--- /dev/null
+/*
+ * max30102.c - Support for MAX30102 heart rate and pulse oximeter sensor
+ *
+ * Copyright (C) 2017 Matt Ranostay <matt@ranostay.consulting>
+ *
+ * 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: proximity power saving feature
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/kfifo_buf.h>
+
+#define MAX30102_REGMAP_NAME "max30102_regmap"
+#define MAX30102_DRV_NAME "max30102"
+
+#define MAX30102_REG_INT_STATUS 0x00
+#define MAX30102_REG_INT_STATUS_PWR_RDY BIT(0)
+#define MAX30102_REG_INT_STATUS_PROX_INT BIT(4)
+#define MAX30102_REG_INT_STATUS_ALC_OVF BIT(5)
+#define MAX30102_REG_INT_STATUS_PPG_RDY BIT(6)
+#define MAX30102_REG_INT_STATUS_FIFO_RDY BIT(7)
+
+#define MAX30102_REG_INT_ENABLE 0x02
+#define MAX30102_REG_INT_ENABLE_PROX_INT_EN BIT(4)
+#define MAX30102_REG_INT_ENABLE_ALC_OVF_EN BIT(5)
+#define MAX30102_REG_INT_ENABLE_PPG_EN BIT(6)
+#define MAX30102_REG_INT_ENABLE_FIFO_EN BIT(7)
+#define MAX30102_REG_INT_ENABLE_MASK 0xf0
+#define MAX30102_REG_INT_ENABLE_MASK_SHIFT 4
+
+#define MAX30102_REG_FIFO_WR_PTR 0x04
+#define MAX30102_REG_FIFO_OVR_CTR 0x05
+#define MAX30102_REG_FIFO_RD_PTR 0x06
+#define MAX30102_REG_FIFO_DATA 0x07
+#define MAX30102_REG_FIFO_DATA_ENTRY_LEN 6
+
+#define MAX30102_REG_FIFO_CONFIG 0x08
+#define MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES BIT(1)
+#define MAX30102_REG_FIFO_CONFIG_AVG_SHIFT 5
+#define MAX30102_REG_FIFO_CONFIG_AFULL BIT(0)
+
+#define MAX30102_REG_MODE_CONFIG 0x09
+#define MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0)
+#define MAX30102_REG_MODE_CONFIG_MODE_HR_EN BIT(1)
+#define MAX30102_REG_MODE_CONFIG_MODE_MASK 0x03
+#define MAX30102_REG_MODE_CONFIG_PWR BIT(7)
+
+#define MAX30102_REG_SPO2_CONFIG 0x0a
+#define MAX30102_REG_SPO2_CONFIG_PULSE_411_US 0x03
+#define MAX30102_REG_SPO2_CONFIG_SR_400HZ 0x03
+#define MAX30102_REG_SPO2_CONFIG_SR_MASK 0x07
+#define MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT 2
+#define MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS BIT(0)
+#define MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT 5
+
+#define MAX30102_REG_RED_LED_CONFIG 0x0c
+#define MAX30102_REG_IR_LED_CONFIG 0x0d
+
+#define MAX30102_REG_TEMP_CONFIG 0x21
+#define MAX30102_REG_TEMP_CONFIG_TEMP_EN BIT(0)
+
+#define MAX30102_REG_TEMP_INTEGER 0x1f
+#define MAX30102_REG_TEMP_FRACTION 0x20
+
+struct max30102_data {
+ struct i2c_client *client;
+ struct iio_dev *indio_dev;
+ struct mutex lock;
+ struct regmap *regmap;
+
+ u8 buffer[8];
+ __be32 processed_buffer[2]; /* 2 x 18-bit (padded to 32-bits) */
+};
+
+static const struct regmap_config max30102_regmap_config = {
+ .name = MAX30102_REGMAP_NAME,
+
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static const unsigned long max30102_scan_masks[] = {0x3, 0};
+
+static const struct iio_chan_spec max30102_channels[] = {
+ {
+ .type = IIO_INTENSITY,
+ .channel2 = IIO_MOD_LIGHT_RED,
+ .modified = 1,
+
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .shift = 8,
+ .realbits = 18,
+ .storagebits = 32,
+ .endianness = IIO_BE,
+ },
+ },
+ {
+ .type = IIO_INTENSITY,
+ .channel2 = IIO_MOD_LIGHT_IR,
+ .modified = 1,
+
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 'u',
+ .shift = 8,
+ .realbits = 18,
+ .storagebits = 32,
+ .endianness = IIO_BE,
+ },
+ },
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = -1,
+ },
+};
+
+static int max30102_set_powermode(struct max30102_data *data, bool state)
+{
+ return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
+ MAX30102_REG_MODE_CONFIG_PWR,
+ state ? 0 : MAX30102_REG_MODE_CONFIG_PWR);
+}
+
+static int max30102_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct max30102_data *data = iio_priv(indio_dev);
+
+ return max30102_set_powermode(data, true);
+}
+
