blob: 7b6b54531ea235bf315f876d7f51577417604139 [file] [log] [blame]
/*
* tpl0102.c - Support for Texas Instruments digital potentiometers
*
* Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* TODO: enable/disable hi-z output control
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
struct tpl0102_cfg {
int wipers;
int max_pos;
int kohms;
};
enum tpl0102_type {
CAT5140_503,
CAT5140_104,
TPL0102_104,
TPL0401_103,
};
static const struct tpl0102_cfg tpl0102_cfg[] = {
/* on-semiconductor parts */
[CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
[CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
/* ti parts */
[TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
[TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
};
struct tpl0102_data {
struct regmap *regmap;
unsigned long devid;
};
static const struct regmap_config tpl0102_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
#define TPL0102_CHANNEL(ch) { \
.type = IIO_RESISTANCE, \
.indexed = 1, \
.output = 1, \
.channel = (ch), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec tpl0102_channels[] = {
TPL0102_CHANNEL(0),
TPL0102_CHANNEL(1),
};
static int tpl0102_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct tpl0102_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW: {
int ret = regmap_read(data->regmap, chan->channel, val);
return ret ? ret : IIO_VAL_INT;
}
case IIO_CHAN_INFO_SCALE:
*val = 1000 * tpl0102_cfg[data->devid].kohms;
*val2 = tpl0102_cfg[data->devid].max_pos;
return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
}
static int tpl0102_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct tpl0102_data *data = iio_priv(indio_dev);
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
return -EINVAL;
return regmap_write(data->regmap, chan->channel, val);
}
static const struct iio_info tpl0102_info = {
.read_raw = tpl0102_read_raw,
.write_raw = tpl0102_write_raw,
.driver_module = THIS_MODULE,
};
static int tpl0102_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct tpl0102_data *data;
struct iio_dev *indio_dev;
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->devid = id->driver_data;
data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
if (IS_ERR(data->regmap)) {
dev_err(dev, "regmap initialization failed\n");
return PTR_ERR(data->regmap);
}
indio_dev->dev.parent = dev;
indio_dev->info = &tpl0102_info;
indio_dev->channels = tpl0102_channels;
indio_dev->num_channels = tpl0102_cfg[data->devid].wipers;
indio_dev->name = client->name;
return devm_iio_device_register(dev, indio_dev);
}
static const struct i2c_device_id tpl0102_id[] = {
{ "cat5140-503", CAT5140_503 },
{ "cat5140-104", CAT5140_104 },
{ "tpl0102-104", TPL0102_104 },
{ "tpl0401-103", TPL0401_103 },
{}
};
MODULE_DEVICE_TABLE(i2c, tpl0102_id);
static struct i2c_driver tpl0102_driver = {
.driver = {
.name = "tpl0102",
},
.probe = tpl0102_probe,
.id_table = tpl0102_id,
};
module_i2c_driver(tpl0102_driver);
MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
MODULE_DESCRIPTION("TPL0102 digital potentiometer");
MODULE_LICENSE("GPL");