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 #define HDC100X_REG_TEMP                        0x00
  36 #define HDC100X_REG_HUMIDITY                    0x01
  37
  38 #define HDC100X_REG_CONFIG                      0x02
  39 #define HDC100X_REG_CONFIG_ACQ_MODE             BIT(12)
  40 #define HDC100X_REG_CONFIG_HEATER_EN            BIT(13)
  41
  42 struct hdc100x_data {
  43         struct i2c_client *client;
  44         struct mutex lock;
  45         u16 config;
  46
  47         /* integration time of the sensor */
  48         int adc_int_us[2];
  49 };
  50
  51 /* integration time in us */
  52 static const int hdc100x_int_time[][3] = {
  53         { 6350, 3650, 0 },      /* IIO_TEMP channel*/
  54         { 6500, 3850, 2500 },   /* IIO_HUMIDITYRELATIVE channel */
  55 };
  56
  57 /* HDC100X_REG_CONFIG shift and mask values */
  58 static const struct {
  59         int shift;
  60         int mask;
  61 } hdc100x_resolution_shift[2] = {
  62         { /* IIO_TEMP channel */
  63                 .shift = 10,
  64                 .mask = 1
  65         },
  66         { /* IIO_HUMIDITYRELATIVE channel */
  67                 .shift = 8,
  68                 .mask = 3,
  69         },
  70 };
  71
  72 static IIO_CONST_ATTR(temp_integration_time_available,
  73                 "0.00365 0.00635");
  74
  75 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
  76                 "0.0025 0.00385 0.0065");
  77
  78 static IIO_CONST_ATTR(out_current_heater_raw_available,
  79                 "0 1");
  80
  81 static struct attribute *hdc100x_attributes[] = {
  82         &iio_const_attr_temp_integration_time_available.dev_attr.attr,
  83         &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
  84         &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
  85         NULL
  86 };
  87
  88 static const struct attribute_group hdc100x_attribute_group = {
  89         .attrs = hdc100x_attributes,
  90 };
  91
  92 static const struct iio_chan_spec hdc100x_channels[] = {
  93         {
  94                 .type = IIO_TEMP,
  95                 .address = HDC100X_REG_TEMP,
  96                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  97                         BIT(IIO_CHAN_INFO_SCALE) |
  98                         BIT(IIO_CHAN_INFO_INT_TIME) |
  99                         BIT(IIO_CHAN_INFO_OFFSET),
 100                 .scan_index = 0,
 101                 .scan_type = {
 102                         .sign = 's',
 103                         .realbits = 16,
 104                         .storagebits = 16,
 105                         .endianness = IIO_BE,
 106                 },
 107         },
 108         {
 109                 .type = IIO_HUMIDITYRELATIVE,
 110                 .address = HDC100X_REG_HUMIDITY,
 111                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 112                         BIT(IIO_CHAN_INFO_SCALE) |
 113                         BIT(IIO_CHAN_INFO_INT_TIME),
 114                 .scan_index = 1,
 115                 .scan_type = {
 116                         .sign = 'u',
 117                         .realbits = 16,
 118                         .storagebits = 16,
 119                         .endianness = IIO_BE,
 120                 },
 121         },
 122         {
 123                 .type = IIO_CURRENT,
 124                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 125                 .extend_name = "heater",
 126                 .output = 1,
 127                 .scan_index = -1,
 128         },
 129         IIO_CHAN_SOFT_TIMESTAMP(2),
 130 };
 131
 132 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
 133
 134 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
 135 {
 136         int tmp = (~mask & data->config) | val;
 137         int ret;
 138
 139         ret = i2c_smbus_write_word_swapped(data->client,
 140                                                 HDC100X_REG_CONFIG, tmp);
 141         if (!ret)
 142                 data->config = tmp;
 143
 144         return ret;
 145 }
 146
 147 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
 148 {
 149         int shift = hdc100x_resolution_shift[chan].shift;
 150         int ret = -EINVAL;
 151         int i;
 152
 153         for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
 154                 if (val2 && val2 == hdc100x_int_time[chan][i]) {
 155                         ret = hdc100x_update_config(data,
 156                                 hdc100x_resolution_shift[chan].mask << shift,
 157                                 i << shift);
 158                         if (!ret)
 159                                 data->adc_int_us[chan] = val2;
 160                         break;
 161                 }
 162         }
 163
 164         return ret;
 165 }
 166
 167 static int hdc100x_get_measurement(struct hdc100x_data *data,
 168                                    struct iio_chan_spec const *chan)
 169 {
 170         struct i2c_client *client = data->client;
 171         int delay = data->adc_int_us[chan->address];
 172         int ret;
 173         __be16 val;
 174
 175         /* start measurement */
 176         ret = i2c_smbus_write_byte(client, chan->address);
