drivers/iio/humidity/hdc100x.c

   1 /*
   2  * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
   3  *
   4  * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * Datasheets:
  17  * http://www.ti.com/product/HDC1000/datasheet
  18  * http://www.ti.com/product/HDC1008/datasheet
  19  * http://www.ti.com/product/HDC1010/datasheet
  20  * http://www.ti.com/product/HDC1050/datasheet
  21  * http://www.ti.com/product/HDC1080/datasheet
  22  */
  23
  24 #include <linux/delay.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/i2c.h>
  28
  29 #include <linux/iio/iio.h>
  30 #include <linux/iio/sysfs.h>
  31 #include <linux/iio/buffer.h>
  32 #include <linux/iio/trigger_consumer.h>
  33 #include <linux/iio/triggered_buffer.h>
  34
  35 #include <linux/time.h>
  36
  37 #define HDC100X_REG_TEMP                        0x00
  38 #define HDC100X_REG_HUMIDITY                    0x01
  39
  40 #define HDC100X_REG_CONFIG                      0x02
  41 #define HDC100X_REG_CONFIG_ACQ_MODE             BIT(12)
  42 #define HDC100X_REG_CONFIG_HEATER_EN            BIT(13)
  43
  44 struct hdc100x_data {
  45         struct i2c_client *client;
  46         struct mutex lock;
  47         u16 config;
  48
  49         /* integration time of the sensor */
  50         int adc_int_us[2];
  51         /* Ensure natural alignment of timestamp */
  52         struct {
  53                 __be16 channels[2];
  54                 s64 ts __aligned(8);
  55         } scan;
  56 };
  57
  58 /* integration time in us */
  59 static const int hdc100x_int_time[][3] = {
  60         { 6350, 3650, 0 },      /* IIO_TEMP channel*/
  61         { 6500, 3850, 2500 },   /* IIO_HUMIDITYRELATIVE channel */
  62 };
  63
  64 /* HDC100X_REG_CONFIG shift and mask values */
  65 static const struct {
  66         int shift;
  67         int mask;
  68 } hdc100x_resolution_shift[2] = {
  69         { /* IIO_TEMP channel */
  70                 .shift = 10,
  71                 .mask = 1
  72         },
  73         { /* IIO_HUMIDITYRELATIVE channel */
  74                 .shift = 8,
  75                 .mask = 3,
  76         },
  77 };
  78
  79 static IIO_CONST_ATTR(temp_integration_time_available,
  80                 "0.00365 0.00635");
  81
  82 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
  83                 "0.0025 0.00385 0.0065");
  84
  85 static IIO_CONST_ATTR(out_current_heater_raw_available,
  86                 "0 1");
  87
  88 static struct attribute *hdc100x_attributes[] = {
  89         &iio_const_attr_temp_integration_time_available.dev_attr.attr,
  90         &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
  91         &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
  92         NULL
  93 };
  94
  95 static const struct attribute_group hdc100x_attribute_group = {
  96         .attrs = hdc100x_attributes,
  97 };
  98
  99 static const struct iio_chan_spec hdc100x_channels[] = {
 100         {
 101                 .type = IIO_TEMP,
 102                 .address = HDC100X_REG_TEMP,
 103                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 104                         BIT(IIO_CHAN_INFO_SCALE) |
 105                         BIT(IIO_CHAN_INFO_INT_TIME) |
 106                         BIT(IIO_CHAN_INFO_OFFSET),
 107                 .scan_index = 0,
 108                 .scan_type = {
 109                         .sign = 's',
 110                         .realbits = 16,
 111                         .storagebits = 16,
 112                         .endianness = IIO_BE,
 113                 },
 114         },
 115         {
 116                 .type = IIO_HUMIDITYRELATIVE,
 117                 .address = HDC100X_REG_HUMIDITY,
 118                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 119                         BIT(IIO_CHAN_INFO_SCALE) |
 120                         BIT(IIO_CHAN_INFO_INT_TIME),
 121                 .scan_index = 1,
 122                 .scan_type = {
 123                         .sign = 'u',
 124                         .realbits = 16,
 125                         .storagebits = 16,
 126                         .endianness = IIO_BE,
 127                 },
 128         },
 129         {
 130                 .type = IIO_CURRENT,
 131                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 132                 .extend_name = "heater",
 133                 .output = 1,
 134                 .scan_index = -1,
 135         },
 136         IIO_CHAN_SOFT_TIMESTAMP(2),
 137 };
 138
 139 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
 140
 141 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
 142 {
 143         int tmp = (~mask & data->config) | val;
 144         int ret;
 145
 146         ret = i2c_smbus_write_word_swapped(data->client,
 147                                                 HDC100X_REG_CONFIG, tmp);
 148         if (!ret)
 149                 data->config = tmp;
 150
 151         return ret;
 152 }
 153
 154 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
 155 {
 156         int shift = hdc100x_resolution_shift[chan].shift;
 157         int ret = -EINVAL;
 158         int i;
 159
 160         for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
 161                 if (val2 && val2 == hdc100x_int_time[chan][i]) {
 162                         ret = hdc100x_update_config(data,
 163                                 hdc100x_resolution_shift[chan].mask << shift,
 164                                 i << shift);
 165                         if (!ret)
