forked from Minki/linux
c34bed923d
These prevent use of this driver with ACPI via PRP0001 and are an example of an anti pattern I'm trying to remove from IIO. Drop them to remove this restriction. Also switch of.h for mod_devicetable.h include given use of struct of_device_id which is defined in that header. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Slawomir Stepien <sst@poczta.fm> Link: https://lore.kernel.org/r/20200910173242.621168-3-jic23@kernel.org
167 lines
3.8 KiB
C
167 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Maxim Integrated DS1803 digital potentiometer driver
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* Copyright (c) 2016 Slawomir Stepien
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*
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* Datasheet: https://datasheets.maximintegrated.com/en/ds/DS1803.pdf
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*
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* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
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* ds1803 2 256 10, 50, 100 0101xxx
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*/
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#include <linux/err.h>
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#include <linux/export.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#define DS1803_MAX_POS 255
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#define DS1803_WRITE(chan) (0xa8 | ((chan) + 1))
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enum ds1803_type {
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DS1803_010,
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DS1803_050,
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DS1803_100,
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};
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struct ds1803_cfg {
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int kohms;
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};
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static const struct ds1803_cfg ds1803_cfg[] = {
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[DS1803_010] = { .kohms = 10, },
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[DS1803_050] = { .kohms = 50, },
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[DS1803_100] = { .kohms = 100, },
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};
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struct ds1803_data {
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struct i2c_client *client;
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const struct ds1803_cfg *cfg;
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};
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#define DS1803_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 ds1803_channels[] = {
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DS1803_CHANNEL(0),
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DS1803_CHANNEL(1),
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};
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static int ds1803_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 ds1803_data *data = iio_priv(indio_dev);
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int pot = chan->channel;
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int ret;
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u8 result[ARRAY_SIZE(ds1803_channels)];
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = i2c_master_recv(data->client, result,
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indio_dev->num_channels);
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if (ret < 0)
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return ret;
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*val = result[pot];
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = 1000 * data->cfg->kohms;
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*val2 = DS1803_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 ds1803_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 ds1803_data *data = iio_priv(indio_dev);
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int pot = chan->channel;
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if (val2 != 0)
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return -EINVAL;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (val > DS1803_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, DS1803_WRITE(pot), val);
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}
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static const struct iio_info ds1803_info = {
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.read_raw = ds1803_read_raw,
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.write_raw = ds1803_write_raw,
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};
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static int ds1803_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 ds1803_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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i2c_set_clientdata(client, indio_dev);
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data = iio_priv(indio_dev);
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data->client = client;
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data->cfg = &ds1803_cfg[id->driver_data];
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indio_dev->info = &ds1803_info;
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indio_dev->channels = ds1803_channels;
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indio_dev->num_channels = ARRAY_SIZE(ds1803_channels);
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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 of_device_id ds1803_dt_ids[] = {
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{ .compatible = "maxim,ds1803-010", .data = &ds1803_cfg[DS1803_010] },
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{ .compatible = "maxim,ds1803-050", .data = &ds1803_cfg[DS1803_050] },
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{ .compatible = "maxim,ds1803-100", .data = &ds1803_cfg[DS1803_100] },
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{}
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};
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MODULE_DEVICE_TABLE(of, ds1803_dt_ids);
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static const struct i2c_device_id ds1803_id[] = {
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{ "ds1803-010", DS1803_010 },
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{ "ds1803-050", DS1803_050 },
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{ "ds1803-100", DS1803_100 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ds1803_id);
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static struct i2c_driver ds1803_driver = {
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.driver = {
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.name = "ds1803",
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.of_match_table = ds1803_dt_ids,
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},
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.probe = ds1803_probe,
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.id_table = ds1803_id,
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};
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module_i2c_driver(ds1803_driver);
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MODULE_AUTHOR("Slawomir Stepien <sst@poczta.fm>");
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MODULE_DESCRIPTION("DS1803 digital potentiometer");
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MODULE_LICENSE("GPL v2");
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