linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * lmp91000.c - Support for Texas Instruments digital potentiostats

 *

 * Copyright (C) 2016, 2018

 * Author: Matt Ranostay <matt.ranostay@konsulko.com>

 *

 * TODO: bias voltage + polarity control, and multiple chip support

 */

​

#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/delay.h>

#include <linux/of.h>

#include <linux/regmap.h>

#include <linux/iio/iio.h>

#include <linux/iio/buffer.h>

#include <linux/iio/consumer.h>

#include <linux/iio/trigger.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>

​

#define LMP91000_REG_LOCK       0x01

#define LMP91000_REG_TIACN      0x10

#define LMP91000_REG_TIACN_GAIN_SHIFT   2

​

#define LMP91000_REG_REFCN      0x11

#define LMP91000_REG_REFCN_EXT_REF  0x20

#define LMP91000_REG_REFCN_50_ZERO  0x80

​

#define LMP91000_REG_MODECN     0x12

#define LMP91000_REG_MODECN_3LEAD   0x03

#define LMP91000_REG_MODECN_TEMP    0x07

​

#define LMP91000_DRV_NAME   "lmp91000"

​

static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000,

                     120000, 350000 };

​

static const int lmp91000_rload[] = { 10, 33, 50, 100 };

​

#define LMP91000_TEMP_BASE  -40

​

static const u16 lmp91000_temp_lut[] = {

    1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805,

    1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727,

    1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648,

    1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568,

    1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488,

    1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407,

    1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326,

    1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244,

    1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162,

    1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079,

    1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004,  996,

     987,  979,  971,  962,  954,  945,  937,  929,  920,  912,

     903,  895,  886,  878,  870,  861 };

​

static const struct regmap_config lmp91000_regmap_config = {

    .reg_bits = 8,

    .val_bits = 8,

};

​

struct lmp91000_data {

    struct regmap *regmap;

    struct device *dev;

​

    struct iio_trigger *trig;

    struct iio_cb_buffer *cb_buffer;

    struct iio_channel *adc_chan;

​

    struct completion completion;

    u8 chan_select;

​

    u32 buffer[4]; /* 64-bit data + 64-bit timestamp */

};

​

static const struct iio_chan_spec lmp91000_channels[] = {

    { /* chemical channel mV */

        .type = IIO_VOLTAGE,

        .channel = 0,

        .address = LMP91000_REG_MODECN_3LEAD,

        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

                      BIT(IIO_CHAN_INFO_OFFSET) |

                      BIT(IIO_CHAN_INFO_SCALE),

        .scan_index = 0,

        .scan_type = {

            .sign = 's',

            .realbits = 32,

            .storagebits = 32,

        },

    },