drivers/iio/temperature/tmp007.c

   1 /*
   2  * tmp007.c - Support for TI TMP007 IR thermopile sensor with integrated math engine
   3  *
   4  * Copyright (c) 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
   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 - 0x47), changeable via ADR pins)
  13  *
  14  * Note: This driver assumes that the sensor has been calibrated beforehand
  15  *
  16  * TODO: ALERT irq, limit threshold events
  17  *
  18  */
  19
  20 #include <linux/err.h>
  21 #include <linux/i2c.h>
  22 #include <linux/delay.h>
  23 #include <linux/module.h>
  24 #include <linux/pm.h>
  25 #include <linux/bitops.h>
  26 #include <linux/of.h>
  27
  28 #include <linux/iio/iio.h>
  29 #include <linux/iio/sysfs.h>
  30
  31 #define TMP007_TDIE 0x01
  32 #define TMP007_CONFIG 0x02
  33 #define TMP007_TOBJECT 0x03
  34 #define TMP007_STATUS 0x04
  35 #define TMP007_STATUS_MASK 0x05
  36 #define TMP007_MANUFACTURER_ID 0x1e
  37 #define TMP007_DEVICE_ID 0x1f
  38
  39 #define TMP007_CONFIG_CONV_EN BIT(12)
  40 #define TMP007_CONFIG_COMP_EN BIT(5)
  41 #define TMP007_CONFIG_TC_EN BIT(6)
  42 #define TMP007_CONFIG_CR_MASK GENMASK(11, 9)
  43 #define TMP007_CONFIG_CR_SHIFT 9
  44
  45 #define TMP007_STATUS_CONV_READY BIT(14)
  46 #define TMP007_STATUS_DATA_VALID BIT(9)
  47
  48 #define TMP007_MANUFACTURER_MAGIC 0x5449
  49 #define TMP007_DEVICE_MAGIC 0x0078
  50
  51 #define TMP007_TEMP_SHIFT 2
  52
  53 struct tmp007_data {
  54         struct i2c_client *client;
  55         u16 config;
  56 };
  57
  58 static const int tmp007_avgs[5][2] = { {4, 0}, {2, 0}, {1, 0},
  59                                         {0, 500000}, {0, 250000} };
  60
  61 static int tmp007_read_temperature(struct tmp007_data *data, u8 reg)
  62 {
  63         s32 ret;
  64         int tries = 50;
  65
  66         while (tries-- > 0) {
  67                 ret = i2c_smbus_read_word_swapped(data->client,
  68                         TMP007_STATUS);
  69                 if (ret < 0)
  70                         return ret;
  71                 if ((ret & TMP007_STATUS_CONV_READY) &&
  72                         !(ret & TMP007_STATUS_DATA_VALID))
  73                                 break;
  74                 msleep(100);
  75         }
  76
  77         if (tries < 0)
  78                 return -EIO;
  79
  80         return i2c_smbus_read_word_swapped(data->client, reg);
  81 }
  82
  83 static int tmp007_powerdown(struct tmp007_data *data)
  84 {
  85         return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
  86                         data->config & ~TMP007_CONFIG_CONV_EN);
  87 }
  88
  89 static int tmp007_read_raw(struct iio_dev *indio_dev,
  90                 struct iio_chan_spec const *channel, int *val,
  91                 int *val2, long mask)
  92 {
  93         struct tmp007_data *data = iio_priv(indio_dev);
  94         s32 ret;
  95         int conv_rate;
  96
  97         switch (mask) {
  98         case IIO_CHAN_INFO_RAW:
  99                 switch (channel->channel2) {
 100                 case IIO_MOD_TEMP_AMBIENT: /* LSB: 0.03125 degree Celsius */
 101                         ret = i2c_smbus_read_word_swapped(data->client, TMP007_TDIE);
 102                         if (ret < 0)
 103                                 return ret;
 104                         break;
 105                 case IIO_MOD_TEMP_OBJECT:
 106                         ret = tmp007_read_temperature(data, TMP007_TOBJECT);
 107                         if (ret < 0)
 108                                 return ret;
 109                         break;
 110                 default:
 111                         return -EINVAL;
 112                 }
 113
 114                 *val = sign_extend32(ret, 15) >> TMP007_TEMP_SHIFT;
 115
 116                 return IIO_VAL_INT;
 117         case IIO_CHAN_INFO_SCALE:
 118                 *val = 31;
 119                 *val2 = 250000;
 120
