drivers/iio/gyro/adis16080.c

   1 /*
   2  * ADIS16080/100 Yaw Rate Gyroscope with SPI driver
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8 #include <linux/delay.h>
   9 #include <linux/mutex.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spi/spi.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/module.h>
  16
  17 #include <linux/iio/iio.h>
  18 #include <linux/iio/sysfs.h>
  19
  20 #define ADIS16080_DIN_GYRO   (0 << 10) /* Gyroscope output */
  21 #define ADIS16080_DIN_TEMP   (1 << 10) /* Temperature output */
  22 #define ADIS16080_DIN_AIN1   (2 << 10)
  23 #define ADIS16080_DIN_AIN2   (3 << 10)
  24
  25 /*
  26  * 1: Write contents on DIN to control register.
  27  * 0: No changes to control register.
  28  */
  29
  30 #define ADIS16080_DIN_WRITE  (1 << 15)
  31
  32 struct adis16080_chip_info {
  33         int scale_val;
  34         int scale_val2;
  35 };
  36
  37 /**
  38  * struct adis16080_state - device instance specific data
  39  * @us:                 actual spi_device to write data
  40  * @info:               chip specific parameters
  41  * @buf:                transmit or receive buffer
  42  **/
  43 struct adis16080_state {
  44         struct spi_device               *us;
  45         const struct adis16080_chip_info *info;
  46
  47         __be16 buf ____cacheline_aligned;
  48 };
  49
  50 static int adis16080_read_sample(struct iio_dev *indio_dev,
  51                 u16 addr, int *val)
  52 {
  53         struct adis16080_state *st = iio_priv(indio_dev);
  54         int ret;
  55         struct spi_transfer     t[] = {
  56                 {
  57                         .tx_buf         = &st->buf,
  58                         .len            = 2,
  59                         .cs_change      = 1,
  60                 }, {
  61                         .rx_buf         = &st->buf,
  62                         .len            = 2,
  63                 },
  64         };
  65
  66         st->buf = cpu_to_be16(addr | ADIS16080_DIN_WRITE);
  67
  68         ret = spi_sync_transfer(st->us, t, ARRAY_SIZE(t));
  69         if (ret == 0)
  70                 *val = sign_extend32(be16_to_cpu(st->buf), 11);
  71
  72         return ret;
  73 }
  74
  75 static int adis16080_read_raw(struct iio_dev *indio_dev,
  76                              struct iio_chan_spec const *chan,
  77                              int *val,
  78                              int *val2,
  79                              long mask)
  80 {
  81         struct adis16080_state *st = iio_priv(indio_dev);
  82         int ret;
  83
  84         switch (mask) {
  85         case IIO_CHAN_INFO_RAW:
  86                 mutex_lock(&indio_dev->mlock);
  87                 ret = adis16080_read_sample(indio_dev, chan->address, val);
  88                 mutex_unlock(&indio_dev->mlock);
  89                 return ret ? ret : IIO_VAL_INT;
  90         case IIO_CHAN_INFO_SCALE:
  91                 switch (chan->type) {
  92                 case IIO_ANGL_VEL:
  93                         *val = st->info->scale_val;
  94                         *val2 = st->info->scale_val2;
  95                         return IIO_VAL_FRACTIONAL;
  96                 case IIO_VOLTAGE:
  97                         /* VREF = 5V, 12 bits */
  98                         *val = 5000;
  99                         *val2 = 12;
 100                         return IIO_VAL_FRACTIONAL_LOG2;
 101                 case IIO_TEMP:
 102                         /* 85 C = 585, 25 C = 0 */
 103                         *val = 85000 - 25000;
 104                         *val2 = 585;
 105                         return IIO_VAL_FRACTIONAL;
 106                 default:
 107                         return -EINVAL;
 108                 }
 109         case IIO_CHAN_INFO_OFFSET:
 110                 switch (chan->type) {
 111                 case IIO_VOLTAGE:
 112                         /* 2.5 V = 0 */
 113                         *val = 2048;
 114                         return IIO_VAL_INT;
 115                 case IIO_TEMP:
 116                         /* 85 C = 585, 25 C = 0 */
 117                         *val = DIV_ROUND_CLOSEST(25 * 585, 85 - 25);
 118                         return IIO_VAL_INT;
 119                 default:
 120                         return -EINVAL;
 121                 }
