1 /* 2 * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity 3 * sensor 4 * 5 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> 6 * Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com> 7 * 8 * This file is subject to the terms and conditions of version 2 of 9 * the GNU General Public License. See the file COPYING in the main 10 * directory of this archive for more details. 11 * 12 * IIO driver for VL6180 (7-bit I2C slave address 0x29) 13 * 14 * Range: 0 to 100mm 15 * ALS: < 1 Lux up to 100 kLux 16 * IR: 850nm 17 * 18 * TODO: irq, threshold events, continuous mode, hardware buffer 19 */ 20 21 #include <linux/module.h> 22 #include <linux/i2c.h> 23 #include <linux/mutex.h> 24 #include <linux/err.h> 25 #include <linux/of.h> 26 #include <linux/delay.h> 27 #include <linux/util_macros.h> 28 29 #include <linux/iio/iio.h> 30 #include <linux/iio/sysfs.h> 31 32 #define VL6180_DRV_NAME "vl6180" 33 34 /* Device identification register and value */ 35 #define VL6180_MODEL_ID 0x000 36 #define VL6180_MODEL_ID_VAL 0xb4 37 38 /* Configuration registers */ 39 #define VL6180_INTR_CONFIG 0x014 40 #define VL6180_INTR_CLEAR 0x015 41 #define VL6180_OUT_OF_RESET 0x016 42 #define VL6180_HOLD 0x017 43 #define VL6180_RANGE_START 0x018 44 #define VL6180_ALS_START 0x038 45 #define VL6180_ALS_GAIN 0x03f 46 #define VL6180_ALS_IT 0x040 47 48 /* Status registers */ 49 #define VL6180_RANGE_STATUS 0x04d 50 #define VL6180_ALS_STATUS 0x04e 51 #define VL6180_INTR_STATUS 0x04f 52 53 /* Result value registers */ 54 #define VL6180_ALS_VALUE 0x050 55 #define VL6180_RANGE_VALUE 0x062 56 #define VL6180_RANGE_RATE 0x066 57 58 /* bits of the RANGE_START and ALS_START register */ 59 #define VL6180_MODE_CONT BIT(1) /* continuous mode */ 60 #define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */ 61 62 /* bits of the INTR_STATUS and INTR_CONFIG register */ 63 #define VL6180_ALS_READY BIT(5) 64 #define VL6180_RANGE_READY BIT(2) 65 66 /* bits of the INTR_CLEAR register */ 67 #define VL6180_CLEAR_ERROR BIT(2) 68 #define VL6180_CLEAR_ALS BIT(1) 69 #define VL6180_CLEAR_RANGE BIT(0) 70 71 /* bits of the HOLD register */ 72 #define VL6180_HOLD_ON BIT(0) 73 74 /* default value for the ALS_IT register */ 75 #define VL6180_ALS_IT_100 0x63 /* 100 ms */ 76 77 /* values for the ALS_GAIN register */ 78 #define VL6180_ALS_GAIN_1 0x46 79 #define VL6180_ALS_GAIN_1_25 0x45 80 #define VL6180_ALS_GAIN_1_67 0x44 81 #define VL6180_ALS_GAIN_2_5 0x43 82 #define VL6180_ALS_GAIN_5 0x42 83 #define VL6180_ALS_GAIN_10 0x41 84 #define VL6180_ALS_GAIN_20 0x40 85 #define VL6180_ALS_GAIN_40 0x47 86 87 struct vl6180_data { 88 struct i2c_client *client; 89 struct mutex lock; 90 unsigned int als_gain_milli; 91 unsigned int als_it_ms; 92 }; 93 94 enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX }; 95 96 /** 97 * struct vl6180_chan_regs - Registers for accessing channels 98 * @drdy_mask: Data ready bit in status register 99 * @start_reg: Conversion start register 100 * @value_reg: Result value register 101 * @word: Register word length 102 */ 103 struct vl6180_chan_regs { 104 u8 drdy_mask; 105 u16 start_reg, value_reg; 106 bool word; 107 }; 108 109 static const struct vl6180_chan_regs vl6180_chan_regs_table[] = { 110 [VL6180_ALS] = { 111 .drdy_mask = VL6180_ALS_READY, 112 .start_reg = VL6180_ALS_START, 113 .value_reg = VL6180_ALS_VALUE, 114 .word = true, 115 }, 116 [VL6180_RANGE] = { 117 .drdy_mask = VL6180_RANGE_READY, 118 .start_reg = VL6180_RANGE_START, 119 .value_reg = VL6180_RANGE_VALUE, 120 .word = false, 121 }, 122 [VL6180_PROX] = { 123 .drdy_mask = VL6180_RANGE_READY, 124 .start_reg = VL6180_RANGE_START, 125 .value_reg = VL6180_RANGE_RATE, 126 .word = true, 127 }, 128 }; 129 130 static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf, 131 u8 len) 132 { 133 __be16 cmdbuf = cpu_to_be16(cmd); 134 struct i2c_msg msgs[2] = { 135 { .