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

   1/*
   2 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
   3 *
   4 * Copyright 2010 Analog Devices Inc.
   5 *
   6 * Licensed under the GPL-2 or later.
   7 */
   8
   9#include <linux/mutex.h>
  10#include <linux/kernel.h>
  11#include <linux/spi/spi.h>
  12#include <linux/module.h>
  13
  14#include <linux/iio/iio.h>
  15
  16#define ADIS16130_CON         0x0
  17#define ADIS16130_CON_RD      (1 << 6)
  18#define ADIS16130_IOP         0x1
  19
  20/* 1 = data-ready signal low when unread data on all channels; */
  21#define ADIS16130_IOP_ALL_RDY (1 << 3)
  22#define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
  23#define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
  24#define ADIS16130_TEMPDATA    0xA /* Temperature output */
  25#define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
  26#define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
  27#define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
  28#define ADIS16130_TEMPCS_EN   (1 << 3)
  29#define ADIS16130_RATECONV    0x30
  30#define ADIS16130_TEMPCONV    0x32
  31#define ADIS16130_MODE        0x38
  32#define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
  33
  34/**
  35 * struct adis16130_state - device instance specific data
  36 * @us:                 actual spi_device to write data
  37 * @buf_lock:           mutex to protect tx and rx
  38 * @buf:                unified tx/rx buffer
  39 **/
  40struct adis16130_state {
  41        struct spi_device               *us;
  42        struct mutex                    buf_lock;
  43        u8                              buf[4] ____cacheline_aligned;
  44};
  45
  46static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
  47{
  48        int ret;
  49        struct adis16130_state *st = iio_priv(indio_dev);
  50        struct spi_transfer xfer = {
  51                .tx_buf = st->buf,
  52                .rx_buf = st->buf,
  53                .len = 4,
  54        };
  55
  56        mutex_lock(&st->buf_lock);
  57
  58        st->buf[0] = ADIS16130_CON_RD | reg_addr;
  59        st->buf[1] = st->buf[2] = st->buf[3] = 0;
  60
  61        ret = spi_sync_transfer(st->us, &xfer, 1);
  62        if (ret == 0)
  63                *val = (st->buf[1] << 16) | (st->buf[2] << 8) | st->buf[3];
  64        mutex_unlock(&st->buf_lock);
  65
  66        return ret;
  67}
  68
  69static int adis16130_read_raw(struct iio_dev *indio_dev,
  70                              struct iio_chan_spec const *chan,
  71                              int *val, int *val2,
  72                              long mask)
  73{
  74        int ret;
  75        u32 temp;
  76
  77        switch (mask) {
  78        case IIO_CHAN_INFO_RAW:
  79                /* Take the iio_dev status lock */
  80                mutex_lock(&indio_dev->mlock);
  81                ret = adis16130_spi_read(indio_dev, chan->address, &temp);
  82                mutex_unlock(&indio_dev->mlock);
  83                if (ret)
  84                        return ret;
  85                *val = temp;
  86                return IIO_VAL_INT;
  87        case IIO_CHAN_INFO_SCALE:
  88                switch (chan->type) {
  89                case IIO_ANGL_VEL:
  90                        /* 0 degree = 838860, 250 degree = 14260608 */
  91                        *val = 250;
  92                        *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
  93                        return IIO_VAL_FRACTIONAL;
  94                case IIO_TEMP:
  95                        /* 0C = 8036283, 105C = 9516048 */
  96                        *val = 105000;
  97                        *val2 = 9516048 - 8036283;
  98                        return IIO_VAL_FRACTIONAL;
  99                default:
 100                        return -EINVAL;
 101                }
 102        case IIO_CHAN_INFO_OFFSET:
 103                switch (chan->type) {
 104                case IIO_ANGL_VEL:
 105                        *val = -8388608;
 106                        return IIO_VAL_INT;
 107                case IIO_TEMP:
 108                        *val = -8036283;
 109                        return IIO_VAL_INT;
 110                default:
 111                        return -EINVAL;
 112                }
 113        }
 114
 115        return -EINVAL;
 116}
 117
 118static const struct iio_chan_spec adis16130_channels[] = {
 119        {
 120                .type = IIO_ANGL_VEL,
 121                .modified = 1,
 122                .channel2 = IIO_MOD_Z,
 123                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 124                        BIT(IIO_CHAN_INFO_SCALE) |
 125                        BIT(IIO_CHAN_INFO_OFFSET),
 126                .address = ADIS16130_RATEDATA,
 127        }, {
 128                .type = IIO_TEMP,
 129                .indexed = 1,
 130                .channel = 0,
 131                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 132                        BIT(IIO_CHAN_INFO_SCALE) |
 133                        BIT(IIO_CHAN_INFO_OFFSET),
 134                .address = ADIS16130_TEMPDATA,
 135        }
 136};
 137
 138static const struct iio_info adis16130_info = {
 139        .read_raw = &adis16130_read_raw,
 140};
 141
 142static int adis16130_probe(struct spi_device *spi)
 143{
 144        struct adis16130_state *st;
 145        struct iio_dev *indio_dev;
 146
 147        /* setup the industrialio driver allocated elements */
 148        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 149        if (!indio_dev)
 150                return -ENOMEM;
 151        st = iio_priv(indio_dev);
 152        /* this is only used for removal purposes */
 153        spi_set_drvdata(spi, indio_dev);
 154        st->us = spi;
 155        mutex_init(&st->buf_lock);
 156        indio_dev->name = spi->dev.driver->name;
 157        indio_dev->channels = adis16130_channels;
 158        indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
 159        indio_dev->dev.parent = &spi->dev;
 160        indio_dev->info = &adis16130_info;
 161        indio_dev->modes = INDIO_DIRECT_MODE;
 162
 163        return devm_iio_device_register(&spi->dev, indio_dev);
 164}
 165
 166static struct spi_driver adis16130_driver = {
 167        .driver = {
 168                .name = "adis16130",
 169        },
 170        .probe = adis16130_probe,
 171};
 172module_spi_driver(adis16130_driver);
 173
 174MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 175MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
 176MODULE_LICENSE("GPL v2");
 177MODULE_ALIAS("spi:adis16130");
 178