1 /* 2 * zopt2201.c - Support for IDT ZOPT2201 ambient light and UV B sensor 3 * 4 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> 5 * 6 * This file is subject to the terms and conditions of version 2 of 7 * the GNU General Public License. See the file COPYING in the main 8 * directory of this archive for more details. 9 * 10 * Datasheet: https://www.idt.com/document/dst/zopt2201-datasheet 11 * 7-bit I2C slave addresses 0x53 (default) or 0x52 (programmed) 12 * 13 * TODO: interrupt support, ALS/UVB raw mode 14 */ 15 16 #include <linux/module.h> 17 #include <linux/i2c.h> 18 #include <linux/mutex.h> 19 #include <linux/err.h> 20 #include <linux/delay.h> 21 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 25 #define ZOPT2201_DRV_NAME "zopt2201" 26 27 /* Registers */ 28 #define ZOPT2201_MAIN_CTRL 0x00 29 #define ZOPT2201_LS_MEAS_RATE 0x04 30 #define ZOPT2201_LS_GAIN 0x05 31 #define ZOPT2201_PART_ID 0x06 32 #define ZOPT2201_MAIN_STATUS 0x07 33 #define ZOPT2201_ALS_DATA 0x0d /* LSB first, 13 to 20 bits */ 34 #define ZOPT2201_UVB_DATA 0x10 /* LSB first, 13 to 20 bits */ 35 #define ZOPT2201_UV_COMP_DATA 0x13 /* LSB first, 13 to 20 bits */ 36 #define ZOPT2201_COMP_DATA 0x16 /* LSB first, 13 to 20 bits */ 37 #define ZOPT2201_INT_CFG 0x19 38 #define ZOPT2201_INT_PST 0x1a 39 40 #define ZOPT2201_MAIN_CTRL_LS_MODE BIT(3) /* 0 .. ALS, 1 .. UV B */ 41 #define ZOPT2201_MAIN_CTRL_LS_EN BIT(1) 42 43 /* Values for ZOPT2201_LS_MEAS_RATE resolution / bit width */ 44 #define ZOPT2201_MEAS_RES_20BIT 0 /* takes 400 ms */ 45 #define ZOPT2201_MEAS_RES_19BIT 1 /* takes 200 ms */ 46 #define ZOPT2201_MEAS_RES_18BIT 2 /* takes 100 ms, default */ 47 #define ZOPT2201_MEAS_RES_17BIT 3 /* takes 50 ms */ 48 #define ZOPT2201_MEAS_RES_16BIT 4 /* takes 25 ms */ 49 #define ZOPT2201_MEAS_RES_13BIT 5 /* takes 3.125 ms */ 50 #define ZOPT2201_MEAS_RES_SHIFT 4 51 52 /* Values for ZOPT2201_LS_MEAS_RATE measurement rate */ 53 #define ZOPT2201_MEAS_FREQ_25MS 0 54 #define ZOPT2201_MEAS_FREQ_50MS 1 55 #define ZOPT2201_MEAS_FREQ_100MS 2 /* default */ 56 #define ZOPT2201_MEAS_FREQ_200MS 3 57 #define ZOPT2201_MEAS_FREQ_500MS 4 58 #define ZOPT2201_MEAS_FREQ_1000MS 5 59 #define ZOPT2201_MEAS_FREQ_2000MS 6 60 61 /* Values for ZOPT2201_LS_GAIN */ 62 #define ZOPT2201_LS_GAIN_1 0 63 #define ZOPT2201_LS_GAIN_3 1 64 #define ZOPT2201_LS_GAIN_6 2 65 #define ZOPT2201_LS_GAIN_9 3 66 #define ZOPT2201_LS_GAIN_18 4 67 68 /* Values for ZOPT2201_MAIN_STATUS */ 69 #define ZOPT2201_MAIN_STATUS_POWERON BIT(5) 70 #define ZOPT2201_MAIN_STATUS_INT BIT(4) 71 #define ZOPT2201_MAIN_STATUS_DRDY BIT(3) 72 73 #define ZOPT2201_PART_NUMBER 0xb2 74 75 struct zopt2201_data { 76 struct i2c_client *client; 77 struct mutex lock; 78 u8 gain; 79 u8 res; 80 u8 rate; 81 }; 82 83 static const struct { 84 unsigned int gain; /* gain factor */ 85 unsigned int scale; /* micro lux per count */ 86 } zopt2201_gain_als[] = { 87 { 1, 19200000 }, 88 { 3, 6400000 }, 89 { 6, 3200000 }, 90 { 9, 2133333 }, 91 { 18, 1066666 }, 92 }; 93 94 static const struct { 95 unsigned int gain; /* gain factor */ 96 unsigned int scale; /* micro W/m2 per count */ 97 } zopt2201_gain_uvb[] = { 98 { 1, 460800 }, 99 { 3, 153600 }, 100 { 6, 76800 }, 101 { 9, 51200 }, 102 { 18, 25600 }, 103 }; 104 105 static const struct { 106 unsigned int bits; /* sensor resolution in bits */ 107 unsigned long us; /* measurement time in micro seconds */ 108 } zopt2201_resolution[] = { 109 { 20, 400000 }, 110 { 19, 200000 }, 111 { 18, 100000 }, 112 { 17, 50000 }, 113 { 16, 25000 }, 114 { 13, 3125 }, 115 }; 116 117 static const struct { 118 unsigned int scale, uscale; /* scale factor as integer + micro */ 119 u8 gain; /* gain register value */ 120 u8 res; /* resolution register value */ 121 } zopt2201_scale_als[] = { 122 { 19, 200000, 0, 5 }, 123 { 6, 400000, 