2 * max30102.c - Support for MAX30102 heart rate and pulse oximeter sensor
6 * Support for MAX30105 optical particle sensor
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * 7-bit I2C chip address: 0x57
20 * TODO: proximity power saving feature
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/err.h>
28 #include <linux/irq.h>
29 #include <linux/i2c.h>
30 #include <linux/mutex.h>
32 #include <linux/regmap.h>
33 #include <linux/iio/iio.h>
34 #include <linux/iio/buffer.h>
35 #include <linux/iio/kfifo_buf.h>
37 #define MAX30102_REGMAP_NAME "max30102_regmap"
38 #define MAX30102_DRV_NAME "max30102"
39 #define MAX30102_PART_NUMBER 0x15
41 enum max30102_chip_id {
46 enum max3012_led_idx {
52 #define MAX30102_REG_INT_STATUS 0x00
53 #define MAX30102_REG_INT_STATUS_PWR_RDY BIT(0)
54 #define MAX30102_REG_INT_STATUS_PROX_INT BIT(4)
55 #define MAX30102_REG_INT_STATUS_ALC_OVF BIT(5)
56 #define MAX30102_REG_INT_STATUS_PPG_RDY BIT(6)
57 #define MAX30102_REG_INT_STATUS_FIFO_RDY BIT(7)
59 #define MAX30102_REG_INT_ENABLE 0x02
60 #define MAX30102_REG_INT_ENABLE_PROX_INT_EN BIT(4)
61 #define MAX30102_REG_INT_ENABLE_ALC_OVF_EN BIT(5)
62 #define MAX30102_REG_INT_ENABLE_PPG_EN BIT(6)
63 #define MAX30102_REG_INT_ENABLE_FIFO_EN BIT(7)
64 #define MAX30102_REG_INT_ENABLE_MASK 0xf0
65 #define MAX30102_REG_INT_ENABLE_MASK_SHIFT 4
67 #define MAX30102_REG_FIFO_WR_PTR 0x04
68 #define MAX30102_REG_FIFO_OVR_CTR 0x05
69 #define MAX30102_REG_FIFO_RD_PTR 0x06
70 #define MAX30102_REG_FIFO_DATA 0x07
71 #define MAX30102_REG_FIFO_DATA_BYTES 3
73 #define MAX30102_REG_FIFO_CONFIG 0x08
74 #define MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES BIT(1)
75 #define MAX30102_REG_FIFO_CONFIG_AVG_SHIFT 5
76 #define MAX30102_REG_FIFO_CONFIG_AFULL BIT(0)
78 #define MAX30102_REG_MODE_CONFIG 0x09
79 #define MAX30102_REG_MODE_CONFIG_MODE_NONE 0x00
80 #define MAX30102_REG_MODE_CONFIG_MODE_HR 0x02 /* red LED */
81 #define MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2 0x03 /* red + IR LED */
82 #define MAX30102_REG_MODE_CONFIG_MODE_MULTI 0x07 /* multi-LED mode */
83 #define MAX30102_REG_MODE_CONFIG_MODE_MASK GENMASK(2, 0)
84 #define MAX30102_REG_MODE_CONFIG_PWR BIT(7)
86 #define MAX30102_REG_MODE_CONTROL_SLOT21 0x11 /* multi-LED control */
87 #define MAX30102_REG_MODE_CONTROL_SLOT43 0x12
88 #define MAX30102_REG_MODE_CONTROL_SLOT_MASK (GENMASK(6, 4) | GENMASK(2, 0))
89 #define MAX30102_REG_MODE_CONTROL_SLOT_SHIFT 4
91 #define MAX30102_REG_SPO2_CONFIG 0x0a
92 #define MAX30102_REG_SPO2_CONFIG_PULSE_411_US 0x03
93 #define MAX30102_REG_SPO2_CONFIG_SR_400HZ 0x03
94 #define MAX30102_REG_SPO2_CONFIG_SR_MASK 0x07
95 #define MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT 2
96 #define MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS BIT(0)
97 #define MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT 5
99 #define MAX30102_REG_RED_LED_CONFIG 0x0c
100 #define MAX30102_REG_IR_LED_CONFIG 0x0d
101 #define MAX30105_REG_GREEN_LED_CONFIG 0x0e
103 #define MAX30102_REG_TEMP_CONFIG 0x21
104 #define MAX30102_REG_TEMP_CONFIG_TEMP_EN BIT(0)
106 #define MAX30102_REG_TEMP_INTEGER 0x1f
107 #define MAX30102_REG_TEMP_FRACTION 0x20
109 #define MAX30102_REG_REV_ID 0xfe
110 #define MAX30102_REG_PART_ID 0xff
112 struct max30102_data {
113 struct i2c_client *client;
114 struct iio_dev *indio_dev;
116 struct regmap *regmap;
117 enum max30102_chip_id chip_id;
120 __be32 processed_buffer[3]; /* 3 x 18-bit (padded to 32-bits) */
123 static const struct regmap_config max30102_regmap_config = {
124 .name = MAX30102_REGMAP_NAME,
130 static const unsigned long max30102_scan_masks[] = {
