163 lines
4.1 KiB
C
163 lines
4.1 KiB
C
/*
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* tpl0102.c - Support for Texas Instruments digital potentiometers
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*
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* Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* TODO: enable/disable hi-z output control
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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/regmap.h>
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#include <linux/iio/iio.h>
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struct tpl0102_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 tpl0102_type {
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CAT5140_503,
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CAT5140_104,
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TPL0102_104,
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TPL0401_103,
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};
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static const struct tpl0102_cfg tpl0102_cfg[] = {
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/* on-semiconductor parts */
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[CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
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[CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
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/* ti parts */
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[TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
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[TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
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};
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struct tpl0102_data {
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struct regmap *regmap;
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unsigned long devid;
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};
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static const struct regmap_config tpl0102_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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};
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#define TPL0102_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 tpl0102_channels[] = {
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TPL0102_CHANNEL(0),
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TPL0102_CHANNEL(1),
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};
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static int tpl0102_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 tpl0102_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW: {
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int ret = regmap_read(data->regmap, chan->channel, val);
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return ret ? ret : IIO_VAL_INT;
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}
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case IIO_CHAN_INFO_SCALE:
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*val = 1000 * tpl0102_cfg[data->devid].kohms;
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*val2 = tpl0102_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 tpl0102_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 tpl0102_data *data = iio_priv(indio_dev);
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if (mask != IIO_CHAN_INFO_RAW)
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return -EINVAL;
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if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
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return -EINVAL;
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return regmap_write(data->regmap, chan->channel, val);
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}
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static const struct iio_info tpl0102_info = {
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.read_raw = tpl0102_read_raw,
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.write_raw = tpl0102_write_raw,
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.driver_module = THIS_MODULE,
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};
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static int tpl0102_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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struct tpl0102_data *data;
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struct iio_dev *indio_dev;
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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->devid = id->driver_data;
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data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
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if (IS_ERR(data->regmap)) {
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dev_err(dev, "regmap initialization failed\n");
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return PTR_ERR(data->regmap);
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}
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indio_dev->dev.parent = dev;
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indio_dev->info = &tpl0102_info;
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indio_dev->channels = tpl0102_channels;
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indio_dev->num_channels = tpl0102_cfg[data->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 tpl0102_id[] = {
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{ "cat5140-503", CAT5140_503 },
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{ "cat5140-104", CAT5140_104 },
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{ "tpl0102-104", TPL0102_104 },
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{ "tpl0401-103", TPL0401_103 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, tpl0102_id);
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static struct i2c_driver tpl0102_driver = {
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.driver = {
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.name = "tpl0102",
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},
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.probe = tpl0102_probe,
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.id_table = tpl0102_id,
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};
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module_i2c_driver(tpl0102_driver);
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MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
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MODULE_DESCRIPTION("TPL0102 digital potentiometer");
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MODULE_LICENSE("GPL");
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