1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * max30102.c - Support for MAX30102 heart rate and pulse oximeter sensor 4 * 5 * Copyright (C) 2017 Matt Ranostay <matt@ranostay.consulting> 6 * 7 * Support for MAX30105 optical particle sensor 8 * Copyright (C) 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> 9 * 10 * 7-bit I2C chip address: 0x57 11 * TODO: proximity power saving feature 12 */ 13 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/interrupt.h> 17 #include <linux/delay.h> 18 #include <linux/err.h> 19 #include <linux/irq.h> 20 #include <linux/i2c.h> 21 #include <linux/mutex.h> 22 #include <linux/of.h> 23 #include <linux/regmap.h> 24 #include <linux/iio/iio.h> 25 #include <linux/iio/buffer.h> 26 #include <linux/iio/kfifo_buf.h> 27 28 #define MAX30102_REGMAP_NAME "max30102_regmap" 29 #define MAX30102_DRV_NAME "max30102" 30 #define MAX30102_PART_NUMBER 0x15 31 32 enum max30102_chip_id { 33 max30102, 34 max30105, 35 }; 36 37 enum max3012_led_idx { 38 MAX30102_LED_RED, 39 MAX30102_LED_IR, 40 MAX30105_LED_GREEN, 41 }; 42 43 #define MAX30102_REG_INT_STATUS 0x00 44 #define MAX30102_REG_INT_STATUS_PWR_RDY BIT(0) 45 #define MAX30102_REG_INT_STATUS_PROX_INT BIT(4) 46 #define MAX30102_REG_INT_STATUS_ALC_OVF BIT(5) 47 #define MAX30102_REG_INT_STATUS_PPG_RDY BIT(6) 48 #define MAX30102_REG_INT_STATUS_FIFO_RDY BIT(7) 49 50 #define MAX30102_REG_INT_ENABLE 0x02 51 #define MAX30102_REG_INT_ENABLE_PROX_INT_EN BIT(4) 52 #define MAX30102_REG_INT_ENABLE_ALC_OVF_EN BIT(5) 53 #define MAX30102_REG_INT_ENABLE_PPG_EN BIT(6) 54 #define MAX30102_REG_INT_ENABLE_FIFO_EN BIT(7) 55 #define MAX30102_REG_INT_ENABLE_MASK 0xf0 56 #define MAX30102_REG_INT_ENABLE_MASK_SHIFT 4 57 58 #define MAX30102_REG_FIFO_WR_PTR 0x04 59 #define MAX30102_REG_FIFO_OVR_CTR 0x05 60 #define MAX30102_REG_FIFO_RD_PTR 0x06 61 #define MAX30102_REG_FIFO_DATA 0x07 62 #define MAX30102_REG_FIFO_DATA_BYTES 3 63 64 #define MAX30102_REG_FIFO_CONFIG 0x08 65 #define MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES BIT(1) 66 #define MAX30102_REG_FIFO_CONFIG_AVG_SHIFT 5 67 #define MAX30102_REG_FIFO_CONFIG_AFULL BIT(0) 68 69 #define MAX30102_REG_MODE_CONFIG 0x09 70 #define MAX30102_REG_MODE_CONFIG_MODE_NONE 0x00 71 #define MAX30102_REG_MODE_CONFIG_MODE_HR 0x02 /* red LED */ 72 #define MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2 0x03 /* red + IR LED */ 73 #define MAX30102_REG_MODE_CONFIG_MODE_MULTI 0x07 /* multi-LED mode */ 74 #define MAX30102_REG_MODE_CONFIG_MODE_MASK GENMASK(2, 0) 75 #define MAX30102_REG_MODE_CONFIG_PWR BIT(7) 76 77 #define MAX30102_REG_MODE_CONTROL_SLOT21 0x11 /* multi-LED control */ 78 #define MAX30102_REG_MODE_CONTROL_SLOT43 0x12 79 #define MAX30102_REG_MODE_CONTROL_SLOT_MASK (GENMASK(6, 4) | GENMASK(2, 0)) 80 #define MAX30102_REG_MODE_CONTROL_SLOT_SHIFT 4 81 82 #define MAX30102_REG_SPO2_CONFIG 0x0a 83 #define MAX30102_REG_SPO2_CONFIG_PULSE_411_US 0x03 84 #define MAX30102_REG_SPO2_CONFIG_SR_400HZ 0x03 85 #define MAX30102_REG_SPO2_CONFIG_SR_MASK 0x07 86 #define MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT 2 87 #define MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS BIT(0) 88 #define MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT 5 89 90 #define MAX30102_REG_RED_LED_CONFIG 0x0c 91 #define MAX30102_REG_IR_LED_CONFIG 0x0d 92 #define MAX30105_REG_GREEN_LED_CONFIG 0x0e 93 94 #define MAX30102_REG_TEMP_CONFIG 0x21 95 #define MAX30102_REG_TEMP_CONFIG_TEMP_EN BIT(0) 96 97 #define MAX30102_REG_TEMP_INTEGER 0x1f 98 #define MAX30102_REG_TEMP_FRACTION 0x20 99 100 #define MAX30102_REG_REV_ID 0xfe 101 #define MAX30102_REG_PART_ID 