1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity 4 * sensor 5 * 6 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> 7 * Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com> 8 * 9 * IIO driver for VL6180 (7-bit I2C slave address 0x29) 10 * 11 * Range: 0 to 100mm 12 * ALS: < 1 Lux up to 100 kLux 13 * IR: 850nm 14 * 15 * TODO: irq, threshold events, continuous mode, hardware buffer 16 */ 17 18 #include <linux/module.h> 19 #include <linux/mod_devicetable.h> 20 #include <linux/i2c.h> 21 #include <linux/mutex.h> 22 #include <linux/err.h> 23 #include <linux/of.h> 24 #include <linux/delay.h> 25 #include <linux/util_macros.h> 26 27 #include <linux/iio/iio.h> 28 #include <linux/iio/sysfs.h> 29 30 #define VL6180_DRV_NAME "vl6180" 31 32 /* Device identification register and value */ 33 #define VL6180_MODEL_ID 0x000 34 #define VL6180_MODEL_ID_VAL 0xb4 35 36 /* Configuration registers */ 37 #define VL6180_INTR_CONFIG 0x014 38 #define VL6180_INTR_CLEAR 0x015 39 #define VL6180_OUT_OF_RESET 0x016 40 #define VL6180_HOLD 0x017 41 #define VL6180_RANGE_START 0x018 42 #define VL6180_ALS_START 0x038 43 #define VL6180_ALS_GAIN 0x03f 44 #define VL6180_ALS_IT 0x040 45 46 /* Status registers */ 47 #define VL6180_RANGE_STATUS 0x04d 48 #define VL6180_ALS_STATUS 0x04e 49 #define VL6180_INTR_STATUS 0x04f 50 51 /* Result value registers */ 52 #define VL6180_ALS_VALUE 0x050 53 #define VL6180_RANGE_VALUE 0x062 54 #define VL6180_RANGE_RATE 0x066 55 56 /* bits of the RANGE_START and ALS_START register */ 57 #define VL6180_MODE_CONT BIT(1) /* continuous mode */ 58 #define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */ 59 60 /* bits of the INTR_STATUS and INTR_CONFIG register */ 61 #define VL6180_ALS_READY BIT(5) 62 #define VL6180_RANGE_READY BIT(2) 63 64 /* bits of the INTR_CLEAR register */ 65 #define VL6180_CLEAR_ERROR BIT(2) 66 #define VL6180_CLEAR_ALS BIT(1) 67 #define VL6180_CLEAR_RANGE BIT(0) 68 69 /* bits of the HOLD register */ 70 #define VL6180_HOLD_ON BIT(0) 71 72 /* default value for the ALS_IT register */ 73 #define VL6180_ALS_IT_100 0x63 /* 100 ms */ 74 75 /* values for the ALS_GAIN register */ 76 #define VL6180_ALS_GAIN_1 0x46 77 #define VL6180_ALS_GAIN_1_25 0x45 78 #define VL6180_ALS_GAIN_1_67 0x44 79 #define VL6180_ALS_GAIN_2_5 0x43 80 #define VL6180_ALS_GAIN_5 0x42 81 #define VL6180_ALS_GAIN_10 0x41 82 #define VL6180_ALS_GAIN_20 0x40 83 #define VL6180_ALS_GAIN_40 0x47 84 85 struct vl6180_data { 86 struct i2c_client *client; 87 struct mutex lock; 88 unsigned int als_gain_milli; 89 unsigned int als_it_ms; 90 }; 91 92 enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX }; 93 94 /** 95 * struct vl6180_chan_regs - Registers for accessing channels 96 * @drdy_mask: Data ready bit in status register 97 * @start_reg: Conversion start register 98 * @value_reg: Result value register 99 * @word: Register word length 100 */ 101 struct vl6180_chan_regs { 102 u8 drdy_mask; 103 u16 start_reg, value_reg; 104 bool word; 105 }; 106 107 static const struct vl6180_chan_regs vl6180_chan_regs_table[] = { 108 [VL6180_ALS] = { 109 .drdy_mask = VL6180_ALS_READY, 110 .start_reg = VL6180_ALS_START, 111 .value_reg = VL6180_ALS_VALUE, 112 .word = true, 113 }, 114 [VL6180_RANGE] = { 115 .drdy_mask = VL6180_RANGE_READY, 116 .start_reg = VL6180_RANGE_START, 117 .value_reg = VL6180_RANGE_VALUE, 118 .word = false, 119 }, 120 [VL6180_PROX] = { 121 .drdy_mask = VL6180_RANGE_READY, 122 .start_reg = VL6180_RANGE_START, 123 .value_reg = VL6180_RANGE_RATE, 124 .word = true, 125 }, 126 }; 127 128 static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf, 129 u8 len) 130 { 131 __be16 cmdbuf = cpu_to_be16(cmd); 132 struct i2c_msg msgs[2] = { 133 { .