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 28 #include <linux/iio/iio.h> 29 #include <linux/iio/sysfs.h> 30 31 #define VL6180_DRV_NAME "vl6180" 32 33 /* Device identification register and value */ 34 #define VL6180_MODEL_ID 0x000 35 #define VL6180_MODEL_ID_VAL 0xb4 36 37 /* Configuration registers */ 38 #define VL6180_INTR_CONFIG 0x014 39 #define VL6180_INTR_CLEAR 0x015 40 #define VL6180_OUT_OF_RESET 0x016 41 #define VL6180_HOLD 0x017 42 #define VL6180_RANGE_START 0x018 43 #define VL6180_ALS_START 0x038 44 #define VL6180_ALS_GAIN 0x03f 45 #define VL6180_ALS_IT 0x040 46 47 /* Status registers */ 48 #define VL6180_RANGE_STATUS 0x04d 49 #define VL6180_ALS_STATUS 0x04e 50 #define VL6180_INTR_STATUS 0x04f 51 52 /* Result value registers */ 53 #define VL6180_ALS_VALUE 0x050 54 #define VL6180_RANGE_VALUE 0x062 55 #define VL6180_RANGE_RATE 0x066 56 57 /* bits of the RANGE_START and ALS_START register */ 58 #define VL6180_MODE_CONT BIT(1) /* continuous mode */ 59 #define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */ 60 61 /* bits of the INTR_STATUS and INTR_CONFIG register */ 62 #define VL6180_ALS_READY BIT(5) 63 #define VL6180_RANGE_READY BIT(2) 64 65 /* bits of the INTR_CLEAR register */ 66 #define VL6180_CLEAR_ERROR BIT(2) 67 #define VL6180_CLEAR_ALS BIT(1) 68 #define VL6180_CLEAR_RANGE BIT(0) 69 70 /* bits of the HOLD register */ 71 #define VL6180_HOLD_ON BIT(0) 72 73 /* default value for the ALS_IT register */ 74 #define VL6180_ALS_IT_100 0x63 /* 100 ms */ 75 76 /* values for the ALS_GAIN register */ 77 #define VL6180_ALS_GAIN_1 0x46 78 #define VL6180_ALS_GAIN_1_25 0x45 79 #define VL6180_ALS_GAIN_1_67 0x44 80 #define VL6180_ALS_GAIN_2_5 0x43 81 #define VL6180_ALS_GAIN_5 0x42 82 #define VL6180_ALS_GAIN_10 0x41 83 #define VL6180_ALS_GAIN_20 0x40 84 #define VL6180_ALS_GAIN_40 0x47 85 86 struct vl6180_data { 87 struct i2c_client *client; 88 struct mutex lock; 89 }; 90 91 enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX }; 92 93 /** 94 * struct vl6180_chan_regs - Registers for accessing channels 95 * @drdy_mask: Data ready bit in status register 96 * @start_reg: Conversion start register 97 * @value_reg: Result value register 98 * @word: Register word length 99 */ 100 struct vl6180_chan_regs { 101 u8 drdy_mask; 102 u16 start_reg, value_reg; 103 bool word; 104 }; 105 106 static const struct vl6180_chan_regs vl6180_chan_regs_table[] = { 107 [VL6180_ALS] = { 108 .drdy_mask = VL6180_ALS_READY, 109 .start_reg = VL6180_ALS_START, 110 .value_reg = VL6180_ALS_VALUE, 111 .word = true, 112 }, 113 [VL6180_RANGE] = { 114 .drdy_mask = VL6180_RANGE_READY, 115 .start_reg = VL6180_RANGE_START, 116 .value_reg = VL6180_RANGE_VALUE, 117 .word = false, 118 }, 119 [VL6180_PROX] = { 120 .drdy_mask = VL6180_RANGE_READY, 121 .start_reg = VL6180_RANGE_START, 122 .value_reg = VL6180_RANGE_RATE, 123 .word = true, 124 }, 125 }; 126 127 static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf, 128 u8 len) 129 { 130 __be16 cmdbuf = cpu_to_be16(cmd); 131 struct i2c_msg msgs[2] = { 132 { .