// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 - Marcin Malagowski <mrc@bourne.st>
 */
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iio/iio.h>

#define ABP060MG_ERROR_MASK   0xC000
#define ABP060MG_RESP_TIME_MS 40
#define ABP060MG_MIN_COUNTS   1638  /* = 0x0666 (10% of u14) */
#define ABP060MG_MAX_COUNTS   14745 /* = 0x3999 (90% of u14) */
#define ABP060MG_NUM_COUNTS   (ABP060MG_MAX_COUNTS - ABP060MG_MIN_COUNTS)

enum abp_variant {
        /* gage [kPa] */
        ABP006KG, ABP010KG, ABP016KG, ABP025KG, ABP040KG, ABP060KG, ABP100KG,
        ABP160KG, ABP250KG, ABP400KG, ABP600KG, ABP001GG,
        /* differential [kPa] */
        ABP006KD, ABP010KD, ABP016KD, ABP025KD, ABP040KD, ABP060KD, ABP100KD,
        ABP160KD, ABP250KD, ABP400KD,
        /* gage [psi] */
        ABP001PG, ABP005PG, ABP015PG, ABP030PG, ABP060PG, ABP100PG, ABP150PG,
        /* differential [psi] */
        ABP001PD, ABP005PD, ABP015PD, ABP030PD, ABP060PD,
};

struct abp_config {
        int min;
        int max;
};

static const struct abp_config abp_config[] = {
        /* mbar & kPa variants */
        [ABP006KG] = { .min =       0, .max =     6000 },
        [ABP010KG] = { .min =       0, .max =    10000 },
        [ABP016KG] = { .min =       0, .max =    16000 },
        [ABP025KG] = { .min =       0, .max =    25000 },
        [ABP040KG] = { .min =       0, .max =    40000 },
        [ABP060KG] = { .min =       0, .max =    60000 },
        [ABP100KG] = { .min =       0, .max =   100000 },
        [ABP160KG] = { .min =       0, .max =   160000 },
        [ABP250KG] = { .min =       0, .max =   250000 },
        [ABP400KG] = { .min =       0, .max =   400000 },
        [ABP600KG] = { .min =       0, .max =   600000 },
        [ABP001GG] = { .min =       0, .max =  1000000 },
        [ABP006KD] = { .min =   -6000, .max =     6000 },
        [ABP010KD] = { .min =  -10000, .max =    10000 },
        [ABP016KD] = { .min =  -16000, .max =    16000 },
        [ABP025KD] = { .min =  -25000, .max =    25000 },
        [ABP040KD] = { .min =  -40000, .max =    40000 },
        [ABP060KD] = { .min =  -60000, .max =    60000 },
        [ABP100KD] = { .min = -100000, .max =   100000 },
        [ABP160KD] = { .min = -160000, .max =   160000 },
        [ABP250KD] = { .min = -250000, .max =   250000 },
        [ABP400KD] = { .min = -400000, .max =   400000 },
        /* psi variants (1 psi ~ 6895 Pa) */
        [ABP001PG] = { .min =       0, .max =     6985 },
        [ABP005PG] = { .min =       0, .max =    34474 },
        [ABP015PG] = { .min =       0, .max =   103421 },
        [ABP030PG] = { .min =       0, .max =   206843 },
        [ABP060PG] = { .min =       0, .max =   413686 },
        [ABP100PG] = { .min =       0, .max =   689476 },
        [ABP150PG] = { .min =       0, .max =  1034214 },
        [ABP001PD] = { .min =   -6895, .max =     6895 },
        [ABP005PD] = { .min =  -34474, .max =    34474 },
        [ABP015PD] = { .min = -103421, .max =   103421 },
        [ABP030PD] = { .min = -206843, .max =   206843 },
        [ABP060PD] = { .min = -413686, .max =   413686 },
};

struct abp_state {
        struct i2c_client *client;
        struct mutex lock;

        /*
         * bus-dependent MEASURE_REQUEST length.
         * If no SMBUS_QUICK support, need to send dummy byte
         */
        int mreq_len;

        /* model-dependent values (calculated on probe) */
        int scale;
        int offset;
};

static const struct iio_chan_spec abp060mg_channels[] = {
        {
                .type = IIO_PRESSURE,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),
        },
};

static int abp060mg_get_measurement(struct abp_state *state, int *val)
{
        struct i2c_client *client = state->client;
        __be16 buf[2];
        u16 pressure;
        int ret;

        buf[0] = 0;
        ret = i2c_master_send(client, (u8 *)&buf, state->mreq_len);
        if (ret < 0)
                return ret;

        msleep_interruptible(ABP060MG_RESP_TIME_MS);

        ret = i2c_master_recv(client, (u8 *)&buf, sizeof(buf));
        if (ret < 0)
                return ret;

        pressure = be16_to_cpu(buf[0]);
        if (pressure & ABP060MG_ERROR_MASK)
                return -EIO;

        if (pressure < ABP060MG_MIN_COUNTS || pressure > ABP060MG_MAX_COUNTS)
                return -EIO;

