MAX30100 is an heart rate and pulse oximeter sensor that works using two LEDS of different wavelengths, and detecting the light reflected back. This patchset adds support for both IR and RED LED channels which can be processed in userspace to determine heart rate and blood oxygen levels. Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx> --- .../devicetree/bindings/iio/light/max30100.txt | 22 ++ drivers/iio/light/Kconfig | 13 + drivers/iio/light/Makefile | 1 + drivers/iio/light/max30100.c | 301 +++++++++++++++++++++ 4 files changed, 337 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/light/max30100.txt create mode 100644 drivers/iio/light/max30100.c diff --git a/Documentation/devicetree/bindings/iio/light/max30100.txt b/Documentation/devicetree/bindings/iio/light/max30100.txt new file mode 100644 index 0000000..c9119aa --- /dev/null +++ b/Documentation/devicetree/bindings/iio/light/max30100.txt @@ -0,0 +1,22 @@ +* Maxim MAX30100 heart rate and pulse oximeter sensor + +https://datasheets.maximintegrated.com/en/ds/MAX30100.pdf + +Required properties: + + - compatible: must be "maxim,max30100" + - reg: the I2c address of the sensor + - interrupt-parent: should be the phandle for the interrupt controller + - interrupts : the sole interrupt generated by the device + + Refer to interrupt-controller/interrupts.txt for generic interrupt client + node bindings. + +Example: + +max30100@57 { + compatible = "maxim,max30100"; + reg = <0x57>; + interrupt-parent = <&gpio1>; + interrupts = <16 1>; +}; diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index cfd3df8..3a94e20 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -223,6 +223,19 @@ config LTR501 This driver can also be built as a module. If so, the module will be called ltr501. +config MAX30100 + tristate "MAX30100 heart rate and pulse oximeter sensor" + depends on I2C + select REGMAP_I2C + select IIO_BUFFER + select IIO_KFIFO_BUF + help + Say Y here to build I2C interface support for the Maxim + MAX30100 heart rate, and pulse oximeter sensor. + + To compile this driver as a module, choose M here: the + module will be called max30100 + config OPT3001 tristate "Texas Instruments OPT3001 Light Sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index b2c3105..0795486 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_ISL29125) += isl29125.o obj-$(CONFIG_JSA1212) += jsa1212.o obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o obj-$(CONFIG_LTR501) += ltr501.o +obj-$(CONFIG_MAX30100) += max30100.o obj-$(CONFIG_OPT3001) += opt3001.o obj-$(CONFIG_PA12203001) += pa12203001.o obj-$(CONFIG_RPR0521) += rpr0521.o diff --git a/drivers/iio/light/max30100.c b/drivers/iio/light/max30100.c new file mode 100644 index 0000000..436318f --- /dev/null +++ b/drivers/iio/light/max30100.c @@ -0,0 +1,301 @@ +/* + * max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor + * + * Copyright (C) 2015 Matt Ranostay <mranostay@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * TODO: temperature reading + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/err.h> +#include <linux/irq.h> +#include <linux/gpio.h> +#include <linux/i2c.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> +#include <linux/iio/sysfs.h> +#include <linux/of_gpio.h> + +#define MAX30100_REGMAP_NAME "max30100_regmap" +#define MAX30100_DRV_NAME "max30100" + +#define MAX30100_REG_INT_STATUS 0x00 +#define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0) +#define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4) +#define MAX30100_REG_INT_STATUS_HR_RDY BIT(5) + +#define MAX30100_REG_INT_ENABLE 0x01 +#define MAX30100_REG_INT_ENABLE_MASK 0xf0 +#define MAX30100_REG_INT_ENABLE_MASK_SHIFT 4 + +#define MAX30100_REG_FIFO_DATA 0x05 + +#define MAX30100_REG_MODE_CONFIG 0x06 +#define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x03 +#define MAX30100_REG_MODE_CONFIG_PWR BIT(7) + +#define MAX30100_REG_SPO2_CONFIG 0x07 +#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6) + +#define MAX30100_REG_LED_CONFIG 0x09 + +struct max30100_data { + struct iio_dev *indio_dev; + struct mutex lock; + struct regmap *regmap; + + u8 buffer[4]; /* 4 8-bit channels */ +}; + +static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX30100_REG_INT_STATUS: + case MAX30100_REG_FIFO_DATA: + return true; + default: + return false; + } +} + +static const struct regmap_config max30100_regmap_config = { + .name = MAX30100_REGMAP_NAME, + + .reg_bits = 8, + .val_bits = 8, + + .max_register = MAX30100_REG_LED_CONFIG, + .cache_type = REGCACHE_FLAT, + + .volatile_reg = max30100_is_volatile_reg, +}; + +static const unsigned long max30100_scan_masks[] = {0x3, 0}; + +static const struct iio_chan_spec max30100_channels[] = { + { + .type = IIO_INTENSITY, + .channel2 = IIO_MOD_LIGHT_IR, + + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + }, + }, + { + .type = IIO_INTENSITY, + .channel2 = IIO_MOD_LIGHT_RED, + + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + }, + }, +}; + +static int max30100_set_powermode(struct max30100_data *data, bool state) +{ + return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, + MAX30100_REG_MODE_CONFIG_PWR, + state ? 