131 lines
2.9 KiB
C
131 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Generic sigma delta modulator driver
|
|
*
|
|
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
|
|
* Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
|
|
*/
|
|
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/iio/triggered_buffer.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/regulator/consumer.h>
|
|
|
|
static const struct iio_chan_spec iio_sd_mod_ch = {
|
|
.type = IIO_VOLTAGE,
|
|
.indexed = 1,
|
|
.scan_type = {
|
|
.sign = 'u',
|
|
.realbits = 1,
|
|
.shift = 0,
|
|
},
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
|
};
|
|
|
|
static const struct iio_chan_spec iio_sd_mod_ch_ads = {
|
|
.type = IIO_VOLTAGE,
|
|
.indexed = 1,
|
|
.scan_type = {
|
|
.sign = 'u',
|
|
.realbits = 1,
|
|
.shift = 0,
|
|
},
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
|
.differential = 1,
|
|
};
|
|
|
|
struct iio_sd_mod_priv {
|
|
int vref_mv;
|
|
};
|
|
|
|
static const struct of_device_id sd_adc_of_match[] = {
|
|
{ .compatible = "sd-modulator", .data = &iio_sd_mod_ch },
|
|
{ .compatible = "ads1201", .data = &iio_sd_mod_ch_ads },
|
|
{ }
|
|
};
|
|
|
|
static int iio_sd_mod_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan, int *val,
|
|
int *val2, long mask)
|
|
{
|
|
struct iio_sd_mod_priv *priv = iio_priv(indio_dev);
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_SCALE:
|
|
*val = priv->vref_mv;
|
|
*val2 = chan->scan_type.realbits;
|
|
return IIO_VAL_INT;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static const struct iio_info iio_sd_mod_iio_info = {
|
|
.read_raw = iio_sd_mod_read_raw,
|
|
};
|
|
|
|
static int iio_sd_mod_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct iio_sd_mod_priv *priv;
|
|
struct regulator *vref;
|
|
struct iio_dev *iio;
|
|
int ret;
|
|
|
|
iio = devm_iio_device_alloc(dev, sizeof(*priv));
|
|
if (!iio)
|
|
return -ENOMEM;
|
|
|
|
iio->channels = (const struct iio_chan_spec *)
|
|
of_match_device(sd_adc_of_match, &pdev->dev)->data;
|
|
|
|
priv = iio_priv(iio);
|
|
|
|
iio->dev.parent = dev;
|
|
iio->dev.of_node = dev->of_node;
|
|
iio->name = dev_name(dev);
|
|
iio->info = &iio_sd_mod_iio_info;
|
|
iio->modes = INDIO_BUFFER_HARDWARE;
|
|
iio->num_channels = 1;
|
|
|
|
vref = devm_regulator_get_optional(dev, "vref");
|
|
if (IS_ERR(vref)) {
|
|
ret = PTR_ERR(vref);
|
|
if (ret != -ENODEV) {
|
|
if (ret != -EPROBE_DEFER)
|
|
dev_err(dev, "vref get failed, %d\n", ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (!IS_ERR(vref)) {
|
|
ret = regulator_get_voltage(vref);
|
|
if (ret < 0) {
|
|
dev_err(dev, "vref get failed, %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
priv->vref_mv = ret / 1000;
|
|
dev_dbg(dev, "vref+=%dmV\n", priv->vref_mv);
|
|
}
|
|
|
|
return devm_iio_device_register(&pdev->dev, iio);
|
|
}
|
|
|
|
MODULE_DEVICE_TABLE(of, sd_adc_of_match);
|
|
|
|
static struct platform_driver iio_sd_mod_adc = {
|
|
.driver = {
|
|
.name = "iio_sd_adc_mod",
|
|
.of_match_table = of_match_ptr(sd_adc_of_match),
|
|
},
|
|
.probe = iio_sd_mod_probe,
|
|
};
|
|
|
|
module_platform_driver(iio_sd_mod_adc);
|
|
|
|
MODULE_DESCRIPTION("Basic sigma delta modulator");
|
|
MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
|
|
MODULE_LICENSE("GPL v2");
|