 166                                 data->adc_int_us[chan] = val2;
 167                         break;
 168                 }
 169         }
 170
 171         return ret;
 172 }
 173
 174 static int hdc100x_get_measurement(struct hdc100x_data *data,
 175                                    struct iio_chan_spec const *chan)
 176 {
 177         struct i2c_client *client = data->client;
 178         int delay = data->adc_int_us[chan->address] + 1*USEC_PER_MSEC;
 179         int ret;
 180         __be16 val;
 181
 182         /* start measurement */
 183         ret = i2c_smbus_write_byte(client, chan->address);
 184         if (ret < 0) {
 185                 dev_err(&client->dev, "cannot start measurement");
 186                 return ret;
 187         }
 188
 189         /* wait for integration time to pass */
 190         usleep_range(delay, delay + 1000);
 191
 192         /* read measurement */
 193         ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
 194         if (ret < 0) {
 195                 dev_err(&client->dev, "cannot read sensor data\n");
 196                 return ret;
 197         }
 198         return be16_to_cpu(val);
 199 }
 200
 201 static int hdc100x_get_heater_status(struct hdc100x_data *data)
 202 {
 203         return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
 204 }
 205
 206 static int hdc100x_read_raw(struct iio_dev *indio_dev,
 207                             struct iio_chan_spec const *chan, int *val,
 208                             int *val2, long mask)
 209 {
 210         struct hdc100x_data *data = iio_priv(indio_dev);
 211
 212         switch (mask) {
 213         case IIO_CHAN_INFO_RAW: {
 214                 int ret;
 215
 216                 mutex_lock(&data->lock);
 217                 if (chan->type == IIO_CURRENT) {
 218                         *val = hdc100x_get_heater_status(data);
 219                         ret = IIO_VAL_INT;
 220                 } else {
 221                         ret = iio_device_claim_direct_mode(indio_dev);
 222                         if (ret) {
 223                                 mutex_unlock(&data->lock);
 224                                 return ret;
 225                         }
 226
 227                         ret = hdc100x_get_measurement(data, chan);
 228                         iio_device_release_direct_mode(indio_dev);
 229                         if (ret >= 0) {
 230                                 *val = ret;
 231                                 ret = IIO_VAL_INT;
 232                         }
 233                 }
 234                 mutex_unlock(&data->lock);
 235                 return ret;
 236         }
 237         case IIO_CHAN_INFO_INT_TIME:
 238                 *val = 0;
 239                 *val2 = data->adc_int_us[chan->address];
 240                 return IIO_VAL_INT_PLUS_MICRO;
 241         case IIO_CHAN_INFO_SCALE:
 242                 if (chan->type == IIO_TEMP) {
 243                         *val = 165000;
 244                         *val2 = 65536;
 245                         return IIO_VAL_FRACTIONAL;
 246                 } else {
 247                         *val = 100000;
 248                         *val2 = 65536;
 249                         return IIO_VAL_FRACTIONAL;
 250                 }
 251                 break;
 252         case IIO_CHAN_INFO_OFFSET:
 253                 *val = -15887;
 254                 *val2 = 515151;
 255                 return IIO_VAL_INT_PLUS_MICRO;
 256         default:
 257                 return -EINVAL;
 258         }
 259 }
 260
 261 static int hdc100x_write_raw(struct iio_dev *indio_dev,
 262                              struct iio_chan_spec const *chan,
 263                              int val, int val2, long mask)
 264 {
 265         struct hdc100x_data *data = iio_priv(indio_dev);
 266         int ret = -EINVAL;
 267
 268         switch (mask) {
 269         case IIO_CHAN_INFO_INT_TIME:
 270                 if (val != 0)
 271                         return -EINVAL;
 272
 273                 mutex_lock(&data->lock);
 274                 ret = hdc100x_set_it_time(data, chan->address, val2);
 275                 mutex_unlock(&data->lock);
 276                 return ret;
 277         case IIO_CHAN_INFO_RAW:
 278                 if (chan->type != IIO_CURRENT || val2 != 0)
 279                         return -EINVAL;
 280
 281                 mutex_lock(&data->lock);
 282                 ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
 283                                         val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
 284                 mutex_unlock(&data->lock);
 285                 return ret;
 286         default:
 287                 return -EINVAL;
 288         }
 289 }
 290
 291 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
 292 {
 293         struct hdc100x_data *data = iio_priv(indio_dev);
 294         int ret;
 295
 296         /* Buffer is enabled. First set ACQ Mode, then attach poll func */
 297         mutex_lock(&data->lock);
 298         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
 299                                     HDC100X_REG_CONFIG_ACQ_MODE);
 300         mutex_unlock(&data->lock);
 301         if (ret)
 302                 return ret;
 303
 304         return iio_triggered_buffer_postenable(indio_dev);
 305 }
 306
 307 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
 308 {
 309         struct hdc100x_data *data = iio_priv(indio_dev);
 310         int ret;
 311
