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