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