drivers/iio/temperature/tmp006.c

   1 /*
   2  * tmp006.c - Support for TI TMP006 IR thermopile sensor
   3  *
   4  * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License.  See the file COPYING in the main
   8  * directory of this archive for more details.
   9  *
  10  * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
  11  *
  12  * (7-bit I2C slave address 0x40, changeable via ADR pins)
  13  *
  14  * TODO: data ready irq
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/i2c.h>
  19 #include <linux/delay.h>
  20 #include <linux/module.h>
  21 #include <linux/pm.h>
  22 #include <linux/bitops.h>
  23
  24 #include <linux/iio/iio.h>
  25 #include <linux/iio/sysfs.h>
  26
  27 #define TMP006_VOBJECT 0x00
  28 #define TMP006_TAMBIENT 0x01
  29 #define TMP006_CONFIG 0x02
  30 #define TMP006_MANUFACTURER_ID 0xfe
  31 #define TMP006_DEVICE_ID 0xff
  32
  33 #define TMP006_TAMBIENT_SHIFT 2
  34
  35 #define TMP006_CONFIG_RESET BIT(15)
  36 #define TMP006_CONFIG_DRDY_EN BIT(8)
  37 #define TMP006_CONFIG_DRDY BIT(7)
  38
  39 #define TMP006_CONFIG_MOD_MASK 0x7000
  40
  41 #define TMP006_CONFIG_CR_MASK 0x0e00
  42 #define TMP006_CONFIG_CR_SHIFT 9
  43
  44 #define MANUFACTURER_MAGIC 0x5449
  45 #define DEVICE_MAGIC 0x0067
  46
  47 struct tmp006_data {
  48         struct i2c_client *client;
  49         u16 config;
  50 };
  51
  52 static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)
  53 {
  54         s32 ret;
  55         int tries = 50;
  56
  57         while (tries-- > 0) {
  58                 ret = i2c_smbus_read_word_swapped(data->client,
  59                         TMP006_CONFIG);
  60                 if (ret < 0)
  61                         return ret;
  62                 if (ret & TMP006_CONFIG_DRDY)
  63                         break;
  64                 msleep(100);
  65         }
  66
  67         if (tries < 0)
  68                 return -EIO;
  69
  70         return i2c_smbus_read_word_swapped(data->client, reg);
  71 }
  72
  73 static int tmp006_read_raw(struct iio_dev *indio_dev,
  74                             struct iio_chan_spec const *channel, int *val,
  75                             int *val2, long mask)
  76 {
  77         struct tmp006_data *data = iio_priv(indio_dev);
  78         s32 ret;
  79
  80         switch (mask) {
  81         case IIO_CHAN_INFO_RAW:
  82                 if (channel->type == IIO_VOLTAGE) {
  83                         /* LSB is 156.25 nV */
  84                         ret = tmp006_read_measurement(data, TMP006_VOBJECT);
  85                         if (ret < 0)
  86                                 return ret;
  87                         *val = sign_extend32(ret, 15);
  88                 } else if (channel->type == IIO_TEMP) {
  89                         /* LSB is 0.03125 degrees Celsius */
  90                         ret = tmp006_read_measurement(data, TMP006_TAMBIENT);
  91                         if (ret < 0)
  92                                 return ret;
  93                         *val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;
  94                 } else {
  95                         break;
  96                 }
  97                 return IIO_VAL_INT;
  98         case IIO_CHAN_INFO_SCALE:
  99                 if (channel->type == IIO_VOLTAGE) {
 100                         *val = 0;
 101                         *val2 = 156250;
 102                 } else if (channel->type == IIO_TEMP) {
 103                         *val = 31;
 104                         *val2 = 250000;
 105                 } else {
 106                         break;
 107                 }
 108                 return IIO_VAL_INT_PLUS_MICRO;
 109         default:
 110                 break;
 111         }
 112
 113         return -EINVAL;
 114 }
 115
 116 static const char * const tmp006_freqs[] = { "4", "2", "1", "0.5", "0.25" };
 117
 118 static ssize_t tmp006_show_freq(struct device *dev,
 119                                 struct device_attribute *attr, char *buf)
 120 {
 121         struct tmp006_data *data = iio_priv(dev_to_iio_dev(dev));
 122         int cr = (data->config & TMP006_CONFIG_CR_MASK)
 123                 >> TMP006_CONFIG_CR_SHIFT;
 124         return sprintf(buf, "%s\n", tmp006_freqs[cr]);
 125 }
 126
 127 static ssize_t tmp006_store_freq(struct device *dev,
 128                                  struct device_attribute *attr,
 129                                  const char *buf, size_t len)
 130 {
 131         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 132         struct tmp006_data *data = iio_priv(indio_dev);
 133         int i;
 134         bool found = false;
 135
 136         for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)
 137                 if (sysfs_streq(buf, tmp006_freqs[i])) {
 138                         found = true;
 139                         break;
 140                 }
 141         if (!found)
 142                 return -EINVAL;
 143
 144         data->config &= ~TMP006_CONFIG_CR_MASK;