 121                 return IIO_VAL_INT_PLUS_MICRO;
 122         case IIO_CHAN_INFO_SAMP_FREQ:
 123                 conv_rate = (data->config & TMP007_CONFIG_CR_MASK)
 124                                 >> TMP007_CONFIG_CR_SHIFT;
 125                 *val = tmp007_avgs[conv_rate][0];
 126                 *val2 = tmp007_avgs[conv_rate][1];
 127
 128                 return IIO_VAL_INT_PLUS_MICRO;
 129         default:
 130                 return -EINVAL;
 131         }
 132 }
 133
 134 static int tmp007_write_raw(struct iio_dev *indio_dev,
 135                 struct iio_chan_spec const *channel, int val,
 136                 int val2, long mask)
 137 {
 138         struct tmp007_data *data = iio_priv(indio_dev);
 139         int i;
 140         u16 tmp;
 141
 142         if (mask == IIO_CHAN_INFO_SAMP_FREQ) {
 143                 for (i = 0; i < ARRAY_SIZE(tmp007_avgs); i++) {
 144                         if ((val == tmp007_avgs[i][0]) &&
 145                         (val2 == tmp007_avgs[i][1])) {
 146                                 tmp = data->config & ~TMP007_CONFIG_CR_MASK;
 147                                 tmp |= (i << TMP007_CONFIG_CR_SHIFT);
 148
 149                                 return i2c_smbus_write_word_swapped(data->client,
 150                                                                 TMP007_CONFIG,
 151                                                                 data->config = tmp);
 152                         }
 153                 }
 154         }
 155
 156         return -EINVAL;
 157 }
 158
 159 static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
 160
 161 static struct attribute *tmp007_attributes[] = {
 162         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 163         NULL
 164 };
 165
 166 static const struct attribute_group tmp007_attribute_group = {
 167         .attrs = tmp007_attributes,
 168 };
 169
 170 static const struct iio_chan_spec tmp007_channels[] = {
 171         {
 172                 .type = IIO_TEMP,
 173                 .modified = 1,
 174                 .channel2 = IIO_MOD_TEMP_AMBIENT,
 175                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 176                                 BIT(IIO_CHAN_INFO_SCALE),
 177                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 178         },
 179         {
 180                 .type = IIO_TEMP,
 181                 .modified = 1,
 182                 .channel2 = IIO_MOD_TEMP_OBJECT,
 183                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 184                                 BIT(IIO_CHAN_INFO_SCALE),
 185                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 186         }
 187 };
 188
 189 static const struct iio_info tmp007_info = {
 190         .read_raw = tmp007_read_raw,
 191         .write_raw = tmp007_write_raw,
 192         .attrs = &tmp007_attribute_group,
 193         .driver_module = THIS_MODULE,
 194 };
 195
 196 static bool tmp007_identify(struct i2c_client *client)
 197 {
 198         int manf_id, dev_id;
 199
 200         manf_id = i2c_smbus_read_word_swapped(client, TMP007_MANUFACTURER_ID);
 201         if (manf_id < 0)
 202                 return false;
 203
 204         dev_id = i2c_smbus_read_word_swapped(client, TMP007_DEVICE_ID);
 205         if (dev_id < 0)
 206                 return false;
 207
 208         return (manf_id == TMP007_MANUFACTURER_MAGIC && dev_id == TMP007_DEVICE_MAGIC);
 209 }
 210
 211 static int tmp007_probe(struct i2c_client *client,
 212                         const struct i2c_device_id *tmp007_id)
 213 {
 214         struct tmp007_data *data;
 215         struct iio_dev *indio_dev;
 216         int ret;
 217         u16  status;
 218
 219         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 220                 return -EOPNOTSUPP;
 221
 222         if (!tmp007_identify(client)) {
 223                 dev_err(&client->dev, "TMP007 not found\n");
 224                 return -ENODEV;
 225         }