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf }, 133 { .addr = client->addr, .len = len, .buf = databuf, 134 .flags = I2C_M_RD } }; 135 int ret; 136 137 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 138 if (ret < 0) 139 dev_err(&client->dev, "failed reading register 0x%04x\n", cmd); 140 141 return ret; 142 } 143 144 static int vl6180_read_byte(struct i2c_client *client, u16 cmd) 145 { 146 u8 data; 147 int ret; 148 149 ret = vl6180_read(client, cmd, &data, sizeof(data)); 150 if (ret < 0) 151 return ret; 152 153 return data; 154 } 155 156 static int vl6180_read_word(struct i2c_client *client, u16 cmd) 157 { 158 __be16 data; 159 int ret; 160 161 ret = vl6180_read(client, cmd, &data, sizeof(data)); 162 if (ret < 0) 163 return ret; 164 165 return be16_to_cpu(data); 166 } 167 168 static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val) 169 { 170 u8 buf[3]; 171 struct i2c_msg msgs[1] = { 172 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 173 int ret; 174 175 buf[0] = cmd >> 8; 176 buf[1] = cmd & 0xff; 177 buf[2] = val; 178 179 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 180 if (ret < 0) { 181 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 182 return ret; 183 } 184 185 return 0; 186 } 187 188 static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val) 189 { 190 __be16 buf[2]; 191 struct i2c_msg msgs[1] = { 192 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } }; 193 int ret; 194 195 buf[0] = cpu_to_be16(cmd); 196 buf[1] = cpu_to_be16(val); 197 198 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 199 if (ret < 0) { 200 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd); 201 return ret; 202 } 203 204 return 0; 205 } 206 207 static int vl6180_measure(struct vl6180_data *data, int addr) 208 { 209 struct i2c_client *client = data->client; 210 int tries = 20, ret; 211 u16 value; 212 213 mutex_lock(&data->lock); 214 /* Start single shot measurement */ 215 ret = vl6180_write_byte(client, 216 vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP); 217 if (ret < 0) 218 goto fail; 219 220 while (tries--) { 221 ret = vl6180_read_byte(client, VL6180_INTR_STATUS); 222 if (ret < 0) 223 goto fail; 224 225 if (ret & vl6180_chan_regs_table[addr].drdy_mask) 226 break; 227 msleep(20); 228 } 229 230 if (tries < 0) { 231 ret = -EIO; 232 goto fail; 233 } 234 235 /* Read result value from appropriate registers */ 236 ret = vl6180_chan_regs_table[addr].word ? 237 vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) : 238 vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg); 239 if (ret < 0) 240 goto fail; 241 value = ret; 242 243 /* Clear the interrupt flag after data read */ 244 ret = vl6180_write_byte(client, VL6180_INTR_CLEAR, 245 VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE); 246 if (ret < 0) 247 goto fail; 248 249 ret = value; 250 251 fail: 252 mutex_unlock(&data->lock); 253 254 return ret; 255 } 256 257 static const struct iio_chan_spec vl6180_channels[] = { 258 { 259 .type = IIO_LIGHT, 260 .address = VL6180_ALS, 261 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 262 BIT(IIO_CHAN_INFO_INT_TIME) | 263 BIT(IIO_CHAN_INFO_SCALE) | 264 BIT(IIO_CHAN_INFO_HARDWAREGAIN), 265 }, { 266 .type = IIO_DISTANCE, 267 .address = VL6180_RANGE, 268 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 269 BIT(IIO_CHAN_INFO_SCALE), 270 }, { 271 .type = IIO_PROXIMITY, 272 .address = VL6180_PROX, 273 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 274 } 275 }; 276 277 /* 278 * Columns 3 & 4 represent the same value in decimal and hex notations. 