1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * max30102.c - Support for MAX30102 heart rate and pulse oximeter sensor
5 * Copyright (C) 2017 Matt Ranostay <matt@ranostay.consulting>
7 * Support for MAX30105 optical particle sensor
8 * Copyright (C) 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
10 * 7-bit I2C chip address: 0x57
11 * TODO: proximity power saving feature
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>
23 #include <linux/regmap.h>
24 #include <linux/iio/iio.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/kfifo_buf.h>
28 #define MAX30102_REGMAP_NAME "max30102_regmap"
29 #define MAX30102_DRV_NAME "max30102"
30 #define MAX30102_PART_NUMBER 0x15
32 enum max30102_chip_id {
37 enum max3012_led_idx {
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)
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
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
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)
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)
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
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
90 #define MAX30102_REG_RED_LED_CONFIG 0x0c
91 #define MAX30102_REG_IR_LED_CONFIG 0x0d
92 #define MAX30105_REG_GREEN_LED_CONFIG 0x0e
94 #define MAX30102_REG_TEMP_CONFIG 0x21
95 #define MAX30102_REG_TEMP_CONFIG_TEMP_EN BIT(0)
97 #define MAX30102_REG_TEMP_INTEGER 0x1f
98 #define MAX30102_REG_TEMP_FRACTION 0x20
100 #define MAX30102_REG_REV_ID 0xfe
101 #define MAX30102_REG_PART_ID 0xff
103 struct max30102_data {
104 struct i2c_client *client;
105 struct iio_dev *indio_dev;
107 struct regmap *regmap;
108 enum max30102_chip_id chip_id;
111 __be32 processed_buffer[3]; /* 3 x 18-bit (padded to 32-bits) */
114 static const struct regmap_config max30102_regmap_config = {
115 .name = MAX30102_REGMAP_NAME,
121 static const unsigned long max30102_scan_masks[] = {
122 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR),
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),
133 #define MAX30102_INTENSITY_CHANNEL(_si, _mod) { \
134 .type = IIO_INTENSITY, \
143 .endianness = IIO_BE, \
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),
152 .info_mask_separate =
153 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
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),
164 .info_mask_separate =
165 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
170 static int max30102_set_power(struct max30102_data *data, bool en)
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);
177 static int max30102_set_powermode(struct max30102_data *data, u8 mode, bool en)
182 reg |= MAX30102_REG_MODE_CONFIG_PWR;
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);
189 #define MAX30102_MODE_CONTROL_LED_SLOTS(slot2, slot1) \
190 ((slot2 << MAX30102_REG_MODE_CONTROL_SLOT_SHIFT) | slot1)
192 static int max30102_buffer_postenable(struct iio_dev *indio_dev)
194 struct max30102_data *data = iio_priv(indio_dev);
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;
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));
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));
218 reg = MAX30102_REG_MODE_CONFIG_MODE_MULTI;
224 return max30102_set_powermode(data, reg, true);
227 static int max30102_buffer_predisable(struct iio_dev *indio_dev)
229 struct max30102_data *data = iio_priv(indio_dev);
231 return max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
235 static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = {
236 .postenable = max30102_buffer_postenable,
237 .predisable = max30102_buffer_predisable,
240 static inline int max30102_fifo_count(struct max30102_data *data)
245 ret = regmap_read(data->regmap, MAX30102_REG_INT_STATUS, &val);
249 /* FIFO has one sample slot left */
250 if (val & MAX30102_REG_INT_STATUS_FIFO_RDY)
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)
261 static int max30102_read_measurement(struct max30102_data *data,
262 unsigned int measurements)
265 u8 *buffer = (u8 *) &data->buffer;
267 ret = i2c_smbus_read_i2c_block_data(data->client,
268 MAX30102_REG_FIFO_DATA,
270 MAX30102_REG_FIFO_DATA_BYTES,
273 switch (measurements) {
275 MAX30102_COPY_DATA(2);
278 MAX30102_COPY_DATA(1);
281 MAX30102_COPY_DATA(0);
287 return (ret == measurements * MAX30102_REG_FIFO_DATA_BYTES) ?
