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 "../iio.h"
  19 #include "../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 0:
  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                 .address = ADIS16060_GYRO,
 124         }, {
 125                 .type = IIO_VOLTAGE,
 126                 .indexed = 1,
 127                 .channel = 0,
 128                 .address = ADIS16060_AIN1,
 129         }, {
 130                 .type = IIO_VOLTAGE,
 131                 .indexed = 1,
 132                 .channel = 1,
 133                 .address = ADIS16060_AIN2,
 134         }, {
 135                 .type = IIO_TEMP,
 136                 .indexed = 1,
 137                 .channel = 0,
 138                 .info_mask = IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 139                 IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
 140                 .address = ADIS16060_TEMP_OUT,
 141         }
 142 };
 143
 144 static int __devinit adis16060_r_probe(struct spi_device *spi)
 145 {
 146         int ret;
 147         struct adis16060_state *st;
 148         struct iio_dev *indio_dev;
 149
 150         /* setup the industrialio driver allocated elements */
 151         indio_dev = iio_allocate_device(sizeof(*st));
 152         if (indio_dev == NULL) {
 153                 ret = -ENOMEM;
 154                 goto error_ret;
 155         }
 156         /* this is only used for removal purposes */
 157         spi_set_drvdata(spi, indio_dev);
 158         st = iio_priv(indio_dev);
 159         st->us_r = spi;
 160         mutex_init(&st->buf_lock);
 161
 162         indio_dev->name = spi->dev.driver->name;
 163         indio_dev->dev.parent = &spi->dev;
 164         indio_dev->info = &adis16060_info;
 165         indio_dev->modes = INDIO_DIRECT_MODE;
 166         indio_dev->channels = adis16060_channels;
 167         indio_dev->num_channels = ARRAY_SIZE(adis16060_channels);
 168
 169         ret = iio_device_register(indio_dev);
 170         if (ret)
 171                 goto error_free_dev;
 172
 173         adis16060_iio_dev = indio_dev;
 174         return 0;
 175
 176 error_free_dev:
 177         iio_free_device(indio_dev);
 178 error_ret:
 179         return ret;
 180 }
 181
 182 /* fixme, confirm ordering in this function */
 183 static int adis16060_r_remove(struct spi_device *spi)
 184 {
 185         iio_device_unregister(spi_get_drvdata(spi));
 186         iio_free_device(spi_get_drvdata(spi));
 187
 188         return 0;
 189 }
 190
 191 static int __devinit adis16060_w_probe(struct spi_device *spi)
 192 {
 193         int ret;
 194         struct iio_dev *indio_dev = adis16060_iio_dev;
 195         struct adis16060_state *st;
 196         if (!indio_dev) {
 197                 ret =  -ENODEV;
 198                 goto error_ret;
 199         }
 200         st = iio_priv(indio_dev);
 201         spi_set_drvdata(spi, indio_dev);
 202         st->us_w = spi;
 203         return 0;
 204
 205 error_ret:
 206         return ret;
 207 }
 208
 209 static int adis16060_w_remove(struct spi_device *spi)
 210 {
 211         return 0;
 212 }
 213
 214 static struct spi_driver adis16060_r_driver = {
 215         .driver = {
 216                 .name = "adis16060_r",
 217                 .owner = THIS_MODULE,
 218         },
 219         .probe = adis16060_r_probe,
 220         .remove = __devexit_p(adis16060_r_remove),
 221 };
 222
 223 static struct spi_driver adis16060_w_driver = {
 224         .driver = {
 225                 .name = "adis16060_w",
 226                 .owner = THIS_MODULE,
 227         },
 228         .probe = adis16060_w_probe,
 229         .remove = __devexit_p(adis16060_w_remove),
 230 };
 231
 232 static __init int adis16060_init(void)
 233 {
 234         int ret;
 235
 236         ret = spi_register_driver(&adis16060_r_driver);
 237         if (ret < 0)
 238                 return ret;
 239
 240         ret = spi_register_driver(&adis16060_w_driver);
 241         if (ret < 0) {
 242                 spi_unregister_driver(&adis16060_r_driver);
 243                 return ret;
 244         }
 245
 246         return 0;
 247 }
 248 module_init(adis16060_init);
 249
 250 static __exit void adis16060_exit(void)
 251 {
 252         spi_unregister_driver(&adis16060_w_driver);
 253         spi_unregister_driver(&adis16060_r_driver);
 254 }
 255 module_exit(adis16060_exit);
 256
 257 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 258 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
 259 MODULE_LICENSE("GPL v2");