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// SPDX-License-Identifier: GPL-2.0
/*
* Maxim MAX11205 16-Bit Delta-Sigma ADC
*
* Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-max11205.pdf
* Copyright (C) 2022 Analog Devices, Inc.
* Author: Ramona Bolboaca <ramona.bolboaca@analog.com>
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#include <linux/iio/adc/ad_sigma_delta.h>
#define MAX11205_BIT_SCALE 15
#define MAX11205A_OUT_DATA_RATE 116
#define MAX11205B_OUT_DATA_RATE 13
enum max11205_chip_type {
TYPE_MAX11205A,
TYPE_MAX11205B,
};
struct max11205_chip_info {
unsigned int out_data_rate;
const char *name;
};
struct max11205_state {
const struct max11205_chip_info *chip_info;
struct regulator *vref;
struct ad_sigma_delta sd;
};
static const struct ad_sigma_delta_info max11205_sigma_delta_info = {
.has_registers = false,
};
static int max11205_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct max11205_state *st = iio_priv(indio_dev);
int reg_mv;
switch (mask) {
case IIO_CHAN_INFO_RAW:
return ad_sigma_delta_single_conversion(indio_dev, chan, val);
case IIO_CHAN_INFO_SCALE:
reg_mv = regulator_get_voltage(st->vref);
if (reg_mv < 0)
return reg_mv;
reg_mv /= 1000;
*val = reg_mv;
*val2 = MAX11205_BIT_SCALE;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = st->chip_info->out_data_rate;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static const struct iio_info max11205_iio_info = {
.read_raw = max11205_read_raw,
.validate_trigger = ad_sd_validate_trigger,
};
static const struct iio_chan_spec max11205_channels[] = {
{
.type = IIO_VOLTAGE,
.indexed = 1,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_BE,
},
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SAMP_FREQ) |
BIT(IIO_CHAN_INFO_SCALE),
},
};
static const struct max11205_chip_info max11205_chip_info[] = {
[TYPE_MAX11205A] = {
.out_data_rate = MAX11205A_OUT_DATA_RATE,
.name = "max11205a",
},
[TYPE_MAX11205B] = {
.out_data_rate = MAX11205B_OUT_DATA_RATE,
.name = "max11205b",
},
};
static void max11205_reg_disable(void *reg)
{
regulator_disable(reg);
}
static int max11205_probe(struct spi_device *spi)
{
struct max11205_state *st;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
ad_sd_init(&st->sd, indio_dev, spi, &max11205_sigma_delta_info);
st->chip_info = device_get_match_data(&spi->dev);
if (!st->chip_info)
st->chip_info =
(const struct max11205_chip_info *)spi_get_device_id(spi)->driver_data;
indio_dev->name = st->chip_info->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = max11205_channels;
indio_dev->num_channels = 1;
indio_dev->info = &max11205_iio_info;
st->vref = devm_regulator_get(&spi->dev, "vref");
if (IS_ERR(st->vref))
return dev_err_probe(&spi->dev, PTR_ERR(st->vref),
"Failed to get vref regulator\n");
ret = regulator_enable(st->vref);
if (ret)
return ret;
ret = devm_add_action_or_reset(&spi->dev, max11205_reg_disable, st->vref);
if (ret)
return ret;
ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct spi_device_id max11205_spi_ids[] = {
{ "max11205a", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205A] },
{ "max11205b", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205B] },
{ }
};
MODULE_DEVICE_TABLE(spi, max11205_spi_ids);
static const struct of_device_id max11205_dt_ids[] = {
{
.compatible = "maxim,max11205a",
.data = &max11205_chip_info[TYPE_MAX11205A],
},
{
.compatible = "maxim,max11205b",
.data = &max11205_chip_info[TYPE_MAX11205B],
},
{ }
};
MODULE_DEVICE_TABLE(of, max11205_dt_ids);
static struct spi_driver max11205_spi_driver = {
.driver = {
.name = "max11205",
.of_match_table = max11205_dt_ids,
},
.probe = max11205_probe,
.id_table = max11205_spi_ids,
};
module_spi_driver(max11205_spi_driver);
MODULE_AUTHOR("Ramona Bolboaca <ramona.bolboaca@analog.com>");
MODULE_DESCRIPTION("MAX11205 ADC driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);
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