+static int max30102_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct max30102_data *data = iio_priv(indio_dev);
+
+ return max30102_set_powermode(data, false);
+}
+
+static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = {
+ .postenable = max30102_buffer_postenable,
+ .predisable = max30102_buffer_predisable,
+};
+
+static inline int max30102_fifo_count(struct max30102_data *data)
+{
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(data->regmap, MAX30102_REG_INT_STATUS, &val);
+ if (ret)
+ return ret;
+
+ /* FIFO has one sample slot left */
+ if (val & MAX30102_REG_INT_STATUS_FIFO_RDY)
+ return 1;
+
+ return 0;
+}
+
+static int max30102_read_measurement(struct max30102_data *data)
+{
+ int ret;
+ u8 *buffer = (u8 *) &data->buffer;
+
+ ret = i2c_smbus_read_i2c_block_data(data->client,
+ MAX30102_REG_FIFO_DATA,
+ MAX30102_REG_FIFO_DATA_ENTRY_LEN,
+ buffer);
+
+ memcpy(&data->processed_buffer[0], &buffer[0], 3);
+ memcpy(&data->processed_buffer[1], &buffer[3], 3);
+
+ return (ret == MAX30102_REG_FIFO_DATA_ENTRY_LEN) ? 0 : -EINVAL;
+}
+
+static irqreturn_t max30102_interrupt_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct max30102_data *data = iio_priv(indio_dev);
+ int ret, cnt = 0;
+
+ mutex_lock(&data->lock);
+
+ while (cnt || (cnt = max30102_fifo_count(data)) > 0) {
+ ret = max30102_read_measurement(data);
+ if (ret)
+ break;
+
+ iio_push_to_buffers(data->indio_dev, data->processed_buffer);
+ cnt--;
+ }
+
+ mutex_unlock(&data->lock);
+
+ return IRQ_HANDLED;
+}
+
+static int max30102_get_current_idx(unsigned int val, int *reg)
+{
+ /* each step is 0.200 mA */
+ *reg = val / 200;
+
+ return *reg > 0xff ? -EINVAL : 0;
+}
+
+static int max30102_led_init(struct max30102_data *data)
+{
+ struct device *dev = &data->client->dev;
+ struct device_node *np = dev->of_node;
+ unsigned int val;
+ int reg, ret;
+
+ ret = of_property_read_u32(np, "maxim,red-led-current-microamp", &val);
+ if (ret) {
+ dev_info(dev, "no red-led-current-microamp set\n");
+
+ /* Default to 7 mA RED LED */
+ val = 7000;
+ }
+
+ ret = max30102_get_current_idx(val, ®);
+ if (ret) {
+ dev_err(dev, "invalid RED LED current setting %d\n", val);
+ return ret;
+ }
+
+ ret = regmap_write(data->regmap, MAX30102_REG_RED_LED_CONFIG, reg);
+ if (ret)
+ return ret;
+
+ ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val);
+ if (ret) {
+ dev_info(dev, "no ir-led-current-microamp set\n");
+
+ /* Default to 7 mA IR LED */
+ val = 7000;
+ }
+
+ ret = max30102_get_current_idx(val, ®);
+ if (ret) {
+ dev_err(dev, "invalid IR LED current setting %d", val);
+ return ret;
+ }
+
+ return regmap_write(data->regmap, MAX30102_REG_IR_LED_CONFIG, reg);
+}
+
+static int max30102_chip_init(struct max30102_data *data)
+{
+ int ret;
+
+ /* setup LED current settings */
+ ret = max30102_led_init(data);
+ if (ret)
+ return ret;
+
+ /* enable 18-bit HR + SPO2 readings at 400Hz */
+ ret = regmap_write(data->regmap, MAX30102_REG_SPO2_CONFIG,
+ (MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS
+ << MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT) |
+ (MAX30102_REG_SPO2_CONFIG_SR_400HZ
+ << MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT) |
+ MAX30102_REG_SPO2_CONFIG_PULSE_411_US);
+ if (ret)
+ return ret;
+
+ /* enable SPO2 mode */
+ ret = regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
+ MAX30102_REG_MODE_CONFIG_MODE_MASK,
+ MAX30102_REG_MODE_CONFIG_MODE_HR_EN |
+ MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN);
+ if (ret)
+ return ret;
+
+ /* average 4 samples + generate FIFO interrupt */
+ ret = regmap_write(data->regmap, MAX30102_REG_FIFO_CONFIG,
+ (MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES
+ << MAX30102_REG_FIFO_CONFIG_AVG_SHIFT) |
+ MAX30102_REG_FIFO_CONFIG_AFULL);
+ if (ret)
+ return ret;
+
+ /* enable FIFO interrupt */
