232 lines
6.4 KiB
C
232 lines
6.4 KiB
C
/*
|
|
* 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");
|