510 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/*3 * max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor4 *5 * Copyright (C) 2015, 20186 * Author: Matt Ranostay <matt.ranostay@konsulko.com>7 *8 * TODO: enable pulse length controls via device tree properties9 */10 11#include <linux/module.h>12#include <linux/init.h>13#include <linux/interrupt.h>14#include <linux/delay.h>15#include <linux/err.h>16#include <linux/irq.h>17#include <linux/i2c.h>18#include <linux/mutex.h>19#include <linux/property.h>20#include <linux/regmap.h>21#include <linux/iio/iio.h>22#include <linux/iio/buffer.h>23#include <linux/iio/kfifo_buf.h>24 25#define MAX30100_REGMAP_NAME "max30100_regmap"26#define MAX30100_DRV_NAME "max30100"27 28#define MAX30100_REG_INT_STATUS 0x0029#define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0)30#define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4)31#define MAX30100_REG_INT_STATUS_HR_RDY BIT(5)32#define MAX30100_REG_INT_STATUS_FIFO_RDY BIT(7)33 34#define MAX30100_REG_INT_ENABLE 0x0135#define MAX30100_REG_INT_ENABLE_SPO2_EN BIT(0)36#define MAX30100_REG_INT_ENABLE_HR_EN BIT(1)37#define MAX30100_REG_INT_ENABLE_FIFO_EN BIT(3)38#define MAX30100_REG_INT_ENABLE_MASK 0xf039#define MAX30100_REG_INT_ENABLE_MASK_SHIFT 440 41#define MAX30100_REG_FIFO_WR_PTR 0x0242#define MAX30100_REG_FIFO_OVR_CTR 0x0343#define MAX30100_REG_FIFO_RD_PTR 0x0444#define MAX30100_REG_FIFO_DATA 0x0545#define MAX30100_REG_FIFO_DATA_ENTRY_COUNT 1646#define MAX30100_REG_FIFO_DATA_ENTRY_LEN 447 48#define MAX30100_REG_MODE_CONFIG 0x0649#define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0)50#define MAX30100_REG_MODE_CONFIG_MODE_HR_EN BIT(1)51#define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x0352#define MAX30100_REG_MODE_CONFIG_TEMP_EN BIT(3)53#define MAX30100_REG_MODE_CONFIG_PWR BIT(7)54 55#define MAX30100_REG_SPO2_CONFIG 0x0756#define MAX30100_REG_SPO2_CONFIG_100HZ BIT(2)57#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6)58#define MAX30100_REG_SPO2_CONFIG_1600US 0x359 60#define MAX30100_REG_LED_CONFIG 0x0961#define MAX30100_REG_LED_CONFIG_LED_MASK 0x0f62#define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT 463 64#define MAX30100_REG_LED_CONFIG_24MA 0x0765#define MAX30100_REG_LED_CONFIG_50MA 0x0f66 67#define MAX30100_REG_TEMP_INTEGER 0x1668#define MAX30100_REG_TEMP_FRACTION 0x1769 70struct max30100_data {71 struct i2c_client *client;72 struct iio_dev *indio_dev;73 struct mutex lock;74 struct regmap *regmap;75 76 __be16 buffer[2]; /* 2 16-bit channels */77};78 79static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg)80{81 switch (reg) {82 case MAX30100_REG_INT_STATUS:83 case MAX30100_REG_MODE_CONFIG:84 case MAX30100_REG_FIFO_WR_PTR:85 case MAX30100_REG_FIFO_OVR_CTR:86 case MAX30100_REG_FIFO_RD_PTR:87 case MAX30100_REG_FIFO_DATA:88 case MAX30100_REG_TEMP_INTEGER:89 case MAX30100_REG_TEMP_FRACTION:90 return true;91 default:92 return false;93 }94}95 96static const struct regmap_config max30100_regmap_config = {97 .name = MAX30100_REGMAP_NAME,98 99 .reg_bits = 8,100 .val_bits = 8,101 102 .max_register = MAX30100_REG_TEMP_FRACTION,103 .cache_type = REGCACHE_FLAT,104 105 .volatile_reg = max30100_is_volatile_reg,106};107 108static const unsigned int max30100_led_current_mapping[] = {109 4400, 7600, 11000, 14200, 17400,110 20800, 24000, 27100, 30600, 33800,111 37000, 40200, 43600, 46800, 50000112};113 114static const unsigned long max30100_scan_masks[] = {0x3, 0};115 116static const struct iio_chan_spec max30100_channels[] = {117 {118 .type = IIO_INTENSITY,119 .channel2 = IIO_MOD_LIGHT_IR,120 .modified = 1,121 122 .scan_index = 0,123 .scan_type = {124 .sign = 'u',125 .realbits = 16,126 .storagebits = 16,127 .endianness = IIO_BE,128 },129 },130 {131 .type = IIO_INTENSITY,132 .channel2 = IIO_MOD_LIGHT_RED,133 .modified = 1,134 135 .scan_index = 1,136 .scan_type = {137 .sign = 'u',138 .realbits = 16,139 .storagebits = 16,140 .endianness = IIO_BE,141 },142 },143 {144 .type = IIO_TEMP,145 .info_mask_separate =146 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),147 .scan_index = -1,148 },149};150 151static int max30100_set_powermode(struct max30100_data *data, bool state)152{153 return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,154 MAX30100_REG_MODE_CONFIG_PWR,155 state ? 