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/*
* Industrial I/O driver for Microchip digital potentiometers
* Copyright (c) 2015 Axentia Technologies AB
* Author: Peter Rosin <peda@axentia.se>
*
* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
*
* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
* mcp4531 1 129 5, 10, 50, 100 010111x
* mcp4532 1 129 5, 10, 50, 100 01011xx
* mcp4551 1 257 5, 10, 50, 100 010111x
* mcp4552 1 257 5, 10, 50, 100 01011xx
* mcp4631 2 129 5, 10, 50, 100 0101xxx
* mcp4632 2 129 5, 10, 50, 100 01011xx
* mcp4651 2 257 5, 10, 50, 100 0101xxx
* mcp4652 2 257 5, 10, 50, 100 01011xx
*
* 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/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
struct mcp4531_cfg {
int wipers;
int max_pos;
int kohms;
};
enum mcp4531_type {
MCP453x_502,
MCP453x_103,
MCP453x_503,
MCP453x_104,
MCP455x_502,
MCP455x_103,
MCP455x_503,
MCP455x_104,
MCP463x_502,
MCP463x_103,
MCP463x_503,
MCP463x_104,
MCP465x_502,
MCP465x_103,
MCP465x_503,
MCP465x_104,
};
static const struct mcp4531_cfg mcp4531_cfg[] = {
[MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
[MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
[MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
[MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
[MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
[MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
[MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
[MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
[MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
[MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
[MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
[MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
[MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
[MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
[MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
[MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
};
#define MCP4531_WRITE (0 << 2)
#define MCP4531_INCR (1 << 2)
#define MCP4531_DECR (2 << 2)
#define MCP4531_READ (3 << 2)
#define MCP4531_WIPER_SHIFT (4)
struct mcp4531_data {
struct i2c_client *client;
unsigned long devid;
};
#define MCP4531_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 mcp4531_channels[] = {
MCP4531_CHANNEL(0),
MCP4531_CHANNEL(1),
};
static int mcp4531_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mcp4531_data *data = iio_priv(indio_dev);
int address = chan->channel << MCP4531_WIPER_SHIFT;
s32 ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_word_swapped(data->client,
MCP4531_READ | address);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 1000 * mcp4531_cfg[data->devid].kohms;
*val2 = mcp4531_cfg[data->devid].max_pos;
return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
}
static int mcp4531_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct mcp4531_data *data = iio_priv(indio_dev);
int address = chan->channel << MCP4531_WIPER_SHIFT;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > mcp4531_cfg[data->devid].max_pos || val < 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
return i2c_smbus_write_byte_data(data->client,
MCP4531_WRITE | address | (val >> 8),
val & 0xff);
}
static const struct iio_info mcp4531_info = {
.read_raw = mcp4531_read_raw,
.write_raw = mcp4531_write_raw,
.driver_module = THIS_MODULE,
};
static int mcp4531_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
unsigned long devid = id->driver_data;
struct mcp4531_data *data;
struct iio_dev *indio_dev;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_err(dev, "SMBUS Word Data not supported\n");
return -EIO;
}
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->devid = devid;
indio_dev->dev.parent = dev;
indio_dev->info = &mcp4531_info;
indio_dev->channels = mcp4531_channels;
indio_dev->num_channels = mcp4531_cfg[devid].wipers;
indio_dev->name = client->name;
return devm_iio_device_register(dev, indio_dev);
}
static const struct i2c_device_id mcp4531_id[] = {
{ "mcp4531-502", MCP453x_502 },
{ "mcp4531-103", MCP453x_103 },
{ "mcp4531-503", MCP453x_503 },
{ "mcp4531-104", MCP453x_104 },
{ "mcp4532-502", MCP453x_502 },
{ "mcp4532-103", MCP453x_103 },
{ "mcp4532-503", MCP453x_503 },
{ "mcp4532-104", MCP453x_104 },
{ "mcp4551-502", MCP455x_502 },
{ "mcp4551-103", MCP455x_103 },
{ "mcp4551-503", MCP455x_503 },
{ "mcp4551-104", MCP455x_104 },
{ "mcp4552-502", MCP455x_502 },
{ "mcp4552-103", MCP455x_103 },
{ "mcp4552-503", MCP455x_503 },
{ "mcp4552-104", MCP455x_104 },
{ "mcp4631-502", MCP463x_502 },
{ "mcp4631-103", MCP463x_103 },
{ "mcp4631-503", MCP463x_503 },
{ "mcp4631-104", MCP463x_104 },
{ "mcp4632-502", MCP463x_502 },
{ "mcp4632-103", MCP463x_103 },
{ "mcp4632-503", MCP463x_503 },
{ "mcp4632-104", MCP463x_104 },
{ "mcp4651-502", MCP465x_502 },
{ "mcp4651-103", MCP465x_103 },
{ "mcp4651-503", MCP465x_503 },
{ "mcp4651-104", MCP465x_104 },
{ "mcp4652-502", MCP465x_502 },
{ "mcp4652-103", MCP465x_103 },
{ "mcp4652-503", MCP465x_503 },
{ "mcp4652-104", MCP465x_104 },
{}
};
MODULE_DEVICE_TABLE(i2c, mcp4531_id);
static struct i2c_driver mcp4531_driver = {
.driver = {
.name = "mcp4531",
},
.probe = mcp4531_probe,
.id_table = mcp4531_id,
};
module_i2c_driver(mcp4531_driver);
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
MODULE_DESCRIPTION("MCP4531 digital potentiometer");
MODULE_LICENSE("GPL");
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