drivers/iio/humidity/hdc100x.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
   4  *
   5  * Copyright (C) 2015, 2018
   6  * Author: Matt Ranostay <[email protected]>
   7  *
   8  * Datasheets:
   9  * https://www.ti.com/product/HDC1000/datasheet
  10  * https://www.ti.com/product/HDC1008/datasheet
  11  * https://www.ti.com/product/HDC1010/datasheet
  12  * https://www.ti.com/product/HDC1050/datasheet
  13  * https://www.ti.com/product/HDC1080/datasheet
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/module.h>
  18 #include <linux/mod_devicetable.h>
  19 #include <linux/init.h>
  20 #include <linux/i2c.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24 #include <linux/iio/buffer.h>
  25 #include <linux/iio/trigger_consumer.h>
  26 #include <linux/iio/triggered_buffer.h>
  27
  28 #define HDC100X_REG_TEMP                        0x00
  29 #define HDC100X_REG_HUMIDITY                    0x01
  30
  31 #define HDC100X_REG_CONFIG                      0x02
  32 #define HDC100X_REG_CONFIG_ACQ_MODE             BIT(12)
  33 #define HDC100X_REG_CONFIG_HEATER_EN            BIT(13)
  34
  35 struct hdc100x_data {
  36         struct i2c_client *client;
  37         struct mutex lock;
  38         u16 config;
  39
  40         /* integration time of the sensor */
  41         int adc_int_us[2];
  42         /* Ensure natural alignment of timestamp */
  43         struct {
  44                 __be16 channels[2];
  45                 s64 ts __aligned(8);
  46         } scan;
  47 };
  48
  49 /* integration time in us */
  50 static const int hdc100x_int_time[][3] = {
  51         { 6350, 3650, 0 },      /* IIO_TEMP channel*/
  52         { 6500, 3850, 2500 },   /* IIO_HUMIDITYRELATIVE channel */
  53 };
  54
  55 /* HDC100X_REG_CONFIG shift and mask values */
  56 static const struct {
  57         int shift;
  58         int mask;
  59 } hdc100x_resolution_shift[2] = {
  60         { /* IIO_TEMP channel */
  61                 .shift = 10,
  62                 .mask = 1
  63         },
  64         { /* IIO_HUMIDITYRELATIVE channel */
  65                 .shift = 8,
  66                 .mask = 3,
  67         },
  68 };
  69
  70 static IIO_CONST_ATTR(temp_integration_time_available,
  71                 "0.00365 0.00635");
  72
  73 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
  74                 "0.0025 0.00385 0.0065");
  75
  76 static IIO_CONST_ATTR(out_current_heater_raw_available,
  77                 "0 1");
  78
  79 static struct attribute *hdc100x_attributes[] = {
  80         &iio_const_attr_temp_integration_time_available.dev_attr.attr,
  81         &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
  82         &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
  83         NULL
  84 };
  85
  86 static const struct attribute_group hdc100x_attribute_group = {
  87         .attrs = hdc100x_attributes,
  88 };
  89
  90 static const struct iio_chan_spec hdc100x_channels[] = {
  91         {
  92                 .type = IIO_TEMP,
  93                 .address = HDC100X_REG_TEMP,
  94                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  95                         BIT(IIO_CHAN_INFO_SCALE) |
  96                         BIT(IIO_CHAN_INFO_INT_TIME) |
  97                         BIT(IIO_CHAN_INFO_OFFSET),
  98                 .scan_index = 0,
  99                 .scan_type = {
 100                         .sign = 's',
 101                         .realbits = 16,
 102                         .storagebits = 16,
 103                         .endianness = IIO_BE,
 104                 },
 105         },
 106         {
 107                 .type = IIO_HUMIDITYRELATIVE,
 108                 .address = HDC100X_REG_HUMIDITY,
 109                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 110                         BIT(IIO_CHAN_INFO_SCALE) |
 111                         BIT(IIO_CHAN_INFO_INT_TIME),
 112                 .scan_index = 1,
 113                 .scan_type = {
 114                         .sign = 'u',
 115                         .realbits = 16,
 116                         .storagebits = 16,
 117                         .endianness = IIO_BE,
 118                 },
 119         },
 120         {
 121                 .type = IIO_CURRENT,
 122                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 123                 .extend_name = "heater",
 124                 .output = 1,
 125                 .scan_index = -1,
 126         },
 127         IIO_CHAN_SOFT_TIMESTAMP(2),
 128 };
 129
 130 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
 131
 132 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
 133 {
 134         int tmp = (~mask & data->config) | val;
 135         int ret;
 136
 137         ret = i2c_smbus_write_word_swapped(data->client,
 138                                                 HDC100X_REG_CONFIG, tmp);
 139         if (!ret)
 140                 data->config = tmp;
 141
 142         return ret;
 143 }
 144
 145 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
 146 {
 147         int shift = hdc100x_resolution_shift[chan].shift;
 148         int ret = -EINVAL;
 149         int i;
 150
 151         for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
