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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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