0xff 102 103 struct max30102_data { 104 struct i2c_client *client; 105 struct iio_dev *indio_dev; 106 struct mutex lock; 107 struct regmap *regmap; 108 enum max30102_chip_id chip_id; 109 110 u8 buffer[12]; 111 __be32 processed_buffer[3]; /* 3 x 18-bit (padded to 32-bits) */ 112 }; 113 114 static const struct regmap_config max30102_regmap_config = { 115 .name = MAX30102_REGMAP_NAME, 116 117 .reg_bits = 8, 118 .val_bits = 8, 119 }; 120 121 static const unsigned long max30102_scan_masks[] = { 122 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR), 123 0 124 }; 125 126 static const unsigned long max30105_scan_masks[] = { 127 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR), 128 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) | 129 BIT(MAX30105_LED_GREEN), 130 0 131 }; 132 133 #define MAX30102_INTENSITY_CHANNEL(_si, _mod) { \ 134 .type = IIO_INTENSITY, \ 135 .channel2 = _mod, \ 136 .modified = 1, \ 137 .scan_index = _si, \ 138 .scan_type = { \ 139 .sign = 'u', \ 140 .shift = 8, \ 141 .realbits = 18, \ 142 .storagebits = 32, \ 143 .endianness = IIO_BE, \ 144 }, \ 145 } 146 147 static const struct iio_chan_spec max30102_channels[] = { 148 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED), 149 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR), 150 { 151 .type = IIO_TEMP, 152 .info_mask_separate = 153 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), 154 .scan_index = -1, 155 }, 156 }; 157 158 static const struct iio_chan_spec max30105_channels[] = { 159 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED), 160 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR), 161 MAX30102_INTENSITY_CHANNEL(MAX30105_LED_GREEN, IIO_MOD_LIGHT_GREEN), 162 { 163 .type = IIO_TEMP, 164 .info_mask_separate = 165 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), 166 .scan_index = -1, 167 }, 168 }; 169 170 static int max30102_set_power(struct max30102_data *data, bool en) 171 { 172 return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG, 173 MAX30102_REG_MODE_CONFIG_PWR, 174 en ? 0 : MAX30102_REG_MODE_CONFIG_PWR); 175 } 176 177 static int max30102_set_powermode(struct max30102_data *data, u8 mode, bool en) 178 { 179 u8 reg = mode; 180 181 if (!en) 182 reg |= MAX30102_REG_MODE_CONFIG_PWR; 183 184 return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG, 185 MAX30102_REG_MODE_CONFIG_PWR | 186 MAX30102_REG_MODE_CONFIG_MODE_MASK, reg); 187 } 188 189 #define MAX30102_MODE_CONTROL_LED_SLOTS(slot2, slot1) \ 190 ((slot2 << MAX30102_REG_MODE_CONTROL_SLOT_SHIFT) | slot1) 191 192 static int max30102_buffer_postenable(struct iio_dev *indio_dev) 193 { 194 struct max30102_data *data = iio_priv(indio_dev); 195 int ret; 196 u8 reg; 197 198 switch (*indio_dev->active_scan_mask) { 199 case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR): 200 reg = MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2; 201 break; 202 case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) | 203 BIT(MAX30105_LED_GREEN): 204 ret = regmap_update_bits(data->regmap, 205 MAX30102_REG_MODE_CONTROL_SLOT21, 206 MAX30102_REG_MODE_CONTROL_SLOT_MASK, 207 MAX30102_MODE_CONTROL_LED_SLOTS(2, 1)); 208 if (ret) 209 return ret; 210 211 ret = regmap_update_bits(data->regmap, 212 MAX30102_REG_MODE_CONTROL_SLOT43, 213 MAX30102_REG_MODE_CONTROL_SLOT_MASK, 214 MAX30102_MODE_CONTROL_LED_SLOTS(0, 3)); 215 if (ret) 216 return ret; 217 218 reg = MAX30102_REG_MODE_CONFIG_MODE_MULTI; 219 break; 220 default: 221 return -EINVAL; 222 } 223 224 return max30102_set_powermode(data, reg, true); 225 } 226 227 static int max30102_buffer_predisable(struct