// SPDX-License-Identifier: GPL-2.0-only
/*
 * ADXRS450/ADXRS453 Digital Output Gyroscope Driver
 *
 * Copyright 2011 Analog Devices Inc.
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/list.h>
#include <linux/module.h>

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

#define ADXRS450_STARTUP_DELAY  50 /* ms */

/* The MSB for the spi commands */
#define ADXRS450_SENSOR_DATA    (0x20 << 24)
#define ADXRS450_WRITE_DATA     (0x40 << 24)
#define ADXRS450_READ_DATA      (0x80 << 24)

#define ADXRS450_RATE1  0x00    /* Rate Registers */
#define ADXRS450_TEMP1  0x02    /* Temperature Registers */
#define ADXRS450_LOCST1 0x04    /* Low CST Memory Registers */
#define ADXRS450_HICST1 0x06    /* High CST Memory Registers */
#define ADXRS450_QUAD1  0x08    /* Quad Memory Registers */
#define ADXRS450_FAULT1 0x0A    /* Fault Registers */
#define ADXRS450_PID1   0x0C    /* Part ID Register 1 */
#define ADXRS450_SNH    0x0E    /* Serial Number Registers, 4 bytes */
#define ADXRS450_SNL    0x10
#define ADXRS450_DNC1   0x12    /* Dynamic Null Correction Registers */
/* Check bits */
#define ADXRS450_P      0x01
#define ADXRS450_CHK    0x02
#define ADXRS450_CST    0x04
#define ADXRS450_PWR    0x08
#define ADXRS450_POR    0x10
#define ADXRS450_NVM    0x20
#define ADXRS450_Q      0x40
#define ADXRS450_PLL    0x80
#define ADXRS450_UV     0x100
#define ADXRS450_OV     0x200
#define ADXRS450_AMP    0x400
#define ADXRS450_FAIL   0x800

#define ADXRS450_WRERR_MASK     (0x7 << 29)

#define ADXRS450_MAX_RX 4
#define ADXRS450_MAX_TX 4

#define ADXRS450_GET_ST(a)      ((a >> 26) & 0x3)

enum {
        ID_ADXRS450,
        ID_ADXRS453,
};

/**
 * struct adxrs450_state - device instance specific data
 * @us:                 actual spi_device
 * @buf_lock:           mutex to protect tx and rx
 * @tx:                 transmit buffer
 * @rx:                 receive buffer
 **/
struct adxrs450_state {
        struct spi_device       *us;
        struct mutex            buf_lock;
        __be32                  tx __aligned(IIO_DMA_MINALIGN);
        __be32                  rx;

};

/**
 * adxrs450_spi_read_reg_16() - read 2 bytes from a register pair
 * @indio_dev: device associated with child of actual iio_dev
 * @reg_address: the address of the lower of the two registers, which should be
 *      an even address, the second register's address is reg_address + 1.
 * @val: somewhere to pass back the value read
 **/
static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev,
                                    u8 reg_address,
                                    u16 *val)
{
        struct adxrs450_state *st = iio_priv(indio_dev);
        u32 tx;
        int ret;
        struct spi_transfer xfers[] = {
                {
                        .tx_buf = &st->tx,
                        .len = sizeof(st->tx),
                        .cs_change = 1,
                }, {
                        .rx_buf = &st->rx,
                        .len = sizeof(st->rx),
                },
        };

        mutex_lock(&st->buf_lock);
        tx = ADXRS450_READ_DATA | (reg_address << 17);

        if (!(hweight32(tx) & 1))
                tx |= ADXRS450_P;

        st->tx = cpu_to_be32(tx);
        ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
        if (ret) {
                dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
                                reg_address);
                goto error_ret;
        }