131 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR),
135 static const unsigned long max30105_scan_masks[] = {
136 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR),
137 BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) |
138 BIT(MAX30105_LED_GREEN),
142 #define MAX30102_INTENSITY_CHANNEL(_si, _mod) { \
143 .type = IIO_INTENSITY, \
152 .endianness = IIO_BE, \
156 static const struct iio_chan_spec max30102_channels[] = {
157 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED),
158 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR),
161 .info_mask_separate =
162 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
167 static const struct iio_chan_spec max30105_channels[] = {
168 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED),
169 MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR),
170 MAX30102_INTENSITY_CHANNEL(MAX30105_LED_GREEN, IIO_MOD_LIGHT_GREEN),
173 .info_mask_separate =
174 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
179 static int max30102_set_power(struct max30102_data *data, bool en)
181 return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
182 MAX30102_REG_MODE_CONFIG_PWR,
183 en ? 0 : MAX30102_REG_MODE_CONFIG_PWR);
186 static int max30102_set_powermode(struct max30102_data *data, u8 mode, bool en)
191 reg |= MAX30102_REG_MODE_CONFIG_PWR;
193 return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
194 MAX30102_REG_MODE_CONFIG_PWR |
195 MAX30102_REG_MODE_CONFIG_MODE_MASK, reg);
198 #define MAX30102_MODE_CONTROL_LED_SLOTS(slot2, slot1) \
199 ((slot2 << MAX30102_REG_MODE_CONTROL_SLOT_SHIFT) | slot1)
201 static int max30102_buffer_postenable(struct iio_dev *indio_dev)
203 struct max30102_data *data = iio_priv(indio_dev);
207 switch (*indio_dev->active_scan_mask) {
208 case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR):
209 reg = MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2;
211 case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) |
212 BIT(MAX30105_LED_GREEN):
213 ret = regmap_update_bits(data->regmap,
214 MAX30102_REG_MODE_CONTROL_SLOT21,
215 MAX30102_REG_MODE_CONTROL_SLOT_MASK,
216 MAX30102_MODE_CONTROL_LED_SLOTS(2, 1));
220 ret = regmap_update_bits(data->regmap,
221 MAX30102_REG_MODE_CONTROL_SLOT43,
222 MAX30102_REG_MODE_CONTROL_SLOT_MASK,
223 MAX30102_MODE_CONTROL_LED_SLOTS(0, 3));
227 reg = MAX30102_REG_MODE_CONFIG_MODE_MULTI;
233 return max30102_set_powermode(data, reg, true);
236 static int max30102_buffer_predisable(struct iio_dev *indio_dev)
238 struct max30102_data *data = iio_priv(indio_dev);
240 return max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
244 static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = {
245 .postenable = max30102_buffer_postenable,
246 .predisable = max30102_buffer_predisable,
249 static inline int max30102_fifo_count(struct max30102_data *data)
254 ret = regmap_read(data->regmap, MAX30102_REG_INT_STATUS, &val);
258 /* FIFO has one sample slot left */
259 if (val & MAX30102_REG_INT_STATUS_FIFO_RDY)
265 #define MAX30102_COPY_DATA(i) \
266 memcpy(&data->processed_buffer[(i)], \
267 &buffer[(i) * MAX30102_REG_FIFO_DATA_BYTES], \
268 MAX30102_REG_FIFO_DATA_BYTES)
270 static int max30102_read_measurement(struct max30102_data *data,
271 unsigned int measurements)
274 u8 *buffer = (u8 *) &data->buffer;
276 ret = i2c_smbus_read_i2c_block_data(data->client,
277 MAX30102_REG_FIFO_DATA,
279 MAX30102_REG_FIFO_DATA_BYTES,
282 switch (measurements) {
284 MAX30102_COPY_DATA(2);
287 MAX30102_COPY_DATA(1);
290 MAX30102_COPY_DATA(0);
296 return (ret == measurements * MAX30102_REG_FIFO_DATA_BYTES) ?