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf }, 134 { .addr = client->addr, .len = len, .buf = databuf, 135 .flags = I2C_M_RD } }; 136 int ret; 137 138 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 139 if (ret < 0) 140 dev_err(&client->dev, "failed reading register 0x%04x\n", cmd); 141 142 return ret; 143 } 144 145 static int vl6180_read_byte(struct i2c_client *client, u16 cmd) 146 { 147 u8 data; 148 int ret; 149 150 ret = vl6180_read(client, cmd, &data, sizeof(data)); 151 if (ret < 0) 152 return ret; 153 154 return data; 155 } 156 157 static int vl6180_read_word(struct i2c_client *client, u16 cmd) 158 { 159 __be16 data; 160 int ret; 161 162 ret = vl6180_read(client, cmd, &data, sizeof(data)); 163 if (ret < 0) 164 return ret; 165 166 return be16_to_cpu(data); 167 } 168 169 static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val) 170 { 171 u8 buf[3]; 172 struct i2c_msg msgs[1] = { 173 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 174 int ret; 175 176 buf[0] = cmd >> 8; 177 buf[1] = cmd & 0xff; 178 buf[2] = val; 179 180 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 181 if (ret < 0) { 182 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 183 return ret; 184 } 185 186 return 0; 187 } 188 189 static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val) 190 { 191 __be16 buf[2]; 192 struct i2c_msg msgs[1] = { 193 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 194 int ret; 195 196 buf[0] = cpu_to_be16(cmd); 197 buf[1] = cpu_to_be16(val); 198 199 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 200 if (ret < 0) { 201 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 202 return ret; 203 } 204 205 return 0; 206 } 207 208 static int vl6180_measure(struct vl6180_data *data, int addr) 209 { 210 struct i2c_client *client = data->client; 211 int tries = 20, ret; 212 u16 value; 213 214 mutex_lock(&data->lock); 215 /* Start single shot measurement */ 216 ret = vl6180_write_byte(client, 217 vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP); 218 if (ret < 0) 219 goto fail; 220 221 while (tries--) { 222 ret = vl6180_read_byte(client, VL6180_INTR_STATUS); 223 if (ret < 0) 224 goto fail; 225 226 if (ret & vl6180_chan_regs_table[addr].drdy_mask) 227 break; 228 msleep(20); 229 } 230 231 if (tries < 0) { 232 ret = -EIO; 233 goto fail; 234 } 235 236 /* Read result value from appropriate registers */ 237 ret = vl6180_chan_regs_table[addr].word ? 238 vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) : 239 vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg); 240 if (ret < 0) 241 goto fail; 242 value = ret; 243 244 /* Clear the interrupt flag after data read */ 245 ret = vl6180_write_byte(client, VL6180_INTR_CLEAR, 246 VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE); 247 if (ret < 0) 248 goto fail; 249 250 ret = value; 251 252 fail: 253 mutex_unlock(&data->lock); 254 255 return ret; 256 } 257 258 static const struct iio_chan_spec vl6180_channels[] = { 259 { 260 .type = IIO_LIGHT, 261 .address = VL6180_ALS, 262 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 263 BIT(IIO_CHAN_INFO_INT_TIME) | 264 BIT(IIO_CHAN_INFO_SCALE) | 265 BIT(IIO_CHAN_INFO_HARDWAREGAIN), 266 }, { 267 .type = IIO_DISTANCE, 268 .address = VL6180_RANGE, 269 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 270 BIT(IIO_CHAN_INFO_SCALE), 271 }, { 272 .type = IIO_PROXIMITY, 273 .address = VL6180_PROX, 274 