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 #include <linux/module.h>
  18
  19 #include "../iio.h"
  20 #include "../sysfs.h"
  21
  22 #define ADIS16060_GYRO          0x20 /* Measure Angular Rate (Gyro) */
  23 #define ADIS16060_TEMP_OUT      0x10 /* Measure Temperature */
  24 #define ADIS16060_AIN2          0x80 /* Measure AIN2 */
  25 #define ADIS16060_AIN1          0x40 /* Measure AIN1 */
  26
  27 /**
  28  * struct adis16060_state - device instance specific data
  29  * @us_w:               actual spi_device to write config
  30  * @us_r:               actual spi_device to read back data
  31  * @buf:                transmit or receive buffer
  32  * @buf_lock:           mutex to protect tx and rx
  33  **/
  34 struct adis16060_state {
  35         struct spi_device               *us_w;
  36         struct spi_device               *us_r;
  37         struct mutex                    buf_lock;
  38
  39         u8 buf[3] ____cacheline_aligned;
  40 };
  41
  42 static struct iio_dev *adis16060_iio_dev;
  43
  44 static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
  45 {
  46         int ret;
  47         struct adis16060_state *st = iio_priv(indio_dev);
  48
  49         mutex_lock(&st->buf_lock);
  50         st->buf[2] = val; /* The last 8 bits clocked in are latched */
  51         ret = spi_write(st->us_w, st->buf, 3);
  52         mutex_unlock(&st->buf_lock);
  53
  54         return ret;
  55 }
  56
  57 static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
  58 {
  59         int ret;
  60         struct adis16060_state *st = iio_priv(indio_dev);
  61
  62         mutex_lock(&st->buf_lock);
  63
  64         ret = spi_read(st->us_r, st->buf, 3);
  65
  66         /* The internal successive approximation ADC begins the
  67          * conversion process on the falling edge of MSEL1 and
  68          * starts to place data MSB first on the DOUT line at
  69          * the 6th falling edge of SCLK
  70          */
  71         if (ret == 0)
  72                 *val = ((st->buf[0] & 0x3) << 12) |
  73                         (st->buf[1] << 4) |
  74                         ((st->buf[2] >> 4) & 0xF);
  75         mutex_unlock(&st->buf_lock);
  76
  77         return ret;
  78 }
  79
  80 static int adis16060_read_raw(struct iio_dev *indio_dev,
  81                               struct iio_chan_spec const *chan,
  82                               int *val, int *val2,
  83                               long mask)
  84 {
  85         u16 tval = 0;
  86         int ret;
  87
  88         switch (mask) {
  89         case 0:
  90                 /* Take the iio_dev status lock */
  91                 mutex_lock(&indio_dev->mlock);
  92                 ret = adis16060_spi_write(indio_dev, chan->address);
  93                 if (ret < 0) {
  94                         mutex_unlock(&indio_dev->mlock);
  95                         return ret;
  96                 }
  97                 ret = adis16060_spi_read(indio_dev, &tval);
  98                 mutex_unlock(&indio_dev->mlock);
  99                 *val = tval;
 100                 return IIO_VAL_INT;
 101         case IIO_CHAN_INFO_OFFSET:
 102                 *val = -7;
 103                 *val2 = 461117;
 104                 return IIO_VAL_INT_PLUS_MICRO;
 105         case IIO_CHAN_INFO_SCALE:
 106                 *val = 0;
 107                 *val2 = 34000;
 108                 return IIO_VAL_INT_PLUS_MICRO;
 109         }
 110
 111         return -EINVAL;
 112 }
 113
 114 static const struct iio_info adis16060_info = {
 115         .read_raw = &adis16060_read_raw,
 116         .driver_module = THIS_MODULE,
 117 };
 118
 119 static const struct iio_chan_spec adis16060_channels[] = {
 120         {
 121                 .type = IIO_ANGL_VEL,
 122                 .modified = 1,
 123                 .channel2 = IIO_MOD_Z,
