drivers/staging/iio/gyro/adis16130_core.c

   1 /*
   2  * ADIS16130 Digital Output, High Precision Angular Rate Sensor 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 #include <linux/list.h>
  17
  18 #include "../iio.h"
  19 #include "../sysfs.h"
  20 #include "gyro.h"
  21 #include "../adc/adc.h"
  22
  23 #define ADIS16130_CON         0x0
  24 #define ADIS16130_CON_RD      (1 << 6)
  25 #define ADIS16130_IOP         0x1
  26
  27 /* 1 = data-ready signal low when unread data on all channels; */
  28 #define ADIS16130_IOP_ALL_RDY (1 << 3)
  29 #define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
  30 #define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
  31 #define ADIS16130_TEMPDATA    0xA /* Temperature output */
  32 #define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
  33 #define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
  34 #define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
  35 #define ADIS16130_TEMPCS_EN   (1 << 3)
  36 #define ADIS16130_RATECONV    0x30
  37 #define ADIS16130_TEMPCONV    0x32
  38 #define ADIS16130_MODE        0x38
  39 #define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
  40
  41 /**
  42  * struct adis16130_state - device instance specific data
  43  * @us:                 actual spi_device to write data
  44  * @indio_dev:          industrial I/O device structure
  45  * @mode:               24 bits (1) or 16 bits (0)
  46  * @buf_lock:           mutex to protect tx and rx
  47  * @buf:                unified tx/rx buffer
  48  **/
  49 struct adis16130_state {
  50         struct spi_device               *us;
  51         struct iio_dev                  *indio_dev;
  52         u32                             mode;
  53         struct mutex                    buf_lock;
  54         u8                              buf[4] ____cacheline_aligned;
  55 };
  56
  57 static int adis16130_spi_write(struct device *dev, u8 reg_addr,
  58                 u8 val)
  59 {
  60         int ret;
  61         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  62         struct adis16130_state *st = iio_dev_get_devdata(indio_dev);
  63
  64         mutex_lock(&st->buf_lock);
  65         st->buf[0] = reg_addr;
  66         st->buf[1] = val;
  67
  68         ret = spi_write(st->us, st->buf, 2);
  69         mutex_unlock(&st->buf_lock);
  70
  71         return ret;
  72 }
  73
  74 static int adis16130_spi_read(struct device *dev, u8 reg_addr,
  75                 u32 *val)
  76 {
  77         int ret;
  78         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  79         struct adis16130_state *st = iio_dev_get_devdata(indio_dev);
  80
  81         mutex_lock(&st->buf_lock);
  82
  83         st->buf[0] = ADIS16130_CON_RD | reg_addr;
  84         if (st->mode)
  85                 ret = spi_read(st->us, st->buf, 4);
  86         else
  87                 ret = spi_read(st->us, st->buf, 3);
  88
  89         if (ret == 0) {
  90                 if (st->mode)
  91                         *val = (st->buf[1] << 16) |
  92                                 (st->buf[2] << 8) |
  93                                 st->buf[3];
  94                 else
  95                         *val = (st->buf[1] << 8) | st->buf[2];
  96         }
  97
  98         mutex_unlock(&st->buf_lock);
  99
 100         return ret;
 101 }
 102
 103 static ssize_t adis16130_val_read(struct device *dev,
 104                 struct device_attribute *attr,
 105                 char *buf)
 106 {
 107         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 108         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 109         u32 val;
 110         ssize_t ret;
 111
 112         /* Take the iio_dev status lock */
 113         mutex_lock(&indio_dev->mlock);
 114         ret =  adis16130_spi_read(dev, this_attr->address, &val);
 115         mutex_unlock(&indio_dev->mlock);
 116
 117         if (ret == 0)
 118                 return sprintf(buf, "%d\n", val);
 119         else
 120                 return ret;
 121 }
 122
 123 static ssize_t adis16130_bitsmode_read(struct device *dev,
 124                 struct device_attribute *attr,
 125                 char *buf)
 126 {
