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/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 #include <linux/time.h>
  29
  30 #define HDC100X_REG_TEMP                        0x00
  31 #define HDC100X_REG_HUMIDITY                    0x01
  32
  33 #define HDC100X_REG_CONFIG                      0x02
  34 #define HDC100X_REG_CONFIG_ACQ_MODE             BIT(12)
  35 #define HDC100X_REG_CONFIG_HEATER_EN            BIT(13)
  36
  37 struct hdc100x_data {
  38         struct i2c_client *client;
  39         struct mutex lock;
  40         u16 config;
  41
  42         /* integration time of the sensor */
  43         int adc_int_us[2];
  44         /* Ensure natural alignment of timestamp */
  45         struct {
  46                 __be16 channels[2];
  47                 s64 ts __aligned(8);
  48         } scan;
  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] + 1*USEC_PER_MSEC;
 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 = 100000;
 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
 295         return ret;
 296 }
 297
 298 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
 299 {
 300         struct hdc100x_data *data = iio_priv(indio_dev);
 301         int ret;
 302
 303         mutex_lock(&data->lock);
 304         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 305         mutex_unlock(&data->lock);
 306
 307         return ret;
 308 }
 309
 310 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 311         .postenable  = hdc100x_buffer_postenable,
 312         .predisable  = hdc100x_buffer_predisable,
 313 };
 314
 315 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 316 {
 317         struct iio_poll_func *pf = p;
 318         struct iio_dev *indio_dev = pf->indio_dev;
 319         struct hdc100x_data *data = iio_priv(indio_dev);
 320         struct i2c_client *client = data->client;
 321         int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC;
 322         int ret;
 323
 324         /* dual read starts at temp register */
 325         mutex_lock(&data->lock);
 326         ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 327         if (ret < 0) {
 328                 dev_err(&client->dev, "cannot start measurement\n");
 329                 goto err;
 330         }
 331         usleep_range(delay, delay + 1000);
 332
 333         ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4);
 334         if (ret < 0) {
 335                 dev_err(&client->dev, "cannot read sensor data\n");
 336                 goto err;
 337         }
 338
 339         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 340                                            iio_get_time_ns(indio_dev));
 341 err:
 342         mutex_unlock(&data->lock);
 343         iio_trigger_notify_done(indio_dev->trig);
 344
 345         return IRQ_HANDLED;
 346 }
 347
 348 static const struct iio_info hdc100x_info = {
 349         .read_raw = hdc100x_read_raw,
 350         .write_raw = hdc100x_write_raw,
 351         .attrs = &hdc100x_attribute_group,
 352 };
 353
 354 static int hdc100x_probe(struct i2c_client *client,
 355                          const struct i2c_device_id *id)
 356 {
 357         struct iio_dev *indio_dev;
 358         struct hdc100x_data *data;
 359         int ret;
 360
 361         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
 362                                      I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 363                 return -EOPNOTSUPP;
 364
 365         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 366         if (!indio_dev)
 367                 return -ENOMEM;
 368
 369         data = iio_priv(indio_dev);
 370         i2c_set_clientdata(client, indio_dev);
 371         data->client = client;
 372         mutex_init(&data->lock);
 373
 374         indio_dev->name = dev_name(&client->dev);
 375         indio_dev->modes = INDIO_DIRECT_MODE;
 376         indio_dev->info = &hdc100x_info;
 377
 378         indio_dev->channels = hdc100x_channels;
 379         indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 380         indio_dev->available_scan_masks = hdc100x_scan_masks;
 381
 382         /* be sure we are in a known state */
 383         hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 384         hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 385         hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 386
 387         ret = devm_iio_triggered_buffer_setup(&client->dev,
 388                                          indio_dev, NULL,
 389                                          hdc100x_trigger_handler,
 390                                          &hdc_buffer_setup_ops);
 391         if (ret < 0) {
 392                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 393                 return ret;
 394         }
 395
 396         return devm_iio_device_register(&client->dev, indio_dev);
 397 }
 398
 399 static const struct i2c_device_id hdc100x_id[] = {
 400         { "hdc100x", 0 },
 401         { "hdc1000", 0 },
 402         { "hdc1008", 0 },
 403         { "hdc1010", 0 },
 404         { "hdc1050", 0 },
 405         { "hdc1080", 0 },
 406         { }
 407 };
 408 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
 409
 410 static const struct of_device_id hdc100x_dt_ids[] = {
 411         { .compatible = "ti,hdc1000" },
 412         { .compatible = "ti,hdc1008" },
 413         { .compatible = "ti,hdc1010" },
 414         { .compatible = "ti,hdc1050" },
 415         { .compatible = "ti,hdc1080" },
 416         { }
 417 };
 418 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
 419
 420 static struct i2c_driver hdc100x_driver = {
 421         .driver = {
 422                 .name   = "hdc100x",
 423                 .of_match_table = hdc100x_dt_ids,
 424         },
 425         .probe = hdc100x_probe,
 426         .id_table = hdc100x_id,
 427 };
 428 module_i2c_driver(hdc100x_driver);
 429
 430 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
 431 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
 432 MODULE_LICENSE("GPL");