iio_dev *indio_dev) 228 { 229 struct max30102_data *data = iio_priv(indio_dev); 230 231 return max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE, 232 false); 233 } 234 235 static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = { 236 .postenable = max30102_buffer_postenable, 237 .predisable = max30102_buffer_predisable, 238 }; 239 240 static inline int max30102_fifo_count(struct max30102_data *data) 241 { 242 unsigned int val; 243 int ret; 244 245 ret = regmap_read(data->regmap, MAX30102_REG_INT_STATUS, &val); 246 if (ret) 247 return ret; 248 249 /* FIFO has one sample slot left */ 250 if (val & MAX30102_REG_INT_STATUS_FIFO_RDY) 251 return 1; 252 253 return 0; 254 } 255 256 #define MAX30102_COPY_DATA(i) \ 257 memcpy(&data->processed_buffer[(i)], \ 258 &buffer[(i) * MAX30102_REG_FIFO_DATA_BYTES], \ 259 MAX30102_REG_FIFO_DATA_BYTES) 260 261 static int max30102_read_measurement(struct max30102_data *data, 262 unsigned int measurements) 263 { 264 int ret; 265 u8 *buffer = (u8 *) &data->buffer; 266 267 ret = i2c_smbus_read_i2c_block_data(data->client, 268 MAX30102_REG_FIFO_DATA, 269 measurements * 270 MAX30102_REG_FIFO_DATA_BYTES, 271 buffer); 272 273 switch (measurements) { 274 case 3: 275 MAX30102_COPY_DATA(2); 276 /* fall through */ 277 case 2: 278 MAX30102_COPY_DATA(1); 279 /* fall through */ 280 case 1: 281 MAX30102_COPY_DATA(0); 282 break; 283 default: 284 return -EINVAL; 285 } 286 287 return (ret == measurements * MAX30102_REG_FIFO_DATA_BYTES) ? 288 0 : -EINVAL; 289 } 290 291 static irqreturn_t max30102_interrupt_handler(int irq, void *private) 292 { 293 struct iio_dev *indio_dev = private; 294 struct max30102_data *data = iio_priv(indio_dev); 295 unsigned int measurements = bitmap_weight(indio_dev->active_scan_mask, 296 indio_dev->masklength); 297 int ret, cnt = 0; 298 299 mutex_lock(&data->lock); 300 301 while (cnt || (cnt = max30102_fifo_count(data)) > 0) { 302 ret = max30102_read_measurement(data, measurements); 303 if (ret) 304 break; 305 306 iio_push_to_buffers(data->indio_dev, data->processed_buffer); 307 cnt--; 308 } 309 310 mutex_unlock(&data->lock); 311 312 return IRQ_HANDLED; 313 } 314 315 static int max30102_get_current_idx(unsigned int val, int *reg) 316 { 317 /* each step is 0.200 mA */ 318 *reg = val / 200; 319 320 return *reg > 0xff ? -EINVAL : 0; 321 } 322 323 static int max30102_led_init(struct max30102_data *data) 324 { 325 struct device *dev = &data->client->dev; 326 struct device_node *np = dev->of_node; 327 unsigned int val; 328 int reg, ret; 329 330 ret = of_property_read_u32(np, "maxim,red-led-current-microamp", &val); 331 if (ret) { 332 dev_info(dev, "no red-led-current-microamp set\n"); 333 334 /* Default to 7 mA RED LED */ 335 val = 7000; 336 } 337 338 ret = max30102_get_current_idx(val, ®); 339 if (ret) { 340 dev_err(dev, "invalid RED LED current setting %d\n", val); 341 return ret; 342 } 343 344 ret = regmap_write(data->regmap, MAX30102_REG_RED_LED_CONFIG, reg); 345 if (ret) 346 return ret; 347 348 if (data->chip_id == max30105) { 349 ret = of_property_read_u32(np, 350 "maxim,green-led-current-microamp", &val); 351 if (ret) { 352 dev_info(dev, "no green-led-current-microamp set\n"); 353 354 /* Default to 7 mA green LED */ 355 val = 7000; 356 } 357 358 ret = max30102_get_current_idx(val, ®); 359 if (ret) { 360 dev_err(dev, "invalid green LED current setting %d\n", 361 val); 362 return ret; 363 } 364 365 ret = regmap_write(data->regmap, MAX30105_REG_GREEN_LED_CONFIG, 366 reg); 367 if (ret) 368 return ret; 369 } 370 371 ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val); 