drivers/iio/light/opt4001.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2023 Axis Communications AB
   4  *
   5  * Datasheet: https://www.ti.com/lit/gpn/opt4001
   6  *
   7  * Device driver for the Texas Instruments OPT4001.
   8  */
   9
  10 #include <linux/bitfield.h>
  11 #include <linux/i2c.h>
  12 #include <linux/iio/iio.h>
  13 #include <linux/math64.h>
  14 #include <linux/module.h>
  15 #include <linux/property.h>
  16 #include <linux/regmap.h>
  17 #include <linux/regulator/consumer.h>
  18
  19 /* OPT4001 register set */
  20 #define OPT4001_LIGHT1_MSB    0x00
  21 #define OPT4001_LIGHT1_LSB    0x01
  22 #define OPT4001_CTRL          0x0A
  23 #define OPT4001_DEVICE_ID     0x11
  24
  25 /* OPT4001 register mask */
  26 #define OPT4001_EXPONENT_MASK    GENMASK(15, 12)
  27 #define OPT4001_MSB_MASK         GENMASK(11, 0)
  28 #define OPT4001_LSB_MASK         GENMASK(15, 8)
  29 #define OPT4001_COUNTER_MASK     GENMASK(7, 4)
  30 #define OPT4001_CRC_MASK         GENMASK(3, 0)
  31
  32 /* OPT4001 device id mask */
  33 #define OPT4001_DEVICE_ID_MASK   GENMASK(11, 0)
  34
  35 /* OPT4001 control registers mask */
  36 #define OPT4001_CTRL_QWAKE_MASK          GENMASK(15, 15)
  37 #define OPT4001_CTRL_RANGE_MASK          GENMASK(13, 10)
  38 #define OPT4001_CTRL_CONV_TIME_MASK      GENMASK(9, 6)
  39 #define OPT4001_CTRL_OPER_MODE_MASK      GENMASK(5, 4)
  40 #define OPT4001_CTRL_LATCH_MASK          GENMASK(3, 3)
  41 #define OPT4001_CTRL_INT_POL_MASK        GENMASK(2, 2)
  42 #define OPT4001_CTRL_FAULT_COUNT         GENMASK(0, 1)
  43
  44 /* OPT4001 constants */
  45 #define OPT4001_DEVICE_ID_VAL            0x121
  46
  47 /* OPT4001 operating modes */
  48 #define OPT4001_CTRL_OPER_MODE_OFF        0x0
  49 #define OPT4001_CTRL_OPER_MODE_FORCED     0x1
  50 #define OPT4001_CTRL_OPER_MODE_ONE_SHOT   0x2
  51 #define OPT4001_CTRL_OPER_MODE_CONTINUOUS 0x3
  52
  53 /* OPT4001 conversion control register definitions */
  54 #define OPT4001_CTRL_CONVERSION_0_6MS   0x0
  55 #define OPT4001_CTRL_CONVERSION_1MS     0x1
  56 #define OPT4001_CTRL_CONVERSION_1_8MS   0x2
  57 #define OPT4001_CTRL_CONVERSION_3_4MS   0x3
  58 #define OPT4001_CTRL_CONVERSION_6_5MS   0x4
  59 #define OPT4001_CTRL_CONVERSION_12_7MS  0x5
  60 #define OPT4001_CTRL_CONVERSION_25MS    0x6
  61 #define OPT4001_CTRL_CONVERSION_50MS    0x7
  62 #define OPT4001_CTRL_CONVERSION_100MS   0x8
  63 #define OPT4001_CTRL_CONVERSION_200MS   0x9
  64 #define OPT4001_CTRL_CONVERSION_400MS   0xa
  65 #define OPT4001_CTRL_CONVERSION_800MS   0xb
  66
  67 /* OPT4001 scale light level range definitions */
  68 #define OPT4001_CTRL_LIGHT_SCALE_AUTO   12
  69
  70 /* OPT4001 default values */
  71 #define OPT4001_DEFAULT_CONVERSION_TIME OPT4001_CTRL_CONVERSION_800MS
  72
  73 /*
  74  * The different packaging of OPT4001 has different constants used when calculating
  75  * lux values.
