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  * @indio_dev:          industrial I/O device structure
  33  * @buf:                transmit or receive buffer
  34  * @buf_lock:           mutex to protect tx and rx
  35  **/
  36 struct adis16060_state {
  37         struct spi_device               *us_w;
  38         struct spi_device               *us_r;
  39         struct iio_dev                  *indio_dev;
  40         struct mutex                    buf_lock;
  41
  42         u8 buf[3] ____cacheline_aligned;
  43 };
  44
  45 static struct adis16060_state *adis16060_st;
  46
  47 static int adis16060_spi_write(struct device *dev,
  48                 u8 val)
  49 {
  50         int ret;
  51         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  52         struct adis16060_state *st = iio_dev_get_devdata(indio_dev);
  53
  54         mutex_lock(&st->buf_lock);
  55         st->buf[2] = val; /* The last 8 bits clocked in are latched */
  56         ret = spi_write(st->us_w, st->buf, 3);
  57         mutex_unlock(&st->buf_lock);
  58
  59         return ret;
  60 }
  61
  62 static int adis16060_spi_read(struct device *dev,
  63                 u16 *val)
  64 {
  65         int ret;
  66         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  67         struct adis16060_state *st = iio_dev_get_devdata(indio_dev);
  68
  69         mutex_lock(&st->buf_lock);
  70
  71         ret = spi_read(st->us_r, st->buf, 3);
  72
  73         /* The internal successive approximation ADC begins the
  74          * conversion process on the falling edge of MSEL1 and
  75          * starts to place data MSB first on the DOUT line at
  76          * the 6th falling edge of SCLK
  77          */
  78         if (ret == 0)
  79                 *val = ((st->buf[0] & 0x3) << 12) |
  80                         (st->buf[1] << 4) |
  81                         ((st->buf[2] >> 4) & 0xF);
  82         mutex_unlock(&st->buf_lock);
  83
  84         return ret;
  85 }
  86
  87 static ssize_t adis16060_read(struct device *dev,
  88                 struct device_attribute *attr,
  89                 char *buf)
  90 {
  91         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
  92         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  93         u16 val = 0;
  94         ssize_t ret;
  95
  96         /* Take the iio_dev status lock */
  97         mutex_lock(&indio_dev->mlock);
  98
  99         ret = adis16060_spi_write(dev, this_attr->address);
 100         if (ret < 0)
 101                 goto error_ret;
 102         ret = adis16060_spi_read(dev, &val);
 103 error_ret:
 104         mutex_unlock(&indio_dev->mlock);
 105
 106         if (ret == 0)
 107                 return sprintf(buf, "%d\n", val);
 108         else
 109                 return ret;
 110 }
 111
 112 static IIO_DEV_ATTR_GYRO_Z(adis16060_read, ADIS16060_GYRO);
 113 static IIO_DEVICE_ATTR(temp_raw, S_IRUGO, adis16060_read, NULL,
 114                        ADIS16060_TEMP_OUT);
 115 static IIO_CONST_ATTR_TEMP_SCALE("34"); /* Milli degrees C */
 116 static IIO_CONST_ATTR_TEMP_OFFSET("-7461.117"); /* Milli degrees C */
 117 static IIO_DEV_ATTR_IN_RAW(0, adis16060_read, ADIS16060_AIN1);
 118 static IIO_DEV_ATTR_IN_RAW(1, adis16060_read, ADIS16060_AIN2);
 119 static IIO_CONST_ATTR(name, "adis16060");
 120
 121 static struct attribute *adis16060_attributes[] = {
 122         &iio_dev_attr_gyro_z_raw.dev_attr.attr,
 123         &iio_dev_attr_temp_raw.dev_attr.attr,
 124         &iio_const_attr_temp_scale.dev_attr.attr,
 125         &iio_const_attr_temp_offset.dev_attr.attr,
 126         &iio_dev_attr_in0_raw.dev_attr.attr,
 127         &iio_dev_attr_in1_raw.dev_attr.attr,
 128         &iio_const_attr_name.dev_attr.attr,
 129         NULL
 130 };
 131
 132 static const struct attribute_group adis16060_attribute_group = {
 133         .attrs = adis16060_attributes,
 134 };
 135
 136 static int __devinit adis16060_r_probe(struct spi_device *spi)
 137 {
 138         int ret, regdone = 0;
 139         struct adis16060_state *st = kzalloc(sizeof *st, GFP_KERNEL);
 140         if (!st) {
 141                 ret =  -ENOMEM;
 142                 goto error_ret;
 143         }
 144         /* this is only used for removal purposes */
 145         spi_set_drvdata(spi, st);
 146
 147         st->us_r = spi;
 148         mutex_init(&st->buf_lock);
 149         /* setup the industrialio driver allocated elements */
 150         st->indio_dev = iio_allocate_device();
 151         if (st->indio_dev == NULL) {
 152                 ret = -ENOMEM;
 153                 goto error_free_st;
 154         }
 155
 156         st->indio_dev->dev.parent = &spi->dev;
 157         st->indio_dev->attrs = &adis16060_attribute_group;
 158         st->indio_dev->dev_data = (void *)(st);
 159         st->indio_dev->driver_module = THIS_MODULE;
 160         st->indio_dev->modes = INDIO_DIRECT_MODE;
 161
 162         ret = iio_device_register(st->indio_dev);
 163         if (ret)
 164                 goto error_free_dev;
 165         regdone = 1;
 166
 167         adis16060_st = st;
 168         return 0;
 169
 170 error_free_dev:
 171         if (regdone)
 172                 iio_device_unregister(st->indio_dev);
 173         else
 174                 iio_free_device(st->indio_dev);
 175 error_free_st:
 176         kfree(st);
 177 error_ret:
 178         return ret;
 179 }
 180
 181 /* fixme, confirm ordering in this function */
 182 static int adis16060_r_remove(struct spi_device *spi)
 183 {
 184         struct adis16060_state *st = spi_get_drvdata(spi);
 185         struct iio_dev *indio_dev = st->indio_dev;
 186
 187         iio_device_unregister(indio_dev);
 188         kfree(st);
 189
 190         return 0;
 191 }
 192
 193 static int __devinit adis16060_w_probe(struct spi_device *spi)
 194 {
 195         int ret;
 196         struct adis16060_state *st = adis16060_st;
 197         if (!st) {
 198                 ret =  -ENODEV;
 199                 goto error_ret;
 200         }
 201         spi_set_drvdata(spi, st);
 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");