372 if (ret) { 373 dev_info(dev, "no ir-led-current-microamp set\n"); 374 375 /* Default to 7 mA IR LED */ 376 val = 7000; 377 } 378 379 ret = max30102_get_current_idx(val, ®); 380 if (ret) { 381 dev_err(dev, "invalid IR LED current setting %d\n", val); 382 return ret; 383 } 384 385 return regmap_write(data->regmap, MAX30102_REG_IR_LED_CONFIG, reg); 386 } 387 388 static int max30102_chip_init(struct max30102_data *data) 389 { 390 int ret; 391 392 /* setup LED current settings */ 393 ret = max30102_led_init(data); 394 if (ret) 395 return ret; 396 397 /* configure 18-bit HR + SpO2 readings at 400Hz */ 398 ret = regmap_write(data->regmap, MAX30102_REG_SPO2_CONFIG, 399 (MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS 400 << MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT) | 401 (MAX30102_REG_SPO2_CONFIG_SR_400HZ 402 << MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT) | 403 MAX30102_REG_SPO2_CONFIG_PULSE_411_US); 404 if (ret) 405 return ret; 406 407 /* average 4 samples + generate FIFO interrupt */ 408 ret = regmap_write(data->regmap, MAX30102_REG_FIFO_CONFIG, 409 (MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES 410 << MAX30102_REG_FIFO_CONFIG_AVG_SHIFT) | 411 MAX30102_REG_FIFO_CONFIG_AFULL); 412 if (ret) 413 return ret; 414 415 /* enable FIFO interrupt */ 416 return regmap_update_bits(data->regmap, MAX30102_REG_INT_ENABLE, 417 MAX30102_REG_INT_ENABLE_MASK, 418 MAX30102_REG_INT_ENABLE_FIFO_EN); 419 } 420 421 static int max30102_read_temp(struct max30102_data *data, int *val) 422 { 423 int ret; 424 unsigned int reg; 425 426 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_INTEGER, ®); 427 if (ret < 0) 428 return ret; 429 *val = reg << 4; 430 431 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_FRACTION, ®); 432 if (ret < 0) 433 return ret; 434 435 *val |= reg & 0xf; 436 *val = sign_extend32(*val, 11); 437 438 return 0; 439 } 440 441 static int max30102_get_temp(struct max30102_data *data, int *val, bool en) 442 { 443 int ret; 444 445 if (en) { 446 ret = max30102_set_power(data, true); 447 if (ret) 448 return ret; 449 } 450 451 /* start acquisition */ 452 ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG, 453 MAX30102_REG_TEMP_CONFIG_TEMP_EN, 454 MAX30102_REG_TEMP_CONFIG_TEMP_EN); 455 if (ret) 456 goto out; 457 458 msleep(35); 459 ret = max30102_read_temp(data, val); 460 461 out: 462 if (en) 463 max30102_set_power(data, false); 464 465 return ret; 466 } 467 468 static int max30102_read_raw(struct iio_dev *indio_dev, 469 struct iio_chan_spec const *chan, 470 int *val, int *val2, long mask) 471 { 472 struct max30102_data *data = iio_priv(indio_dev); 473 int ret = -EINVAL; 474 475 switch (mask) { 476 case IIO_CHAN_INFO_RAW: 477 /* 478 * Temperature reading can only be acquired when not in 479 * shutdown; leave shutdown briefly when buffer not running 480 */ 481 mutex_lock(&indio_dev->mlock); 482 if (!iio_buffer_enabled(indio_dev)) 483 ret = max30102_get_temp(data, val, true); 484 else 485 ret = max30102_get_temp(data, val, false); 486 mutex_unlock(&indio_dev->mlock); 487 if (ret) 488 return ret; 489 490 ret = IIO_VAL_INT; 491 break; 492 case IIO_CHAN_INFO_SCALE: 493 *val = 1000; /* 62.5 */ 494 *val2 = 16; 495 ret = IIO_VAL_FRACTIONAL; 496 break; 497 } 498 499 return ret; 500 } 501 502 static const struct iio_info max30102_info = { 503 .read_raw = max30102_read_raw, 504 }; 505 506 static int max30102_probe(struct i2c_client *client, 507 const struct i2c_device_id *id) 508 { 509 struct max30102_data *data; 510 struct iio_buffer *buffer; 511 struct iio_dev *indio_dev; 512 int ret; 513 