 122         default:
 123                 break;
 124         }
 125
 126         return -EINVAL;
 127 }
 128
 129 static const struct iio_chan_spec adis16080_channels[] = {
 130         {
 131                 .type = IIO_ANGL_VEL,
 132                 .modified = 1,
 133                 .channel2 = IIO_MOD_Z,
 134                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 135                         BIT(IIO_CHAN_INFO_SCALE),
 136                 .address = ADIS16080_DIN_GYRO,
 137         }, {
 138                 .type = IIO_VOLTAGE,
 139                 .indexed = 1,
 140                 .channel = 0,
 141                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 142                         BIT(IIO_CHAN_INFO_SCALE) |
 143                         BIT(IIO_CHAN_INFO_OFFSET),
 144                 .address = ADIS16080_DIN_AIN1,
 145         }, {
 146                 .type = IIO_VOLTAGE,
 147                 .indexed = 1,
 148                 .channel = 1,
 149                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 150                         BIT(IIO_CHAN_INFO_SCALE) |
 151                         BIT(IIO_CHAN_INFO_OFFSET),
 152                 .address = ADIS16080_DIN_AIN2,
 153         }, {
 154                 .type = IIO_TEMP,
 155                 .indexed = 1,
 156                 .channel = 0,
 157                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 158                         BIT(IIO_CHAN_INFO_SCALE) |
 159                         BIT(IIO_CHAN_INFO_OFFSET),
 160                 .address = ADIS16080_DIN_TEMP,
 161         }
 162 };
 163
 164 static const struct iio_info adis16080_info = {
 165         .read_raw = &adis16080_read_raw,
 166         .driver_module = THIS_MODULE,
 167 };
 168
 169 enum {
 170         ID_ADIS16080,
 171         ID_ADIS16100,
 172 };
 173
 174 static const struct adis16080_chip_info adis16080_chip_info[] = {
 175         [ID_ADIS16080] = {
 176                 /* 80 degree = 819, 819 rad = 46925 degree */
 177                 .scale_val = 80,
 178                 .scale_val2 = 46925,
 179         },
 180         [ID_ADIS16100] = {
 181                 /* 300 degree = 1230, 1230 rad = 70474 degree */
 182                 .scale_val = 300,
 183                 .scale_val2 = 70474,
 184         },
 185 };
 186
 187 static int adis16080_probe(struct spi_device *spi)
 188 {
 189         const struct spi_device_id *id = spi_get_device_id(spi);
 190         struct adis16080_state *st;
 191         struct iio_dev *indio_dev;
 192
 193         /* setup the industrialio driver allocated elements */
 194         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 195         if (!indio_dev)
 196                 return -ENOMEM;
 197         st = iio_priv(indio_dev);
 198         /* this is only used for removal purposes */
 199         spi_set_drvdata(spi, indio_dev);
 200
 201         /* Allocate the comms buffers */
 202         st->us = spi;
 203         st->info = &adis16080_chip_info[id->driver_data];
 204
 205         indio_dev->name = spi->dev.driver->name;
 206         indio_dev->channels = adis16080_channels;
 207         indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
 208         indio_dev->dev.parent = &spi->dev;
 209         indio_dev->info = &adis16080_info;
 210         indio_dev->modes = INDIO_DIRECT_MODE;
 211
 212         return iio_device_register(indio_dev);
 213 }
 214
 215 static int adis16080_remove(struct spi_device *spi)
 216 {
 217         iio_device_unregister(spi_get_drvdata(spi));
 218         return 0;
 219 }
 220
 221 static const struct spi_device_id adis16080_ids[] = {
 222         { "adis16080", ID_ADIS16080 },
 223         { "adis16100", ID_ADIS16100 },
 224         {},
 225 };
 226 MODULE_DEVICE_TABLE(spi, adis16080_ids);
 227
 228 static struct spi_driver adis16080_driver = {
 229         .driver = {
 230                 .name = "adis16080",
 231                 .owner = THIS_MODULE,
 232         },
 233         .probe = adis16080_probe,
 234         .remove = adis16080_remove,
 235         .id_table = adis16080_ids,
 236 };
 237 module_spi_driver(adis16080_driver);
 238
 239 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 240 MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
 241 MODULE_LICENSE("GPL v2");