 226
 227         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 228         if (!indio_dev)
 229                 return -ENOMEM;
 230
 231         data = iio_priv(indio_dev);
 232         i2c_set_clientdata(client, indio_dev);
 233         data->client = client;
 234
 235         indio_dev->dev.parent = &client->dev;
 236         indio_dev->name = "tmp007";
 237         indio_dev->modes = INDIO_DIRECT_MODE;
 238         indio_dev->info = &tmp007_info;
 239
 240         indio_dev->channels = tmp007_channels;
 241         indio_dev->num_channels = ARRAY_SIZE(tmp007_channels);
 242
 243         /*
 244          * Set Configuration register:
 245          * 1. Conversion ON
 246          * 2. Comparator mode
 247          * 3. Transient correction enable
 248          */
 249
 250         ret = i2c_smbus_read_word_swapped(data->client, TMP007_CONFIG);
 251         if (ret < 0)
 252                 return ret;
 253
 254         data->config = ret;
 255         data->config |= (TMP007_CONFIG_CONV_EN | TMP007_CONFIG_COMP_EN | TMP007_CONFIG_TC_EN);
 256
 257         ret = i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
 258                                         data->config);
 259         if (ret < 0)
 260                 return ret;
 261
 262         /*
 263          * Set Status Mask register:
 264          * 1. Conversion ready enable
 265          * 2. Data valid enable
 266          */
 267
 268         ret = i2c_smbus_read_word_swapped(data->client, TMP007_STATUS_MASK);
 269         if (ret < 0)
 270                 goto error_powerdown;
 271
 272         status = ret;
 273         status |= (TMP007_STATUS_CONV_READY | TMP007_STATUS_DATA_VALID);
 274
 275         ret = i2c_smbus_write_word_swapped(data->client, TMP007_STATUS_MASK, status);
 276         if (ret < 0)
 277                 goto error_powerdown;
 278
 279         return iio_device_register(indio_dev);
 280
 281 error_powerdown:
 282         tmp007_powerdown(data);
 283
 284         return ret;
 285 }
 286
 287 static int tmp007_remove(struct i2c_client *client)
 288 {
 289         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 290         struct tmp007_data *data = iio_priv(indio_dev);
 291
 292         iio_device_unregister(indio_dev);
 293         tmp007_powerdown(data);
 294
 295         return 0;
 296 }
 297
 298 #ifdef CONFIG_PM_SLEEP
 299 static int tmp007_suspend(struct device *dev)
 300 {
 301         struct tmp007_data *data = iio_priv(i2c_get_clientdata(
 302                         to_i2c_client(dev)));
 303
 304         return tmp007_powerdown(data);
 305 }
 306
 307 static int tmp007_resume(struct device *dev)
 308 {
 309         struct tmp007_data *data = iio_priv(i2c_get_clientdata(
 310                         to_i2c_client(dev)));
 311
 312         return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
 313                         data->config | TMP007_CONFIG_CONV_EN);
 314 }
 315 #endif
 316
 317 static SIMPLE_DEV_PM_OPS(tmp007_pm_ops, tmp007_suspend, tmp007_resume);
 318
 319 static const struct of_device_id tmp007_of_match[] = {
 320         { .compatible = "ti,tmp007", },
 321         { },
 322 };
 323 MODULE_DEVICE_TABLE(of, tmp007_of_match);
 324
 325 static const struct i2c_device_id tmp007_id[] = {
 326         { "tmp007", 0 },
 327         { }
 328 };
 329 MODULE_DEVICE_TABLE(i2c, tmp007_id);
 330
 331 static struct i2c_driver tmp007_driver = {
 332         .driver = {
 333                 .name   = "tmp007",
 334                 .of_match_table = of_match_ptr(tmp007_of_match),
 335                 .pm     = &tmp007_pm_ops,
 336         },
 337         .probe          = tmp007_probe,
 338         .remove         = tmp007_remove,
 339         .id_table       = tmp007_id,
 340 };
 341 module_i2c_driver(tmp007_driver);
 342
 343 MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
 344 MODULE_DESCRIPTION("TI TMP007 IR thermopile sensor driver");
 345 MODULE_LICENSE("GPL");