300 static irqreturn_t max30102_interrupt_handler(int irq, void *private)
302 struct iio_dev *indio_dev = private;
303 struct max30102_data *data = iio_priv(indio_dev);
304 unsigned int measurements = bitmap_weight(indio_dev->active_scan_mask,
305 indio_dev->masklength);
308 mutex_lock(&data->lock);
310 while (cnt || (cnt = max30102_fifo_count(data)) > 0) {
311 ret = max30102_read_measurement(data, measurements);
315 iio_push_to_buffers(data->indio_dev, data->processed_buffer);
319 mutex_unlock(&data->lock);
324 static int max30102_get_current_idx(unsigned int val, int *reg)
326 /* each step is 0.200 mA */
329 return *reg > 0xff ? -EINVAL : 0;
332 static int max30102_led_init(struct max30102_data *data)
334 struct device *dev = &data->client->dev;
335 struct device_node *np = dev->of_node;
339 ret = of_property_read_u32(np, "maxim,red-led-current-microamp", &val);
341 dev_info(dev, "no red-led-current-microamp set\n");
343 /* Default to 7 mA RED LED */
347 ret = max30102_get_current_idx(val, ®);
349 dev_err(dev, "invalid RED LED current setting %d\n", val);
353 ret = regmap_write(data->regmap, MAX30102_REG_RED_LED_CONFIG, reg);
357 if (data->chip_id == max30105) {
358 ret = of_property_read_u32(np,
359 "maxim,green-led-current-microamp", &val);
361 dev_info(dev, "no green-led-current-microamp set\n");
363 /* Default to 7 mA green LED */
367 ret = max30102_get_current_idx(val, ®);
369 dev_err(dev, "invalid green LED current setting %d\n",
374 ret = regmap_write(data->regmap, MAX30105_REG_GREEN_LED_CONFIG,
380 ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val);
382 dev_info(dev, "no ir-led-current-microamp set\n");
384 /* Default to 7 mA IR LED */
388 ret = max30102_get_current_idx(val, ®);
390 dev_err(dev, "invalid IR LED current setting %d\n", val);
394 return regmap_write(data->regmap, MAX30102_REG_IR_LED_CONFIG, reg);
397 static int max30102_chip_init(struct max30102_data *data)
401 /* setup LED current settings */
402 ret = max30102_led_init(data);
406 /* configure 18-bit HR + SpO2 readings at 400Hz */
407 ret = regmap_write(data->regmap, MAX30102_REG_SPO2_CONFIG,
408 (MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS
409 << MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT) |
410 (MAX30102_REG_SPO2_CONFIG_SR_400HZ
411 << MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT) |
412 MAX30102_REG_SPO2_CONFIG_PULSE_411_US);
416 /* average 4 samples + generate FIFO interrupt */
417 ret = regmap_write(data->regmap, MAX30102_REG_FIFO_CONFIG,
418 (MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES
419 << MAX30102_REG_FIFO_CONFIG_AVG_SHIFT) |
420 MAX30102_REG_FIFO_CONFIG_AFULL);
424 /* enable FIFO interrupt */
425 return regmap_update_bits(data->regmap, MAX30102_REG_INT_ENABLE,
426 MAX30102_REG_INT_ENABLE_MASK,
427 MAX30102_REG_INT_ENABLE_FIFO_EN);
430 static int max30102_read_temp(struct max30102_data *data, int *val)
435 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_INTEGER, ®);
440 ret = regmap_read(data->regmap, MAX30102_REG_TEMP_FRACTION, ®);
445 *val = sign_extend32(*val, 11);
450 static int max30102_get_temp(struct max30102_data *data, int *val, bool en)
455 ret = max30102_set_power(data, true);
460 /* start acquisition */
461 ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG,
462 MAX30102_REG_TEMP_CONFIG_TEMP_EN,
463 MAX30102_REG_TEMP_CONFIG_TEMP_EN);
468 ret = max30102_read_temp(data, val);
472 max30102_set_power(data, false);
477 static int max30102_read_raw(struct iio_dev *indio_dev,
478 struct iio_chan_spec const *chan,
479 int *val, int *val2, long mask)
481 struct max30102_data *data = iio_priv(indio_dev);