        *val = pressure;

        return IIO_VAL_INT;
}

static int abp060mg_read_raw(struct iio_dev *indio_dev,
                        struct iio_chan_spec const *chan, int *val,
                        int *val2, long mask)
{
        struct abp_state *state = iio_priv(indio_dev);
        int ret;

        mutex_lock(&state->lock);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = abp060mg_get_measurement(state, val);
                break;
        case IIO_CHAN_INFO_OFFSET:
                *val = state->offset;
                ret = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_SCALE:
                *val = state->scale;
                *val2 = ABP060MG_NUM_COUNTS * 1000; /* to kPa */
                ret = IIO_VAL_FRACTIONAL;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        mutex_unlock(&state->lock);
        return ret;
}

static const struct iio_info abp060mg_info = {
        .read_raw = abp060mg_read_raw,
};

static void abp060mg_init_device(struct iio_dev *indio_dev, unsigned long id)
{
        struct abp_state *state = iio_priv(indio_dev);
        const struct abp_config *cfg = &abp_config[id];

        state->scale = cfg->max - cfg->min;
        state->offset = -ABP060MG_MIN_COUNTS;

        if (cfg->min < 0) /* differential */
                state->offset -= ABP060MG_NUM_COUNTS >> 1;
}

static int abp060mg_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct iio_dev *indio_dev;
        struct abp_state *state;
        unsigned long cfg_id = id->driver_data;

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

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

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_QUICK))
                state->mreq_len = 1;

        abp060mg_init_device(indio_dev, cfg_id);

        indio_dev->name = dev_name(&client->dev);
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->info = &abp060mg_info;

        indio_dev->channels = abp060mg_channels;
        indio_dev->num_channels = ARRAY_SIZE(abp060mg_channels);

        mutex_init(&state->lock);

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

static const struct i2c_device_id abp060mg_id_table[] = {
        /* mbar & kPa variants (abp060m [60 mbar] == abp006k [6 kPa]) */
        /*    gage: */
        { "abp060mg", ABP006KG }, { "abp006kg", ABP006KG },
        { "abp100mg", ABP010KG }, { "abp010kg", ABP010KG },
        { "abp160mg", ABP016KG }, { "abp016kg", ABP016KG },
        { "abp250mg", ABP025KG }, { "abp025kg", ABP025KG },
        { "abp400mg", ABP040KG }, { "abp040kg", ABP040KG },
        { "abp600mg", ABP060KG }, { "abp060kg", ABP060KG },
        { "abp001bg", ABP100KG }, { "abp100kg", ABP100KG },
        { "abp1_6bg", ABP160KG }, { "abp160kg", ABP160KG },
        { "abp2_5bg", ABP250KG }, { "abp250kg", ABP250KG },
        { "abp004bg", ABP400KG }, { "abp400kg", ABP400KG },
        { "abp006bg", ABP600KG }, { "abp600kg", ABP600KG },
        { "abp010bg", ABP001GG }, { "abp001gg", ABP001GG },
        /*    differential: */
        { "abp060md", ABP006KD }, { "abp006kd", ABP006KD },
        { "abp100md", ABP010KD }, { "abp010kd", ABP010KD },
        { "abp160md", ABP016KD }, { "abp016kd", ABP016KD },
        { "abp250md", ABP025KD }, { "abp025kd", ABP025KD },
        { "abp400md", ABP040KD }, { "abp040kd", ABP040KD },
        { "abp600md", ABP060KD }, { "abp060kd", ABP060KD },
        { "abp001bd", ABP100KD }, { "abp100kd", ABP100KD },
        { "abp1_6bd", ABP160KD }, { "abp160kd", ABP160KD },
        { "abp2_5bd", ABP250KD }, { "abp250kd", ABP250KD },
        { "abp004bd", ABP400KD }, { "abp400kd", ABP400KD },
        /* psi variants */
        /*    gage: */
        { "abp001pg", ABP001PG },
        { "abp005pg", ABP005PG },
        { "abp015pg", ABP015PG },
        { "abp030pg", ABP030PG },
        { "abp060pg", ABP060PG },
        { "abp100pg", ABP100PG },
        { "abp150pg", ABP150PG },
        /*    differential: */
        { "abp001pd", ABP001PD },
        { "abp005pd", ABP005PD },
        { "abp015pd", ABP015PD },
        { "abp030pd", ABP030PD },
        { "abp060pd", ABP060PD },
        { }
};
MODULE_DEVICE_TABLE(i2c, abp060mg_id_table);

static struct i2c_driver abp060mg_driver = {
        .driver = {
                .name = "abp060mg",
        },
        .probe = abp060mg_probe,
        .id_table = abp060mg_id_table,
};
module_i2c_driver(abp060mg_driver);

MODULE_AUTHOR("Marcin Malagowski <mrc@bourne.st>");
MODULE_DESCRIPTION("Honeywell ABP pressure sensor driver");
MODULE_LICENSE("GPL");