1, 5 }, 124 { 3, 200000, 2, 5 }, 125 { 2, 400000, 0, 4 }, 126 { 2, 133333, 3, 5 }, 127 { 1, 200000, 0, 3 }, 128 { 1, 66666, 4, 5 }, 129 { 0, 800000, 1, 4 }, 130 { 0, 600000, 0, 2 }, 131 { 0, 400000, 2, 4 }, 132 { 0, 300000, 0, 1 }, 133 { 0, 266666, 3, 4 }, 134 { 0, 200000, 2, 3 }, 135 { 0, 150000, 0, 0 }, 136 { 0, 133333, 4, 4 }, 137 { 0, 100000, 2, 2 }, 138 { 0, 66666, 4, 3 }, 139 { 0, 50000, 2, 1 }, 140 { 0, 33333, 4, 2 }, 141 { 0, 25000, 2, 0 }, 142 { 0, 16666, 4, 1 }, 143 { 0, 8333, 4, 0 }, 144 }; 145 146 static const struct { 147 unsigned int scale, uscale; /* scale factor as integer + micro */ 148 u8 gain; /* gain register value */ 149 u8 res; /* resolution register value */ 150 } zopt2201_scale_uvb[] = { 151 { 0, 460800, 0, 5 }, 152 { 0, 153600, 1, 5 }, 153 { 0, 76800, 2, 5 }, 154 { 0, 57600, 0, 4 }, 155 { 0, 51200, 3, 5 }, 156 { 0, 28800, 0, 3 }, 157 { 0, 25600, 4, 5 }, 158 { 0, 19200, 1, 4 }, 159 { 0, 14400, 0, 2 }, 160 { 0, 9600, 2, 4 }, 161 { 0, 7200, 0, 1 }, 162 { 0, 6400, 3, 4 }, 163 { 0, 4800, 2, 3 }, 164 { 0, 3600, 0, 0 }, 165 { 0, 3200, 4, 4 }, 166 { 0, 2400, 2, 2 }, 167 { 0, 1600, 4, 3 }, 168 { 0, 1200, 2, 1 }, 169 { 0, 800, 4, 2 }, 170 { 0, 600, 2, 0 }, 171 { 0, 400, 4, 1 }, 172 { 0, 200, 4, 0 }, 173 }; 174 175 static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode) 176 { 177 u8 out = ZOPT2201_MAIN_CTRL_LS_EN; 178 179 if (uvb_mode) 180 out |= ZOPT2201_MAIN_CTRL_LS_MODE; 181 182 return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out); 183 } 184 185 static int zopt2201_read(struct zopt2201_data *data, u8 reg) 186 { 187 struct i2c_client *client = data->client; 188 int tries = 10; 189 u8 buf[3]; 190 int ret; 191 192 mutex_lock(&data->lock); 193 ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA); 194 if (ret < 0) 195 goto fail; 196 197 while (tries--) { 198 unsigned long t = zopt2201_resolution[data->res].us; 199 200 if (t <= 20000) 201 usleep_range(t, t + 1000); 202 else 203 msleep(t / 1000); 204 ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS); 205 if (ret < 0) 206 goto fail; 207 if (ret & ZOPT2201_MAIN_STATUS_DRDY) 208 break; 209 } 210 211 if (tries < 0) { 212 ret = -ETIMEDOUT; 213 goto fail; 214 } 215 216 ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf); 217 if (ret < 0) 218 goto fail; 219 220 ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00); 221 if (ret < 0) 222 goto fail; 223 mutex_unlock(&data->lock); 224 225 return (buf[2] << 16) | (buf[1] << 8) | buf[0]; 226 227 fail: 228 mutex_unlock(&data->lock); 229 return ret; 230 } 231 232 static const struct iio_chan_spec zopt2201_channels[] = { 233 { 234 .type = IIO_LIGHT, 235 .address = ZOPT2201_ALS_DATA, 236 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 237 BIT(IIO_CHAN_INFO_SCALE), 238 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), 239 }, 240 { 241 .type = IIO_INTENSITY, 242 .modified = 1, 243 .channel2 = IIO_MOD_LIGHT_UV, 244 .address = ZOPT2201_UVB_DATA, 245 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 246 BIT(IIO_CHAN_INFO_SCALE), 247 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), 248 }, 249 { 250 .type = IIO_UVINDEX, 251 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 252 }, 253 }; 254 255 static int zopt2201_read_raw(struct iio_dev *indio_dev, 256 struct iio_chan_spec const *chan, 257 int *val, int *val2, long mask) 258 { 259 struct zopt2201_data *data = iio_priv(indio_dev); 260 u64 tmp; 261 int ret; 262 263 switch (mask) { 264 case IIO_CHAN_INFO_RAW: 265 ret = zopt2201_read(data, chan->address); 266 if (ret < 0) 267 return ret; 268 *val = ret; 269 return IIO_VAL_INT; 270 case IIO_CHAN_INFO_PROCESSED: 271 ret = zopt2201_read(data, ZOPT2201_UVB_DATA); 272 if (ret < 0) 273 return ret; 274 *val = ret * 18 * 275 (1 << (20 - zopt2201_resolution[data->res].bits)) / 276 