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf }, 136 { .addr = client->addr, .len = len, .buf = databuf, 137 .flags = I2C_M_RD } }; 138 int ret; 139 140 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 141 if (ret < 0) 142 dev_err(&client->dev, "failed reading register 0x%04x\n", cmd); 143 144 return ret; 145 } 146 147 static int vl6180_read_byte(struct i2c_client *client, u16 cmd) 148 { 149 u8 data; 150 int ret; 151 152 ret = vl6180_read(client, cmd, &data, sizeof(data)); 153 if (ret < 0) 154 return ret; 155 156 return data; 157 } 158 159 static int vl6180_read_word(struct i2c_client *client, u16 cmd) 160 { 161 __be16 data; 162 int ret; 163 164 ret = vl6180_read(client, cmd, &data, sizeof(data)); 165 if (ret < 0) 166 return ret; 167 168 return be16_to_cpu(data); 169 } 170 171 static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val) 172 { 173 u8 buf[3]; 174 struct i2c_msg msgs[1] = { 175 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 176 int ret; 177 178 buf[0] = cmd >> 8; 179 buf[1] = cmd & 0xff; 180 buf[2] = val; 181 182 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 183 if (ret < 0) { 184 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 185 return ret; 186 } 187 188 return 0; 189 } 190 191 static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val) 192 { 193 __be16 buf[2]; 194 struct i2c_msg msgs[1] = { 195 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 196 int ret; 197 198 buf[0] = cpu_to_be16(cmd); 199 buf[1] = cpu_to_be16(val); 200 201 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 202 if (ret < 0) { 203 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 204 return ret; 205 } 206 207 return 0; 208 } 209 210 static int vl6180_measure(struct vl6180_data *data, int addr) 211 { 212 struct i2c_client *client = data->client; 213 int tries = 20, ret; 214 u16 value; 215 216 mutex_lock(&data->lock); 217 /* Start single shot measurement */ 218 ret = vl6180_write_byte(client, 219 vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP); 220 if (ret < 0) 221 goto fail; 222 223 while (tries--) { 224 ret = vl6180_read_byte(client, VL6180_INTR_STATUS); 225 if (ret < 0) 226 goto fail; 227 228 if (ret & vl6180_chan_regs_table[addr].drdy_mask) 229 break; 230 msleep(20); 231 } 232 233 if (tries < 0) { 234 ret = -EIO; 235 goto fail; 236 } 237 238 /* Read result value from appropriate registers */ 239 ret = vl6180_chan_regs_table[addr].word ? 240 vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) : 241 vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg); 242 if (ret < 0) 243 goto fail; 244 value = ret; 245 246 /* Clear the interrupt flag after data read */ 247 ret = vl6180_write_byte(client, VL6180_INTR_CLEAR, 248 VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE); 249 if (ret < 0) 250 goto fail; 251 252 ret = value; 253 254 fail: 255 mutex_unlock(&data->lock); 256 257 return ret; 258 } 259 260 static const struct iio_chan_spec vl6180_channels[] = { 261 { 262 .type = IIO_LIGHT, 263 .address = VL6180_ALS, 264 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 265 BIT(IIO_CHAN_INFO_INT_TIME) | 266 BIT(IIO_CHAN_INFO_SCALE) | 267 BIT(IIO_CHAN_INFO_HARDWAREGAIN), 268 }, { 269 .type = IIO_DISTANCE, 270 .address = VL6180_RANGE, 271 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 272 BIT(IIO_CHAN_INFO_SCALE), 273 }, { 274 .type = IIO_PROXIMITY, 275 .address = VL6180_PROX, 276 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 277 } 278 }; 279 280 /* 281 * Available Ambient Light Sensor gain settings, 1/1000th, and 282 * corresponding setting for the VL6180_ALS_GAIN register 283 */ 284 static const int vl6180_als_gain_tab[8] = { 285 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000 286 }; 287 static const u8 vl6180_als_gain_tab_bits[8] = { 288 VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25, 289 VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5, 290 VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10, 291 VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40 292 }; 293 294 static int vl6180_read_raw(struct iio_dev *indio_dev, 295 struct iio_chan_spec const *chan, 296 int *val, int *val2, long mask) 297 { 298 struct vl6180_data *data = iio_priv(indio_dev); 299 int ret; 300 301 switch (mask) { 302 case IIO_CHAN_INFO_RAW: 303 ret = vl6180_measure(data, chan->address); 304 if (ret < 0) 305 return ret; 306 *val = ret; 307 308 return IIO_VAL_INT; 309 case IIO_CHAN_INFO_INT_TIME: 310 *val = data->als_it_ms; 311 *val2 = 1000; 312 313 return IIO_VAL_FRACTIONAL; 314 315 case IIO_CHAN_INFO_SCALE: 316 switch (chan->type) { 317 case IIO_LIGHT: 318 /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */ 319 *val = 32000; /* 0.32 * 1000 * 100 */ 320 *val2 = data->als_gain_milli * data->als_it_ms; 321 322 return IIO_VAL_FRACTIONAL; 323 324 case IIO_DISTANCE: 325 *val = 0; /* sensor reports mm, scale to meter */ 326 *val2 = 1000; 327 break; 328 default: 329 return -EINVAL; 330 } 331 332 return IIO_VAL_INT_PLUS_MICRO; 333 case IIO_CHAN_INFO_HARDWAREGAIN: 334 *val = data->als_gain_milli; 335 *val2 = 1000; 336 337 return IIO_VAL_FRACTIONAL; 338 339 default: 340 return -EINVAL; 341 } 342 } 343 344 static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40"); 345 346 static struct attribute *vl6180_attributes[] = { 347 &iio_const_attr_als_gain_available.dev_attr.attr, 348 NULL 349 }; 350 351 static const struct attribute_group vl6180_attribute_group = { 352 .attrs = vl6180_attributes, 353 }; 354 355 /* HOLD is needed before updating any config registers */ 356 static int vl6180_hold(struct vl6180_data *data, bool hold) 357 { 358 return vl6180_write_byte(data->client, VL6180_HOLD, 359 hold ? VL6180_HOLD_ON : 0); 360 } 361 362 static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2) 363 { 364 int i, ret, gain; 365 366 if (val < 1 || val > 40) 367 return -EINVAL; 368 369 gain = (val * 1000000 + val2) / 1000; 370 if (gain < 1 || gain > 40000) 371 return -EINVAL; 372 373 i = find_closest(gain, vl6180_als_gain_tab, 374 ARRAY_SIZE(vl6180_als_gain_tab)); 375 376 mutex_lock(&data->lock); 377 ret = vl6180_hold(data, true); 378 if (ret < 0) 379 goto fail; 380 381 ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, 382 vl6180_als_gain_tab_bits[i]); 383 384 if (ret >= 0) 385 data->als_gain_milli = vl6180_als_gain_tab[i]; 386 387 fail: 388 vl6180_hold(data, false); 389 mutex_unlock(&data->lock); 390 return ret; 391 } 392 393 static int vl6180_set_it(struct vl6180_data *data, int val, int val2) 394 { 395 int ret, it_ms; 396 397 it_ms = (val2 + 500) / 1000; /* round to ms */ 398 if (val != 0 || it_ms < 1 || it_ms > 512) 399 return -EINVAL; 400 401 mutex_lock(&data->lock); 402 ret = vl6180_hold(data, true); 403 if (ret < 0) 404 goto fail; 405 406 ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1); 407 408 if (ret >= 0) 409 data->als_it_ms = it_ms; 410 411 fail: 412 vl6180_hold(data, false); 413 mutex_unlock(&data->lock); 414 415 return ret; 416 } 417 418 