, &data->vcnl4200_al, val);
}

static int vcnl4000_measure_proximity(struct vcnl4000_data *data, int *val)
{
        return vcnl4000_measure(data,
                        VCNL4000_PS_OD, VCNL4000_PS_RDY,
                        VCNL4000_PS_RESULT_HI, val);
}

static int vcnl4200_measure_proximity(struct vcnl4000_data *data, int *val)
{
        return vcnl4200_measure(data, &data->vcnl4200_ps, val);
}

static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
        [VCNL4000] = {
                .prod = "VCNL4000",
                .init = vcnl4000_init,
                .measure_light = vcnl4000_measure_light,
                .measure_proximity = vcnl4000_measure_proximity,
        },
        [VCNL4010] = {
                .prod = "VCNL4010/4020",
                .init = vcnl4000_init,
                .measure_light = vcnl4000_measure_light,
                .measure_proximity = vcnl4000_measure_proximity,
        },
        [VCNL4040] = {
                .prod = "VCNL4040",
                .init = vcnl4200_init,
                .measure_light = vcnl4200_measure_light,
                .measure_proximity = vcnl4200_measure_proximity,
        },
        [VCNL4200] = {
                .prod = "VCNL4200",
                .init = vcnl4200_init,
                .measure_light = vcnl4200_measure_light,
                .measure_proximity = vcnl4200_measure_proximity,
        },
};

static const struct iio_chan_spec vcnl4000_channels[] = {
        {
                .type = IIO_LIGHT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE),
        }, {
                .type = IIO_PROXIMITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
        }
};

static int vcnl4000_read_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int *val, int *val2, long mask)
{
        int ret;
        struct vcnl4000_data *data = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_LIGHT:
                        ret = data->chip_spec->measure_light(data, val);
                        if (ret < 0)
                                return ret;
                        return IIO_VAL_INT;
                case IIO_PROXIMITY:
                        ret = data->chip_spec->measure_proximity(data, val);
                        if (ret < 0)
                                return ret;
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SCALE:
                if (chan->type != IIO_LIGHT)
                        return -EINVAL;

                *val = 0;
                *val2 = data->al_scale;
                return IIO_VAL_INT_PLUS_MICRO;
        default:
                return -EINVAL;
        }
}

static const struct iio_info vcnl4000_info = {
        .read_raw = vcnl4000_read_raw,
};

static int vcnl4000_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
{
        struct vcnl4000_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;
        data->id = id->driver_data;
        data->chip_spec = &vcnl4000_chip_spec_cfg[data->id];

        ret = data->chip_spec->init(data);
        if (ret < 0)
                return ret;

        dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
                data->chip_spec->prod, data->rev);

        indio_dev->dev.parent = &client->dev;
        indio_dev->info = &vcnl4000_info;
        indio_dev->channels = vcnl4000_channels;
        indio_dev->num_channels = ARRAY_SIZE(vcnl4000_channels);
        indio_dev->name = VCNL4000_DRV_NAME;
        indio_dev->modes = INDIO_DIRECT_MODE;

        return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct of_device_id vcnl_4000_of_match[] = {
        {
                .compatible = "vishay,vcnl4000",
                .data = (void *)VCNL4000,
        },
        {
                .compatible = "vishay,vcnl4010",
                .data = (void *)VCNL4010,
        },
        {
                .compatible = "vishay,vcnl4020",
                .data = (void *)VCNL4010,
        },
        {
                .compatible = "vishay,vcnl4040",
                .data = (void *)VCNL4040,
        },
        {
                .compatible = "vishay,vcnl4200",
                .data = (void *)VCNL4200,
        },
        {},
};
MODULE_DEVICE_TABLE(of, vcnl_4000_of_match);

static struct i2c_driver vcnl4000_driver = {
        .driver = {
                .name   = VCNL4000_DRV_NAME,
                .of_match_table = vcnl_4000_of_match,
        },
        .probe  = vcnl4000_probe,
        .id_table = vcnl4000_id,
};

module_i2c_driver(vcnl4000_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Vishay VCNL4000 proximity/ambient light sensor driver");
MODULE_LICENSE("GPL");