1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * VEML3235 Ambient Light Sensor 4 * 5 * Copyright (c) 2024, Javier Carrasco <javier.carrasco.cruz@gmail.com> 6 * 7 * Datasheet: https://www.vishay.com/docs/80131/veml3235.pdf 8 * Appnote-80222: https://www.vishay.com/docs/80222/designingveml3235.pdf 9 */ 10 11 #include <linux/err.h> 12 #include <linux/i2c.h> 13 #include <linux/iio/iio.h> 14 #include <linux/module.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/regmap.h> 17 #include <linux/regulator/consumer.h> 18 19 #define VEML3235_REG_CONF 0x00 20 #define VEML3235_REG_WH_DATA 0x04 21 #define VEML3235_REG_ALS_DATA 0x05 22 #define VEML3235_REG_ID 0x09 23 24 #define VEML3235_CONF_SD BIT(0) 25 #define VEML3235_CONF_SD0 BIT(15) 26 27 struct veml3235_rf { 28 struct regmap_field *it; 29 struct regmap_field *gain; 30 struct regmap_field *id; 31 }; 32 33 struct veml3235_data { 34 struct i2c_client *client; 35 struct device *dev; 36 struct regmap *regmap; 37 struct veml3235_rf rf; 38 }; 39 40 static const int veml3235_it_times[][2] = { 41 { 0, 50000 }, 42 { 0, 100000 }, 43 { 0, 200000 }, 44 { 0, 400000 }, 45 { 0, 800000 }, 46 }; 47 48 static const int veml3235_scale_vals[] = { 1, 2, 4, 8 }; 49 50 static int veml3235_power_on(struct veml3235_data *data) 51 { 52 int ret; 53 54 ret = regmap_clear_bits(data->regmap, VEML3235_REG_CONF, 55 VEML3235_CONF_SD | VEML3235_CONF_SD0); 56 if (ret) 57 return ret; 58 59 /* Wait 4 ms to let processor & oscillator start correctly */ 60 fsleep(4000); 61 62 return 0; 63 } 64 65 static int veml3235_shut_down(struct veml3235_data *data) 66 { 67 return regmap_set_bits(data->regmap, VEML3235_REG_CONF, 68 VEML3235_CONF_SD | VEML3235_CONF_SD0); 69 } 70 71 static void veml3235_shut_down_action(void *data) 72 { 73 veml3235_shut_down(data); 74 } 75 76 enum veml3235_chan { 77 CH_ALS, 78 CH_WHITE, 79 }; 80 81 static const struct iio_chan_spec veml3235_channels[] = { 82 { 83 .type = IIO_LIGHT, 84 .channel = CH_ALS, 85 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 86 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | 87 BIT(IIO_CHAN_INFO_SCALE), 88 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | 89 BIT(IIO_CHAN_INFO_SCALE), 90 }, 91 { 92 .type = IIO_INTENSITY, 93 .channel = CH_WHITE, 94 .modified = 1, 95 .channel2 = IIO_MOD_LIGHT_BOTH, 96 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 97 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | 98 BIT(IIO_CHAN_INFO_SCALE), 99 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | 100 BIT(IIO_CHAN_INFO_SCALE), 101 }, 102 }; 103 104 static const struct regmap_config veml3235_regmap_config = { 105 .name = "veml3235_regmap", 106 .reg_bits = 8, 107 .val_bits = 16, 108 .max_register = VEML3235_REG_ID, 109 .val_format_endian = REGMAP_ENDIAN_LITTLE, 110 }; 111 112 static int veml3235_get_it(struct veml3235_data *data, int *val, int *val2) 113 { 114 int ret, reg; 115 116 ret = regmap_field_read(data->rf.it, ®); 117 if (ret) 118 return ret; 119 120 switch (reg) { 121 case 0: 122 *val2 = 50000; 123 break; 124 case 1: 125 *val2 = 100000; 126 break; 127 case 2: 128 *val2 = 200000; 129 break; 130 case 3: 131 *val2 = 400000; 132 break; 133 case 4: 134 *val2 = 800000; 135 break; 136 default: 137 return -EINVAL; 138 } 139 140 *val = 0; 141 142 return IIO_VAL_INT_PLUS_MICRO; 143 } 144 145 static int veml3235_set_it(struct iio_dev *indio_dev, int val, int val2) 146 { 147 struct veml3235_data *data = iio_priv(indio_dev); 148 int ret, new_it; 149 150 if (val) 151 return -EINVAL; 152 153 switch (val2) { 154 case 50000: 155 new_it = 0x00; 156 break; 157 case 100000: 158 new_it = 0x01; 159 break; 160 case 200000: 161 new_it = 0x02; 162 break; 163 case 400000: 164 new_it = 0x03; 165 break; 166 case 800000: 167 new_it = 0x04; 168 break; 169 default: 170 return -EINVAL; 171 } 172 173 ret = regmap_field_write(data->rf.it, new_it); 174 if (ret) { 175 dev_err(data->dev, 176 "failed to update integration time: %d\n", ret); 177 