485 case IIO_CHAN_INFO_RAW:
487 * Temperature reading can only be acquired when not in
488 * shutdown; leave shutdown briefly when buffer not running
490 mutex_lock(&indio_dev->mlock);
491 if (!iio_buffer_enabled(indio_dev))
492 ret = max30102_get_temp(data, val, true);
494 ret = max30102_get_temp(data, val, false);
495 mutex_unlock(&indio_dev->mlock);
501 case IIO_CHAN_INFO_SCALE:
502 *val = 1000; /* 62.5 */
504 ret = IIO_VAL_FRACTIONAL;
511 static const struct iio_info max30102_info = {
512 .read_raw = max30102_read_raw,
515 static int max30102_probe(struct i2c_client *client,
516 const struct i2c_device_id *id)
518 struct max30102_data *data;
519 struct iio_buffer *buffer;
520 struct iio_dev *indio_dev;
524 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
528 buffer = devm_iio_kfifo_allocate(&client->dev);
532 iio_device_attach_buffer(indio_dev, buffer);
534 indio_dev->name = MAX30102_DRV_NAME;
535 indio_dev->info = &max30102_info;
536 indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
537 indio_dev->setup_ops = &max30102_buffer_setup_ops;
538 indio_dev->dev.parent = &client->dev;
540 data = iio_priv(indio_dev);
541 data->indio_dev = indio_dev;
542 data->client = client;
543 data->chip_id = id->driver_data;
545 mutex_init(&data->lock);
546 i2c_set_clientdata(client, indio_dev);
548 switch (data->chip_id) {
550 indio_dev->channels = max30105_channels;
551 indio_dev->num_channels = ARRAY_SIZE(max30105_channels);
552 indio_dev->available_scan_masks = max30105_scan_masks;
555 indio_dev->channels = max30102_channels;
556 indio_dev->num_channels = ARRAY_SIZE(max30102_channels);
557 indio_dev->available_scan_masks = max30102_scan_masks;
563 data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config);
564 if (IS_ERR(data->regmap)) {
565 dev_err(&client->dev, "regmap initialization failed\n");
566 return PTR_ERR(data->regmap);
570 ret = regmap_read(data->regmap, MAX30102_REG_PART_ID, ®);
573 if (reg != MAX30102_PART_NUMBER)
576 /* show revision ID */
577 ret = regmap_read(data->regmap, MAX30102_REG_REV_ID, ®);
580 dev_dbg(&client->dev, "max3010x revision %02x\n", reg);
582 /* clear mode setting, chip shutdown */
583 ret = max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
588 ret = max30102_chip_init(data);
592 if (client->irq <= 0) {
593 dev_err(&client->dev, "no valid irq defined\n");
597 ret = devm_request_threaded_irq(&client->dev, client->irq,
598 NULL, max30102_interrupt_handler,
599 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
600 "max30102_irq", indio_dev);
602 dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
606 return iio_device_register(indio_dev);
609 static int max30102_remove(struct i2c_client *client)
611 struct iio_dev *indio_dev = i2c_get_clientdata(client);
612 struct max30102_data *data = iio_priv(indio_dev);
614 iio_device_unregister(indio_dev);
615 max30102_set_power(data, false);
620 static const struct i2c_device_id max30102_id[] = {
621 { "max30102", max30102 },
622 { "max30105", max30105 },
625 MODULE_DEVICE_TABLE(i2c, max30102_id);
627 static const struct of_device_id max30102_dt_ids[] = {
628 { .compatible = "maxim,max30102" },
629 { .compatible = "maxim,max30105" },
632 MODULE_DEVICE_TABLE(of, max30102_dt_ids);
634 static struct i2c_driver max30102_driver = {
636 .name = MAX30102_DRV_NAME,
637 .of_match_table = of_match_ptr(max30102_dt_ids),
639 .probe = max30102_probe,
640 .remove = max30102_remove,
641 .id_table = max30102_id,
643 module_i2c_driver(max30102_driver);
646 MODULE_DESCRIPTION("MAX30102 heart rate/pulse oximeter and MAX30105 particle sensor driver");
647 MODULE_LICENSE("GPL");