// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
 *
 * Copyright 2010 Analog Devices Inc.
 */

#include <linux/mutex.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/module.h>

#include <linux/iio/iio.h>

#include <linux/unaligned.h>

#define ADIS16130_CON         0x0
#define ADIS16130_CON_RD      (1 << 6)
#define ADIS16130_IOP         0x1

/* 1 = data-ready signal low when unread data on all channels; */
#define ADIS16130_IOP_ALL_RDY (1 << 3)
#define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
#define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
#define ADIS16130_TEMPDATA    0xA /* Temperature output */
#define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
#define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
#define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
#define ADIS16130_TEMPCS_EN   (1 << 3)
#define ADIS16130_RATECONV    0x30
#define ADIS16130_TEMPCONV    0x32
#define ADIS16130_MODE        0x38
#define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */

/**
 * struct adis16130_state - device instance specific data
 * @us:                 actual spi_device to write data
 * @buf_lock:           mutex to protect tx and rx
 * @buf:                unified tx/rx buffer
 **/
struct adis16130_state {
        struct spi_device               *us;
        struct mutex                    buf_lock;
        u8                              buf[4] __aligned(IIO_DMA_MINALIGN);
};

static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
{
        int ret;
        struct adis16130_state *st = iio_priv(indio_dev);
        struct spi_transfer xfer = {
                .tx_buf = st->buf,
                .rx_buf = st->buf,
                .len = 4,
        };

        mutex_lock(&st->buf_lock);

        st->buf[0] = ADIS16130_CON_RD | reg_addr;
        st->buf[1] = st->buf[2] = st->buf[3] = 0;

        ret = spi_sync_transfer(st->us, &xfer, 1);
        if (ret == 0)
                *val = get_unaligned_be24(&st->buf[1]);
        mutex_unlock(&st->buf_lock);

        return ret;
}

static int adis16130_read_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int *val, int *val2,
                              long mask)
{
        int ret;
        u32 temp;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                /* Take the iio_dev status lock */
                ret = adis16130_spi_read(indio_dev, chan->address, &temp);
                if (ret)
                        return ret;
                *val = temp;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_ANGL_VEL:
                        /* 0 degree = 838860, 250 degree = 14260608 */
                        *val = 250;
                        *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
                        return IIO_VAL_FRACTIONAL;
                case IIO_TEMP:
                        /* 0C = 8036283, 105C = 9516048 */
                        *val = 105000;
                        *val2 = 9516048 - 8036283;
                        return IIO_VAL_FRACTIONAL;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_OFFSET:
                switch (chan->type) {
                case IIO_ANGL_VEL:
                        *val = -8388608;
                        return IIO_VAL_INT;
                case IIO_TEMP:
                        *val = -8036283;
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        }

        return -EINVAL;
}

static const struct iio_chan_spec adis16130_channels[] = {
        {
                .type = IIO_ANGL_VEL,
                .modified = 1,
                .channel2 = IIO_MOD_Z,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE) |
                        BIT(IIO_CHAN_INFO_OFFSET),
                .address = ADIS16130_RATEDATA,
        }, {
                .type = IIO_TEMP,
                .indexed = 1,
                .channel = 0,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE) |
                        BIT(IIO_CHAN_INFO_OFFSET),
                .address = ADIS16130_TEMPDATA,
        }
};

static const struct iio_info adis16130_info = {
        .read_raw = &adis16130_read_raw,
};

static int adis16130_probe(struct spi_device *spi)
{
        struct adis16130_state *st;
        struct iio_dev *indio_dev;

        /* setup the industrialio driver allocated elements */
        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
        if (!indio_dev)
                return -ENOMEM;
        st = iio_priv(indio_dev);
        /* this is only used for removal purposes */
        spi_set_drvdata(spi, indio_dev);
        st->us = spi;
        mutex_init(&st->buf_lock);
        indio_dev->name = spi->dev.driver->name;
        indio_dev->channels = adis16130_channels;
        indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
        indio_dev->info = &adis16130_info;
        indio_dev->modes = INDIO_DIRECT_MODE;

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

static struct spi_driver adis16130_driver = {
        .driver = {
                .name = "adis16130",
        },
        .probe = adis16130_probe,
};
module_spi_driver(adis16130_driver);

MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:adis16130");