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// SPDX-License-Identifier: GPL-2.0-only
/*
* TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
*
* Copyright (C) 2012 Avionic Design GmbH
* Copyright (C) 2016 Intel
*
* Datasheets:
* https://www.ti.com/lit/ds/symlink/adc081c021.pdf
* https://www.ti.com/lit/ds/symlink/adc101c021.pdf
* https://www.ti.com/lit/ds/symlink/adc121c021.pdf
*
* The devices have a very similar interface and differ mostly in the number of
* bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
* bits of value registers are reserved.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regulator/consumer.h>
struct adc081c {
struct i2c_client *i2c;
struct regulator *ref;
/* 8, 10 or 12 */
int bits;
/* Ensure natural alignment of buffer elements */
struct {
u16 channel;
s64 ts __aligned(8);
} scan;
};
#define REG_CONV_RES 0x00
static int adc081c_read_raw(struct iio_dev *iio,
struct iio_chan_spec const *channel, int *value,
int *shift, long mask)
{
struct adc081c *adc = iio_priv(iio);
int err;
switch (mask) {
case IIO_CHAN_INFO_RAW:
err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
if (err < 0)
return err;
*value = (err & 0xFFF) >> (12 - adc->bits);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
err = regulator_get_voltage(adc->ref);
if (err < 0)
return err;
*value = err / 1000;
*shift = adc->bits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
#define ADCxx1C_CHAN(_bits) { \
.type = IIO_VOLTAGE, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 16, \
.shift = 12 - (_bits), \
.endianness = IIO_CPU, \
}, \
}
#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
static const struct iio_chan_spec _name ## _channels[] = { \
ADCxx1C_CHAN((_bits)), \
IIO_CHAN_SOFT_TIMESTAMP(1), \
}; \
#define ADC081C_NUM_CHANNELS 2
struct adcxx1c_model {
const struct iio_chan_spec* channels;
int bits;
};
#define ADCxx1C_MODEL(_name, _bits) \
{ \
.channels = _name ## _channels, \
.bits = (_bits), \
}
DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
/* Model ids are indexes in _models array */
enum adcxx1c_model_id {
ADC081C = 0,
ADC101C = 1,
ADC121C = 2,
};
static struct adcxx1c_model adcxx1c_models[] = {
ADCxx1C_MODEL(adc081c, 8),
ADCxx1C_MODEL(adc101c, 10),
ADCxx1C_MODEL(adc121c, 12),
};
static const struct iio_info adc081c_info = {
.read_raw = adc081c_read_raw,
};
static irqreturn_t adc081c_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct adc081c *data = iio_priv(indio_dev);
int ret;
ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
if (ret < 0)
goto out;
data->scan.channel = ret;
iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
iio_get_time_ns(indio_dev));
out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static void adc081c_reg_disable(void *reg)
{
regulator_disable(reg);
}
static int adc081c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *iio;
struct adc081c *adc;
struct adcxx1c_model *model;
int err;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -EOPNOTSUPP;
model = &adcxx1c_models[id->driver_data];
iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
if (!iio)
return -ENOMEM;
adc = iio_priv(iio);
adc->i2c = client;
adc->bits = model->bits;
adc->ref = devm_regulator_get(&client->dev, "vref");
if (IS_ERR(adc->ref))
return PTR_ERR(adc->ref);
err = regulator_enable(adc->ref);
if (err < 0)
return err;
err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
adc->ref);
if (err)
return err;
iio->name = dev_name(&client->dev);
iio->modes = INDIO_DIRECT_MODE;
iio->info = &adc081c_info;
iio->channels = model->channels;
iio->num_channels = ADC081C_NUM_CHANNELS;
err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
adc081c_trigger_handler, NULL);
if (err < 0) {
dev_err(&client->dev, "iio triggered buffer setup failed\n");
return err;
}
return devm_iio_device_register(&client->dev, iio);
}
static const struct i2c_device_id adc081c_id[] = {
{ "adc081c", ADC081C },
{ "adc101c", ADC101C },
{ "adc121c", ADC121C },
{ }
};
MODULE_DEVICE_TABLE(i2c, adc081c_id);
static const struct of_device_id adc081c_of_match[] = {
{ .compatible = "ti,adc081c" },
{ .compatible = "ti,adc101c" },
{ .compatible = "ti,adc121c" },
{ }
};
MODULE_DEVICE_TABLE(of, adc081c_of_match);
static struct i2c_driver adc081c_driver = {
.driver = {
.name = "adc081c",
.of_match_table = adc081c_of_match,
},
.probe = adc081c_probe,
.id_table = adc081c_id,
};
module_i2c_driver(adc081c_driver);
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
MODULE_LICENSE("GPL v2");
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