  76  */
  77 struct opt4001_chip_info {
  78         int mul;
  79         int div;
  80         const char *name;
  81 };
  82
  83 struct opt4001_chip {
  84         struct regmap *regmap;
  85         struct i2c_client *client;
  86         u8 int_time;
  87         const struct opt4001_chip_info *chip_info;
  88 };
  89
  90 static const struct opt4001_chip_info opt4001_sot_5x3_info = {
  91         .mul = 4375,
  92         .div = 10000000,
  93         .name = "opt4001-sot-5x3"
  94 };
  95
  96 static const struct opt4001_chip_info opt4001_picostar_info = {
  97         .mul = 3125,
  98         .div = 10000000,
  99         .name = "opt4001-picostar"
 100 };
 101
 102 static const int opt4001_int_time_available[][2] = {
 103         { 0,    600 },
 104         { 0,   1000 },
 105         { 0,   1800 },
 106         { 0,   3400 },
 107         { 0,   6500 },
 108         { 0,  12700 },
 109         { 0,  25000 },
 110         { 0,  50000 },
 111         { 0, 100000 },
 112         { 0, 200000 },
 113         { 0, 400000 },
 114         { 0, 800000 },
 115 };
 116
 117 /*
 118  * Conversion time is integration time + time to set register
 119  * this is used as integration time.
 120  */
 121 static const int opt4001_int_time_reg[][2] = {
 122         {    600,  OPT4001_CTRL_CONVERSION_0_6MS  },
 123         {   1000,  OPT4001_CTRL_CONVERSION_1MS    },
 124         {   1800,  OPT4001_CTRL_CONVERSION_1_8MS  },
 125         {   3400,  OPT4001_CTRL_CONVERSION_3_4MS  },
 126         {   6500,  OPT4001_CTRL_CONVERSION_6_5MS  },
 127         {  12700,  OPT4001_CTRL_CONVERSION_12_7MS },
 128         {  25000,  OPT4001_CTRL_CONVERSION_25MS   },
 129         {  50000,  OPT4001_CTRL_CONVERSION_50MS   },
 130         { 100000,  OPT4001_CTRL_CONVERSION_100MS  },
 131         { 200000,  OPT4001_CTRL_CONVERSION_200MS  },
 132         { 400000,  OPT4001_CTRL_CONVERSION_400MS  },
 133         { 800000,  OPT4001_CTRL_CONVERSION_800MS  },
 134 };
 135
 136 static int opt4001_als_time_to_index(const u32 als_integration_time)
 137 {
 138         int i;
 139
 140         for (i = 0; i < ARRAY_SIZE(opt4001_int_time_available); i++) {
 141                 if (als_integration_time == opt4001_int_time_available[i][1])
 142                         return i;
 143         }
 144
 145         return -EINVAL;
 146 }
 147
 148 static u8 opt4001_calculate_crc(u8 exp, u32 mantissa, u8 count)
 149 {
 150         u8 crc;
 151
 152         crc = (hweight32(mantissa) + hweight32(exp) + hweight32(count)) % 2;
 153         crc |= ((hweight32(mantissa & 0xAAAAA) + hweight32(exp & 0xA)
 154                  + hweight32(count & 0xA)) % 2) << 1;
 155         crc |= ((hweight32(mantissa & 0x88888) + hweight32(exp & 0x8)
 156                  + hweight32(count & 0x8)) % 2) << 2;
 157         crc |= (hweight32(mantissa & 0x80808) % 2) << 3;
 158
 159         return crc;
 160 }
 161
 162 static int opt4001_read_lux_value(struct iio_dev *indio_dev,
 163                                   int *val, int *val2)
 164 {
 165         struct opt4001_chip *chip = iio_priv(indio_dev);
 166         struct device *dev = &chip->client->dev;
 167         unsigned int light1;
 168         unsigned int light2;
 169         u16 msb;
 170         u16 lsb;
 171         u8 exp;
 172         u8 count;
 173         u8 crc;
 174         u8 calc_crc;
 175         u64 lux_raw;
 176         int ret;
 177
 178         ret = regmap_read(chip->regmap, OPT4001_LIGHT1_MSB, &light1);
 179         if (ret < 0) {
 180                 dev_err(dev, "Failed to read data bytes");
