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/delay.h>
  10 #include <linux/mutex.h>
  11 #include <linux/device.h>
  12 #include <linux/kernel.h>
  13 #include <linux/spi/spi.h>
  14 #include <linux/slab.h>
  15 #include <linux/sysfs.h>
  16
  17
  18 #include "../iio.h"
  19 #include "../sysfs.h"
  20 #include "gyro.h"
  21 #include "../adc/adc.h"
  22
  23 #define ADIS16060_GYRO          0x20 /* Measure Angular Rate (Gyro) */
  24 #define ADIS16060_TEMP_OUT      0x10 /* Measure Temperature */
  25 #define ADIS16060_AIN2          0x80 /* Measure AIN2 */
  26 #define ADIS16060_AIN1          0x40 /* Measure AIN1 */
  27
  28 /**
  29  * struct adis16060_state - device instance specific data
  30  * @us_w:               actual spi_device to write config
  31  * @us_r:               actual spi_device to read back data
  32  * @buf:                transmit or receive buffer
  33  * @buf_lock:           mutex to protect tx and rx
  34  **/
  35 struct adis16060_state {
  36         struct spi_device               *us_w;
  37         struct spi_device               *us_r;
  38         struct mutex                    buf_lock;
  39
  40         u8 buf[3] ____cacheline_aligned;
  41 };
  42
  43 static struct iio_dev *adis16060_iio_dev;
  44
  45 static int adis16060_spi_write(struct device *dev,
  46                 u8 val)
  47 {
  48         int ret;
  49         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  50         struct adis16060_state *st = iio_priv(indio_dev);
  51
  52         mutex_lock(&st->buf_lock);
  53         st->buf[2] = val; /* The last 8 bits clocked in are latched */
  54         ret = spi_write(st->us_w, st->buf, 3);
  55         mutex_unlock(&st->buf_lock);
  56
  57         return ret;
  58 }
  59
  60 static int adis16060_spi_read(struct device *dev,
  61                 u16 *val)
  62 {
  63         int ret;
  64         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  65         struct adis16060_state *st = iio_priv(indio_dev);
  66
  67         mutex_lock(&st->buf_lock);
  68
  69         ret = spi_read(st->us_r, st->buf, 3);
  70
  71         /* The internal successive approximation ADC begins the
  72          * conversion process on the falling edge of MSEL1 and
  73          * starts to place data MSB first on the DOUT line at
  74          * the 6th falling edge of SCLK
  75          */
  76         if (ret == 0)
  77                 *val = ((st->buf[0] & 0x3) << 12) |
  78                         (st->buf[1] << 4) |
  79                         ((st->buf[2] >> 4) & 0xF);
  80         mutex_unlock(&st->buf_lock);
  81
  82         return ret;
  83 }
  84
  85 static ssize_t adis16060_read(struct device *dev,
  86                 struct device_attribute *attr,
  87                 char *buf)
  88 {
  89         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
  90         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  91         u16 val = 0;
  92         ssize_t ret;
  93
  94         /* Take the iio_dev status lock */
  95         mutex_lock(&indio_dev->mlock);
  96
  97         ret = adis16060_spi_write(dev, this_attr->address);
  98         if (ret < 0)
  99                 goto error_ret;
 100         ret = adis16060_spi_read(dev, &val);
 101 error_ret:
 102         mutex_unlock(&indio_dev->mlock);
 103
 104         if (ret == 0)
 105                 return sprintf(buf, "%d\n", val);
 106         else
 107                 return ret;
 108 }
 109
 110 static IIO_DEV_ATTR_GYRO_Z(adis16060_read, ADIS16060_GYRO);
 111 static IIO_DEVICE_ATTR(temp_raw, S_IRUGO, adis16060_read, NULL,
 112                        ADIS16060_TEMP_OUT);
 113 static IIO_CONST_ATTR_TEMP_SCALE("34"); /* Milli degrees C */
 114 static IIO_CONST_ATTR_TEMP_OFFSET("-7461.117"); /* Milli degrees C */
 115 static IIO_DEV_ATTR_IN_RAW(0, adis16060_read, ADIS16060_AIN1);
 116 static IIO_DEV_ATTR_IN_RAW(1, adis16060_read, ADIS16060_AIN2);
 117 static IIO_CONST_ATTR(name, "adis16060");
 118
 119 static struct attribute *adis16060_attributes[] = {
 120         &iio_dev_attr_gyro_z_raw.dev_attr.attr,