0 : MAX30100_REG_MODE_CONFIG_PWR);156}157 158static int max30100_clear_fifo(struct max30100_data *data)159{160 int ret;161 162 ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0);163 if (ret)164 return ret;165 166 ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0);167 if (ret)168 return ret;169 170 return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0);171}172 173static int max30100_buffer_postenable(struct iio_dev *indio_dev)174{175 struct max30100_data *data = iio_priv(indio_dev);176 int ret;177 178 ret = max30100_set_powermode(data, true);179 if (ret)180 return ret;181 182 return max30100_clear_fifo(data);183}184 185static int max30100_buffer_predisable(struct iio_dev *indio_dev)186{187 struct max30100_data *data = iio_priv(indio_dev);188 189 return max30100_set_powermode(data, false);190}191 192static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = {193 .postenable = max30100_buffer_postenable,194 .predisable = max30100_buffer_predisable,195};196 197static inline int max30100_fifo_count(struct max30100_data *data)198{199 unsigned int val;200 int ret;201 202 ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val);203 if (ret)204 return ret;205 206 /* FIFO is almost full */207 if (val & MAX30100_REG_INT_STATUS_FIFO_RDY)208 return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1;209 210 return 0;211}212 213static int max30100_read_measurement(struct max30100_data *data)214{215 int ret;216 217 ret = i2c_smbus_read_i2c_block_data(data->client,218 MAX30100_REG_FIFO_DATA,219 MAX30100_REG_FIFO_DATA_ENTRY_LEN,220 (u8 *) &data->buffer);221 222 return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret;223}224 225static irqreturn_t max30100_interrupt_handler(int irq, void *private)226{227 struct iio_dev *indio_dev = private;228 struct max30100_data *data = iio_priv(indio_dev);229 int ret, cnt = 0;230 231 mutex_lock(&data->lock);232 233 while (cnt || (cnt = max30100_fifo_count(data)) > 0) {234 ret = max30100_read_measurement(data);235 if (ret)236 break;237 238 iio_push_to_buffers(data->indio_dev, data->buffer);239 cnt--;240 }241 242 mutex_unlock(&data->lock);243 244 return IRQ_HANDLED;245}246 247static int max30100_get_current_idx(unsigned int val, int *reg)248{249 int idx;250 251 /* LED turned off */252 if (val == 0) {253 *reg = 0;254 return 0;255 }256 257 for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) {258 if (max30100_led_current_mapping[idx] == val) {259 *reg = idx + 1;260 return 0;261 }262 }263 264 return -EINVAL;265}266 267static int max30100_led_init(struct max30100_data *data)268{269 struct device *dev = &data->client->dev;270 unsigned int val[2];271 int reg, ret;272 273 ret = device_property_read_u32_array(dev, "maxim,led-current-microamp",274 (unsigned int *) &val, 2);275 if (ret) {276 /* Default to 24 mA RED LED, 50 mA IR LED */277 reg = (MAX30100_REG_LED_CONFIG_24MA <<278 MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) |279 MAX30100_REG_LED_CONFIG_50MA;280 dev_warn(dev, "no led-current-microamp set");281 282 return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg);283 }284 285 /* RED LED current */286 ret = max30100_get_current_idx(val[0], ®);287 if (ret) {288 dev_err(dev, "invalid RED current setting %d", val[0]);289 return ret;290 }291 292 ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,293 MAX30100_REG_LED_CONFIG_LED_MASK <<294 MAX30100_REG_LED_CONFIG_RED_LED_SHIFT,295 reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT);296 if (ret)297 return ret;298 299 /* IR LED current */300 ret = max30100_get_current_idx(val[1], ®);301 if (ret) {302 dev_err(dev, "invalid IR current setting %d", val[1]);303 return ret;304 }305 306 return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,307 MAX30100_REG_LED_CONFIG_LED_MASK, reg);308}309 310static int max30100_chip_init(struct max30100_data *data)311{312 int ret;313 314 /* setup LED current settings */315 ret = max30100_led_init(data);316 if (ret)317 return ret;318 319 /* enable hi-res SPO2 readings at 100Hz */320 ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG,321 MAX30100_REG_SPO2_CONFIG_HI_RES_EN |322 MAX30100_REG_SPO2_CONFIG_100HZ);323 if (ret)324 return ret;325 326 /* enable SPO2 mode */327 ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,328 MAX30100_REG_MODE_CONFIG_MODE_MASK,329 MAX30100_REG_MODE_CONFIG_MODE_HR_EN |330 MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN);331 if (ret)332 return ret;333 334 /* enable FIFO interrupt */335 