249 lines
5.5 KiB
C
249 lines
5.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors
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*
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* Copyright (C) 2020 Konsulko Group
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* Author: Matt Ranostay <matt.ranostay@konsulko.com>
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*/
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/property.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#define ATLAS_EZO_DRV_NAME "atlas-ezo-sensor"
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#define ATLAS_INT_TIME_IN_MS 950
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#define ATLAS_INT_HUM_TIME_IN_MS 350
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enum {
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ATLAS_CO2_EZO,
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ATLAS_O2_EZO,
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ATLAS_HUM_EZO,
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};
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struct atlas_ezo_device {
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const struct iio_chan_spec *channels;
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int num_channels;
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int delay;
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};
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struct atlas_ezo_data {
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struct i2c_client *client;
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const struct atlas_ezo_device *chip;
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/* lock to avoid multiple concurrent read calls */
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struct mutex lock;
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u8 buffer[8];
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};
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#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \
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{ \
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.type = IIO_CONCENTRATION, \
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.modified = 1,\
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.channel2 = _modifier, \
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.info_mask_separate = \
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BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
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.scan_index = 0, \
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.scan_type = { \
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.sign = 'u', \
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.realbits = 32, \
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.storagebits = 32, \
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.endianness = IIO_CPU, \
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}, \
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}
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static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
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ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2),
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};
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static const struct iio_chan_spec atlas_o2_ezo_channels[] = {
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ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2),
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};
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static const struct iio_chan_spec atlas_hum_ezo_channels[] = {
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_separate =
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BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
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.scan_index = 0,
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.scan_type = {
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.sign = 'u',
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.realbits = 32,
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.storagebits = 32,
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.endianness = IIO_CPU,
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},
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},
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};
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static struct atlas_ezo_device atlas_ezo_devices[] = {
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[ATLAS_CO2_EZO] = {
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.channels = atlas_co2_ezo_channels,
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.num_channels = 1,
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.delay = ATLAS_INT_TIME_IN_MS,
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},
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[ATLAS_O2_EZO] = {
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.channels = atlas_o2_ezo_channels,
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.num_channels = 1,
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.delay = ATLAS_INT_TIME_IN_MS,
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},
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[ATLAS_HUM_EZO] = {
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.channels = atlas_hum_ezo_channels,
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.num_channels = 1,
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.delay = ATLAS_INT_HUM_TIME_IN_MS,
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},
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};
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static void atlas_ezo_sanitize(char *buf)
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{
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char *ptr = strchr(buf, '.');
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if (!ptr)
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return;
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memmove(ptr, ptr + 1, strlen(ptr));
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}
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static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct atlas_ezo_data *data = iio_priv(indio_dev);
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struct i2c_client *client = data->client;
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if (chan->type != IIO_CONCENTRATION)
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return -EINVAL;
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switch (mask) {
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case IIO_CHAN_INFO_RAW: {
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int ret;
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long tmp;
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mutex_lock(&data->lock);
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tmp = i2c_smbus_write_byte(client, 'R');
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if (tmp < 0) {
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mutex_unlock(&data->lock);
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return tmp;
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}
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msleep(data->chip->delay);
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tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer));
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if (tmp < 0 || data->buffer[0] != 1) {
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mutex_unlock(&data->lock);
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return -EBUSY;
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}
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/* removing floating point for fixed number representation */
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atlas_ezo_sanitize(data->buffer + 2);
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ret = kstrtol(data->buffer + 1, 10, &tmp);
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*val = tmp;
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mutex_unlock(&data->lock);
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return ret ? ret : IIO_VAL_INT;
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}
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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_HUMIDITYRELATIVE:
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*val = 10;
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return IIO_VAL_INT;
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case IIO_CONCENTRATION:
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break;
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default:
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return -EINVAL;
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}
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/* IIO_CONCENTRATION modifiers */
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switch (chan->channel2) {
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case IIO_MOD_CO2:
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*val = 0;
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*val2 = 100; /* 0.0001 */
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_MOD_O2:
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*val = 100;
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return IIO_VAL_INT;
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}
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return -EINVAL;
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}
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return 0;
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}
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static const struct iio_info atlas_info = {
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.read_raw = atlas_ezo_read_raw,
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};
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static const struct i2c_device_id atlas_ezo_id[] = {
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{ "atlas-co2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_CO2_EZO] },
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{ "atlas-o2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_O2_EZO] },
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{ "atlas-hum-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_HUM_EZO] },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);
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static const struct of_device_id atlas_ezo_dt_ids[] = {
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{ .compatible = "atlas,co2-ezo", .data = &atlas_ezo_devices[ATLAS_CO2_EZO], },
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{ .compatible = "atlas,o2-ezo", .data = &atlas_ezo_devices[ATLAS_O2_EZO], },
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{ .compatible = "atlas,hum-ezo", .data = &atlas_ezo_devices[ATLAS_HUM_EZO], },
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{}
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};
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MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);
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static int atlas_ezo_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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const struct atlas_ezo_device *chip;
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struct atlas_ezo_data *data;
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struct iio_dev *indio_dev;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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if (dev_fwnode(&client->dev))
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chip = device_get_match_data(&client->dev);
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else
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chip = (const struct atlas_ezo_device *)id->driver_data;
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if (!chip)
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return -EINVAL;
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indio_dev->info = &atlas_info;
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indio_dev->name = ATLAS_EZO_DRV_NAME;
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indio_dev->channels = chip->channels;
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indio_dev->num_channels = chip->num_channels;
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indio_dev->modes = INDIO_DIRECT_MODE;
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data = iio_priv(indio_dev);
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data->client = client;
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data->chip = chip;
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mutex_init(&data->lock);
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return devm_iio_device_register(&client->dev, indio_dev);
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};
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static struct i2c_driver atlas_ezo_driver = {
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.driver = {
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.name = ATLAS_EZO_DRV_NAME,
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.of_match_table = atlas_ezo_dt_ids,
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},
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.probe = atlas_ezo_probe,
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.id_table = atlas_ezo_id,
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};
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module_i2c_driver(atlas_ezo_driver);
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MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
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MODULE_DESCRIPTION("Atlas Scientific EZO sensors");
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MODULE_LICENSE("GPL");
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