static int vl6180_write_raw(struct iio_dev *indio_dev, 419 struct iio_chan_spec const *chan, 420 int val, int val2, long mask) 421 { 422 struct vl6180_data *data = iio_priv(indio_dev); 423 424 switch (mask) { 425 case IIO_CHAN_INFO_INT_TIME: 426 return vl6180_set_it(data, val, val2); 427 428 case IIO_CHAN_INFO_HARDWAREGAIN: 429 if (chan->type != IIO_LIGHT) 430 return -EINVAL; 431 432 return vl6180_set_als_gain(data, val, val2); 433 default: 434 return -EINVAL; 435 } 436 } 437 438 static const struct iio_info vl6180_info = { 439 .read_raw = vl6180_read_raw, 440 .write_raw = vl6180_write_raw, 441 .attrs = &vl6180_attribute_group, 442 }; 443 444 static int vl6180_init(struct vl6180_data *data) 445 { 446 struct i2c_client *client = data->client; 447 int ret; 448 449 ret = vl6180_read_byte(client, VL6180_MODEL_ID); 450 if (ret < 0) 451 return ret; 452 453 if (ret != VL6180_MODEL_ID_VAL) { 454 dev_err(&client->dev, "invalid model ID %02x\n", ret); 455 return -ENODEV; 456 } 457 458 ret = vl6180_hold(data, true); 459 if (ret < 0) 460 return ret; 461 462 ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET); 463 if (ret < 0) 464 return ret; 465 466 /* 467 * Detect false reset condition here. This bit is always set when the 468 * system comes out of reset. 469 */ 470 if (ret != 0x01) 471 dev_info(&client->dev, "device is not fresh out of reset\n"); 472 473 /* Enable ALS and Range ready interrupts */ 474 ret = vl6180_write_byte(client, VL6180_INTR_CONFIG, 475 VL6180_ALS_READY | VL6180_RANGE_READY); 476 if (ret < 0) 477 return ret; 478 479 /* ALS integration time: 100ms */ 480 data->als_it_ms = 100; 481 ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100); 482 if (ret < 0) 483 return ret; 484 485 /* ALS gain: 1 */ 486 data->als_gain_milli = 1000; 487 ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1); 488 if (ret < 0) 489 return ret; 490 491 ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00); 492 if (ret < 0) 493 return ret; 494 495 return vl6180_hold(data, false); 496 } 497 498 static int vl6180_probe(struct i2c_client *client, 499 const struct i2c_device_id *id) 500 { 501 struct vl6180_data *data; 502 struct iio_dev *indio_dev; 503 int ret; 504 505 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 506 if (!indio_dev) 507 return -ENOMEM; 508 509 data = iio_priv(indio_dev); 510 i2c_set_clientdata(client, indio_dev); 511 data->client = client; 512 mutex_init(&data->lock); 513 514 indio_dev->dev.parent = &client->dev; 515 indio_dev->info = &vl6180_info; 516 indio_dev->channels = vl6180_channels; 517 indio_dev->num_channels = ARRAY_SIZE(vl6180_channels); 518 indio_dev->name = VL6180_DRV_NAME; 519 indio_dev->modes = INDIO_DIRECT_MODE; 520 521 ret = vl6180_init(data); 522 if (ret < 0) 523 return ret; 524 525 return devm_iio_device_register(&client->dev, indio_dev); 526 } 527 528 static const struct of_device_id vl6180_of_match[] = { 529 { .compatible = "st,vl6180", }, 530 { }, 531 }; 532 MODULE_DEVICE_TABLE(of, vl6180_of_match); 533 534 static const struct i2c_device_id vl6180_id[] = { 535 { "vl6180", 0 }, 536 { } 537 }; 538 MODULE_DEVICE_TABLE(i2c, vl6180_id); 539 540 static struct i2c_driver vl6180_driver = { 541 .driver = { 542 .name = VL6180_DRV_NAME, 543 .of_match_table = of_match_ptr(vl6180_of_match), 544 }, 545 .probe = vl6180_probe, 546 .id_table = vl6180_id, 547 }; 548 549 module_i2c_driver(vl6180_driver); 550 551 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); 552 MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>"); 553 MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver"); 554 MODULE_LICENSE("GPL"); 555