 145         data->config |= i << TMP006_CONFIG_CR_SHIFT;
 146
 147         return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 148                 data->config);
 149 }
 150
 151 static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR,
 152                         tmp006_show_freq, tmp006_store_freq);
 153
 154 static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
 155
 156 static struct attribute *tmp006_attributes[] = {
 157         &iio_dev_attr_sampling_frequency.dev_attr.attr,
 158         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 159         NULL
 160 };
 161
 162 static const struct attribute_group tmp006_attribute_group = {
 163         .attrs = tmp006_attributes,
 164 };
 165
 166 static const struct iio_chan_spec tmp006_channels[] = {
 167         {
 168                 .type = IIO_VOLTAGE,
 169                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 170                         BIT(IIO_CHAN_INFO_SCALE),
 171         },
 172         {
 173                 .type = IIO_TEMP,
 174                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 175                         BIT(IIO_CHAN_INFO_SCALE),
 176         }
 177 };
 178
 179 static const struct iio_info tmp006_info = {
 180         .read_raw = tmp006_read_raw,
 181         .attrs = &tmp006_attribute_group,
 182         .driver_module = THIS_MODULE,
 183 };
 184
 185 static bool tmp006_check_identification(struct i2c_client *client)
 186 {
 187         int mid, did;
 188
 189         mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);
 190         if (mid < 0)
 191                 return false;
 192
 193         did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);
 194         if (did < 0)
 195                 return false;
 196
 197         return mid == MANUFACTURER_MAGIC && did == DEVICE_MAGIC;
 198 }
 199
 200 static int tmp006_probe(struct i2c_client *client,
 201                          const struct i2c_device_id *id)
 202 {
 203         struct iio_dev *indio_dev;
 204         struct tmp006_data *data;
 205         int ret;
 206
 207         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 208                 return -ENODEV;
 209
 210         if (!tmp006_check_identification(client)) {
 211                 dev_err(&client->dev, "no TMP006 sensor\n");
 212                 return -ENODEV;
 213         }
 214
 215         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 216         if (!indio_dev)
 217                 return -ENOMEM;
 218
 219         data = iio_priv(indio_dev);
 220         i2c_set_clientdata(client, indio_dev);
 221         data->client = client;
 222
 223         indio_dev->dev.parent = &client->dev;
 224         indio_dev->name = dev_name(&client->dev);
 225         indio_dev->modes = INDIO_DIRECT_MODE;
 226         indio_dev->info = &tmp006_info;
 227
 228         indio_dev->channels = tmp006_channels;
 229         indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);
 230
 231         ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);
 232         if (ret < 0)
 233                 return ret;
 234         data->config = ret;
 235
 236         return iio_device_register(indio_dev);
 237 }
 238
 239 static int tmp006_powerdown(struct tmp006_data *data)
 240 {
 241         return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 242                 data->config & ~TMP006_CONFIG_MOD_MASK);
 243 }
 244
 245 static int tmp006_remove(struct i2c_client *client)
 246 {
 247         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 248
 249         iio_device_unregister(indio_dev);
 250         tmp006_powerdown(iio_priv(indio_dev));
 251
 252         return 0;
 253 }
 254
 255 #ifdef CONFIG_PM_SLEEP
 256 static int tmp006_suspend(struct device *dev)
 257 {
 258         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 259         return tmp006_powerdown(iio_priv(indio_dev));
 260 }
 261
 262 static int tmp006_resume(struct device *dev)
 263 {
 264         struct tmp006_data *data = iio_priv(i2c_get_clientdata(
 265                 to_i2c_client(dev)));
 266         return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 267                 data->config | TMP006_CONFIG_MOD_MASK);
 268 }
 269 #endif
 270
 271 static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);
 272
 273 static const struct i2c_device_id tmp006_id[] = {
 274         { "tmp006", 0 },
 275         { }
 276 };
 277 MODULE_DEVICE_TABLE(i2c, tmp006_id);
 278
 279 static struct i2c_driver tmp006_driver = {
 280         .driver = {
 281                 .name   = "tmp006",
 282                 .pm     = &tmp006_pm_ops,
 283                 .owner  = THIS_MODULE,
 284         },
 285         .probe = tmp006_probe,
 286         .remove = tmp006_remove,
 287         .id_table = tmp006_id,
 288 };
 289 module_i2c_driver(tmp006_driver);
 290
 291 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 292 MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");
 293 MODULE_LICENSE("GPL");