drivers/staging/iio/gyro/adis16060_core.c

   1 /*
   2  * ADIS16060 Wide Bandwidth Yaw Rate Gyroscope with SPI driver
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/delay.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/slab.h>
  16 #include <linux/sysfs.h>
  17
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/sysfs.h>
  20
  21 #define ADIS16060_GYRO          0x20 /* Measure Angular Rate (Gyro) */
  22 #define ADIS16060_TEMP_OUT      0x10 /* Measure Temperature */
  23 #define ADIS16060_AIN2          0x80 /* Measure AIN2 */
  24 #define ADIS16060_AIN1          0x40 /* Measure AIN1 */
  25
  26 /**
  27  * struct adis16060_state - device instance specific data
  28  * @us_w:               actual spi_device to write config
  29  * @us_r:               actual spi_device to read back data
  30  * @buf:                transmit or receive buffer
  31  * @buf_lock:           mutex to protect tx and rx
  32  **/
  33 struct adis16060_state {
  34         struct spi_device               *us_w;
  35         struct spi_device               *us_r;
  36         struct mutex                    buf_lock;
  37
  38         u8 buf[3] ____cacheline_aligned;
  39 };
  40
  41 static struct iio_dev *adis16060_iio_dev;
  42
  43 static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
  44 {
  45         int ret;
  46         struct adis16060_state *st = iio_priv(indio_dev);
  47
  48         mutex_lock(&st->buf_lock);
  49         st->buf[2] = val; /* The last 8 bits clocked in are latched */
  50         ret = spi_write(st->us_w, st->buf, 3);
  51         mutex_unlock(&st->buf_lock);
  52
  53         return ret;
  54 }
  55
  56 static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
  57 {
  58         int ret;
  59         struct adis16060_state *st = iio_priv(indio_dev);
  60
  61         mutex_lock(&st->buf_lock);
  62
  63         ret = spi_read(st->us_r, st->buf, 3);
  64
  65         /* The internal successive approximation ADC begins the
  66          * conversion process on the falling edge of MSEL1 and
  67          * starts to place data MSB first on the DOUT line at
  68          * the 6th falling edge of SCLK
  69          */
  70         if (ret == 0)
  71                 *val = ((st->buf[0] & 0x3) << 12) |
  72                         (st->buf[1] << 4) |
  73                         ((st->buf[2] >> 4) & 0xF);
  74         mutex_unlock(&st->buf_lock);
  75
  76         return ret;
  77 }
  78
  79 static int adis16060_read_raw(struct iio_dev *indio_dev,
  80                               struct iio_chan_spec const *chan,
  81                               int *val, int *val2,
  82                               long mask)
  83 {
  84         u16 tval = 0;
  85         int ret;
  86
  87         switch (mask) {
  88         case IIO_CHAN_INFO_RAW:
  89                 /* Take the iio_dev status lock */
  90                 mutex_lock(&indio_dev->mlock);
  91                 ret = adis16060_spi_write(indio_dev, chan->address);
  92                 if (ret < 0) {
  93                         mutex_unlock(&indio_dev->mlock);
  94                         return ret;
  95                 }
  96                 ret = adis16060_spi_read(indio_dev, &tval);
  97                 mutex_unlock(&indio_dev->mlock);
  98                 *val = tval;
  99                 return IIO_VAL_INT;
 100         case IIO_CHAN_INFO_OFFSET:
 101                 *val = -7;
 102                 *val2 = 461117;
 103                 return IIO_VAL_INT_PLUS_MICRO;
 104         case IIO_CHAN_INFO_SCALE:
 105                 *val = 0;
 106                 *val2 = 34000;
 107                 return IIO_VAL_INT_PLUS_MICRO;
 108         }
 109
 110         return -EINVAL;
 111 }
 112
 113 static const struct iio_info adis16060_info = {
 114         .read_raw = &adis16060_read_raw,
 115         .driver_module = THIS_MODULE,
 116 };
 117
 118 static const struct iio_chan_spec adis16060_channels[] = {
 119         {
 120                 .type = IIO_ANGL_VEL,
 121                 .modified = 1,