zopt2201_gain_uvb[data->gain].gain; 277 return IIO_VAL_INT; 278 case IIO_CHAN_INFO_SCALE: 279 switch (chan->address) { 280 case ZOPT2201_ALS_DATA: 281 *val = zopt2201_gain_als[data->gain].scale; 282 break; 283 case ZOPT2201_UVB_DATA: 284 *val = zopt2201_gain_uvb[data->gain].scale; 285 break; 286 default: 287 return -EINVAL; 288 } 289 290 *val2 = 1000000; 291 *val2 *= (1 << (zopt2201_resolution[data->res].bits - 13)); 292 tmp = div_s64(*val * 1000000ULL, *val2); 293 *val = div_s64_rem(tmp, 1000000, val2); 294 295 return IIO_VAL_INT_PLUS_MICRO; 296 case IIO_CHAN_INFO_INT_TIME: 297 *val = 0; 298 *val2 = zopt2201_resolution[data->res].us; 299 return IIO_VAL_INT_PLUS_MICRO; 300 default: 301 return -EINVAL; 302 } 303 } 304 305 static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res) 306 { 307 int ret; 308 309 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE, 310 (res << ZOPT2201_MEAS_RES_SHIFT) | 311 data->rate); 312 if (ret < 0) 313 return ret; 314 315 data->res = res; 316 317 return 0; 318 } 319 320 static int zopt2201_write_resolution(struct zopt2201_data *data, 321 int val, int val2) 322 { 323 int i, ret; 324 325 if (val != 0) 326 return -EINVAL; 327 328 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++) 329 if (val2 == zopt2201_resolution[i].us) { 330 mutex_lock(&data->lock); 331 ret = zopt2201_set_resolution(data, i); 332 mutex_unlock(&data->lock); 333 return ret; 334 } 335 336 return -EINVAL; 337 } 338 339 static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain) 340 { 341 int ret; 342 343 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain); 344 if (ret < 0) 345 return ret; 346 347 data->gain = gain; 348 349 return 0; 350 } 351 352 static int zopt2201_write_scale_als_by_idx(struct zopt2201_data *data, int idx) 353 { 354 int ret; 355 356 mutex_lock(&data->lock); 357 ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res); 358 if (ret < 0) 359 goto unlock; 360 361 ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain); 362 363 unlock: 364 mutex_unlock(&data->lock); 365 return ret; 366 } 367 368 static int zopt2201_write_scale_als(struct zopt2201_data *data, 369 int val, int val2) 370 { 371 int i; 372 373 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++) 374 if (val == zopt2201_scale_als[i].scale && 375 val2 == zopt2201_scale_als[i].uscale) { 376 return zopt2201_write_scale_als_by_idx(data, i); 377 } 378 379 return -EINVAL; 380 } 381 382 static int zopt2201_write_scale_uvb_by_idx(struct zopt2201_data *data, int idx) 383 { 384 int ret; 385 386 mutex_lock(&data->lock); 387 ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res); 388 if (ret < 0) 389 goto unlock; 390 391 ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain); 392 393 unlock: 394 mutex_unlock(&data->lock); 395 return ret; 396 } 397 398 static int zopt2201_write_scale_uvb(struct zopt2201_data *data, 399 int val, int val2) 400 { 401 int i; 402 403 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++) 404 if (val == zopt2201_scale_uvb[i].scale && 405 val2 == zopt2201_scale_uvb[i].uscale) 406 return zopt2201_write_scale_uvb_by_idx(data, i); 407 408 return -EINVAL; 409 } 410 411 static int zopt2201_write_raw(struct iio_dev *indio_dev, 412 struct iio_chan_spec const *chan, 413 int val, int val2, long mask) 414 { 415 struct zopt2201_data *data = iio_priv(indio_dev); 416 417 switch (mask) { 418 case IIO_CHAN_INFO_INT_TIME: 419 return zopt2201_write_resolution(data, val, val2); 420 case IIO_CHAN_INFO_SCALE: 421 switch (chan->address) { 422 case ZOPT2201_ALS_DATA: 423 return zopt2201_write_scale_als(data, val, val2); 424 case ZOPT2201_UVB_DATA: 425 return zopt2201_write_scale_uvb(data, val, val2); 426 default: 427 return -EINVAL; 428 } 429 } 430 431 return -EINVAL; 432 } 433 434 static ssize_t zopt2201_show_int_time_available(struct