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 275 } 276 }; 277 278 /* 279 * Available Ambient Light Sensor gain settings, 1/1000th, and 280 * corresponding setting for the VL6180_ALS_GAIN register 281 */ 282 static const int vl6180_als_gain_tab[8] = { 283 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000 284 }; 285 static const u8 vl6180_als_gain_tab_bits[8] = { 286 VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25, 287 VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5, 288 VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10, 289 VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40 290 }; 291 292 static int vl6180_read_raw(struct iio_dev *indio_dev, 293 struct iio_chan_spec const *chan, 294 int *val, int *val2, long mask) 295 { 296 struct vl6180_data *data = iio_priv(indio_dev); 297 int ret; 298 299 switch (mask) { 300 case IIO_CHAN_INFO_RAW: 301 ret = vl6180_measure(data, chan->address); 302 if (ret < 0) 303 return ret; 304 *val = ret; 305 306 return IIO_VAL_INT; 307 case IIO_CHAN_INFO_INT_TIME: 308 *val = data->als_it_ms; 309 *val2 = 1000; 310 311 return IIO_VAL_FRACTIONAL; 312 313 case IIO_CHAN_INFO_SCALE: 314 switch (chan->type) { 315 case IIO_LIGHT: 316 /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */ 317 *val = 32000; /* 0.32 * 1000 * 100 */ 318 *val2 = data->als_gain_milli * data->als_it_ms; 319 320 return IIO_VAL_FRACTIONAL; 321 322 case IIO_DISTANCE: 323 *val = 0; /* sensor reports mm, scale to meter */ 324 *val2 = 1000; 325 break; 326 default: 327 return -EINVAL; 328 } 329 330 return IIO_VAL_INT_PLUS_MICRO; 331 case IIO_CHAN_INFO_HARDWAREGAIN: 332 *val = data->als_gain_milli; 333 *val2 = 1000; 334 335 return IIO_VAL_FRACTIONAL; 336 337 default: 338 return -EINVAL; 339 } 340 } 341 342 static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40"); 343 344 static struct attribute *vl6180_attributes[] = { 345 &iio_const_attr_als_gain_available.dev_attr.attr, 346 NULL 347 }; 348 349 static const struct attribute_group vl6180_attribute_group = { 350 .attrs = vl6180_attributes, 351 }; 352 353 /* HOLD is needed before updating any config registers */ 354 static int vl6180_hold(struct vl6180_data *data, bool hold) 355 { 356 return vl6180_write_byte(data->client, VL6180_HOLD, 357 hold ? VL6180_HOLD_ON : 0); 358 } 359 360 static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2) 361 { 362 int i, ret, gain; 363 364 if (val < 1 || val > 40) 365 return -EINVAL; 366 367 gain = (val * 1000000 + val2) / 1000; 368 if (gain < 1 || gain > 40000) 369 return -EINVAL; 370 371 i = find_closest(gain, vl6180_als_gain_tab, 372 ARRAY_SIZE(vl6180_als_gain_tab)); 373 374 mutex_lock(&data->lock); 375 ret = vl6180_hold(data, true); 376 if (ret < 0) 377 goto fail; 378 379 ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, 380 vl6180_als_gain_tab_bits[i]); 381 382 if (ret >= 0) 383 data->als_gain_milli = vl6180_als_gain_tab[i]; 384 385 fail: 386 vl6180_hold(data, false); 387 mutex_unlock(&data->lock); 388 return ret; 389 } 390 391 static int vl6180_set_it(struct vl6180_data *data, int val, int val2) 392 { 393 int ret, it_ms; 394 395 it_ms = (val2 + 500) / 1000; /* round to ms */ 396 if (val != 0 || it_ms < 1 || it_ms > 512) 397 return -EINVAL; 398 399 mutex_lock(&data->lock); 400 ret = vl6180_hold(data, true); 401 if (ret < 0) 402 goto fail; 403 404 ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1); 405 406 if (ret >= 0) 407 data->als_it_ms = it_ms; 408 409 fail: 410 vl6180_hold(data, false); 411 mutex_unlock(&data->lock); 412 413 return ret; 414 } 415 416 