 122                 .channel2 = IIO_MOD_Z,
 123                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 124                 .address = ADIS16060_GYRO,
 125         }, {
 126                 .type = IIO_VOLTAGE,
 127                 .indexed = 1,
 128                 .channel = 0,
 129                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 130                 .address = ADIS16060_AIN1,
 131         }, {
 132                 .type = IIO_VOLTAGE,
 133                 .indexed = 1,
 134                 .channel = 1,
 135                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 136                 .address = ADIS16060_AIN2,
 137         }, {
 138                 .type = IIO_TEMP,
 139                 .indexed = 1,
 140                 .channel = 0,
 141                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 142                 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),
 143                 .address = ADIS16060_TEMP_OUT,
 144         }
 145 };
 146
 147 static int adis16060_r_probe(struct spi_device *spi)
 148 {
 149         int ret;
 150         struct adis16060_state *st;
 151         struct iio_dev *indio_dev;
 152
 153         /* setup the industrialio driver allocated elements */
 154         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 155         if (!indio_dev)
 156                 return -ENOMEM;
 157         /* this is only used for removal purposes */
 158         spi_set_drvdata(spi, indio_dev);
 159         st = iio_priv(indio_dev);
 160         st->us_r = spi;
 161         mutex_init(&st->buf_lock);
 162
 163         indio_dev->name = spi->dev.driver->name;
 164         indio_dev->dev.parent = &spi->dev;
 165         indio_dev->info = &adis16060_info;
 166         indio_dev->modes = INDIO_DIRECT_MODE;
 167         indio_dev->channels = adis16060_channels;
 168         indio_dev->num_channels = ARRAY_SIZE(adis16060_channels);
 169
 170         ret = devm_iio_device_register(&spi->dev, indio_dev);
 171         if (ret)
 172                 return ret;
 173
 174         adis16060_iio_dev = indio_dev;
 175         return 0;
 176 }
 177
 178 static int adis16060_w_probe(struct spi_device *spi)
 179 {
 180         int ret;
 181         struct iio_dev *indio_dev = adis16060_iio_dev;
 182         struct adis16060_state *st;
 183
 184         if (!indio_dev) {
 185                 ret =  -ENODEV;
 186                 goto error_ret;
 187         }
 188         st = iio_priv(indio_dev);
 189         spi_set_drvdata(spi, indio_dev);
 190         st->us_w = spi;
 191         return 0;
 192
 193 error_ret:
 194         return ret;
 195 }
 196
 197 static int adis16060_w_remove(struct spi_device *spi)
 198 {
 199         return 0;
 200 }
 201
 202 static struct spi_driver adis16060_r_driver = {
 203         .driver = {
 204                 .name = "adis16060_r",
 205         },
 206         .probe = adis16060_r_probe,
 207 };
 208
 209 static struct spi_driver adis16060_w_driver = {
 210         .driver = {
 211                 .name = "adis16060_w",
 212         },
 213         .probe = adis16060_w_probe,
 214         .remove = adis16060_w_remove,
 215 };
 216
 217 static __init int adis16060_init(void)
 218 {
 219         int ret;
 220
 221         ret = spi_register_driver(&adis16060_r_driver);
 222         if (ret < 0)
 223                 return ret;
 224
 225         ret = spi_register_driver(&adis16060_w_driver);
 226         if (ret < 0) {
 227                 spi_unregister_driver(&adis16060_r_driver);
 228                 return ret;
 229         }
 230
 231         return 0;
 232 }
 233 module_init(adis16060_init);
 234
 235 static __exit void adis16060_exit(void)
 236 {
 237         spi_unregister_driver(&adis16060_w_driver);
 238         spi_unregister_driver(&adis16060_r_driver);
 239 }
 240 module_exit(adis16060_exit);
 241
 242 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 243 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
 244 MODULE_LICENSE("GPL v2");