 177         if (ret < 0) {
 178                 dev_err(&client->dev, "cannot start measurement");
 179                 return ret;
 180         }
 181
 182         /* wait for integration time to pass */
 183         usleep_range(delay, delay + 1000);
 184
 185         /* read measurement */
 186         ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
 187         if (ret < 0) {
 188                 dev_err(&client->dev, "cannot read sensor data\n");
 189                 return ret;
 190         }
 191         return be16_to_cpu(val);
 192 }
 193
 194 static int hdc100x_get_heater_status(struct hdc100x_data *data)
 195 {
 196         return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
 197 }
 198
 199 static int hdc100x_read_raw(struct iio_dev *indio_dev,
 200                             struct iio_chan_spec const *chan, int *val,
 201                             int *val2, long mask)
 202 {
 203         struct hdc100x_data *data = iio_priv(indio_dev);
 204
 205         switch (mask) {
 206         case IIO_CHAN_INFO_RAW: {
 207                 int ret;
 208
 209                 mutex_lock(&data->lock);
 210                 if (chan->type == IIO_CURRENT) {
 211                         *val = hdc100x_get_heater_status(data);
 212                         ret = IIO_VAL_INT;
 213                 } else {
 214                         ret = iio_device_claim_direct_mode(indio_dev);
 215                         if (ret) {
 216                                 mutex_unlock(&data->lock);
 217                                 return ret;
 218                         }
 219
 220                         ret = hdc100x_get_measurement(data, chan);
 221                         iio_device_release_direct_mode(indio_dev);
 222                         if (ret >= 0) {
 223                                 *val = ret;
 224                                 ret = IIO_VAL_INT;
 225                         }
 226                 }
 227                 mutex_unlock(&data->lock);
 228                 return ret;
 229         }
 230         case IIO_CHAN_INFO_INT_TIME:
 231                 *val = 0;
 232                 *val2 = data->adc_int_us[chan->address];
 233                 return IIO_VAL_INT_PLUS_MICRO;
 234         case IIO_CHAN_INFO_SCALE:
 235                 if (chan->type == IIO_TEMP) {
 236                         *val = 165000;
 237                         *val2 = 65536;
 238                         return IIO_VAL_FRACTIONAL;
 239                 } else {
 240                         *val = 100;
 241                         *val2 = 65536;
 242                         return IIO_VAL_FRACTIONAL;
 243                 }
 244                 break;
 245         case IIO_CHAN_INFO_OFFSET:
 246                 *val = -15887;
 247                 *val2 = 515151;
 248                 return IIO_VAL_INT_PLUS_MICRO;
 249         default:
 250                 return -EINVAL;
 251         }
 252 }
 253
 254 static int hdc100x_write_raw(struct iio_dev *indio_dev,
 255                              struct iio_chan_spec const *chan,
 256                              int val, int val2, long mask)
 257 {
 258         struct hdc100x_data *data = iio_priv(indio_dev);
 259         int ret = -EINVAL;
 260
 261         switch (mask) {
 262         case IIO_CHAN_INFO_INT_TIME:
 263                 if (val != 0)
 264                         return -EINVAL;
 265
 266                 mutex_lock(&data->lock);
 267                 ret = hdc100x_set_it_time(data, chan->address, val2);
 268                 mutex_unlock(&data->lock);
 269                 return ret;
 270         case IIO_CHAN_INFO_RAW:
 271                 if (chan->type != IIO_CURRENT || val2 != 0)
 272                         return -EINVAL;
 273
 274                 mutex_lock(&data->lock);
 275                 ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
 276                                         val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
 277                 mutex_unlock(&data->lock);
 278                 return ret;
 279         default:
 280                 return -EINVAL;
 281         }
 282 }
 283
 284 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
 285 {
 286         struct hdc100x_data *data = iio_priv(indio_dev);
 287         int ret;
 288
 289         /* Buffer is enabled. First set ACQ Mode, then attach poll func */
 290         mutex_lock(&data->lock);
 291         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
 292                                     HDC100X_REG_CONFIG_ACQ_MODE);
 293         mutex_unlock(&data->lock);
 294         if (ret)
 295                 return ret;
 296
 297         return iio_triggered_buffer_postenable(indio_dev);
 298 }
 299
 300 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
 301 {
 302         struct hdc100x_data *data = iio_priv(indio_dev);
 303         int ret;
 304
 305         /* First detach poll func, then reset ACQ mode. OK to disable buffer */
 306         ret = iio_triggered_buffer_predisable(indio_dev);
 307         if (ret)
 308                 return ret;
 309
 310         mutex_lock(&data->lock);
 311         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 312         mutex_unlock(&data->lock);
