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         struct spi_message m;
  55         int ret;
  56         struct spi_transfer     t[] = {
  57                 {
  58                         .tx_buf         = &st->buf,
  59                         .len            = 2,
  60                         .cs_change      = 1,
  61                 }, {
  62                         .rx_buf         = &st->buf,
  63                         .len            = 2,
  64                 },
  65         };
  66
  67         st->buf = cpu_to_be16(addr | ADIS16080_DIN_WRITE);
  68
  69         spi_message_init(&m);
  70         spi_message_add_tail(&t[0], &m);
  71         spi_message_add_tail(&t[1], &m);
  72
  73         ret = spi_sync(st->us, &m);
  74         if (ret == 0)
  75                 *val = sign_extend32(be16_to_cpu(st->buf), 11);
  76
  77         return ret;
  78 }
  79
  80 static int adis16080_read_raw(struct iio_dev *indio_dev,
  81                              struct iio_chan_spec const *chan,
  82                              int *val,
  83                              int *val2,
  84                              long mask)
  85 {
  86         struct adis16080_state *st = iio_priv(indio_dev);
  87         int ret;
  88
  89         switch (mask) {
  90         case IIO_CHAN_INFO_RAW:
  91                 mutex_lock(&indio_dev->mlock);
  92                 ret = adis16080_read_sample(indio_dev, chan->address, val);
  93                 mutex_unlock(&indio_dev->mlock);
  94                 return ret ? ret : IIO_VAL_INT;
  95         case IIO_CHAN_INFO_SCALE:
  96                 switch (chan->type) {
  97                 case IIO_ANGL_VEL:
  98                         *val = st->info->scale_val;
  99                         *val2 = st->info->scale_val2;
 100                         return IIO_VAL_FRACTIONAL;
 101                 case IIO_VOLTAGE:
 102                         /* VREF = 5V, 12 bits */
 103                         *val = 5000;
 104                         *val2 = 12;
 105                         return IIO_VAL_FRACTIONAL_LOG2;
 106                 case IIO_TEMP:
 107                         /* 85 C = 585, 25 C = 0 */
 108                         *val = 85000 - 25000;
 109                         *val2 = 585;
 110                         return IIO_VAL_FRACTIONAL;
 111                 default:
 112                         return -EINVAL;
 113                 }
 114         case IIO_CHAN_INFO_OFFSET:
 115                 switch (chan->type) {
 116                 case IIO_VOLTAGE:
 117                         /* 2.5 V = 0 */
 118                         *val = 2048;
 119                         return IIO_VAL_INT;
 120                 case IIO_TEMP:
 121                         /* 85 C = 585, 25 C = 0 */
 122                         *val = DIV_ROUND_CLOSEST(25 * 585, 85 - 25);
 123                         return IIO_VAL_INT;
 124                 default:
 125                         return -EINVAL;
 126                 }
 127         default:
 128                 break;
 129         }
 130
 131         return -EINVAL;
 132 }
 133
 134 static const struct iio_chan_spec adis16080_channels[] = {
 135         {
 136                 .type = IIO_ANGL_VEL,
 137                 .modified = 1,
 138                 .channel2 = IIO_MOD_Z,
 139                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 140                         BIT(IIO_CHAN_INFO_SCALE),
 141                 .address = ADIS16080_DIN_GYRO,
 142         }, {
 143                 .type = IIO_VOLTAGE,
 144                 .indexed = 1,
 145                 .channel = 0,
 146                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 147                         BIT(IIO_CHAN_INFO_SCALE) |
 148                         BIT(IIO_CHAN_INFO_OFFSET),
 149                 .address = ADIS16080_DIN_AIN1,
 150         }, {
 151                 .type = IIO_VOLTAGE,
 152                 .indexed = 1,
 153                 .channel = 1,
 154                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 155                         BIT(IIO_CHAN_INFO_SCALE) |
 156                         BIT(IIO_CHAN_INFO_OFFSET),
 157                 .address = ADIS16080_DIN_AIN2,
 158         }, {
 159                 .type = IIO_TEMP,
 160                 .indexed = 1,
 161                 .channel = 0,
 162                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 163                         BIT(IIO_CHAN_INFO_SCALE) |
 164                         BIT(IIO_CHAN_INFO_OFFSET),
 165                 .address = ADIS16080_DIN_TEMP,
 166         }
 167 };
 168
 169 static const struct iio_info adis16080_info = {
 170         .read_raw = &adis16080_read_raw,
 171         .driver_module = THIS_MODULE,
 172 };
 173
 174 enum {
 175         ID_ADIS16080,
 176         ID_ADIS16100,
 177 };
 178
 179 static const struct adis16080_chip_info adis16080_chip_info[] = {
 180         [ID_ADIS16080] = {
 181                 /* 80 degree = 819, 819 rad = 46925 degree */
 182                 .scale_val = 80,
 183                 .scale_val2 = 46925,
 184         },
 185         [ID_ADIS16100] = {
 186                 /* 300 degree = 1230, 1230 rad = 70474 degree */
 187                 .scale_val = 300,
 188                 .scale_val2 = 70474,
 189         },
 190 };
 191
 192 static int adis16080_probe(struct spi_device *spi)
 193 {
 194         const struct spi_device_id *id = spi_get_device_id(spi);
 195         struct adis16080_state *st;
 196         struct iio_dev *indio_dev;
 197
 198         /* setup the industrialio driver allocated elements */
 199         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 200         if (!indio_dev)
 201                 return -ENOMEM;
 202         st = iio_priv(indio_dev);
 203         /* this is only used for removal purposes */
 204         spi_set_drvdata(spi, indio_dev);
 205
 206         /* Allocate the comms buffers */
 207         st->us = spi;
 208         st->info = &adis16080_chip_info[id->driver_data];
 209
 210         indio_dev->name = spi->dev.driver->name;
 211         indio_dev->channels = adis16080_channels;
 212         indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
 213         indio_dev->dev.parent = &spi->dev;
 214         indio_dev->info = &adis16080_info;
 215         indio_dev->modes = INDIO_DIRECT_MODE;
 216
 217         return iio_device_register(indio_dev);
 218 }
 219
 220 static int adis16080_remove(struct spi_device *spi)
 221 {
 222         iio_device_unregister(spi_get_drvdata(spi));
 223         return 0;
 224 }
 225
 226 static const struct spi_device_id adis16080_ids[] = {
 227         { "adis16080", ID_ADIS16080 },
 228         { "adis16100", ID_ADIS16100 },
 229         {},
 230 };
 231 MODULE_DEVICE_TABLE(spi, adis16080_ids);
 232
 233 static struct spi_driver adis16080_driver = {
 234         .driver = {
 235                 .name = "adis16080",
 236                 .owner = THIS_MODULE,
 237         },
 238         .probe = adis16080_probe,
 239         .remove = adis16080_remove,
 240         .id_table = adis16080_ids,
 241 };
 242 module_spi_driver(adis16080_driver);
 243
 244 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 245 MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
 246 MODULE_LICENSE("GPL v2");