 181                 return ret;
 182         }
 183
 184         ret = regmap_read(chip->regmap, OPT4001_LIGHT1_LSB, &light2);
 185         if (ret < 0) {
 186                 dev_err(dev, "Failed to read data bytes");
 187                 return ret;
 188         }
 189
 190         count = FIELD_GET(OPT4001_COUNTER_MASK, light2);
 191         exp = FIELD_GET(OPT4001_EXPONENT_MASK, light1);
 192         crc = FIELD_GET(OPT4001_CRC_MASK, light2);
 193         msb = FIELD_GET(OPT4001_MSB_MASK, light1);
 194         lsb = FIELD_GET(OPT4001_LSB_MASK, light2);
 195         lux_raw = (msb << 8) + lsb;
 196         calc_crc = opt4001_calculate_crc(exp, lux_raw, count);
 197         if (calc_crc != crc)
 198                 return -EIO;
 199
 200         lux_raw = lux_raw << exp;
 201         lux_raw = lux_raw * chip->chip_info->mul;
 202         *val = div_u64_rem(lux_raw, chip->chip_info->div, val2);
 203         *val2 = *val2 * 100;
 204
 205         return IIO_VAL_INT_PLUS_NANO;
 206 }
 207
 208 static int opt4001_set_conf(struct opt4001_chip *chip)
 209 {
 210         struct device *dev = &chip->client->dev;
 211         u16 reg;
 212         int ret;
 213
 214         reg = FIELD_PREP(OPT4001_CTRL_RANGE_MASK, OPT4001_CTRL_LIGHT_SCALE_AUTO);
 215         reg |= FIELD_PREP(OPT4001_CTRL_CONV_TIME_MASK, chip->int_time);
 216         reg |= FIELD_PREP(OPT4001_CTRL_OPER_MODE_MASK, OPT4001_CTRL_OPER_MODE_CONTINUOUS);
 217
 218         ret = regmap_write(chip->regmap, OPT4001_CTRL, reg);
 219         if (ret)
 220                 dev_err(dev, "Failed to set configuration\n");
 221
 222         return ret;
 223 }
 224
 225 static int opt4001_power_down(struct opt4001_chip *chip)
 226 {
 227         struct device *dev = &chip->client->dev;
 228         int ret;
 229         unsigned int reg;
 230
 231         ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, &reg);
 232         if (ret) {
 233                 dev_err(dev, "Failed to read configuration\n");
 234                 return ret;
 235         }
 236
 237         /* MODE_OFF is 0x0 so just set bits to 0 */
 238         reg &= ~OPT4001_CTRL_OPER_MODE_MASK;
 239
 240         ret = regmap_write(chip->regmap, OPT4001_CTRL, reg);
 241         if (ret)
 242                 dev_err(dev, "Failed to set configuration to power down\n");
 243
 244         return ret;
 245 }
 246
 247 static void opt4001_chip_off_action(void *data)
 248 {
 249         struct opt4001_chip *chip = data;
 250
 251         opt4001_power_down(chip);
 252 }
 253
 254 static const struct iio_chan_spec opt4001_channels[] = {
 255         {
 256                 .type = IIO_LIGHT,
 257                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 258                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
 259                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME)
 260         },
 261 };
 262
 263 static int opt4001_read_raw(struct iio_dev *indio_dev,
 264                             struct iio_chan_spec const *chan,
 265                             int *val, int *val2, long mask)
 266 {
 267         struct opt4001_chip *chip = iio_priv(indio_dev);
 268
 269         switch (mask) {
 270         case IIO_CHAN_INFO_PROCESSED:
 271                 return opt4001_read_lux_value(indio_dev, val, val2);
 272         case IIO_CHAN_INFO_INT_TIME:
 273                 *val = 0;
 274                 *val2 = opt4001_int_time_reg[chip->int_time][0];
 275                 return IIO_VAL_INT_PLUS_MICRO;