279 * Kept in order to avoid the datatype conversion while reading the 280 * hardware_gain. 281 */ 282 static const int vl6180_als_gain[8][4] = { 283 { 1, 0, 70, VL6180_ALS_GAIN_1 }, 284 { 1, 250000, 69, VL6180_ALS_GAIN_1_25 }, 285 { 1, 670000, 68, VL6180_ALS_GAIN_1_67 }, 286 { 2, 500000, 67, VL6180_ALS_GAIN_2_5 }, 287 { 5, 0, 66, VL6180_ALS_GAIN_5 }, 288 { 10, 0, 65, VL6180_ALS_GAIN_10 }, 289 { 20, 0, 64, VL6180_ALS_GAIN_20 }, 290 { 40, 0, 71, VL6180_ALS_GAIN_40 } 291 }; 292 293 static int vl6180_read_raw(struct iio_dev *indio_dev, 294 struct iio_chan_spec const *chan, 295 int *val, int *val2, long mask) 296 { 297 struct vl6180_data *data = iio_priv(indio_dev); 298 int ret, i; 299 300 switch (mask) { 301 case IIO_CHAN_INFO_RAW: 302 ret = vl6180_measure(data, chan->address); 303 if (ret < 0) 304 return ret; 305 *val = ret; 306 307 return IIO_VAL_INT; 308 case IIO_CHAN_INFO_INT_TIME: 309 ret = vl6180_read_word(data->client, VL6180_ALS_IT); 310 if (ret < 0) 311 return ret; 312 *val = 0; /* 1 count = 1ms (0 = 1ms) */ 313 *val2 = (ret + 1) * 1000; /* convert to seconds */ 314 315 return IIO_VAL_INT_PLUS_MICRO; 316 case IIO_CHAN_INFO_SCALE: 317 switch (chan->type) { 318 case IIO_LIGHT: 319 *val = 0; /* one ALS count is 0.32 Lux */ 320 *val2 = 320000; 321 break; 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 ret = vl6180_read_byte(data->client, VL6180_ALS_GAIN); 333 if (ret < 0) 334 return -EINVAL; 335 for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) { 336 if (ret == vl6180_als_gain[i][2]) { 337 *val = vl6180_als_gain[i][0]; 338 *val2 = vl6180_als_gain[i][1]; 339 } 340 } 341 342 return IIO_VAL_INT_PLUS_MICRO; 343 default: 344 return -EINVAL; 345 } 346 } 347 348 static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40"); 349 350 static struct attribute *vl6180_attributes[] = { 351 &iio_const_attr_als_gain_available.dev_attr.attr, 352 NULL 353 }; 354 355 static const struct attribute_group vl6180_attribute_group = { 356 .attrs = vl6180_attributes, 357 }; 358 359 /* HOLD is needed before updating any config registers */ 360 static int vl6180_hold(struct vl6180_data *data, bool hold) 361 { 362 return vl6180_write_byte(data->client, VL6180_HOLD, 363 hold ? VL6180_HOLD_ON : 0); 364 } 365 366 static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2) 367 { 368 int i, ret; 369 370 for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) { 371 if (val == vl6180_als_gain[i][0] && 372 val2 == vl6180_als_gain[i][1]) { 373 mutex_lock(&data->lock); 374 ret = vl6180_hold(data, true); 375 if (ret < 0) 376 goto fail; 377 ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN, 378 vl6180_als_gain[i][3]); 379 fail: 380 vl6180_hold(data, false); 381 mutex_unlock(&data->lock); 382 return ret; 383 } 384 } 385 386 return -EINVAL; 387 } 388 389 static int vl6180_set_it(struct vl6180_data *data, int val2) 390 { 391 int ret; 392 393 mutex_lock(&data->lock); 394 ret = vl6180_hold(data, true); 395 if (ret < 0) 396 goto fail; 397 ret = vl6180_write_word(data->client, VL6180_ALS_IT, 398 (val2 - 500) / 1000); /* write value in ms */ 399 fail: 400 vl6180_hold(data, false); 401 mutex_unlock(&data->lock); 402 403 return ret; 404 } 405 406 static int vl6180_write_raw(struct iio_dev *indio_dev, 407 struct iio_chan_spec const *chan, 408 int val, int val2, long mask) 409 { 410 struct vl6180_data *data = iio_priv(indio_dev); 411 412 switch (mask) { 413 case IIO_CHAN_INFO_INT_TIME: 414 if (val != 0 || val2 < 500 || val2 >= 512500) 