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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
*
* Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip.
* Datasheets can be found here:
* https://www.ti.com/lit/ds/symlink/adc128s052.pdf
* https://www.ti.com/lit/ds/symlink/adc122s021.pdf
* https://www.ti.com/lit/ds/symlink/adc124s021.pdf
*/
#include <linux/acpi.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/iio/iio.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
struct adc128_configuration {
const struct iio_chan_spec *channels;
u8 num_channels;
};
struct adc128 {
struct spi_device *spi;
struct regulator *reg;
struct mutex lock;
u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
};
static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
{
int ret;
mutex_lock(&adc->lock);
adc->buffer[0] = channel << 3;
adc->buffer[1] = 0;
ret = spi_write(adc->spi, &adc->buffer, 2);
if (ret < 0) {
mutex_unlock(&adc->lock);
return ret;
}
ret = spi_read(adc->spi, &adc->buffer, 2);
mutex_unlock(&adc->lock);
if (ret < 0)
return ret;
return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
}
static int adc128_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct adc128 *adc = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = adc128_adc_conversion(adc, channel->channel);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(adc->reg);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
#define ADC128_VOLTAGE_CHANNEL(num) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (num), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
}
static const struct iio_chan_spec adc128s052_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
ADC128_VOLTAGE_CHANNEL(2),
ADC128_VOLTAGE_CHANNEL(3),
ADC128_VOLTAGE_CHANNEL(4),
ADC128_VOLTAGE_CHANNEL(5),
ADC128_VOLTAGE_CHANNEL(6),
ADC128_VOLTAGE_CHANNEL(7),
};
static const struct iio_chan_spec adc122s021_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
};
static const struct iio_chan_spec adc124s021_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
ADC128_VOLTAGE_CHANNEL(2),
ADC128_VOLTAGE_CHANNEL(3),
};
static const struct adc128_configuration adc128_config[] = {
{ adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
{ adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
{ adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
};
static const struct iio_info adc128_info = {
.read_raw = adc128_read_raw,
};
static void adc128_disable_regulator(void *reg)
{
regulator_disable(reg);
}
static int adc128_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
unsigned int config;
struct adc128 *adc;
int ret;
if (dev_fwnode(&spi->dev))
config = (unsigned long) device_get_match_data(&spi->dev);
else
config = spi_get_device_id(spi)->driver_data;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
if (!indio_dev)
return -ENOMEM;
adc = iio_priv(indio_dev);
adc->spi = spi;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &adc128_info;
indio_dev->channels = adc128_config[config].channels;
indio_dev->num_channels = adc128_config[config].num_channels;
adc->reg = devm_regulator_get(&spi->dev, "vref");
if (IS_ERR(adc->reg))
return PTR_ERR(adc->reg);
ret = regulator_enable(adc->reg);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
adc->reg);
if (ret)
return ret;
mutex_init(&adc->lock);
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id adc128_of_match[] = {
{ .compatible = "ti,adc128s052", },
{ .compatible = "ti,adc122s021", },
{ .compatible = "ti,adc122s051", },
{ .compatible = "ti,adc122s101", },
{ .compatible = "ti,adc124s021", },
{ .compatible = "ti,adc124s051", },
{ .compatible = "ti,adc124s101", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, adc128_of_match);
static const struct spi_device_id adc128_id[] = {
{ "adc128s052", 0 }, /* index into adc128_config */
{ "adc122s021", 1 },
{ "adc122s051", 1 },
{ "adc122s101", 1 },
{ "adc124s021", 2 },
{ "adc124s051", 2 },
{ "adc124s101", 2 },
{ }
};
MODULE_DEVICE_TABLE(spi, adc128_id);
#ifdef CONFIG_ACPI
static const struct acpi_device_id adc128_acpi_match[] = {
{ "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */
{ }
};
MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
#endif
static struct spi_driver adc128_driver = {
.driver = {
.name = "adc128s052",
.of_match_table = adc128_of_match,
.acpi_match_table = ACPI_PTR(adc128_acpi_match),
},
.probe = adc128_probe,
.id_table = adc128_id,
};
module_spi_driver(adc128_driver);
MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
MODULE_DESCRIPTION("Texas Instruments ADC128S052");
MODULE_LICENSE("GPL v2");
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