 276         default:
 277                 return -EINVAL;
 278         }
 279 }
 280
 281 static int opt4001_write_raw(struct iio_dev *indio_dev,
 282                              struct iio_chan_spec const *chan,
 283                              int val, int val2, long mask)
 284 {
 285         struct opt4001_chip *chip = iio_priv(indio_dev);
 286         int int_time;
 287
 288         switch (mask) {
 289         case IIO_CHAN_INFO_INT_TIME:
 290                 int_time = opt4001_als_time_to_index(val2);
 291                 if (int_time < 0)
 292                         return int_time;
 293                 chip->int_time = int_time;
 294                 return opt4001_set_conf(chip);
 295         default:
 296                 return -EINVAL;
 297         }
 298 }
 299
 300 static int opt4001_read_available(struct iio_dev *indio_dev,
 301                                   struct iio_chan_spec const *chan,
 302                                   const int **vals, int *type, int *length,
 303                                   long mask)
 304 {
 305         switch (mask) {
 306         case IIO_CHAN_INFO_INT_TIME:
 307                 *length = ARRAY_SIZE(opt4001_int_time_available) * 2;
 308                 *vals = (const int *)opt4001_int_time_available;
 309                 *type = IIO_VAL_INT_PLUS_MICRO;
 310                 return IIO_AVAIL_LIST;
 311
 312         default:
 313                 return -EINVAL;
 314         }
 315 }
 316
 317 static const struct iio_info opt4001_info_no_irq = {
 318         .read_raw = opt4001_read_raw,
 319         .write_raw = opt4001_write_raw,
 320         .read_avail = opt4001_read_available,
 321 };
 322
 323 static int opt4001_load_defaults(struct opt4001_chip *chip)
 324 {
 325         chip->int_time = OPT4001_DEFAULT_CONVERSION_TIME;
 326
 327         return opt4001_set_conf(chip);
 328 }
 329
 330 static bool opt4001_readable_reg(struct device *dev, unsigned int reg)
 331 {
 332         switch (reg) {
 333         case OPT4001_LIGHT1_MSB:
 334         case OPT4001_LIGHT1_LSB:
 335         case OPT4001_CTRL:
 336         case OPT4001_DEVICE_ID:
 337                 return true;
 338         default:
 339                 return false;
 340         }
 341 }
 342
 343 static bool opt4001_writable_reg(struct device *dev, unsigned int reg)
 344 {
 345         switch (reg) {
 346         case OPT4001_CTRL:
 347                 return true;
 348         default:
 349                 return false;
 350         }
 351 }
 352
 353 static bool opt4001_volatile_reg(struct device *dev, unsigned int reg)
 354 {
 355         switch (reg) {
 356         case OPT4001_LIGHT1_MSB:
 357         case OPT4001_LIGHT1_LSB:
 358                 return true;
 359         default:
 360                 return false;
 361         }
 362 }
 363
 364 static const struct regmap_config opt4001_regmap_config = {
 365         .name = "opt4001",
 366         .reg_bits = 8,
 367         .val_bits = 16,
 368         .cache_type = REGCACHE_RBTREE,
 369         .max_register = OPT4001_DEVICE_ID,
 370         .readable_reg = opt4001_readable_reg,
 371         .writeable_reg = opt4001_writable_reg,
 372         .volatile_reg = opt4001_volatile_reg,
 373         .val_format_endian = REGMAP_ENDIAN_BIG,
 374 };
 375
 376 static int opt4001_probe(struct i2c_client *client)
 377 {
 378         struct opt4001_chip *chip;
 379         struct iio_dev *indio_dev;
 380         int ret;
 381         uint dev_id;
 382
 383         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 384         if (!indio_dev)