 124                 .address = ADIS16060_GYRO,
 125         }, {
 126                 .type = IIO_VOLTAGE,
 127                 .indexed = 1,
 128                 .channel = 0,
 129                 .address = ADIS16060_AIN1,
 130         }, {
 131                 .type = IIO_VOLTAGE,
 132                 .indexed = 1,
 133                 .channel = 1,
 134                 .address = ADIS16060_AIN2,
 135         }, {
 136                 .type = IIO_TEMP,
 137                 .indexed = 1,
 138                 .channel = 0,
 139                 .info_mask = IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 140                 IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
 141                 .address = ADIS16060_TEMP_OUT,
 142         }
 143 };
 144
 145 static int __devinit adis16060_r_probe(struct spi_device *spi)
 146 {
 147         int ret;
 148         struct adis16060_state *st;
 149         struct iio_dev *indio_dev;
 150
 151         /* setup the industrialio driver allocated elements */
 152         indio_dev = iio_allocate_device(sizeof(*st));
 153         if (indio_dev == NULL) {
 154                 ret = -ENOMEM;
 155                 goto error_ret;
 156         }
 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 = iio_device_register(indio_dev);
 171         if (ret)
 172                 goto error_free_dev;
 173
 174         adis16060_iio_dev = indio_dev;
 175         return 0;
 176
 177 error_free_dev:
 178         iio_free_device(indio_dev);
 179 error_ret:
 180         return ret;
 181 }
 182
 183 /* fixme, confirm ordering in this function */
 184 static int adis16060_r_remove(struct spi_device *spi)
 185 {
 186         iio_device_unregister(spi_get_drvdata(spi));
 187         iio_free_device(spi_get_drvdata(spi));
 188
 189         return 0;
 190 }
 191
 192 static int __devinit adis16060_w_probe(struct spi_device *spi)
 193 {
 194         int ret;
 195         struct iio_dev *indio_dev = adis16060_iio_dev;
 196         struct adis16060_state *st;
 197         if (!indio_dev) {
 198                 ret =  -ENODEV;
 199                 goto error_ret;
 200         }
 201         st = iio_priv(indio_dev);
 202         spi_set_drvdata(spi, indio_dev);
 203         st->us_w = spi;
 204         return 0;
 205
 206 error_ret:
 207         return ret;
 208 }
 209
 210 static int adis16060_w_remove(struct spi_device *spi)
 211 {
 212         return 0;
 213 }
 214
 215 static struct spi_driver adis16060_r_driver = {
 216         .driver = {
 217                 .name = "adis16060_r",
 218                 .owner = THIS_MODULE,
 219         },
 220         .probe = adis16060_r_probe,
 221         .remove = __devexit_p(adis16060_r_remove),
 222 };
 223
 224 static struct spi_driver adis16060_w_driver = {
 225         .driver = {
 226                 .name = "adis16060_w",
 227                 .owner = THIS_MODULE,
 228         },
 229         .probe = adis16060_w_probe,
 230         .remove = __devexit_p(adis16060_w_remove),
 231 };
 232
 233 static __init int adis16060_init(void)
 234 {
 235         int ret;
 236
 237         ret = spi_register_driver(&adis16060_r_driver);
 238         if (ret < 0)
 239                 return ret;
 240
 241         ret = spi_register_driver(&adis16060_w_driver);
 242         if (ret < 0) {
 243                 spi_unregister_driver(&adis16060_r_driver);
 244                 return ret;
 245         }
 246
 247         return 0;
 248 }
 249 module_init(adis16060_init);
 250
 251 static __exit void adis16060_exit(void)
 252 {
 253         spi_unregister_driver(&adis16060_w_driver);
 254         spi_unregister_driver(&adis16060_r_driver);
 255 }
 256 module_exit(adis16060_exit);
 257
 258 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 259 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
 260 MODULE_LICENSE("GPL v2");