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 <linux/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  **/
  41 struct adis16130_state {
  42         struct spi_device               *us;
  43         struct mutex                    buf_lock;
  44         u8                              buf[4] __aligned(IIO_DMA_MINALIGN);
  45 };
  46
  47 static 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
  70 static 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
 117 static 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
 137 static const struct iio_info adis16130_info = {
 138         .read_raw = &adis16130_read_raw,
 139 };
 140
 141 static 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
 164 static struct spi_driver adis16130_driver = {
 165         .driver = {
 166                 .name = "adis16130",
 167         },
 168         .probe = adis16130_probe,
 169 };
 170 module_spi_driver(adis16130_driver);
 171
 172 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 173 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
 174 MODULE_LICENSE("GPL v2");
 175 MODULE_ALIAS("spi:adis16130");