device *dev, 435 struct device_attribute *attr, 436 char *buf) 437 { 438 size_t len = 0; 439 int i; 440 441 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++) 442 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ", 443 zopt2201_resolution[i].us); 444 buf[len - 1] = '\n'; 445 446 return len; 447 } 448 449 static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available); 450 451 static ssize_t zopt2201_show_als_scale_avail(struct device *dev, 452 struct device_attribute *attr, 453 char *buf) 454 { 455 ssize_t len = 0; 456 int i; 457 458 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++) 459 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ", 460 zopt2201_scale_als[i].scale, 461 zopt2201_scale_als[i].uscale); 462 buf[len - 1] = '\n'; 463 464 return len; 465 } 466 467 static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev, 468 struct device_attribute *attr, 469 char *buf) 470 { 471 ssize_t len = 0; 472 int i; 473 474 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++) 475 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ", 476 zopt2201_scale_uvb[i].scale, 477 zopt2201_scale_uvb[i].uscale); 478 buf[len - 1] = '\n'; 479 480 return len; 481 } 482 483 static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444, 484 zopt2201_show_als_scale_avail, NULL, 0); 485 static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444, 486 zopt2201_show_uvb_scale_avail, NULL, 0); 487 488 static struct attribute *zopt2201_attributes[] = { 489 &iio_dev_attr_integration_time_available.dev_attr.attr, 490 &iio_dev_attr_in_illuminance_scale_available.dev_attr.attr, 491 &iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr, 492 NULL 493 }; 494 495 static const struct attribute_group zopt2201_attribute_group = { 496 .attrs = zopt2201_attributes, 497 }; 498 499 static const struct iio_info zopt2201_info = { 500 .read_raw = zopt2201_read_raw, 501 .write_raw = zopt2201_write_raw, 502 .attrs = &zopt2201_attribute_group, 503 }; 504 505 static int zopt2201_probe(struct i2c_client *client, 506 const struct i2c_device_id *id) 507 { 508 struct zopt2201_data *data; 509 struct iio_dev *indio_dev; 510 int ret; 511 512 if (!i2c_check_functionality(client->adapter, 513 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) 514 return -EOPNOTSUPP; 515 516 ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID); 517 if (ret < 0) 518 return ret; 519 if (ret != ZOPT2201_PART_NUMBER) 520 return -ENODEV; 521 522 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 523 if (!indio_dev) 524 return -ENOMEM; 525 526 data = iio_priv(indio_dev); 527 i2c_set_clientdata(client, indio_dev); 528 data->client = client; 529 mutex_init(&data->lock); 530 531 indio_dev->dev.parent = &client->dev; 532 indio_dev->info = &zopt2201_info; 533 indio_dev->channels = zopt2201_channels; 534 indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels); 535 indio_dev->name = ZOPT2201_DRV_NAME; 536 indio_dev->modes = INDIO_DIRECT_MODE; 537 538 data->rate = ZOPT2201_MEAS_FREQ_100MS; 539 ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT); 540 if (ret < 0) 541 return ret; 542 543 ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3); 544 if (ret < 0) 545 return ret; 546 547 return devm_iio_device_register(&client->dev, indio_dev); 548 } 549 550 static const struct i2c_device_id zopt2201_id[] = { 551 { "zopt2201", 0 }, 552 { } 553 }; 554 MODULE_DEVICE_TABLE(i2c, zopt2201_id); 555 556 static struct i2c_driver zopt2201_driver = { 557 .driver = { 558 .name = ZOPT2201_DRV_NAME, 559 }, 560 .probe = zopt2201_probe, 561 .id_table = zopt2201_id, 562 }; 563 564 module_i2c_driver(zopt2201_driver); 565 566 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); 567 MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver"); 568 MODULE_LICENSE("GPL"); 569