unsigned int reg; 514 515 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 516 if (!indio_dev) 517 return -ENOMEM; 518 519 buffer = devm_iio_kfifo_allocate(&client->dev); 520 if (!buffer) 521 return -ENOMEM; 522 523 iio_device_attach_buffer(indio_dev, buffer); 524 525 indio_dev->name = MAX30102_DRV_NAME; 526 indio_dev->info = &max30102_info; 527 indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE); 528 indio_dev->setup_ops = &max30102_buffer_setup_ops; 529 indio_dev->dev.parent = &client->dev; 530 531 data = iio_priv(indio_dev); 532 data->indio_dev = indio_dev; 533 data->client = client; 534 data->chip_id = id->driver_data; 535 536 mutex_init(&data->lock); 537 i2c_set_clientdata(client, indio_dev); 538 539 switch (data->chip_id) { 540 case max30105: 541 indio_dev->channels = max30105_channels; 542 indio_dev->num_channels = ARRAY_SIZE(max30105_channels); 543 indio_dev->available_scan_masks = max30105_scan_masks; 544 break; 545 case max30102: 546 indio_dev->channels = max30102_channels; 547 indio_dev->num_channels = ARRAY_SIZE(max30102_channels); 548 indio_dev->available_scan_masks = max30102_scan_masks; 549 break; 550 default: 551 return -ENODEV; 552 } 553 554 data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config); 555 if (IS_ERR(data->regmap)) { 556 dev_err(&client->dev, "regmap initialization failed\n"); 557 return PTR_ERR(data->regmap); 558 } 559 560 /* check part ID */ 561 ret = regmap_read(data->regmap, MAX30102_REG_PART_ID, ®); 562 if (ret) 563 return ret; 564 if (reg != MAX30102_PART_NUMBER) 565 return -ENODEV; 566 567 /* show revision ID */ 568 ret = regmap_read(data->regmap, MAX30102_REG_REV_ID, ®); 569 if (ret) 570 return ret; 571 dev_dbg(&client->dev, "max3010x revision %02x\n", reg); 572 573 /* clear mode setting, chip shutdown */ 574 ret = max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE, 575 false); 576 if (ret) 577 return ret; 578 579 ret = max30102_chip_init(data); 580 if (ret) 581 return ret; 582 583 if (client->irq <= 0) { 584 dev_err(&client->dev, "no valid irq defined\n"); 585 return -EINVAL; 586 } 587 588 ret = devm_request_threaded_irq(&client->dev, client->irq, 589 NULL, max30102_interrupt_handler, 590 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 591 "max30102_irq", indio_dev); 592 if (ret) { 593 dev_err(&client->dev, "request irq (%d) failed\n", client->irq); 594 return ret; 595 } 596 597 return iio_device_register(indio_dev); 598 } 599 600 static int max30102_remove(struct i2c_client *client) 601 { 602 struct iio_dev *indio_dev = i2c_get_clientdata(client); 603 struct max30102_data *data = iio_priv(indio_dev); 604 605 iio_device_unregister(indio_dev); 606 max30102_set_power(data, false); 607 608 return 0; 609 } 610 611 static const struct i2c_device_id max30102_id[] = { 612 { "max30102", max30102 }, 613 { "max30105", max30105 }, 614 {} 615 }; 616 MODULE_DEVICE_TABLE(i2c, max30102_id); 617 618 static const struct of_device_id max30102_dt_ids[] = { 619 { .compatible = "maxim,max30102" }, 620 { .compatible = "maxim,max30105" }, 621 { } 622 }; 623 MODULE_DEVICE_TABLE(of, max30102_dt_ids); 624 625 static struct i2c_driver max30102_driver = { 626 .driver = { 627 .name = MAX30102_DRV_NAME, 628 .of_match_table = of_match_ptr(max30102_dt_ids), 629 }, 630 .probe = max30102_probe, 631 .remove = max30102_remove, 632 .id_table = max30102_id, 633 }; 634 module_i2c_driver(max30102_driver); 635 636 MODULE_AUTHOR("Matt Ranostay <matt@ranostay.consulting>"); 637 MODULE_DESCRIPTION("MAX30102 heart rate/pulse oximeter and MAX30105 particle sensor driver"); 638 MODULE_LICENSE("GPL"); 639