 127         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 128         struct adis16130_state *st = iio_dev_get_devdata(indio_dev);
 129
 130         if (st->mode == 1)
 131                 return sprintf(buf, "s24\n");
 132         else
 133                 return sprintf(buf, "s16\n");
 134 }
 135
 136 static ssize_t adis16130_bitsmode_write(struct device *dev,
 137                 struct device_attribute *attr,
 138                 const char *buf,
 139                 size_t len)
 140 {
 141         int ret;
 142         u8 val;
 143
 144         if (sysfs_streq(buf, "s16"))
 145                 val = 0;
 146         else if (sysfs_streq(buf, "s24"))
 147                 val = 1;
 148         else
 149                 return -EINVAL;
 150
 151         ret = adis16130_spi_write(dev, ADIS16130_MODE, val);
 152
 153         return ret ? ret : len;
 154 }
 155 static IIO_DEVICE_ATTR(temp_raw, S_IRUGO, adis16130_val_read, NULL,
 156                       ADIS16130_TEMPDATA);
 157
 158 static IIO_DEV_ATTR_GYRO_Z(adis16130_val_read, ADIS16130_RATEDATA);
 159
 160 static IIO_DEVICE_ATTR(gyro_z_type, S_IWUSR | S_IRUGO, adis16130_bitsmode_read,
 161                         adis16130_bitsmode_write,
 162                         ADIS16130_MODE);
 163
 164 static IIO_CONST_ATTR(gyro_z_type_available, "s16 s24");
 165
 166 static struct attribute *adis16130_attributes[] = {
 167         &iio_dev_attr_temp_raw.dev_attr.attr,
 168         &iio_dev_attr_gyro_z_raw.dev_attr.attr,
 169         &iio_dev_attr_gyro_z_type.dev_attr.attr,
 170         &iio_const_attr_gyro_z_type_available.dev_attr.attr,
 171         NULL
 172 };
 173
 174 static const struct attribute_group adis16130_attribute_group = {
 175         .attrs = adis16130_attributes,
 176 };
 177
 178 static int __devinit adis16130_probe(struct spi_device *spi)
 179 {
 180         int ret;
 181         struct adis16130_state *st = kzalloc(sizeof *st, GFP_KERNEL);
 182         if (!st) {
 183                 ret =  -ENOMEM;
 184                 goto error_ret;
 185         }
 186         /* this is only used for removal purposes */
 187         spi_set_drvdata(spi, st);
 188         st->us = spi;
 189         mutex_init(&st->buf_lock);
 190         /* setup the industrialio driver allocated elements */
 191         st->indio_dev = iio_allocate_device(0);
 192         if (st->indio_dev == NULL) {
 193                 ret = -ENOMEM;
 194                 goto error_free_st;
 195         }
 196
 197         st->indio_dev->name = spi->dev.driver->name;
 198         st->indio_dev->dev.parent = &spi->dev;
 199         st->indio_dev->attrs = &adis16130_attribute_group;
 200         st->indio_dev->dev_data = (void *)(st);
 201         st->indio_dev->driver_module = THIS_MODULE;
 202         st->indio_dev->modes = INDIO_DIRECT_MODE;
 203         st->mode = 1;
 204
 205         ret = iio_device_register(st->indio_dev);
 206         if (ret)
 207                 goto error_free_dev;
 208
 209         return 0;
 210
 211 error_free_dev:
 212         iio_free_device(st->indio_dev);
 213 error_free_st:
 214         kfree(st);
 215 error_ret:
 216         return ret;
 217 }
 218
 219 /* fixme, confirm ordering in this function */
 220 static int adis16130_remove(struct spi_device *spi)
 221 {
 222         struct adis16130_state *st = spi_get_drvdata(spi);
 223         struct iio_dev *indio_dev = st->indio_dev;
 224
 225         iio_device_unregister(indio_dev);
 226         kfree(st);
 227
 228         return 0;
 229 }
 230
 231 static struct spi_driver adis16130_driver = {
 232         .driver = {
 233                 .name = "adis16130",
 234                 .owner = THIS_MODULE,
 235         },
 236         .probe = adis16130_probe,
 237         .remove = __devexit_p(adis16130_remove),
 238 };
 239
 240 static __init int adis16130_init(void)
 241 {
 242         return spi_register_driver(&adis16130_driver);
 243 }
 244 module_init(adis16130_init);
 245
 246 static __exit void adis16130_exit(void)
 247 {
 248         spi_unregister_driver(&adis16130_driver);
 249 }
 250 module_exit(adis16130_exit);
 251
 252 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 253 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
 254 MODULE_LICENSE("GPL v2");