 121         &iio_dev_attr_temp_raw.dev_attr.attr,
 122         &iio_const_attr_temp_scale.dev_attr.attr,
 123         &iio_const_attr_temp_offset.dev_attr.attr,
 124         &iio_dev_attr_in0_raw.dev_attr.attr,
 125         &iio_dev_attr_in1_raw.dev_attr.attr,
 126         &iio_const_attr_name.dev_attr.attr,
 127         NULL
 128 };
 129
 130 static const struct attribute_group adis16060_attribute_group = {
 131         .attrs = adis16060_attributes,
 132 };
 133
 134 static const struct iio_info adis16060_info = {
 135         .attrs = &adis16060_attribute_group,
 136         .driver_module = THIS_MODULE,
 137 };
 138
 139 static int __devinit adis16060_r_probe(struct spi_device *spi)
 140 {
 141         int ret, regdone = 0;
 142         struct adis16060_state *st;
 143         struct iio_dev *indio_dev;
 144
 145         /* setup the industrialio driver allocated elements */
 146         indio_dev = iio_allocate_device(sizeof(*st));
 147         if (indio_dev == NULL) {
 148                 ret = -ENOMEM;
 149                 goto error_ret;
 150         }
 151         /* this is only used for removal purposes */
 152         spi_set_drvdata(spi, indio_dev);
 153         st = iio_priv(indio_dev);
 154         st->us_r = spi;
 155         mutex_init(&st->buf_lock);
 156
 157         indio_dev->dev.parent = &spi->dev;
 158         indio_dev->info = &adis16060_info;
 159         indio_dev->modes = INDIO_DIRECT_MODE;
 160
 161         ret = iio_device_register(indio_dev);
 162         if (ret)
 163                 goto error_free_dev;
 164         regdone = 1;
 165
 166         adis16060_iio_dev = indio_dev;
 167         return 0;
 168
 169 error_free_dev:
 170         if (regdone)
 171                 iio_device_unregister(indio_dev);
 172         else
 173                 iio_free_device(indio_dev);
 174 error_ret:
 175         return ret;
 176 }
 177
 178 /* fixme, confirm ordering in this function */
 179 static int adis16060_r_remove(struct spi_device *spi)
 180 {
 181         iio_device_unregister(spi_get_drvdata(spi));
 182
 183         return 0;
 184 }
 185
 186 static int __devinit adis16060_w_probe(struct spi_device *spi)
 187 {
 188         int ret;
 189         struct iio_dev *indio_dev = adis16060_iio_dev;
 190         struct adis16060_state *st;
 191         if (!indio_dev) {
 192                 ret =  -ENODEV;
 193                 goto error_ret;
 194         }
 195         st = iio_priv(indio_dev);
 196         spi_set_drvdata(spi, indio_dev);
 197         st->us_w = spi;
 198         return 0;
 199
 200 error_ret:
 201         return ret;
 202 }
 203
 204 static int adis16060_w_remove(struct spi_device *spi)
 205 {
 206         return 0;
 207 }
 208
 209 static struct spi_driver adis16060_r_driver = {
 210         .driver = {
 211                 .name = "adis16060_r",
 212                 .owner = THIS_MODULE,
 213         },
 214         .probe = adis16060_r_probe,
 215         .remove = __devexit_p(adis16060_r_remove),
 216 };
 217
 218 static struct spi_driver adis16060_w_driver = {
 219         .driver = {
 220                 .name = "adis16060_w",
 221                 .owner = THIS_MODULE,
 222         },
 223         .probe = adis16060_w_probe,
 224         .remove = __devexit_p(adis16060_w_remove),
 225 };
 226
 227 static __init int adis16060_init(void)
 228 {
 229         int ret;
 230
 231         ret = spi_register_driver(&adis16060_r_driver);
 232         if (ret < 0)
 233                 return ret;
 234
 235         ret = spi_register_driver(&adis16060_w_driver);
 236         if (ret < 0) {
 237                 spi_unregister_driver(&adis16060_r_driver);
 238                 return ret;
 239         }
 240
 241         return 0;
 242 }
 243 module_init(adis16060_init);
 244
 245 static __exit void adis16060_exit(void)
 246 {
 247         spi_unregister_driver(&adis16060_w_driver);
 248         spi_unregister_driver(&adis16060_r_driver);
 249 }
 250 module_exit(adis16060_exit);
 251
 252 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 253 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
 254 MODULE_LICENSE("GPL v2");