ti-adc081c.c
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/*
* Copyright (C) 2012 Avionic Design GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/iio/iio.h>
#include <linux/regulator/consumer.h>
struct adc081c {
struct i2c_client *i2c;
struct regulator *ref;
};
#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 >> 4) & 0xff;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
err = regulator_get_voltage(adc->ref);
if (err < 0)
return err;
*value = err / 1000;
*shift = 8;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static const struct iio_chan_spec adc081c_channel = {
.type = IIO_VOLTAGE,
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
};
static const struct iio_info adc081c_info = {
.read_raw = adc081c_read_raw,
.driver_module = THIS_MODULE,
};
static int adc081c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *iio;
struct adc081c *adc;
int err;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
if (!iio)
return -ENOMEM;
adc = iio_priv(iio);
adc->i2c = client;
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;
iio->dev.parent = &client->dev;
iio->name = dev_name(&client->dev);
iio->modes = INDIO_DIRECT_MODE;
iio->info = &adc081c_info;
iio->channels = &adc081c_channel;
iio->num_channels = 1;
err = iio_device_register(iio);
if (err < 0)
goto regulator_disable;
i2c_set_clientdata(client, iio);
return 0;
regulator_disable:
regulator_disable(adc->ref);
return err;
}
static int adc081c_remove(struct i2c_client *client)
{
struct iio_dev *iio = i2c_get_clientdata(client);
struct adc081c *adc = iio_priv(iio);
iio_device_unregister(iio);
regulator_disable(adc->ref);
return 0;
}
static const struct i2c_device_id adc081c_id[] = {
{ "adc081c", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, adc081c_id);
#ifdef CONFIG_OF
static const struct of_device_id adc081c_of_match[] = {
{ .compatible = "ti,adc081c" },
{ }
};
MODULE_DEVICE_TABLE(of, adc081c_of_match);
#endif
static struct i2c_driver adc081c_driver = {
.driver = {
.name = "adc081c",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(adc081c_of_match),
},
.probe = adc081c_probe,
.remove = adc081c_remove,
.id_table = adc081c_id,
};
module_i2c_driver(adc081c_driver);
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Texas Instruments ADC081C021/027 driver");
MODULE_LICENSE("GPL v2");