 385                 return -ENOMEM;
 386
 387         chip = iio_priv(indio_dev);
 388
 389         ret = devm_regulator_get_enable(&client->dev, "vdd");
 390         if (ret)
 391                 return dev_err_probe(&client->dev, ret, "Failed to enable vdd supply\n");
 392
 393         chip->regmap = devm_regmap_init_i2c(client, &opt4001_regmap_config);
 394         if (IS_ERR(chip->regmap))
 395                 return dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
 396                                      "regmap initialization failed\n");
 397         chip->client = client;
 398
 399         indio_dev->info = &opt4001_info_no_irq;
 400
 401         ret = regmap_reinit_cache(chip->regmap, &opt4001_regmap_config);
 402         if (ret)
 403                 return dev_err_probe(&client->dev, ret,
 404                                      "failed to reinit regmap cache\n");
 405
 406         ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, &dev_id);
 407         if (ret < 0)
 408                 return dev_err_probe(&client->dev, ret,
 409                         "Failed to read the device ID register\n");
 410
 411         dev_id = FIELD_GET(OPT4001_DEVICE_ID_MASK, dev_id);
 412         if (dev_id != OPT4001_DEVICE_ID_VAL)
 413                 dev_warn(&client->dev, "Device ID: %#04x unknown\n", dev_id);
 414
 415         chip->chip_info = i2c_get_match_data(client);
 416
 417         indio_dev->channels = opt4001_channels;
 418         indio_dev->num_channels = ARRAY_SIZE(opt4001_channels);
 419         indio_dev->modes = INDIO_DIRECT_MODE;
 420         indio_dev->name = chip->chip_info->name;
 421
 422         ret = opt4001_load_defaults(chip);
 423         if (ret < 0)
 424                 return dev_err_probe(&client->dev, ret,
 425                                      "Failed to set sensor defaults\n");
 426
 427         ret = devm_add_action_or_reset(&client->dev,
 428                                         opt4001_chip_off_action,
 429                                         chip);
 430         if (ret < 0)
 431                 return dev_err_probe(&client->dev, ret,
 432                                      "Failed to setup power off action\n");
 433
 434         return devm_iio_device_register(&client->dev, indio_dev);
 435 }
 436
 437 /*
 438  * The compatible string determines which constants to use depending on
 439  * opt4001 packaging
 440  */
 441 static const struct i2c_device_id opt4001_id[] = {
 442         { "opt4001-sot-5x3", (kernel_ulong_t)&opt4001_sot_5x3_info },
 443         { "opt4001-picostar", (kernel_ulong_t)&opt4001_picostar_info },
 444         { }
 445 };
 446 MODULE_DEVICE_TABLE(i2c, opt4001_id);
 447
 448 static const struct of_device_id opt4001_of_match[] = {
 449         { .compatible = "ti,opt4001-sot-5x3", .data = &opt4001_sot_5x3_info},
 450         { .compatible = "ti,opt4001-picostar", .data = &opt4001_picostar_info},
 451         {}
 452 };
 453 MODULE_DEVICE_TABLE(of, opt4001_of_match);
 454
 455 static struct i2c_driver opt4001_driver = {
 456         .driver = {
 457                 .name = "opt4001",
 458                 .of_match_table = opt4001_of_match,
 459         },
 460         .probe = opt4001_probe,
 461         .id_table = opt4001_id,
 462 };
 463 module_i2c_driver(opt4001_driver);
 464
 465 MODULE_AUTHOR("Stefan Windfeldt-Prytz <stefan.windfeldt-prytz@axis.com>");
 466 MODULE_DESCRIPTION("Texas Instruments opt4001 ambient light sensor driver");
 467 MODULE_LICENSE("GPL");