return ret; 178 } 179 180 return 0; 181 } 182 183 static int veml3235_set_gain(struct iio_dev *indio_dev, int val, int val2) 184 { 185 struct veml3235_data *data = iio_priv(indio_dev); 186 int ret, new_gain; 187 188 if (val2 != 0) 189 return -EINVAL; 190 191 switch (val) { 192 case 1: 193 new_gain = 0x00; 194 break; 195 case 2: 196 new_gain = 0x01; 197 break; 198 case 4: 199 new_gain = 0x03; 200 break; 201 case 8: 202 new_gain = 0x07; 203 break; 204 default: 205 return -EINVAL; 206 } 207 208 ret = regmap_field_write(data->rf.gain, new_gain); 209 if (ret) { 210 dev_err(data->dev, "failed to set gain: %d\n", ret); 211 return ret; 212 } 213 214 return 0; 215 } 216 217 static int veml3235_get_gain(struct veml3235_data *data, int *val) 218 { 219 int ret, reg; 220 221 ret = regmap_field_read(data->rf.gain, ®); 222 if (ret) { 223 dev_err(data->dev, "failed to read gain %d\n", ret); 224 return ret; 225 } 226 227 switch (reg & 0x03) { 228 case 0: 229 *val = 1; 230 break; 231 case 1: 232 *val = 2; 233 break; 234 case 3: 235 *val = 4; 236 break; 237 default: 238 return -EINVAL; 239 } 240 241 /* Double gain */ 242 if (reg & 0x04) 243 *val *= 2; 244 245 return IIO_VAL_INT; 246 } 247 248 static int veml3235_read_raw(struct iio_dev *indio_dev, 249 struct iio_chan_spec const *chan, int *val, 250 int *val2, long mask) 251 { 252 struct veml3235_data *data = iio_priv(indio_dev); 253 struct regmap *regmap = data->regmap; 254 int ret, reg; 255 256 switch (mask) { 257 case IIO_CHAN_INFO_RAW: 258 switch (chan->type) { 259 case IIO_LIGHT: 260 ret = regmap_read(regmap, VEML3235_REG_ALS_DATA, ®); 261 if (ret < 0) 262 return ret; 263 264 *val = reg; 265 return IIO_VAL_INT; 266 case IIO_INTENSITY: 267 ret = regmap_read(regmap, VEML3235_REG_WH_DATA, ®); 268 if (ret < 0) 269 return ret; 270 271 *val = reg; 272 return IIO_VAL_INT; 273 default: 274 return -EINVAL; 275 } 276 case IIO_CHAN_INFO_INT_TIME: 277 return veml3235_get_it(data, val, val2); 278 case IIO_CHAN_INFO_SCALE: 279 return veml3235_get_gain(data, val); 280 default: 281 return -EINVAL; 282 } 283 } 284 285 static int veml3235_read_avail(struct iio_dev *indio_dev, 286 struct iio_chan_spec const *chan, 287 const int **vals, int *type, int *length, 288 long mask) 289 { 290 switch (mask) { 291 case IIO_CHAN_INFO_INT_TIME: 292 *vals = (int *)&veml3235_it_times; 293 *length = 2 * ARRAY_SIZE(veml3235_it_times); 294 *type = IIO_VAL_INT_PLUS_MICRO; 295 return IIO_AVAIL_LIST; 296 case IIO_CHAN_INFO_SCALE: 297 *vals = (int *)&veml3235_scale_vals; 298 *length = ARRAY_SIZE(veml3235_scale_vals); 299 *type = IIO_VAL_INT; 300 return IIO_AVAIL_LIST; 301 default: 302 return -EINVAL; 303 } 304 } 305 306 static int veml3235_write_raw(struct iio_dev *indio_dev, 307 struct iio_chan_spec const *chan, 308 int val, int val2, long mask) 309 { 310 switch (mask) { 311 case IIO_CHAN_INFO_INT_TIME: 312 return veml3235_set_it(indio_dev, val, val2); 313 case IIO_CHAN_INFO_SCALE: 314 return veml3235_set_gain(indio_dev, val, val2); 315 } 316 317 return -EINVAL; 318 } 319 320 static void veml3235_read_id(struct veml3235_data *data) 321 { 322 int ret, reg; 323 324 ret = regmap_field_read(data->rf.id, ®); 325 if (ret) { 326 dev_info(data->dev, "failed to read ID\n"); 327 return; 328 } 329 330 if (reg != 0x35) 331 dev_info(data->dev, "Unknown ID %d\n", reg); 332 } 333 334 static const struct reg_field veml3235_rf_it = 335 REG_FIELD(VEML3235_REG_CONF, 4, 6); 336 337 static const struct reg_field veml3235_rf_gain = 338 REG_FIELD(VEML3235_REG_CONF, 11, 13); 339 340 static const struct reg_field veml3235_rf_id = 341 REG_FIELD(VEML3235_REG_ID, 0, 7); 342 343 static int veml3235_regfield_init(struct veml3235_data *data) 344 { 345 struct regmap *regmap = data->regmap; 346 struct device *dev = data->dev; 347 struct regmap_field *rm_field; 348 struct veml3235_rf *rf = &data->rf; 349 350 rm_field = devm_regmap_field_alloc(dev, regmap, veml3235_rf_it); 351 if (IS_ERR(rm_field)) 352 return PTR_ERR(rm_field); 