0 : MAX30100_REG_MODE_CONFIG_PWR); +} + +static int max30100_buffer_postenable(struct iio_dev *indio_dev) +{ + struct max30100_data *data = iio_priv(indio_dev); + + return max30100_set_powermode(data, true); +} + +static int max30100_buffer_predisable(struct iio_dev *indio_dev) +{ + struct max30100_data *data = iio_priv(indio_dev); + + return max30100_set_powermode(data, false); +} + +static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = { + .postenable = max30100_buffer_postenable, + .predisable = max30100_buffer_predisable, +}; + +static inline int max30100_fifo_is_empty(struct max30100_data *data) +{ + int ret, val; + + ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val); + if (ret) + return ret; + + return !!(val >> 4); +} + +static irqreturn_t max30100_interrupt_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct max30100_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->lock); + + while (max30100_fifo_is_empty(data) != 0) { + ret = regmap_bulk_read(data->regmap, MAX30100_REG_FIFO_DATA, + &data->buffer, 4); + + if (ret) + goto err_read; + + iio_push_to_buffers(data->indio_dev, data->buffer); + } + +err_read: + mutex_unlock(&data->lock); + + return IRQ_HANDLED; +} + +static int max30100_chip_init(struct max30100_data *data) +{ + int ret; + + /* RED IR LED = 24mA, IR LED = 50mA */ + ret = regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, 0x7f); + if (ret) + return ret; + + /* enable hi-res SPO2 readings with 100 samples a second */ + ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG, + MAX30100_REG_SPO2_CONFIG_HI_RES_EN | 0x13); + if (ret) + return ret; + + /* enable SPO2 + HR mode */ + ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG, + MAX30100_REG_MODE_CONFIG_MODE_MASK, 0x3); + if (ret) + return ret; + + /* enable SPO2 + HR interrupts */ + return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE_MASK, + MAX30100_REG_INT_ENABLE_MASK, + 0x3 << MAX30100_REG_INT_ENABLE_MASK_SHIFT); +} + +static int max30100_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max30100_data *data; + struct iio_buffer *buffer; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + buffer = devm_iio_kfifo_allocate(&client->dev); + if (!buffer) + return -ENOMEM; + + iio_device_attach_buffer(indio_dev, buffer); + + indio_dev->name = MAX30100_DRV_NAME; + indio_dev->channels = max30100_channels; + indio_dev->num_channels = ARRAY_SIZE(max30100_channels); + indio_dev->available_scan_masks = max30100_scan_masks; + indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE); + indio_dev->setup_ops = &max30100_buffer_setup_ops; + + data = iio_priv(indio_dev); + data->indio_dev = indio_dev; + + mutex_init(&data->lock); + i2c_set_clientdata(client, indio_dev); + + data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config); + if (IS_ERR(data->regmap)) { + dev_err(&client->dev, "regmap initialization failed.\n"); + return PTR_ERR(data->regmap); + } + max30100_set_powermode(data, false); + + ret = max30100_chip_init(data); + if (ret) + goto error_out; + + if (client->irq <= 0) { + dev_err(&client->dev, "no valid irq defined\n"); + ret = -EINVAL; + goto error_out; + } + ret = devm_request_threaded_irq(&client->dev, client->irq, + NULL, max30100_interrupt_handler, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "max30100_irq", indio_dev); + if (ret) { + dev_err(&client->dev, "request irq (%d) failed\n", client->irq); + goto error_out; + } + + return iio_device_register(indio_dev); +error_out: + + return ret; +} + +static int max30100_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct max30100_data *data = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + max30100_set_powermode(data, false); + + return 0; +} + +static const struct i2c_device_id max30100_id[] = { + { "max30100", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, max30100_id); + +static const struct of_device_id max30100_dt_ids[] = { + { .compatible = "maxim,max30100" }, + { } +}; +MODULE_DEVICE_TABLE(of, max30100_dt_ids); + +static struct i2c_driver max30100_driver = { + .driver = { + .name = MAX30100_DRV_NAME, + .of_match_table = of_match_ptr(max30100_dt_ids), + }, + .probe = max30100_probe, + .remove = max30100_remove, + .id_table = max30100_id, +}; +module_i2c_driver(max30100_driver); + +MODULE_AUTHOR("Matt Ranostay <mranostay@xxxxxxxxx>"); +MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor"); +MODULE_LICENSE("GPL"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
