232 lines
6.4 KiB
C
232 lines
6.4 KiB
C
/*
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* Industrial I/O driver for Microchip digital potentiometers
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* Copyright (c) 2015 Axentia Technologies AB
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* Author: Peter Rosin <peda@axentia.se>
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*
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* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
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*
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* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
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* mcp4531 1 129 5, 10, 50, 100 010111x
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* mcp4532 1 129 5, 10, 50, 100 01011xx
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* mcp4551 1 257 5, 10, 50, 100 010111x
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* mcp4552 1 257 5, 10, 50, 100 01011xx
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* mcp4631 2 129 5, 10, 50, 100 0101xxx
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* mcp4632 2 129 5, 10, 50, 100 01011xx
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* mcp4651 2 257 5, 10, 50, 100 0101xxx
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* mcp4652 2 257 5, 10, 50, 100 01011xx
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/iio/iio.h>
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struct mcp4531_cfg {
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int wipers;
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int max_pos;
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int kohms;
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};
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enum mcp4531_type {
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MCP453x_502,
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MCP453x_103,
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MCP453x_503,
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MCP453x_104,
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MCP455x_502,
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MCP455x_103,
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MCP455x_503,
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MCP455x_104,
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MCP463x_502,
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MCP463x_103,
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MCP463x_503,
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MCP463x_104,
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MCP465x_502,
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MCP465x_103,
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MCP465x_503,
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MCP465x_104,
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};
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static const struct mcp4531_cfg mcp4531_cfg[] = {
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[MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
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[MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
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[MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
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[MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
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[MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
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[MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
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[MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
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[MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
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[MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
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[MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
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[MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
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[MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
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[MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
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[MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
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[MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
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[MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
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};
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#define MCP4531_WRITE (0 << 2)
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#define MCP4531_INCR (1 << 2)
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#define MCP4531_DECR (2 << 2)
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#define MCP4531_READ (3 << 2)
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#define MCP4531_WIPER_SHIFT (4)
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struct mcp4531_data {
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struct i2c_client *client;
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unsigned long devid;
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};
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#define MCP4531_CHANNEL(ch) { \
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.type = IIO_RESISTANCE, \
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.indexed = 1, \
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.output = 1, \
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.channel = (ch), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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}
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static const struct iio_chan_spec mcp4531_channels[] = {
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MCP4531_CHANNEL(0),
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MCP4531_CHANNEL(1),
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};
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static int mcp4531_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct mcp4531_data *data = iio_priv(indio_dev);
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int address = chan->channel << MCP4531_WIPER_SHIFT;
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s32 ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = i2c_smbus_read_word_swapped(data->client,
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MCP4531_READ | address);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = 1000 * mcp4531_cfg[data->devid].kohms;
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*val2 = mcp4531_cfg[data->devid].max_pos;
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return IIO_VAL_FRACTIONAL;
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}
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return -EINVAL;
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}
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static int mcp4531_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct mcp4531_data *data = iio_priv(indio_dev);
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int address = chan->channel << MCP4531_WIPER_SHIFT;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (val > mcp4531_cfg[data->devid].max_pos || val < 0)
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return -EINVAL;
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break;
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default:
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return -EINVAL;
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}
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return i2c_smbus_write_byte_data(data->client,
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MCP4531_WRITE | address | (val >> 8),
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val & 0xff);
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}
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static const struct iio_info mcp4531_info = {
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.read_raw = mcp4531_read_raw,
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.write_raw = mcp4531_write_raw,
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.driver_module = THIS_MODULE,
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};
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static int mcp4531_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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unsigned long devid = id->driver_data;
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struct mcp4531_data *data;
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struct iio_dev *indio_dev;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WORD_DATA)) {
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dev_err(dev, "SMBUS Word Data not supported\n");
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return -EOPNOTSUPP;
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}
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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data->client = client;
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data->devid = devid;
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indio_dev->dev.parent = dev;
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indio_dev->info = &mcp4531_info;
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indio_dev->channels = mcp4531_channels;
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indio_dev->num_channels = mcp4531_cfg[devid].wipers;
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indio_dev->name = client->name;
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return devm_iio_device_register(dev, indio_dev);
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}
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static const struct i2c_device_id mcp4531_id[] = {
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{ "mcp4531-502", MCP453x_502 },
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{ "mcp4531-103", MCP453x_103 },
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{ "mcp4531-503", MCP453x_503 },
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{ "mcp4531-104", MCP453x_104 },
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{ "mcp4532-502", MCP453x_502 },
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{ "mcp4532-103", MCP453x_103 },
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{ "mcp4532-503", MCP453x_503 },
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{ "mcp4532-104", MCP453x_104 },
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{ "mcp4551-502", MCP455x_502 },
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{ "mcp4551-103", MCP455x_103 },
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{ "mcp4551-503", MCP455x_503 },
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{ "mcp4551-104", MCP455x_104 },
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{ "mcp4552-502", MCP455x_502 },
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{ "mcp4552-103", MCP455x_103 },
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{ "mcp4552-503", MCP455x_503 },
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{ "mcp4552-104", MCP455x_104 },
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{ "mcp4631-502", MCP463x_502 },
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{ "mcp4631-103", MCP463x_103 },
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{ "mcp4631-503", MCP463x_503 },
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{ "mcp4631-104", MCP463x_104 },
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{ "mcp4632-502", MCP463x_502 },
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{ "mcp4632-103", MCP463x_103 },
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{ "mcp4632-503", MCP463x_503 },
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{ "mcp4632-104", MCP463x_104 },
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{ "mcp4651-502", MCP465x_502 },
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{ "mcp4651-103", MCP465x_103 },
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{ "mcp4651-503", MCP465x_503 },
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{ "mcp4651-104", MCP465x_104 },
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{ "mcp4652-502", MCP465x_502 },
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{ "mcp4652-103", MCP465x_103 },
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{ "mcp4652-503", MCP465x_503 },
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{ "mcp4652-104", MCP465x_104 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, mcp4531_id);
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static struct i2c_driver mcp4531_driver = {
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.driver = {
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.name = "mcp4531",
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},
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.probe = mcp4531_probe,
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.id_table = mcp4531_id,
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};
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module_i2c_driver(mcp4531_driver);
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MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
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MODULE_DESCRIPTION("MCP4531 digital potentiometer");
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MODULE_LICENSE("GPL");
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