static int vl6180_write_raw(struct iio_dev *indio_dev, 417 struct iio_chan_spec const *chan, 418 int val, int val2, long mask) 419 { 420 struct vl6180_data *data = iio_priv(indio_dev); 421 422 switch (mask) { 423 case IIO_CHAN_INFO_INT_TIME: 424 return vl6180_set_it(data, val, val2); 425 426 case IIO_CHAN_INFO_HARDWAREGAIN: 427 if (chan->type != IIO_LIGHT) 428 return -EINVAL; 429 430 return vl6180_set_als_gain(data, val, val2); 431 default: 432 return -EINVAL; 433 } 434 } 435 436 static const struct iio_info vl6180_info = { 437 .read_raw = vl6180_read_raw, 438 .write_raw = vl6180_write_raw, 439 .attrs = &vl6180_attribute_group, 440 }; 441 442 static int vl6180_init(struct vl6180_data *data) 443 { 444 struct i2c_client *client = data->client; 445 int ret; 446 447 ret = vl6180_read_byte(client, VL6180_MODEL_ID); 448 if (ret < 0) 449 return ret; 450 451 if (ret != VL6180_MODEL_ID_VAL) { 452 dev_err(&client->dev, "invalid model ID %02x\n", ret); 453 return -ENODEV; 454 } 455 456 ret = vl6180_hold(data, true); 457 if (ret < 0) 458 return ret; 459 460 ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET); 461 if (ret < 0) 462 return ret; 463 464 /* 465 * Detect false reset condition here. This bit is always set when the 466 * system comes out of reset. 467 */ 468 if (ret != 0x01) 469 dev_info(&client->dev, "device is not fresh out of reset\n"); 470 471 /* Enable ALS and Range ready interrupts */ 472 ret = vl6180_write_byte(client, VL6180_INTR_CONFIG, 473 VL6180_ALS_READY | VL6180_RANGE_READY); 474 if (ret < 0) 475 return ret; 476 477 /* ALS integration time: 100ms */ 478 data->als_it_ms = 100; 479 ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100); 480 if (ret < 0) 481 return ret; 482 483 /* ALS gain: 1 */ 484 data->als_gain_milli = 1000; 485 ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1); 486 if (ret < 0) 487 return ret; 488 489 ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00); 490 if (ret < 0) 491 return ret; 492 493 return vl6180_hold(data, false); 494 } 495 496 static int vl6180_probe(struct i2c_client *client, 497 const struct i2c_device_id *id) 498 { 499 struct vl6180_data *data; 500 struct iio_dev *indio_dev; 501 int ret; 502 503 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 504 if (!indio_dev) 505 return -ENOMEM; 506 507 data = iio_priv(indio_dev); 508 i2c_set_clientdata(client, indio_dev); 509 data->client = client; 510 mutex_init(&data->lock); 511 512 indio_dev->info = &vl6180_info; 513 indio_dev->channels = vl6180_channels; 514 indio_dev->num_channels = ARRAY_SIZE(vl6180_channels); 515 indio_dev->name = VL6180_DRV_NAME; 516 indio_dev->modes = INDIO_DIRECT_MODE; 517 518 ret = vl6180_init(data); 519 if (ret < 0) 520 return ret; 521 522 return devm_iio_device_register(&client->dev, indio_dev); 523 } 524 525 static const struct of_device_id vl6180_of_match[] = { 526 { .compatible = "st,vl6180", }, 527 { }, 528 }; 529 MODULE_DEVICE_TABLE(of, vl6180_of_match); 530 531 static const struct i2c_device_id vl6180_id[] = { 532 { "vl6180", 0 }, 533 { } 534 }; 535 MODULE_DEVICE_TABLE(i2c, vl6180_id); 536 537 static struct i2c_driver vl6180_driver = { 538 .driver = { 539 .name = VL6180_DRV_NAME, 540 .of_match_table = vl6180_of_match, 541 }, 542 .probe = vl6180_probe, 543 .id_table = vl6180_id, 544 }; 545 546 module_i2c_driver(vl6180_driver); 547 548 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); 549 MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>"); 550 MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver"); 551 MODULE_LICENSE("GPL"); 552