415 return -EINVAL; 416 417 return vl6180_set_it(data, val2); 418 case IIO_CHAN_INFO_HARDWAREGAIN: 419 if (chan->type != IIO_LIGHT) 420 return -EINVAL; 421 422 return vl6180_set_als_gain(data, val, val2); 423 default: 424 return -EINVAL; 425 } 426 } 427 428 static const struct iio_info vl6180_info = { 429 .read_raw = vl6180_read_raw, 430 .write_raw = vl6180_write_raw, 431 .attrs = &vl6180_attribute_group, 432 .driver_module = THIS_MODULE, 433 }; 434 435 static int vl6180_init(struct vl6180_data *data) 436 { 437 struct i2c_client *client = data->client; 438 int ret; 439 440 ret = vl6180_read_byte(client, VL6180_MODEL_ID); 441 if (ret < 0) 442 return ret; 443 444 if (ret != VL6180_MODEL_ID_VAL) { 445 dev_err(&client->dev, "invalid model ID %02x\n", ret); 446 return -ENODEV; 447 } 448 449 ret = vl6180_hold(data, true); 450 if (ret < 0) 451 return ret; 452 453 ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET); 454 if (ret < 0) 455 return ret; 456 457 /* 458 * Detect false reset condition here. This bit is always set when the 459 * system comes out of reset. 460 */ 461 if (ret != 0x01) 462 dev_info(&client->dev, "device is not fresh out of reset\n"); 463 464 /* Enable ALS and Range ready interrupts */ 465 ret = vl6180_write_byte(client, VL6180_INTR_CONFIG, 466 VL6180_ALS_READY | VL6180_RANGE_READY); 467 if (ret < 0) 468 return ret; 469 470 /* ALS integration time: 100ms */ 471 ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100); 472 if (ret < 0) 473 return ret; 474 475 /* ALS gain: 1 */ 476 ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1); 477 if (ret < 0) 478 return ret; 479 480 ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00); 481 if (ret < 0) 482 return ret; 483 484 return vl6180_hold(data, false); 485 } 486 487 static int vl6180_probe(struct i2c_client *client, 488 const struct i2c_device_id *id) 489 { 490 struct vl6180_data *data; 491 struct iio_dev *indio_dev; 492 int ret; 493 494 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 495 if (!indio_dev) 496 return -ENOMEM; 497 498 data = iio_priv(indio_dev); 499 i2c_set_clientdata(client, indio_dev); 500 data->client = client; 501 mutex_init(&data->lock); 502 503 indio_dev->dev.parent = &client->dev; 504 indio_dev->info = &vl6180_info; 505 indio_dev->channels = vl6180_channels; 506 indio_dev->num_channels = ARRAY_SIZE(vl6180_channels); 507 indio_dev->name = VL6180_DRV_NAME; 508 indio_dev->modes = INDIO_DIRECT_MODE; 509 510 ret = vl6180_init(data); 511 if (ret < 0) 512 return ret; 513 514 return devm_iio_device_register(&client->dev, indio_dev); 515 } 516 517 static const struct of_device_id vl6180_of_match[] = { 518 { .compatible = "st,vl6180", }, 519 { }, 520 }; 521 MODULE_DEVICE_TABLE(of, vl6180_of_match); 522 523 static const struct i2c_device_id vl6180_id[] = { 524 { "vl6180", 0 }, 525 { } 526 }; 527 MODULE_DEVICE_TABLE(i2c, vl6180_id); 528 529 static struct i2c_driver vl6180_driver = { 530 .driver = { 531 .name = VL6180_DRV_NAME, 532 .of_match_table = of_match_ptr(vl6180_of_match), 533 }, 534 .probe = vl6180_probe, 535 .id_table = vl6180_id, 536 }; 537 538 module_i2c_driver(vl6180_driver); 539 540 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>"); 541 MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>"); 542 MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver"); 543 MODULE_LICENSE("GPL"); 544