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  */
  17
  18 #include <linux/delay.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/i2c.h>
  22
  23 #include <linux/iio/iio.h>
  24 #include <linux/iio/sysfs.h>
  25 #include <linux/iio/buffer.h>
  26 #include <linux/iio/trigger_consumer.h>
  27 #include <linux/iio/triggered_buffer.h>
  28
  29 #define HDC100X_REG_TEMP                        0x00
  30 #define HDC100X_REG_HUMIDITY                    0x01
  31
  32 #define HDC100X_REG_CONFIG                      0x02
  33 #define HDC100X_REG_CONFIG_ACQ_MODE             BIT(12)
  34 #define HDC100X_REG_CONFIG_HEATER_EN            BIT(13)
  35
  36 struct hdc100x_data {
  37         struct i2c_client *client;
  38         struct mutex lock;
  39         u16 config;
  40
  41         /* integration time of the sensor */
  42         int adc_int_us[2];
  43 };
  44
  45 /* integration time in us */
  46 static const int hdc100x_int_time[][3] = {
  47         { 6350, 3650, 0 },      /* IIO_TEMP channel*/
  48         { 6500, 3850, 2500 },   /* IIO_HUMIDITYRELATIVE channel */
  49 };
  50
  51 /* HDC100X_REG_CONFIG shift and mask values */
  52 static const struct {
  53         int shift;
  54         int mask;
  55 } hdc100x_resolution_shift[2] = {
  56         { /* IIO_TEMP channel */
  57                 .shift = 10,
  58                 .mask = 1
  59         },
  60         { /* IIO_HUMIDITYRELATIVE channel */
  61                 .shift = 8,
  62                 .mask = 3,
  63         },
  64 };
  65
  66 static IIO_CONST_ATTR(temp_integration_time_available,
  67                 "0.00365 0.00635");
  68
  69 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
  70                 "0.0025 0.00385 0.0065");
  71
  72 static IIO_CONST_ATTR(out_current_heater_raw_available,
  73                 "0 1");
  74
  75 static struct attribute *hdc100x_attributes[] = {
  76         &iio_const_attr_temp_integration_time_available.dev_attr.attr,
  77         &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
  78         &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
  79         NULL
  80 };
  81
  82 static struct attribute_group hdc100x_attribute_group = {
  83         .attrs = hdc100x_attributes,
  84 };
  85
  86 static const struct iio_chan_spec hdc100x_channels[] = {
  87         {
  88                 .type = IIO_TEMP,
  89                 .address = HDC100X_REG_TEMP,
  90                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  91                         BIT(IIO_CHAN_INFO_SCALE) |
  92                         BIT(IIO_CHAN_INFO_INT_TIME) |
  93                         BIT(IIO_CHAN_INFO_OFFSET),
  94                 .scan_index = 0,
  95                 .scan_type = {
  96                         .sign = 's',
  97                         .realbits = 16,
  98                         .storagebits = 16,
  99                         .endianness = IIO_BE,
 100                 },
 101         },
 102         {
 103                 .type = IIO_HUMIDITYRELATIVE,
 104                 .address = HDC100X_REG_HUMIDITY,
 105                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 106                         BIT(IIO_CHAN_INFO_SCALE) |
 107                         BIT(IIO_CHAN_INFO_INT_TIME),
 108                 .scan_index = 1,
 109                 .scan_type = {
 110                         .sign = 'u',
 111                         .realbits = 16,
 112                         .storagebits = 16,
 113                         .endianness = IIO_BE,
 114                 },
 115         },
 116         {
 117                 .type = IIO_CURRENT,
 118                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 119                 .extend_name = "heater",
 120                 .output = 1,
 121                 .scan_index = -1,
 122         },
 123         IIO_CHAN_SOFT_TIMESTAMP(2),
 124 };
 125
 126 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
 127
 128 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
 129 {
 130         int tmp = (~mask & data->config) | val;
 131         int ret;
 132
 133         ret = i2c_smbus_write_word_swapped(data->client,
 134                                                 HDC100X_REG_CONFIG, tmp);
 135         if (!ret)
 136                 data->config = tmp;
 137
 138         return ret;
 139 }
 140
 141 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
 142 {
 143         int shift = hdc100x_resolution_shift[chan].shift;
 144         int ret = -EINVAL;
 145         int i;
 146
 147         for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
 148                 if (val2 && val2 == hdc100x_int_time[chan][i]) {
 149                         ret = hdc100x_update_config(data,
 150                                 hdc100x_resolution_shift[chan].mask << shift,
 151                                 i << shift);
 152                         if (!ret)
 153                                 data->adc_int_us[chan] = val2;
 154                         break;
 155                 }
 156         }
 157
 158         return ret;
 159 }
 160