 313
 314         return ret;
 315 }
 316
 317 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 318         .postenable  = hdc100x_buffer_postenable,
 319         .predisable  = hdc100x_buffer_predisable,
 320 };
 321
 322 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 323 {
 324         struct iio_poll_func *pf = p;
 325         struct iio_dev *indio_dev = pf->indio_dev;
 326         struct hdc100x_data *data = iio_priv(indio_dev);
 327         struct i2c_client *client = data->client;
 328         int delay = data->adc_int_us[0] + data->adc_int_us[1];
 329         int ret;
 330         s16 buf[8];  /* 2x s16 + padding + 8 byte timestamp */
 331
 332         /* dual read starts at temp register */
 333         mutex_lock(&data->lock);
 334         ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 335         if (ret < 0) {
 336                 dev_err(&client->dev, "cannot start measurement\n");
 337                 goto err;
 338         }
 339         usleep_range(delay, delay + 1000);
 340
 341         ret = i2c_master_recv(client, (u8 *)buf, 4);
 342         if (ret < 0) {
 343                 dev_err(&client->dev, "cannot read sensor data\n");
 344                 goto err;
 345         }
 346
 347         iio_push_to_buffers_with_timestamp(indio_dev, buf,
 348                                            iio_get_time_ns(indio_dev));
 349 err:
 350         mutex_unlock(&data->lock);
 351         iio_trigger_notify_done(indio_dev->trig);
 352
 353         return IRQ_HANDLED;
 354 }
 355
 356 static const struct iio_info hdc100x_info = {
 357         .read_raw = hdc100x_read_raw,
 358         .write_raw = hdc100x_write_raw,
 359         .attrs = &hdc100x_attribute_group,
 360 };
 361
 362 static int hdc100x_probe(struct i2c_client *client,
 363                          const struct i2c_device_id *id)
 364 {
 365         struct iio_dev *indio_dev;
 366         struct hdc100x_data *data;
 367         int ret;
 368
 369         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
 370                                      I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 371                 return -EOPNOTSUPP;
 372
 373         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 374         if (!indio_dev)
 375                 return -ENOMEM;
 376
 377         data = iio_priv(indio_dev);
 378         i2c_set_clientdata(client, indio_dev);
 379         data->client = client;
 380         mutex_init(&data->lock);
 381
 382         indio_dev->dev.parent = &client->dev;
 383         indio_dev->name = dev_name(&client->dev);
 384         indio_dev->modes = INDIO_DIRECT_MODE;
 385         indio_dev->info = &hdc100x_info;
 386
 387         indio_dev->channels = hdc100x_channels;
 388         indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 389         indio_dev->available_scan_masks = hdc100x_scan_masks;
 390
 391         /* be sure we are in a known state */
 392         hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 393         hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 394         hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 395
 396         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 397                                          hdc100x_trigger_handler,
 398                                          &hdc_buffer_setup_ops);
 399         if (ret < 0) {
 400                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 401                 return ret;
 402         }
 403         ret = iio_device_register(indio_dev);
 404         if (ret < 0)
 405                 iio_triggered_buffer_cleanup(indio_dev);
 406
 407         return ret;
 408 }
 409
 410 static int hdc100x_remove(struct i2c_client *client)
 411 {
 412         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 413
 414         iio_device_unregister(indio_dev);
 415         iio_triggered_buffer_cleanup(indio_dev);
 416
 417         return 0;
 418 }
 419
 420 static const struct i2c_device_id hdc100x_id[] = {
 421         { "hdc100x", 0 },
 422         { "hdc1000", 0 },
 423         { "hdc1008", 0 },
 424         { "hdc1010", 0 },
 425         { "hdc1050", 0 },
 426         { "hdc1080", 0 },
 427         { }
 428 };
 429 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
 430
 431 static const struct of_device_id hdc100x_dt_ids[] = {
 432         { .compatible = "ti,hdc1000" },
 433         { .compatible = "ti,hdc1008" },
 434         { .compatible = "ti,hdc1010" },
 435         { .compatible = "ti,hdc1050" },
 436         { .compatible = "ti,hdc1080" },
 437         { }
 438 };
 439 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
 440
 441 static struct i2c_driver hdc100x_driver = {
 442         .driver = {
 443                 .name   = "hdc100x",
 444                 .of_match_table = of_match_ptr(hdc100x_dt_ids),
 445         },
 446         .probe = hdc100x_probe,
 447         .remove = hdc100x_remove,
 448         .id_table = hdc100x_id,
 449 };
 450 module_i2c_driver(hdc100x_driver);
 451
 452 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
 453 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
 454 MODULE_LICENSE("GPL");