291 static irqreturn_t max30102_interrupt_handler(int irq, void *private)
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);
299 mutex_lock(&data->lock);
301 while (cnt || (cnt = max30102_fifo_count(data)) > 0) {
302 ret = max30102_read_measurement(data, measurements);
306 iio_push_to_buffers(data->indio_dev, data->processed_buffer);
310 mutex_unlock(&data->lock);
315 static int max30102_get_current_idx(unsigned int val, int *reg)
317 /* each step is 0.200 mA */
320 return *reg > 0xff ? -EINVAL : 0;
323 static int max30102_led_init(struct max30102_data *data)
325 struct device *dev = &data->client->dev;
326 struct device_node *np = dev->of_node;
330 ret = of_property_read_u32(np, "maxim,red-led-current-microamp", &val);
332 dev_info(dev, "no red-led-current-microamp set\n");
334 /* Default to 7 mA RED LED */
338 ret = max30102_get_current_idx(val, ®);
340 dev_err(dev, "invalid RED LED current setting %d\n", val);
344 ret = regmap_write(data->regmap, MAX30102_REG_RED_LED_CONFIG, reg);
348 if (data->chip_id == max30105) {
349 ret = of_property_read_u32(np,
350 "maxim,green-led-current-microamp", &val);
352 dev_info(dev, "no green-led-current-microamp set\n");
354 /* Default to 7 mA green LED */
358 ret = max30102_get_current_idx(val, ®);
360 dev_err(dev, "invalid green LED current setting %d\n",
365 ret = regmap_write(data->regmap, MAX30105_REG_GREEN_LED_CONFIG,
371 ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val);
373 dev_info(dev, "no ir-led-current-microamp set\n");
375 /* Default to 7 mA IR LED */
379 ret = max30102_get_current_idx(val, ®);
381 dev_err(dev, "invalid IR LED current setting %d\n", val);
385 return regmap_write(data->regmap, MAX30102_REG_IR_LED_CONFIG, reg);
388 static int max30102_chip_init(struct max30102_data *data)
392 /* setup LED current settings */
393 ret = max30102_led_init(data);
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);
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);
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);
421 static int max30102_read_temp(struct max30102_data *data, int *val)
426 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_INTEGER, ®);
431 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_FRACTION, ®);
436 *val = sign_extend32(*val, 11);
441 static int max30102_get_temp(struct max30102_data *data, int *val, bool en)
446 ret = max30102_set_power(data, true);
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);
459 ret = max30102_read_temp(data, val);
463 max30102_set_power(data, false);
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)
472 struct max30102_data *data = iio_priv(indio_dev);
476 case IIO_CHAN_INFO_RAW:
478 * Temperature reading can only be acquired when not in
479 * shutdown; leave shutdown briefly when buffer not running
481 mutex_lock(&indio_dev->mlock);
482 if (!iio_buffer_enabled(indio_dev))
483 ret = max30102_get_temp(data, val, true);
485 ret = max30102_get_temp(data, val, false);
486 mutex_unlock(&indio_dev->mlock);
492 case IIO_CHAN_INFO_SCALE:
493 *val = 1000; /* 62.5 */
495 ret = IIO_VAL_FRACTIONAL;
502 static const struct iio_info max30102_info = {
503 .read_raw = max30102_read_raw,
506 static int max30102_probe(struct i2c_client *client,
507 const struct i2c_device_id *id)
509 struct max30102_data *data;
510 struct iio_buffer *buffer;
511 struct iio_dev *indio_dev;
515 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
519 buffer = devm_iio_kfifo_allocate(&client->dev);
523 iio_device_attach_buffer(indio_dev, buffer);
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;
530 data = iio_priv(indio_dev);
531 data->indio_dev = indio_dev;
532 data->client = client;
533 data->chip_id = id->driver_data;
535 mutex_init(&data->lock);
536 i2c_set_clientdata(client, indio_dev);
538 switch (data->chip_id) {
540 indio_dev->channels = max30105_channels;
541 indio_dev->num_channels = ARRAY_SIZE(max30105_channels);
542 indio_dev->available_scan_masks = max30105_scan_masks;
545 indio_dev->channels = max30102_channels;
546 indio_dev->num_channels = ARRAY_SIZE(max30102_channels);
547 indio_dev->available_scan_masks = max30102_scan_masks;
553 data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config);
554 if (IS_ERR(data->regmap)) {
555 dev_err(&client->dev, "regmap initialization failed\n");
556 return PTR_ERR(data->regmap);
560 ret = regmap_read(data->regmap, MAX30102_REG_PART_ID, ®);
563 if (reg != MAX30102_PART_NUMBER)
566 /* show revision ID */
567 ret = regmap_read(data->regmap, MAX30102_REG_REV_ID, ®);
570 dev_dbg(&client->dev, "max3010x revision %02x\n", reg);
572 /* clear mode setting, chip shutdown */
573 ret = max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
578 ret = max30102_chip_init(data);
582 if (client->irq <= 0) {
583 dev_err(&client->dev, "no valid irq defined\n");
587 ret = devm_request_threaded_irq(&client->dev, client->irq,
588 NULL, max30102_interrupt_handler,
589 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
590 "max30102_irq", indio_dev);
592 dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
596 return iio_device_register(indio_dev);
599 static int max30102_remove(struct i2c_client *client)
601 struct iio_dev *indio_dev = i2c_get_clientdata(client);
602 struct max30102_data *data = iio_priv(indio_dev);
604 iio_device_unregister(indio_dev);
605 max30102_set_power(data, false);
610 static const struct i2c_device_id max30102_id[] = {
611 { "max30102", max30102 },
612 { "max30105", max30105 },
615 MODULE_DEVICE_TABLE(i2c, max30102_id);
617 static const struct of_device_id max30102_dt_ids[] = {
618 { .compatible = "maxim,max30102" },
619 { .compatible = "maxim,max30105" },
622 MODULE_DEVICE_TABLE(of, max30102_dt_ids);
624 static struct i2c_driver max30102_driver = {
626 .name = MAX30102_DRV_NAME,
627 .of_match_table = of_match_ptr(max30102_dt_ids),
629 .probe = max30102_probe,
630 .remove = max30102_remove,
631 .id_table = max30102_id,
633 module_i2c_driver(max30102_driver);
635 MODULE_AUTHOR("Matt Ranostay <matt@ranostay.consulting>");
636 MODULE_DESCRIPTION("MAX30102 heart rate/pulse oximeter and MAX30105 particle sensor driver");
637 MODULE_LICENSE("GPL");