On 22/01/17 09:00, Peter Meerwald-Stadler wrote:
> On Thu, 19 Jan 2017, Matt Ranostay wrote:
>
>> MAX30102 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. The MAX30102 part isn't completely register and functional
>> compatible with the existing MAX30100 driver.
>
> comments below
>
>> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
>> ---
>> drivers/iio/health/Kconfig | 13 ++
>> drivers/iio/health/Makefile | 1 +
>> drivers/iio/health/max30102.c | 478 ++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 492 insertions(+)
>> create mode 100644 drivers/iio/health/max30102.c
>>
>> diff --git a/drivers/iio/health/Kconfig b/drivers/iio/health/Kconfig
>> index c5f004a8e447..a2ecb4c94c2a 100644
>> --- a/drivers/iio/health/Kconfig
>> +++ b/drivers/iio/health/Kconfig
>> @@ -46,6 +46,19 @@ config MAX30100
>> To compile this driver as a module, choose M here: the
>> module will be called max30100.
>>
>> +config MAX30102
>> + tristate "MAX30102 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
>> + MAX30102 heart rate, and pulse oximeter sensor.
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called max30102.
>> +
>> endmenu
>>
>> endmenu
>> diff --git a/drivers/iio/health/Makefile b/drivers/iio/health/Makefile
>> index 9955a2ae8df1..3558f9d64954 100644
>> --- a/drivers/iio/health/Makefile
>> +++ b/drivers/iio/health/Makefile
>> @@ -7,3 +7,4 @@
>> obj-$(CONFIG_AFE4403) += afe4403.o
>> obj-$(CONFIG_AFE4404) += afe4404.o
>> obj-$(CONFIG_MAX30100) += max30100.o
>> +obj-$(CONFIG_MAX30102) += max30102.o
>> diff --git a/drivers/iio/health/max30102.c b/drivers/iio/health/max30102.c
>> new file mode 100644
>> index 000000000000..3d18a63d2280
>> --- /dev/null
>> +++ b/drivers/iio/health/max30102.c
>> @@ -0,0 +1,478 @@
>> +/*
>> + * 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
>
> link to datasheet and i2c address would be nice to have here
>
>> + */
>> +
>> +#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 4
>> +
>> +#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
>
> keep registers sorted?
>
>> +
>> +struct max30102_data {
>> + struct i2c_client *client;
>> + struct iio_dev *indio_dev;
>> + struct mutex lock;
>> + struct regmap *regmap;
>> +
>> + u8 buffer[8]; /* 2 x 18-bit (padded to 24-bits) channels + 2 bytes pad */
>
> not sure; is storagebits supposed to be power-of-2?
> scantype documentation in iio.h doesn't state any requirement (but
> probably should)
>
Yes - it must be or the demux stuff messes up. Should add a note about that.
Patches welcome! We spent a while unwinding this in the ST drivers after
some 24 bit devices turned up there.
> why the padding? could use MAX30102_REG_FIFO_DATA_ENTRY_LEN (== 6) instead
> of 8?
>
>> +};
>> +
>> +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',
>> + .realbits = 18,
>> + .storagebits = 24,
>> + .endianness = IIO_BE,
>> + },
>> + },
>> + {
>> + .type = IIO_INTENSITY,
>> + .channel2 = IIO_MOD_LIGHT_IR,
>> + .modified = 1,
>> +
>> + .scan_index = 1,
>> + .scan_type = {
>> + .sign = 'u',
>> + .realbits = 18,
>> + .storagebits = 24,
>> + .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)
>
> no inline please, let the compiler decide (as it does anyways ...)
>
>> +{
>> + 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;
>> +
>> + ret = i2c_smbus_read_i2c_block_data(data->client,
>
> this mixes regmap with direct i2c, isn't there another way?
There was a proposal to do a 'repeated read' regmap operation which
is basically what this is doing. Not sure what happened to it
though...
>
>> + MAX30102_REG_FIFO_DATA,
>> + MAX30102_REG_FIFO_DATA_ENTRY_LEN,
>> + (u8 *) &data->buffer);
>> +
>
> what happens when ret is positive, but != MAX30102_REG_FIFO_DATA_ENTRY_LEN?
>
>> + return (ret == MAX30102_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret;
>> +}
>> +
>> +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->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 */
>
> saying that it is 200 µA saves some mental unit conversion effort (as
> documented in DT and 200 in the code below)
>
>> + *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 missing, here and elsewhere
>
>> +
>> + /* 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", 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");
>> +
>> + /* 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 100Hz */
>> + 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
>
> 100Hz in the comment vs 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))
>
> unusual; why not start the engine and make the read work?
Or don't support _raw at all. If there is a need to start the buffer
then why is anyone using the sysfs access?
>
>> + ret = -EAGAIN;
>> + 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");
>>
>
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