return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE,336 MAX30100_REG_INT_ENABLE_MASK,337 MAX30100_REG_INT_ENABLE_FIFO_EN338 << MAX30100_REG_INT_ENABLE_MASK_SHIFT);339}340 341static int max30100_read_temp(struct max30100_data *data, int *val)342{343 int ret;344 unsigned int reg;345 346 ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, ®);347 if (ret < 0)348 return ret;349 *val = reg << 4;350 351 ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, ®);352 if (ret < 0)353 return ret;354 355 *val |= reg & 0xf;356 *val = sign_extend32(*val, 11);357 358 return 0;359}360 361static int max30100_get_temp(struct max30100_data *data, int *val)362{363 int ret;364 365 /* start acquisition */366 ret = regmap_set_bits(data->regmap, MAX30100_REG_MODE_CONFIG,367 MAX30100_REG_MODE_CONFIG_TEMP_EN);368 if (ret)369 return ret;370 371 msleep(35);372 373 return max30100_read_temp(data, val);374}375 376static int max30100_read_raw(struct iio_dev *indio_dev,377 struct iio_chan_spec const *chan,378 int *val, int *val2, long mask)379{380 struct max30100_data *data = iio_priv(indio_dev);381 int ret = -EINVAL;382 383 switch (mask) {384 case IIO_CHAN_INFO_RAW:385 /*386 * Temperature reading can only be acquired while engine387 * is running388 */389 if (iio_device_claim_buffer_mode(indio_dev)) {390 /*391 * Replacing -EBUSY or other error code392 * returned by iio_device_claim_buffer_mode()393 * because user space may rely on the current394 * one.395 */396 ret = -EAGAIN;397 } else {398 ret = max30100_get_temp(data, val);399 if (!ret)400 ret = IIO_VAL_INT;401 402 iio_device_release_buffer_mode(indio_dev);403 }404 break;405 case IIO_CHAN_INFO_SCALE:406 *val = 1; /* 0.0625 */407 *val2 = 16;408 ret = IIO_VAL_FRACTIONAL;409 break;410 }411 412 return ret;413}414 415static const struct iio_info max30100_info = {416 .read_raw = max30100_read_raw,417};418 419static int max30100_probe(struct i2c_client *client)420{421 struct max30100_data *data;422 struct iio_dev *indio_dev;423 int ret;424 425 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));426 if (!indio_dev)427 return -ENOMEM;428 429 indio_dev->name = MAX30100_DRV_NAME;430 indio_dev->channels = max30100_channels;431 indio_dev->info = &max30100_info;432 indio_dev->num_channels = ARRAY_SIZE(max30100_channels);433 indio_dev->available_scan_masks = max30100_scan_masks;434 indio_dev->modes = INDIO_DIRECT_MODE;435 436 ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,437 &max30100_buffer_setup_ops);438 if (ret)439 return ret;440 441 data = iio_priv(indio_dev);442 data->indio_dev = indio_dev;443 data->client = client;444 445 mutex_init(&data->lock);446 i2c_set_clientdata(client, indio_dev);447 448 data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config);449 if (IS_ERR(data->regmap)) {450 dev_err(&client->dev, "regmap initialization failed.\n");451 return PTR_ERR(data->regmap);452 }453 max30100_set_powermode(data, false);454 455 ret = max30100_chip_init(data);456 if (ret)457 return ret;458 459 if (client->irq <= 0) {460 dev_err(&client->dev, "no valid irq defined\n");461 return -EINVAL;462 }463 ret = devm_request_threaded_irq(&client->dev, client->irq,464 NULL, max30100_interrupt_handler,465 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,466 "max30100_irq", indio_dev);467 if (ret) {468 dev_err(&client->dev, "request irq (%d) failed\n", client->irq);469 return ret;470 }471 472 return iio_device_register(indio_dev);473}474 475static void max30100_remove(struct i2c_client *client)476{477 struct iio_dev *indio_dev = i2c_get_clientdata(client);478 struct max30100_data *data = iio_priv(indio_dev);479 480 iio_device_unregister(indio_dev);481 max30100_set_powermode(data, false);482}483 484static const struct i2c_device_id max30100_id[] = {485 { "max30100" },486 {}487};488MODULE_DEVICE_TABLE(i2c, max30100_id);489 490static const struct of_device_id max30100_dt_ids[] = {491 { .compatible = "maxim,max30100" },492 { }493};494MODULE_DEVICE_TABLE(of, max30100_dt_ids);495 496static struct i2c_driver max30100_driver = {497 .driver = {498 .name = MAX30100_DRV_NAME,499 .of_match_table = max30100_dt_ids,500 },501 .probe = max30100_probe,502 .remove = max30100_remove,503 .id_table = max30100_id,504};505module_i2c_driver(max30100_driver);506 507MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");508MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor");509MODULE_LICENSE("GPL");510