 312         /* First detach poll func, then reset ACQ mode. OK to disable buffer */
 313         ret = iio_triggered_buffer_predisable(indio_dev);
 314         if (ret)
 315                 return ret;
 316
 317         mutex_lock(&data->lock);
 318         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 319         mutex_unlock(&data->lock);
 320
 321         return ret;
 322 }
 323
 324 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 325         .postenable  = hdc100x_buffer_postenable,
 326         .predisable  = hdc100x_buffer_predisable,
 327 };
 328
 329 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 330 {
 331         struct iio_poll_func *pf = p;
 332         struct iio_dev *indio_dev = pf->indio_dev;
 333         struct hdc100x_data *data = iio_priv(indio_dev);
 334         struct i2c_client *client = data->client;
 335         int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC;
 336         int ret;
 337
 338         /* dual read starts at temp register */
 339         mutex_lock(&data->lock);
 340         ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 341         if (ret < 0) {
 342                 dev_err(&client->dev, "cannot start measurement\n");
 343                 goto err;
 344         }
 345         usleep_range(delay, delay + 1000);
 346
 347         ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4);
 348         if (ret < 0) {
 349                 dev_err(&client->dev, "cannot read sensor data\n");
 350                 goto err;
 351         }
 352
 353         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 354                                            iio_get_time_ns(indio_dev));
 355 err:
 356         mutex_unlock(&data->lock);
 357         iio_trigger_notify_done(indio_dev->trig);
 358
 359         return IRQ_HANDLED;
 360 }
 361
 362 static const struct iio_info hdc100x_info = {
 363         .read_raw = hdc100x_read_raw,
 364         .write_raw = hdc100x_write_raw,
 365         .attrs = &hdc100x_attribute_group,
 366         .driver_module = THIS_MODULE,
 367 };
 368
 369 static int hdc100x_probe(struct i2c_client *client,
 370                          const struct i2c_device_id *id)
 371 {
 372         struct iio_dev *indio_dev;
 373         struct hdc100x_data *data;
 374         int ret;
 375
 376         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
 377                                      I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 378                 return -EOPNOTSUPP;
 379
 380         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 381         if (!indio_dev)
 382                 return -ENOMEM;
 383
 384         data = iio_priv(indio_dev);
 385         i2c_set_clientdata(client, indio_dev);
 386         data->client = client;
 387         mutex_init(&data->lock);
 388
 389         indio_dev->dev.parent = &client->dev;
 390         indio_dev->name = dev_name(&client->dev);
 391         indio_dev->modes = INDIO_DIRECT_MODE;
 392         indio_dev->info = &hdc100x_info;
 393
 394         indio_dev->channels = hdc100x_channels;
 395         indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 396         indio_dev->available_scan_masks = hdc100x_scan_masks;
 397
 398         /* be sure we are in a known state */
 399         hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 400         hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 401         hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 402
 403         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 404                                          hdc100x_trigger_handler,
 405                                          &hdc_buffer_setup_ops);
 406         if (ret < 0) {
 407                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 408                 return ret;
 409         }
 410         ret = iio_device_register(indio_dev);
 411         if (ret < 0)
 412                 iio_triggered_buffer_cleanup(indio_dev);
 413
 414         return ret;
 415 }
 416
 417 static int hdc100x_remove(struct i2c_client *client)
 418 {
 419         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 420
 421         iio_device_unregister(indio_dev);
 422         iio_triggered_buffer_cleanup(indio_dev);
 423
 424         return 0;
 425 }
 426
 427 static const struct i2c_device_id hdc100x_id[] = {
 428         { "hdc100x", 0 },
 429         { "hdc1000", 0 },
 430         { "hdc1008", 0 },
 431         { "hdc1010", 0 },
 432         { "hdc1050", 0 },
 433         { "hdc1080", 0 },
 434         { }
 435 };
 436 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
 437
 438 static const struct of_device_id hdc100x_dt_ids[] = {
 439         { .compatible = "ti,hdc1000" },
 440         { .compatible = "ti,hdc1008" },
 441         { .compatible = "ti,hdc1010" },
 442         { .compatible = "ti,hdc1050" },
 443         { .compatible = "ti,hdc1080" },
 444         { }
 445 };
 446 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
 447
 448 static struct i2c_driver hdc100x_driver = {
 449         .driver = {
 450                 .name   = "hdc100x",
 451                 .of_match_table = of_match_ptr(hdc100x_dt_ids),
 452         },
 453         .probe = hdc100x_probe,
 454         .remove = hdc100x_remove,
 455         .id_table = hdc100x_id,
 456 };
 457 module_i2c_driver(hdc100x_driver);
 458
 459 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
 460 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
 461 MODULE_LICENSE("GPL");