LXR linux/drivers/iio/gyro/adis16130.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
   4 *
   5 * Copyright 2010 Analog Devices Inc.
   6 */
   7
   8#include <linux/mutex.h>
   9#include <linux/kernel.h>
  10#include <linux/spi/spi.h>
  11#include <linux/module.h>
  12
  13#include <linux/iio/iio.h>
  14
  15#include <asm/unaligned.h>
  16
  17#define ADIS16130_CON         0x0
  18#define ADIS16130_CON_RD      (1 << 6)
  19#define ADIS16130_IOP         0x1
  20
  21/* 1 = data-ready signal low when unread data on all channels; */
  22#define ADIS16130_IOP_ALL_RDY (1 << 3)
  23#define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
  24#define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
  25#define ADIS16130_TEMPDATA    0xA /* Temperature output */
  26#define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
  27#define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
  28#define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
  29#define ADIS16130_TEMPCS_EN   (1 << 3)
  30#define ADIS16130_RATECONV    0x30
  31#define ADIS16130_TEMPCONV    0x32
  32#define ADIS16130_MODE        0x38
  33#define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
  34
  35/**
  36 * struct adis16130_state - device instance specific data
  37 * @us:                 actual spi_device to write data
  38 * @buf_lock:           mutex to protect tx and rx
  39 * @buf:                unified tx/rx buffer
  40 **/
  41struct adis16130_state {
  42        struct spi_device               *us;
  43        struct mutex                    buf_lock;
  44        u8                              buf[4] ____cacheline_aligned;
  45};
  46
  47static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
  48{
  49        int ret;
  50        struct adis16130_state *st = iio_priv(indio_dev);
  51        struct spi_transfer xfer = {
  52                .tx_buf = st->buf,
  53                .rx_buf = st->buf,
  54                .len = 4,
  55        };
  56
  57        mutex_lock(&st->buf_lock);
  58
  59        st->buf[0] = ADIS16130_CON_RD | reg_addr;
  60        st->buf[1] = st->buf[2] = st->buf[3] = 0;
  61
  62        ret = spi_sync_transfer(st->us, &xfer, 1);
  63        if (ret == 0)
  64                *val = get_unaligned_be24(&st->buf[1]);
  65        mutex_unlock(&st->buf_lock);
  66
  67        return ret;
  68}
  69
  70static int adis16130_read_raw(struct iio_dev *indio_dev,
  71                              struct iio_chan_spec const *chan,
  72                              int *val, int *val2,
  73                              long mask)
  74{
  75        int ret;
  76        u32 temp;
  77
  78        switch (mask) {
  79        case IIO_CHAN_INFO_RAW:
  80                /* Take the iio_dev status lock */
  81                ret = adis16130_spi_read(indio_dev, chan->address, &temp);
  82                if (ret)
  83                        return ret;
  84                *val = temp;
  85                return IIO_VAL_INT;
  86        case IIO_CHAN_INFO_SCALE:
  87                switch (chan->type) {
  88                case IIO_ANGL_VEL:
  89                        /* 0 degree = 838860, 250 degree = 14260608 */
  90                        *val = 250;
  91                        *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
  92                        return IIO_VAL_FRACTIONAL;
  93                case IIO_TEMP:
  94                        /* 0C = 8036283, 105C = 9516048 */
  95                        *val = 105000;
  96                        *val2 = 9516048 - 8036283;
  97                        return IIO_VAL_FRACTIONAL;
  98                default:
  99                        return -EINVAL;
 100                }
 101        case IIO_CHAN_INFO_OFFSET:
 102                switch (chan->type) {
 103                case IIO_ANGL_VEL:
 104                        *val = -8388608;
 105                        return IIO_VAL_INT;
 106                case IIO_TEMP:
 107                        *val = -8036283;
 108                        return IIO_VAL_INT;
 109                default:
 110                        return -EINVAL;
 111                }
 112        }
 113
 114        return -EINVAL;
 115}
 116
 117static const struct iio_chan_spec adis16130_channels[] = {
 118        {
 119                .type = IIO_ANGL_VEL,
 120                .modified = 1,
 121                .channel2 = IIO_MOD_Z,
 122                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 123                        BIT(IIO_CHAN_INFO_SCALE) |
 124                        BIT(IIO_CHAN_INFO_OFFSET),
 125                .address = ADIS16130_RATEDATA,
 126        }, {
 127                .type = IIO_TEMP,
 128                .indexed = 1,
 129                .channel = 0,
 130                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 131                        BIT(IIO_CHAN_INFO_SCALE) |
 132                        BIT(IIO_CHAN_INFO_OFFSET),
 133                .address = ADIS16130_TEMPDATA,
 134        }
 135};
 136
 137static const struct iio_info adis16130_info = {
 138        .read_raw = &adis16130_read_raw,
 139};
 140
 141static int adis16130_probe(struct spi_device *spi)
 142{
 143        struct adis16130_state *st;
 144        struct iio_dev *indio_dev;
 145
 146        /* setup the industrialio driver allocated elements */
 147        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 148        if (!indio_dev)
 149                return -ENOMEM;
 150        st = iio_priv(indio_dev);
 151        /* this is only used for removal purposes */
 152        spi_set_drvdata(spi, indio_dev);
 153        st->us = spi;
 154        mutex_init(&st->buf_lock);
 155        indio_dev->name = spi->dev.driver->name;
 156        indio_dev->channels = adis16130_channels;
 157        indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
 158        indio_dev->info = &adis16130_info;
 159        indio_dev->modes = INDIO_DIRECT_MODE;
 160
 161        return devm_iio_device_register(&spi->dev, indio_dev);
 162}
 163
 164static struct spi_driver adis16130_driver = {
 165        .driver = {
 166                .name = "adis16130",
 167        },
 168        .probe = adis16130_probe,
 169};
 170module_spi_driver(adis16130_driver);
 171
 172MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 173MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
 174MODULE_LICENSE("GPL v2");
 175MODULE_ALIAS("spi:adis16130");
 176