// SPDX-License-Identifier: GPL-2.0
|
/*
|
* Industrial I/O driver for Microchip digital potentiometers
|
* Copyright (c) 2018 Axentia Technologies AB
|
* Author: Peter Rosin <peda@axentia.se>
|
*
|
* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf
|
*
|
* DEVID #Wipers #Positions Resistor Opts (kOhm)
|
* mcp4017 1 128 5, 10, 50, 100
|
* mcp4018 1 128 5, 10, 50, 100
|
* mcp4019 1 128 5, 10, 50, 100
|
*/
|
|
#include <linux/err.h>
|
#include <linux/i2c.h>
|
#include <linux/iio/iio.h>
|
#include <linux/module.h>
|
#include <linux/mod_devicetable.h>
|
#include <linux/property.h>
|
|
#define MCP4018_WIPER_MAX 127
|
|
struct mcp4018_cfg {
|
int kohms;
|
};
|
|
enum mcp4018_type {
|
MCP4018_502,
|
MCP4018_103,
|
MCP4018_503,
|
MCP4018_104,
|
};
|
|
static const struct mcp4018_cfg mcp4018_cfg[] = {
|
[MCP4018_502] = { .kohms = 5, },
|
[MCP4018_103] = { .kohms = 10, },
|
[MCP4018_503] = { .kohms = 50, },
|
[MCP4018_104] = { .kohms = 100, },
|
};
|
|
struct mcp4018_data {
|
struct i2c_client *client;
|
const struct mcp4018_cfg *cfg;
|
};
|
|
static const struct iio_chan_spec mcp4018_channel = {
|
.type = IIO_RESISTANCE,
|
.indexed = 1,
|
.output = 1,
|
.channel = 0,
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
};
|
|
static int mcp4018_read_raw(struct iio_dev *indio_dev,
|
struct iio_chan_spec const *chan,
|
int *val, int *val2, long mask)
|
{
|
struct mcp4018_data *data = iio_priv(indio_dev);
|
s32 ret;
|
|
switch (mask) {
|
case IIO_CHAN_INFO_RAW:
|
ret = i2c_smbus_read_byte(data->client);
|
if (ret < 0)
|
return ret;
|
*val = ret;
|
return IIO_VAL_INT;
|
case IIO_CHAN_INFO_SCALE:
|
*val = 1000 * data->cfg->kohms;
|
*val2 = MCP4018_WIPER_MAX;
|
return IIO_VAL_FRACTIONAL;
|
}
|
|
return -EINVAL;
|
}
|
|
static int mcp4018_write_raw(struct iio_dev *indio_dev,
|
struct iio_chan_spec const *chan,
|
int val, int val2, long mask)
|
{
|
struct mcp4018_data *data = iio_priv(indio_dev);
|
|
switch (mask) {
|
case IIO_CHAN_INFO_RAW:
|
if (val > MCP4018_WIPER_MAX || val < 0)
|
return -EINVAL;
|
break;
|
default:
|
return -EINVAL;
|
}
|
|
return i2c_smbus_write_byte(data->client, val);
|
}
|
|
static const struct iio_info mcp4018_info = {
|
.read_raw = mcp4018_read_raw,
|
.write_raw = mcp4018_write_raw,
|
};
|
|
static const struct i2c_device_id mcp4018_id[] = {
|
{ "mcp4017-502", MCP4018_502 },
|
{ "mcp4017-103", MCP4018_103 },
|
{ "mcp4017-503", MCP4018_503 },
|
{ "mcp4017-104", MCP4018_104 },
|
{ "mcp4018-502", MCP4018_502 },
|
{ "mcp4018-103", MCP4018_103 },
|
{ "mcp4018-503", MCP4018_503 },
|
{ "mcp4018-104", MCP4018_104 },
|
{ "mcp4019-502", MCP4018_502 },
|
{ "mcp4019-103", MCP4018_103 },
|
{ "mcp4019-503", MCP4018_503 },
|
{ "mcp4019-104", MCP4018_104 },
|
{}
|
};
|
MODULE_DEVICE_TABLE(i2c, mcp4018_id);
|
|
#define MCP4018_COMPATIBLE(of_compatible, cfg) { \
|
.compatible = of_compatible, \
|
.data = &mcp4018_cfg[cfg], \
|
}
|
|
static const struct of_device_id mcp4018_of_match[] = {
|
MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502),
|
MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103),
|
MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503),
|
MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104),
|
MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502),
|
MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103),
|
MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503),
|
MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104),
|
MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502),
|
MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103),
|
MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503),
|
MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104),
|
{ /* sentinel */ }
|
};
|
MODULE_DEVICE_TABLE(of, mcp4018_of_match);
|
|
static int mcp4018_probe(struct i2c_client *client)
|
{
|
struct device *dev = &client->dev;
|
struct mcp4018_data *data;
|
struct iio_dev *indio_dev;
|
|
if (!i2c_check_functionality(client->adapter,
|
I2C_FUNC_SMBUS_BYTE)) {
|
dev_err(dev, "SMBUS Byte transfers not supported\n");
|
return -EOPNOTSUPP;
|
}
|
|
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->client = client;
|
|
data->cfg = device_get_match_data(dev);
|
if (!data->cfg)
|
data->cfg = &mcp4018_cfg[i2c_match_id(mcp4018_id, client)->driver_data];
|
|
indio_dev->info = &mcp4018_info;
|
indio_dev->channels = &mcp4018_channel;
|
indio_dev->num_channels = 1;
|
indio_dev->name = client->name;
|
|
return devm_iio_device_register(dev, indio_dev);
|
}
|
|
static struct i2c_driver mcp4018_driver = {
|
.driver = {
|
.name = "mcp4018",
|
.of_match_table = mcp4018_of_match,
|
},
|
.probe_new = mcp4018_probe,
|
.id_table = mcp4018_id,
|
};
|
|
module_i2c_driver(mcp4018_driver);
|
|
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
|
MODULE_DESCRIPTION("MCP4018 digital potentiometer");
|
MODULE_LICENSE("GPL v2");
|
