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  **/
  40 struct adis16130_state {
  41         struct spi_device               *us;
  42         struct mutex                    buf_lock;
  43         u8                              buf[4] ____cacheline_aligned;
  44 };
  45
  46 static 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_message msg;
  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         spi_message_init(&msg);
  63         spi_message_add_tail(&xfer, &msg);
  64         ret = spi_sync(st->us, &msg);
  65
  66         if (ret == 0)
  67                 *val = (st->buf[1] << 16) | (st->buf[2] << 8) | st->buf[3];
  68         mutex_unlock(&st->buf_lock);
  69
  70         return ret;
  71 }
  72
  73 static int adis16130_read_raw(struct iio_dev *indio_dev,
  74                               struct iio_chan_spec const *chan,
  75                               int *val, int *val2,
  76                               long mask)
  77 {
  78         int ret;
  79         u32 temp;
  80
  81         switch (mask) {
  82         case IIO_CHAN_INFO_RAW:
  83                 /* Take the iio_dev status lock */
  84                 mutex_lock(&indio_dev->mlock);
  85                 ret = adis16130_spi_read(indio_dev, chan->address, &temp);
  86                 mutex_unlock(&indio_dev->mlock);
  87                 if (ret)
  88                         return ret;
  89                 *val = temp;
  90                 return IIO_VAL_INT;
  91         case IIO_CHAN_INFO_SCALE:
  92                 switch (chan->type) {
  93                 case IIO_ANGL_VEL:
  94                         /* 0 degree = 838860, 250 degree = 14260608 */
  95                         *val = 250;
  96                         *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
  97                         return IIO_VAL_FRACTIONAL;
  98                 case IIO_TEMP:
  99                         /* 0C = 8036283, 105C = 9516048 */
 100                         *val = 105000;
 101                         *val2 = 9516048 - 8036283;
 102                         return IIO_VAL_FRACTIONAL;
 103                 default:
 104                         return -EINVAL;
 105                 }
 106                 break;
 107         case IIO_CHAN_INFO_OFFSET:
 108                 switch (chan->type) {
 109                 case IIO_ANGL_VEL:
 110                         *val = -8388608;
 111                         return IIO_VAL_INT;
 112                 case IIO_TEMP:
 113                         *val = -8036283;
 114                         return IIO_VAL_INT;
 115                 default:
 116                         return -EINVAL;
 117                 }
 118                 break;
 119         }
 120
 121         return -EINVAL;
 122 }
 123
 124 static const struct iio_chan_spec adis16130_channels[] = {
 125         {
 126                 .type = IIO_ANGL_VEL,
 127                 .modified = 1,
 128                 .channel2 = IIO_MOD_Z,
 129                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 130                         BIT(IIO_CHAN_INFO_SCALE) |
 131                         BIT(IIO_CHAN_INFO_OFFSET),
 132                 .address = ADIS16130_RATEDATA,
 133         }, {
 134                 .type = IIO_TEMP,
 135                 .indexed = 1,
 136                 .channel = 0,
 137                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 138                         BIT(IIO_CHAN_INFO_SCALE) |
 139                         BIT(IIO_CHAN_INFO_OFFSET),
 140                 .address = ADIS16130_TEMPDATA,
 141         }
 142 };
 143
 144 static const struct iio_info adis16130_info = {
 145         .read_raw = &adis16130_read_raw,
 146         .driver_module = THIS_MODULE,
 147 };
 148
 149 static int adis16130_probe(struct spi_device *spi)
 150 {
 151         int ret;
 152         struct adis16130_state *st;
 153         struct iio_dev *indio_dev;
 154
 155         /* setup the industrialio driver allocated elements */
 156         indio_dev = iio_device_alloc(sizeof(*st));
 157         if (indio_dev == NULL) {
 158                 ret = -ENOMEM;
 159                 goto error_ret;
 160         }
 161         st = iio_priv(indio_dev);
 162         /* this is only used for removal purposes */
 163         spi_set_drvdata(spi, indio_dev);
 164         st->us = spi;
 165         mutex_init(&st->buf_lock);
 166         indio_dev->name = spi->dev.driver->name;
 167         indio_dev->channels = adis16130_channels;
 168         indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
 169         indio_dev->dev.parent = &spi->dev;
 170         indio_dev->info = &adis16130_info;
 171         indio_dev->modes = INDIO_DIRECT_MODE;
 172
 173         ret = iio_device_register(indio_dev);
 174         if (ret)
 175                 goto error_free_dev;
 176
 177         return 0;
 178
 179 error_free_dev:
 180         iio_device_free(indio_dev);
 181
 182 error_ret:
 183         return ret;
 184 }
 185
 186 static int adis16130_remove(struct spi_device *spi)
 187 {
 188         iio_device_unregister(spi_get_drvdata(spi));
 189         iio_device_free(spi_get_drvdata(spi));
 190
 191         return 0;
 192 }
 193
 194 static struct spi_driver adis16130_driver = {
 195         .driver = {
 196                 .name = "adis16130",
 197                 .owner = THIS_MODULE,
 198         },
 199         .probe = adis16130_probe,
 200         .remove = adis16130_remove,
 201 };
 202 module_spi_driver(adis16130_driver);
 203
 204 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 205 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
 206 MODULE_LICENSE("GPL v2");
 207 MODULE_ALIAS("spi:adis16130");