+ return regmap_update_bits(data->regmap, MAX30102_REG_INT_ENABLE,
+ MAX30102_REG_INT_ENABLE_MASK,
+ MAX30102_REG_INT_ENABLE_FIFO_EN);
+}
+
+static int max30102_read_temp(struct max30102_data *data, int *val)
+{
+ int ret;
+ unsigned int reg;
+
+ ret = regmap_read(data->regmap, MAX30102_REG_TEMP_INTEGER, ®);
+ if (ret < 0)
+ return ret;
+ *val = reg << 4;
+
+ ret = regmap_read(data->regmap, MAX30102_REG_TEMP_FRACTION, ®);
+ if (ret < 0)
+ return ret;
+
+ *val |= reg & 0xf;
+ *val = sign_extend32(*val, 11);
+
+ return 0;
+}
+
+static int max30102_get_temp(struct max30102_data *data, int *val)
+{
+ int ret;
+
+ /* start acquisition */
+ ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG,
+ MAX30102_REG_TEMP_CONFIG_TEMP_EN,
+ MAX30102_REG_TEMP_CONFIG_TEMP_EN);
+ if (ret)
+ return ret;
+
+ msleep(35);
+
+ return max30102_read_temp(data, val);
+}
+
+static int max30102_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct max30102_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /*
+ * Temperature reading can only be acquired while engine
+ * is running
+ */
+ mutex_lock(&indio_dev->mlock);
+
+ if (!iio_buffer_enabled(indio_dev))
+ ret = -EBUSY;
+ else {
+ ret = max30102_get_temp(data, val);
+ if (!ret)
+ ret = IIO_VAL_INT;
+ }
+
+ mutex_unlock(&indio_dev->mlock);
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1; /* 0.0625 */
+ *val2 = 16;
+ ret = IIO_VAL_FRACTIONAL;
+ break;
+ }
+
+ return ret;
+}
+
+static const struct iio_info max30102_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = max30102_read_raw,
+};
+
+static int max30102_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct max30102_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 = MAX30102_DRV_NAME;
+ indio_dev->channels = max30102_channels;
+ indio_dev->info = &max30102_info;
+ indio_dev->num_channels = ARRAY_SIZE(max30102_channels);
+ indio_dev->available_scan_masks = max30102_scan_masks;
+ indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
+ indio_dev->setup_ops = &max30102_buffer_setup_ops;
+
+ data = iio_priv(indio_dev);
+ data->indio_dev = indio_dev;
+ data->client = client;
+
+ mutex_init(&data->lock);
+ i2c_set_clientdata(client, indio_dev);
+
+ data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config);
+ if (IS_ERR(data->regmap)) {
+ dev_err(&client->dev, "regmap initialization failed.\n");
+ return PTR_ERR(data->regmap);
+ }
+ max30102_set_powermode(data, false);
+
+ ret = max30102_chip_init(data);
+ if (ret)
+ return ret;
+
+ if (client->irq <= 0) {
+ dev_err(&client->dev, "no valid irq defined\n");
+ return -EINVAL;
+ }
+
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, max30102_interrupt_handler,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ "max30102_irq", indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
+ return ret;
+ }
+
+ return iio_device_register(indio_dev);
+}
+
+static int max30102_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct max30102_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ max30102_set_powermode(data, false);
+
+ return 0;
+}
+
+static const struct i2c_device_id max30102_id[] = {
+ { "max30102", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, max30102_id);
+
+static const struct of_device_id max30102_dt_ids[] = {
+ { .compatible = "maxim,max30102" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max30102_dt_ids);
+
+static struct i2c_driver max30102_driver = {
+ .driver = {
+ .name = MAX30102_DRV_NAME,
+ .of_match_table = of_match_ptr(max30102_dt_ids),
+ },
+ .probe = max30102_probe,
+ .remove = max30102_remove,
+ .id_table = max30102_id,
+};
+module_i2c_driver(max30102_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt@ranostay.consulting>");
+MODULE_DESCRIPTION("MAX30102 heart rate and pulse oximeter sensor");
+MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff