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// SPDX-License-Identifier: GPL-2.0+
/*
* atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors
*
* Copyright (C) 2020 Konsulko Group
* Author: Matt Ranostay <matt.ranostay@konsulko.com>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/of_device.h>
#include <linux/iio/iio.h>
#define ATLAS_EZO_DRV_NAME "atlas-ezo-sensor"
#define ATLAS_CO2_INT_TIME_IN_MS 950
enum {
ATLAS_CO2_EZO,
};
struct atlas_ezo_device {
const struct iio_chan_spec *channels;
int num_channels;
int delay;
};
struct atlas_ezo_data {
struct i2c_client *client;
struct atlas_ezo_device *chip;
/* lock to avoid multiple concurrent read calls */
struct mutex lock;
u8 buffer[8];
};
static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
{
.type = IIO_CONCENTRATION,
.modified = 1,
.channel2 = IIO_MOD_CO2,
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 32,
.storagebits = 32,
.endianness = IIO_CPU,
},
},
};
static struct atlas_ezo_device atlas_ezo_devices[] = {
[ATLAS_CO2_EZO] = {
.channels = atlas_co2_ezo_channels,
.num_channels = 1,
.delay = ATLAS_CO2_INT_TIME_IN_MS,
},
};
static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct atlas_ezo_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
if (chan->type != IIO_CONCENTRATION)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW: {
int ret;
long tmp;
mutex_lock(&data->lock);
tmp = i2c_smbus_write_byte(client, 'R');
if (tmp < 0) {
mutex_unlock(&data->lock);
return tmp;
}
msleep(data->chip->delay);
tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer));
if (tmp < 0 || data->buffer[0] != 1) {
mutex_unlock(&data->lock);
return -EBUSY;
}
ret = kstrtol(data->buffer + 1, 10, &tmp);
*val = tmp;
mutex_unlock(&data->lock);
return ret ? ret : IIO_VAL_INT;
}
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = 100; /* 0.0001 */
return IIO_VAL_INT_PLUS_MICRO;
}
return 0;
}
static const struct iio_info atlas_info = {
.read_raw = atlas_ezo_read_raw,
};
static const struct i2c_device_id atlas_ezo_id[] = {
{ "atlas-co2-ezo", ATLAS_CO2_EZO },
{}
};
MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);
static const struct of_device_id atlas_ezo_dt_ids[] = {
{ .compatible = "atlas,co2-ezo", .data = (void *)ATLAS_CO2_EZO, },
{}
};
MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);
static int atlas_ezo_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct atlas_ezo_data *data;
struct atlas_ezo_device *chip;
const struct of_device_id *of_id;
struct iio_dev *indio_dev;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
of_id = of_match_device(atlas_ezo_dt_ids, &client->dev);
if (!of_id)
chip = &atlas_ezo_devices[id->driver_data];
else
chip = &atlas_ezo_devices[(unsigned long)of_id->data];
indio_dev->info = &atlas_info;
indio_dev->name = ATLAS_EZO_DRV_NAME;
indio_dev->channels = chip->channels;
indio_dev->num_channels = chip->num_channels;
indio_dev->modes = INDIO_DIRECT_MODE;
data = iio_priv(indio_dev);
data->client = client;
data->chip = chip;
mutex_init(&data->lock);
return devm_iio_device_register(&client->dev, indio_dev);
};
static struct i2c_driver atlas_ezo_driver = {
.driver = {
.name = ATLAS_EZO_DRV_NAME,
.of_match_table = atlas_ezo_dt_ids,
},
.probe = atlas_ezo_probe,
.id_table = atlas_ezo_id,
};
module_i2c_driver(atlas_ezo_driver);
MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("Atlas Scientific EZO sensors");
MODULE_LICENSE("GPL");
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