        *val = (be32_to_cpu(st->rx) >> 5) & 0xFFFF;

error_ret:
        mutex_unlock(&st->buf_lock);
        return ret;
}

/**
 * adxrs450_spi_write_reg_16() - write 2 bytes data to a register pair
 * @indio_dev: device associated with child of actual actual iio_dev
 * @reg_address: the address of the lower of the two registers,which should be
 *      an even address, the second register's address is reg_address + 1.
 * @val: value to be written.
 **/
static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev,
                                     u8 reg_address,
                                     u16 val)
{
        struct adxrs450_state *st = iio_priv(indio_dev);
        u32 tx;
        int ret;

        mutex_lock(&st->buf_lock);
        tx = ADXRS450_WRITE_DATA | (reg_address << 17) | (val << 1);

        if (!(hweight32(tx) & 1))
                tx |= ADXRS450_P;

        st->tx = cpu_to_be32(tx);
        ret = spi_write(st->us, &st->tx, sizeof(st->tx));
        if (ret)
                dev_err(&st->us->dev, "problem while writing 16 bit register 0x%02x\n",
                        reg_address);
        usleep_range(100, 1000); /* enforce sequential transfer delay 0.1ms */
        mutex_unlock(&st->buf_lock);
        return ret;
}

/**
 * adxrs450_spi_sensor_data() - read 2 bytes sensor data
 * @indio_dev: device associated with child of actual iio_dev
 * @val: somewhere to pass back the value read
 **/
static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val)
{
        struct adxrs450_state *st = iio_priv(indio_dev);
        int ret;
        struct spi_transfer xfers[] = {
                {
                        .tx_buf = &st->tx,
                        .len = sizeof(st->tx),
                        .cs_change = 1,
                }, {
                        .rx_buf = &st->rx,
                        .len = sizeof(st->rx),
                },
        };

        mutex_lock(&st->buf_lock);
        st->tx = cpu_to_be32(ADXRS450_SENSOR_DATA);

        ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
        if (ret) {
                dev_err(&st->us->dev, "Problem while reading sensor data\n");
                goto error_ret;
        }

        *val = (be32_to_cpu(st->rx) >> 10) & 0xFFFF;

error_ret:
        mutex_unlock(&st->buf_lock);
        return ret;
}

/**
 * adxrs450_spi_initial() - use for initializing procedure.
 * @st: device instance specific data
 * @val: somewhere to pass back the value read
 * @chk: Whether to perform fault check
 **/
static int adxrs450_spi_initial(struct adxrs450_state *st,
                u32 *val, char chk)
{
        int ret;
        u32 tx;
        struct spi_transfer xfers = {
                .tx_buf = &st->tx,
                .rx_buf = &st->rx,
                .len = sizeof(st->tx),
        };

        mutex_lock(&st->buf_lock);
        tx = ADXRS450_SENSOR_DATA;
        if (chk)
                tx |= (ADXRS450_CHK | ADXRS450_P);
        st->tx = cpu_to_be32(tx);
        ret = spi_sync_transfer(st->us, &xfers, 1);
        if (ret) {
                dev_err(&st->us->dev, "Problem while reading initializing data\n");
                goto error_ret;
        }

        *val = be32_to_cpu(st->rx);

error_ret:
        mutex_unlock(&st->buf_lock);
        return ret;
}

/* Recommended Startup Sequence by spec */
static int adxrs450_initial_setup(struct iio_dev *indio_dev)
{
        u32 t;
        u16 data;
        int ret;
        struct adxrs450_state *st = iio_priv(indio_dev);

        msleep(ADXRS450_STARTUP_DELAY*2);
        ret = adxrs450_spi_initial(st, &t, 1);
        if (ret)
                return ret;
        if (t != 0x01)
                dev_warn(&st->us->dev, "The initial power on response is not correct! Restart without reset?\n");

        msleep(ADXRS450_STARTUP_DELAY);
        ret = adxrs450_spi_initial(st, &t, 0);
        if (ret)
                return ret;

        msleep(ADXRS450_STARTUP_DELAY);
        ret = adxrs450_spi_initial(st, &t, 0);
        if (ret)
                return ret;
        if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) {
                dev_err(&st->us->dev, "The second response is not correct!\n");
                return -EIO;

        }
        ret = adxrs450_spi_initial(st, &t, 0);
        if (ret)
                return ret;
        if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) {
                dev_err(&st->us->dev, "The third response is not correct!\n");
                return -EIO;