 161 static int hdc100x_get_measurement(struct hdc100x_data *data,
 162                                    struct iio_chan_spec const *chan)
 163 {
 164         struct i2c_client *client = data->client;
 165         int delay = data->adc_int_us[chan->address];
 166         int ret;
 167         __be16 val;
 168
 169         /* start measurement */
 170         ret = i2c_smbus_write_byte(client, chan->address);
 171         if (ret < 0) {
 172                 dev_err(&client->dev, "cannot start measurement");
 173                 return ret;
 174         }
 175
 176         /* wait for integration time to pass */
 177         usleep_range(delay, delay + 1000);
 178
 179         /* read measurement */
 180         ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
 181         if (ret < 0) {
 182                 dev_err(&client->dev, "cannot read sensor data\n");
 183                 return ret;
 184         }
 185         return be16_to_cpu(val);
 186 }
 187
 188 static int hdc100x_get_heater_status(struct hdc100x_data *data)
 189 {
 190         return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
 191 }
 192
 193 static int hdc100x_read_raw(struct iio_dev *indio_dev,
 194                             struct iio_chan_spec const *chan, int *val,
 195                             int *val2, long mask)
 196 {
 197         struct hdc100x_data *data = iio_priv(indio_dev);
 198
 199         switch (mask) {
 200         case IIO_CHAN_INFO_RAW: {
 201                 int ret;
 202
 203                 mutex_lock(&data->lock);
 204                 if (chan->type == IIO_CURRENT) {
 205                         *val = hdc100x_get_heater_status(data);
 206                         ret = IIO_VAL_INT;
 207                 } else {
 208                         ret = iio_device_claim_direct_mode(indio_dev);
 209                         if (ret) {
 210                                 mutex_unlock(&data->lock);
 211                                 return ret;
 212                         }
 213
 214                         ret = hdc100x_get_measurement(data, chan);
 215                         iio_device_release_direct_mode(indio_dev);
 216                         if (ret >= 0) {
 217                                 *val = ret;
 218                                 ret = IIO_VAL_INT;
 219                         }
 220                 }
 221                 mutex_unlock(&data->lock);
 222                 return ret;
 223         }
 224         case IIO_CHAN_INFO_INT_TIME:
 225                 *val = 0;
 226                 *val2 = data->adc_int_us[chan->address];
 227                 return IIO_VAL_INT_PLUS_MICRO;
 228         case IIO_CHAN_INFO_SCALE:
 229                 if (chan->type == IIO_TEMP) {
 230                         *val = 165000;
 231                         *val2 = 65536;
 232                         return IIO_VAL_FRACTIONAL;
 233                 } else {
 234                         *val = 100;
 235                         *val2 = 65536;
 236                         return IIO_VAL_FRACTIONAL;
 237                 }
 238                 break;
 239         case IIO_CHAN_INFO_OFFSET:
 240                 *val = -15887;
 241                 *val2 = 515151;
 242                 return IIO_VAL_INT_PLUS_MICRO;
 243         default:
 244                 return -EINVAL;
 245         }
 246 }
 247
 248 static int hdc100x_write_raw(struct iio_dev *indio_dev,
 249                              struct iio_chan_spec const *chan,
 250                              int val, int val2, long mask)
 251 {
 252         struct hdc100x_data *data = iio_priv(indio_dev);
 253         int ret = -EINVAL;
 254
 255         switch (mask) {
 256         case IIO_CHAN_INFO_INT_TIME:
 257                 if (val != 0)
 258                         return -EINVAL;
 259
 260                 mutex_lock(&data->lock);
 261                 ret = hdc100x_set_it_time(data, chan->address, val2);
 262                 mutex_unlock(&data->lock);
 263                 return ret;
 264         case IIO_CHAN_INFO_RAW:
 265                 if (chan->type != IIO_CURRENT || val2 != 0)
 266                         return -EINVAL;
 267
 268                 mutex_lock(&data->lock);
 269                 ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
 270                                         val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
 271                 mutex_unlock(&data->lock);
 272                 return ret;
 273         default:
 274                 return -EINVAL;
 275         }
 276 }
 277
 278 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
 279 {
 280         struct hdc100x_data *data = iio_priv(indio_dev);
 281         int ret;
 282
 283         /* Buffer is enabled. First set ACQ Mode, then attach poll func */
 284         mutex_lock(&data->lock);
 285         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
 286                                     HDC100X_REG_CONFIG_ACQ_MODE);
 287         mutex_unlock(&data->lock);
 288         if (ret)
 289                 return ret;
 290
 291         return iio_triggered_buffer_postenable(indio_dev);
 292 }
 293