 152                 if (val2 && val2 == hdc100x_int_time[chan][i]) {
 153                         ret = hdc100x_update_config(data,
 154                                 hdc100x_resolution_shift[chan].mask << shift,
 155                                 i << shift);
 156                         if (!ret)
 157                                 data->adc_int_us[chan] = val2;
 158                         break;
 159                 }
 160         }
 161
 162         return ret;
 163 }
 164
 165 static int hdc100x_get_measurement(struct hdc100x_data *data,
 166                                    struct iio_chan_spec const *chan)
 167 {
 168         struct i2c_client *client = data->client;
 169         int delay = data->adc_int_us[chan->address];
 170         int ret;
 171         __be16 val;
 172
 173         /* start measurement */
 174         ret = i2c_smbus_write_byte(client, chan->address);
 175         if (ret < 0) {
 176                 dev_err(&client->dev, "cannot start measurement");
 177                 return ret;
 178         }
 179
 180         /* wait for integration time to pass */
 181         usleep_range(delay, delay + 1000);
 182
 183         /* read measurement */
 184         ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
 185         if (ret < 0) {
 186                 dev_err(&client->dev, "cannot read sensor data\n");
 187                 return ret;
 188         }
 189         return be16_to_cpu(val);
 190 }
 191
 192 static int hdc100x_get_heater_status(struct hdc100x_data *data)
 193 {
 194         return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
 195 }
 196
 197 static int hdc100x_read_raw(struct iio_dev *indio_dev,
 198                             struct iio_chan_spec const *chan, int *val,
 199                             int *val2, long mask)
 200 {
 201         struct hdc100x_data *data = iio_priv(indio_dev);
 202
 203         switch (mask) {
 204         case IIO_CHAN_INFO_RAW: {
 205                 int ret;
 206
 207                 mutex_lock(&data->lock);
 208                 if (chan->type == IIO_CURRENT) {
 209                         *val = hdc100x_get_heater_status(data);
 210                         ret = IIO_VAL_INT;
 211                 } else {
 212                         ret = iio_device_claim_direct_mode(indio_dev);
 213                         if (ret) {
 214                                 mutex_unlock(&data->lock);
 215                                 return ret;
 216                         }
 217
 218                         ret = hdc100x_get_measurement(data, chan);
 219                         iio_device_release_direct_mode(indio_dev);
 220                         if (ret >= 0) {
 221                                 *val = ret;
 222                                 ret = IIO_VAL_INT;
 223                         }
 224                 }
 225                 mutex_unlock(&data->lock);
 226                 return ret;
 227         }
 228         case IIO_CHAN_INFO_INT_TIME:
 229                 *val = 0;
 230                 *val2 = data->adc_int_us[chan->address];
 231                 return IIO_VAL_INT_PLUS_MICRO;
 232         case IIO_CHAN_INFO_SCALE:
 233                 if (chan->type == IIO_TEMP) {
 234                         *val = 165000;
 235                         *val2 = 65536;
 236                         return IIO_VAL_FRACTIONAL;
 237                 } else {
 238                         *val = 100000;
 239                         *val2 = 65536;
 240                         return IIO_VAL_FRACTIONAL;
 241                 }
 242                 break;
 243         case IIO_CHAN_INFO_OFFSET:
 244                 *val = -15887;
 245                 *val2 = 515151;
 246                 return IIO_VAL_INT_PLUS_MICRO;
 247         default:
 248                 return -EINVAL;
 249         }
 250 }
 251
 252 static int hdc100x_write_raw(struct iio_dev *indio_dev,
 253                              struct iio_chan_spec const *chan,
 254                              int val, int val2, long mask)
 255 {
 256         struct hdc100x_data *data = iio_priv(indio_dev);
 257         int ret = -EINVAL;
 258
 259         switch (mask) {
 260         case IIO_CHAN_INFO_INT_TIME:
 261                 if (val != 0)
 262                         return -EINVAL;
 263
 264                 mutex_lock(&data->lock);
 265                 ret = hdc100x_set_it_time(data, chan->address, val2);
 266                 mutex_unlock(&data->lock);
 267                 return ret;
 268         case IIO_CHAN_INFO_RAW:
 269                 if (chan->type != IIO_CURRENT || val2 != 0)
 270                         return -EINVAL;
 271
 272                 mutex_lock(&data->lock);
 273                 ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
 274                                         val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
 275                 mutex_unlock(&data->lock);
 276                 return ret;
 277         default:
 278                 return -EINVAL;
 279         }
 280 }
 281
 282 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
 283 {
 284         struct hdc100x_data *data = iio_priv(indio_dev);
 285         int ret;
 286
 287         /* Buffer is enabled. First set ACQ Mode, then attach poll func */
 288         mutex_lock(&data->lock);
 289         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
 290                                     HDC100X_REG_CONFIG_ACQ_MODE);
 291         mutex_unlock(&data->lock);
 292
 293         return ret;
 294 }
 295
 296 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
 297 {
 298         struct hdc100x_data *data = iio_priv(indio_dev);
 299         int ret;
 300
 301         mutex_lock(&data->lock);
 302         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 303         mutex_unlock(&data->lock);
 304
 305         return ret;
 306 }
 307
 308 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 309         .postenable  = hdc100x_buffer_postenable,
 310         .predisable  = hdc100x_buffer_predisable,
 311 };
 312
 313 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 314 {
 315         struct iio_poll_func *pf = p;
 316         struct iio_dev *indio_dev = pf->indio_dev;
 317         struct hdc100x_data *data = iio_priv(indio_dev);
 318         struct i2c_client *client = data->client;
 319         int delay = data->adc_int_us[0] + data->adc_int_us[1];
 320         int ret;
 321
 322         /* dual read starts at temp register */
 323         mutex_lock(&data->lock);
 324         ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 325         if (ret < 0) {
 326                 dev_err(&client->dev, "cannot start measurement\n");
 327                 goto err;
 328         }
 329         usleep_range(delay, delay + 1000);
 330
 331         ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4);
 332         if (ret < 0) {
 333                 dev_err(&client->dev, "cannot read sensor data\n");
 334                 goto err;
 335         }
 336
 337         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 338                                            iio_get_time_ns(indio_dev));
 339 err:
 340         mutex_unlock(&data->lock);
 341         iio_trigger_notify_done(indio_dev->trig);
 342
 343         return IRQ_HANDLED;
 344 }
 345
 346 static const struct iio_info hdc100x_info = {
 347         .read_raw = hdc100x_read_raw,
 348         .write_raw = hdc100x_write_raw,
 349         .attrs = &hdc100x_attribute_group,
 350 };
 351
 352 static int hdc100x_probe(struct i2c_client *client,
 353                          const struct i2c_device_id *id)
 354 {
 355         struct iio_dev *indio_dev;
 356         struct hdc100x_data *data;
 357         int ret;
 358
 359         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
 360                                      I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 361                 return -EOPNOTSUPP;
 362
 363         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 364         if (!indio_dev)
 365                 return -ENOMEM;
 366
 367         data = iio_priv(indio_dev);
 368         i2c_set_clientdata(client, indio_dev);
 369         data->client = client;
 370         mutex_init(&data->lock);
 371
 372         indio_dev->name = dev_name(&client->dev);
 373         indio_dev->modes = INDIO_DIRECT_MODE;
 374         indio_dev->info = &hdc100x_info;
 375
 376         indio_dev->channels = hdc100x_channels;
 377         indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 378         indio_dev->available_scan_masks = hdc100x_scan_masks;
 379
 380         /* be sure we are in a known state */
 381         hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 382         hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 383         hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 384
 385         ret = devm_iio_triggered_buffer_setup(&client->dev,
 386                                          indio_dev, NULL,
 387                                          hdc100x_trigger_handler,
 388                                          &hdc_buffer_setup_ops);
 389         if (ret < 0) {
 390                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 391                 return ret;
 392         }
 393
 394         return devm_iio_device_register(&client->dev, indio_dev);
 395 }
 396
 397 static const struct i2c_device_id hdc100x_id[] = {
 398         { "hdc100x", 0 },
 399         { "hdc1000", 0 },
 400         { "hdc1008", 0 },
 401         { "hdc1010", 0 },
 402         { "hdc1050", 0 },
 403         { "hdc1080", 0 },
 404         { }
 405 };
 406 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
 407
 408 static const struct of_device_id hdc100x_dt_ids[] = {
 409         { .compatible = "ti,hdc1000" },
 410         { .compatible = "ti,hdc1008" },
 411         { .compatible = "ti,hdc1010" },
 412         { .compatible = "ti,hdc1050" },
 413         { .compatible = "ti,hdc1080" },
 414         { }
 415 };
 416 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
 417
 418 static struct i2c_driver hdc100x_driver = {
 419         .driver = {
 420                 .name   = "hdc100x",
 421                 .of_match_table = hdc100x_dt_ids,
 422         },
 423         .probe = hdc100x_probe,
 424         .id_table = hdc100x_id,
 425 };
 426 module_i2c_driver(hdc100x_driver);
 427
 428 MODULE_AUTHOR("Matt Ranostay <[email protected]>");
 429 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
 430 MODULE_LICENSE("GPL");