        }
        ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_FAULT1, &data);
        if (ret)
                return ret;
        if (data & 0x0fff) {
                dev_err(&st->us->dev, "The device is not in normal status!\n");
                return -EINVAL;
        }

        return 0;
}

static int adxrs450_write_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int val,
                              int val2,
                              long mask)
{
        int ret;
        switch (mask) {
        case IIO_CHAN_INFO_CALIBBIAS:
                if (val < -0x400 || val >= 0x400)
                        return -EINVAL;
                ret = adxrs450_spi_write_reg_16(indio_dev,
                                                ADXRS450_DNC1, val);
                break;
        default:
                ret = -EINVAL;
                break;
        }
        return ret;
}

static int adxrs450_read_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             int *val,
                             int *val2,
                             long mask)
{
        int ret;
        s16 t;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                switch (chan->type) {
                case IIO_ANGL_VEL:
                        ret = adxrs450_spi_sensor_data(indio_dev, &t);
                        if (ret)
                                break;
                        *val = t;
                        ret = IIO_VAL_INT;
                        break;
                case IIO_TEMP:
                        ret = adxrs450_spi_read_reg_16(indio_dev,
                                                       ADXRS450_TEMP1, &t);
                        if (ret)
                                break;
                        *val = (t >> 6) + 225;
                        ret = IIO_VAL_INT;
                        break;
                default:
                        ret = -EINVAL;
                        break;
                }
                break;
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_ANGL_VEL:
                        *val = 0;
                        *val2 = 218166;
                        return IIO_VAL_INT_PLUS_NANO;
                case IIO_TEMP:
                        *val = 200;
                        *val2 = 0;
                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW:
                ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_QUAD1, &t);
                if (ret)
                        break;
                *val = t;
                ret = IIO_VAL_INT;
                break;
        case IIO_CHAN_INFO_CALIBBIAS:
                ret = adxrs450_spi_read_reg_16(indio_dev, ADXRS450_DNC1, &t);
                if (ret)
                        break;
                *val = sign_extend32(t, 9);
                ret = IIO_VAL_INT;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static const struct iio_chan_spec adxrs450_channels[2][2] = {
        [ID_ADXRS450] = {
                {
                        .type = IIO_ANGL_VEL,
                        .modified = 1,
                        .channel2 = IIO_MOD_Z,
                        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_CALIBBIAS) |
                        BIT(IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE),
                }, {
                        .type = IIO_TEMP,
                        .indexed = 1,
                        .channel = 0,
                        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE),
                }
        },
        [ID_ADXRS453] = {
                {
                        .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_QUADRATURE_CORRECTION_RAW),
                }, {
                        .type = IIO_TEMP,
                        .indexed = 1,
                        .channel = 0,
                        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE),
                }
        },
};

static const struct iio_info adxrs450_info = {
        .read_raw = &adxrs450_read_raw,
        .write_raw = &adxrs450_write_raw,
};

static int adxrs450_probe(struct spi_device *spi)
{
        int ret;
        struct adxrs450_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);
        st->us = spi;
        mutex_init(&st->buf_lock);
        /* This is only used for removal purposes */
        spi_set_drvdata(spi, indio_dev);

        indio_dev->info = &adxrs450_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels =
                adxrs450_channels[spi_get_device_id(spi)->driver_data];
        indio_dev->num_channels = ARRAY_SIZE(adxrs450_channels);
        indio_dev->name = spi->dev.driver->name;

        ret = devm_iio_device_register(&spi->dev, indio_dev);
        if (ret)
                return ret;

        /* Get the device into a sane initial state */
        ret = adxrs450_initial_setup(indio_dev);
        if (ret)
                return ret;

        return 0;
}

static const struct spi_device_id adxrs450_id[] = {
        {"adxrs450", ID_ADXRS450},
        {"adxrs453", ID_ADXRS453},
        { }
};
MODULE_DEVICE_TABLE(spi, adxrs450_id);

static struct spi_driver adxrs450_driver = {
        .driver = {
                .name = "adxrs450",
        },
        .probe = adxrs450_probe,
        .id_table       = adxrs450_id,
};
module_spi_driver(adxrs450_driver);

MODULE_AUTHOR("Cliff Cai <cliff.cai@xxxxxxxxxx>");
MODULE_DESCRIPTION("Analog Devices ADXRS450/ADXRS453 Gyroscope SPI driver");
MODULE_LICENSE("GPL v2");