 294 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
 295 {
 296         struct hdc100x_data *data = iio_priv(indio_dev);
 297         int ret;
 298
 299         /* First detach poll func, then reset ACQ mode. OK to disable buffer */
 300         ret = iio_triggered_buffer_predisable(indio_dev);
 301         if (ret)
 302                 return ret;
 303
 304         mutex_lock(&data->lock);
 305         ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 306         mutex_unlock(&data->lock);
 307
 308         return ret;
 309 }
 310
 311 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 312         .postenable  = hdc100x_buffer_postenable,
 313         .predisable  = hdc100x_buffer_predisable,
 314 };
 315
 316 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 317 {
 318         struct iio_poll_func *pf = p;
 319         struct iio_dev *indio_dev = pf->indio_dev;
 320         struct hdc100x_data *data = iio_priv(indio_dev);
 321         struct i2c_client *client = data->client;
 322         int delay = data->adc_int_us[0] + data->adc_int_us[1];
 323         int ret;
 324         s16 buf[8];  /* 2x s16 + padding + 8 byte timestamp */
 325
 326         /* dual read starts at temp register */
 327         mutex_lock(&data->lock);
 328         ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 329         if (ret < 0) {
 330                 dev_err(&client->dev, "cannot start measurement\n");
 331                 goto err;
 332         }
 333         usleep_range(delay, delay + 1000);
 334
 335         ret = i2c_master_recv(client, (u8 *)buf, 4);
 336         if (ret < 0) {
 337                 dev_err(&client->dev, "cannot read sensor data\n");
 338                 goto err;
 339         }
 340
 341         iio_push_to_buffers_with_timestamp(indio_dev, buf,
 342                                            iio_get_time_ns(indio_dev));
 343 err:
 344         mutex_unlock(&data->lock);
 345         iio_trigger_notify_done(indio_dev->trig);
 346
 347         return IRQ_HANDLED;
 348 }
 349
 350 static const struct iio_info hdc100x_info = {
 351         .read_raw = hdc100x_read_raw,
 352         .write_raw = hdc100x_write_raw,
 353         .attrs = &hdc100x_attribute_group,
 354         .driver_module = THIS_MODULE,
 355 };
 356
 357 static int hdc100x_probe(struct i2c_client *client,
 358                          const struct i2c_device_id *id)
 359 {
 360         struct iio_dev *indio_dev;
 361         struct hdc100x_data *data;
 362         int ret;
 363
 364         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
 365                                      I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
 366                 return -EOPNOTSUPP;
 367
 368         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 369         if (!indio_dev)
 370                 return -ENOMEM;
 371
 372         data = iio_priv(indio_dev);
 373         i2c_set_clientdata(client, indio_dev);
 374         data->client = client;
 375         mutex_init(&data->lock);
 376
 377         indio_dev->dev.parent = &client->dev;
 378         indio_dev->name = dev_name(&client->dev);
 379         indio_dev->modes = INDIO_DIRECT_MODE;
 380         indio_dev->info = &hdc100x_info;
 381
 382         indio_dev->channels = hdc100x_channels;
 383         indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 384         indio_dev->available_scan_masks = hdc100x_scan_masks;
 385
 386         /* be sure we are in a known state */
 387         hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 388         hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 389         hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
 390
 391         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 392                                          hdc100x_trigger_handler,
 393                                          &hdc_buffer_setup_ops);
 394         if (ret < 0) {
 395                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 396                 return ret;
 397         }
 398         ret = iio_device_register(indio_dev);
 399         if (ret < 0)
 400                 iio_triggered_buffer_cleanup(indio_dev);
 401
 402         return ret;
 403 }
 404
 405 static int hdc100x_remove(struct i2c_client *client)
 406 {
 407         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 408
 409         iio_device_unregister(indio_dev);
 410         iio_triggered_buffer_cleanup(indio_dev);
 411
 412         return 0;
 413 }
 414
 415 static const struct i2c_device_id hdc100x_id[] = {
 416         { "hdc100x", 0 },
 417         { }
 418 };
 419 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
 420
 421 static struct i2c_driver hdc100x_driver = {
 422         .driver = {
 423                 .name   = "hdc100x",
 424         },
 425         .probe = hdc100x_probe,
 426         .remove = hdc100x_remove,
 427         .id_table = hdc100x_id,
 428 };
 429 module_i2c_driver(hdc100x_driver);
 430
 431 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
 432 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
 433 MODULE_LICENSE("GPL");