353 rf->it = rm_field; 354 355 rm_field = devm_regmap_field_alloc(dev, regmap, veml3235_rf_gain); 356 if (IS_ERR(rm_field)) 357 return PTR_ERR(rm_field); 358 rf->gain = rm_field; 359 360 rm_field = devm_regmap_field_alloc(dev, regmap, veml3235_rf_id); 361 if (IS_ERR(rm_field)) 362 return PTR_ERR(rm_field); 363 rf->id = rm_field; 364 365 return 0; 366 } 367 368 static int veml3235_hw_init(struct iio_dev *indio_dev) 369 { 370 struct veml3235_data *data = iio_priv(indio_dev); 371 struct device *dev = data->dev; 372 int ret; 373 374 /* Set gain to 1 and integration time to 100 ms */ 375 ret = regmap_field_write(data->rf.gain, 0x00); 376 if (ret) 377 return dev_err_probe(data->dev, ret, "failed to set gain\n"); 378 379 ret = regmap_field_write(data->rf.it, 0x01); 380 if (ret) 381 return dev_err_probe(data->dev, ret, 382 "failed to set integration time\n"); 383 384 ret = veml3235_power_on(data); 385 if (ret) 386 return dev_err_probe(dev, ret, "failed to power on\n"); 387 388 return devm_add_action_or_reset(dev, veml3235_shut_down_action, data); 389 } 390 391 static const struct iio_info veml3235_info = { 392 .read_raw = veml3235_read_raw, 393 .read_avail = veml3235_read_avail, 394 .write_raw = veml3235_write_raw, 395 }; 396 397 static int veml3235_probe(struct i2c_client *client) 398 { 399 struct device *dev = &client->dev; 400 struct veml3235_data *data; 401 struct iio_dev *indio_dev; 402 struct regmap *regmap; 403 int ret; 404 405 regmap = devm_regmap_init_i2c(client, &veml3235_regmap_config); 406 if (IS_ERR(regmap)) 407 return dev_err_probe(dev, PTR_ERR(regmap), 408 "failed to setup regmap\n"); 409 410 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 411 if (!indio_dev) 412 return -ENOMEM; 413 414 data = iio_priv(indio_dev); 415 i2c_set_clientdata(client, indio_dev); 416 data->client = client; 417 data->dev = dev; 418 data->regmap = regmap; 419 420 ret = veml3235_regfield_init(data); 421 if (ret) 422 return dev_err_probe(dev, ret, "failed to init regfield\n"); 423 424 ret = devm_regulator_get_enable(dev, "vdd"); 425 if (ret) 426 return dev_err_probe(dev, ret, "failed to enable regulator\n"); 427 428 indio_dev->name = "veml3235"; 429 indio_dev->channels = veml3235_channels; 430 indio_dev->num_channels = ARRAY_SIZE(veml3235_channels); 431 indio_dev->modes = INDIO_DIRECT_MODE; 432 indio_dev->info = &veml3235_info; 433 434 veml3235_read_id(data); 435 436 ret = veml3235_hw_init(indio_dev); 437 if (ret < 0) 438 return ret; 439 440 return devm_iio_device_register(dev, indio_dev); 441 } 442 443 static int veml3235_runtime_suspend(struct device *dev) 444 { 445 struct veml3235_data *data = iio_priv(dev_get_drvdata(dev)); 446 int ret; 447 448 ret = veml3235_shut_down(data); 449 if (ret < 0) 450 dev_err(data->dev, "failed to suspend: %d\n", ret); 451 452 return ret; 453 } 454 455 static int veml3235_runtime_resume(struct device *dev) 456 { 457 struct veml3235_data *data = iio_priv(dev_get_drvdata(dev)); 458 int ret; 459 460 ret = veml3235_power_on(data); 461 if (ret < 0) 462 dev_err(data->dev, "failed to resume: %d\n", ret); 463 464 return ret; 465 } 466 467 static DEFINE_RUNTIME_DEV_PM_OPS(veml3235_pm_ops, veml3235_runtime_suspend, 468 veml3235_runtime_resume, NULL); 469 470 static const struct of_device_id veml3235_of_match[] = { 471 { .compatible = "vishay,veml3235" }, 472 { } 473 }; 474 MODULE_DEVICE_TABLE(of, veml3235_of_match); 475 476 static const struct i2c_device_id veml3235_id[] = { 477 { "veml3235" }, 478 { } 479 }; 480 MODULE_DEVICE_TABLE(i2c, veml3235_id); 481 482 static struct i2c_driver veml3235_driver = { 483 .driver = { 484 .name = "veml3235", 485 .of_match_table = veml3235_of_match, 486 .pm = pm_ptr(&veml3235_pm_ops), 487 }, 488 .probe = veml3235_probe, 489 .id_table = veml3235_id, 490 }; 491 module_i2c_driver(veml3235_driver); 492 493 MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>"); 494 MODULE_DESCRIPTION("VEML3235 Ambient Light Sensor"); 495 MODULE_LICENSE("GPL"); 496