[mirror_ubuntu-bionic-kernel.git] / drivers / iio / potentiometer / ds1803.c

/*
 * Maxim Integrated DS1803 digital potentiometer driver
 * Copyright (c) 2016 Slawomir Stepien
 *
 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS1803.pdf
 *
 * DEVID	#Wipers	#Positions	Resistor Opts (kOhm)	i2c address
 * ds1803	2	256		10, 50, 100		0101xxx
 *
 * 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/err.h>
#include <linux/export.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/of.h>

#define DS1803_MAX_POS		255
#define DS1803_WRITE(chan)	(0xa8 | ((chan) + 1))

enum ds1803_type {
	DS1803_010,
	DS1803_050,
	DS1803_100,
};

struct ds1803_cfg {
	int kohms;
};

static const struct ds1803_cfg ds1803_cfg[] = {
	[DS1803_010] = { .kohms =  10, },
	[DS1803_050] = { .kohms =  50, },
	[DS1803_100] = { .kohms = 100, },
};

struct ds1803_data {
	struct i2c_client *client;
	const struct ds1803_cfg *cfg;
};

#define DS1803_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 ds1803_channels[] = {
	DS1803_CHANNEL(0),
	DS1803_CHANNEL(1),
};

static int ds1803_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct ds1803_data *data = iio_priv(indio_dev);
	int pot = chan->channel;
	int ret;
	u8 result[indio_dev->num_channels];

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = i2c_master_recv(data->client, result,
				indio_dev->num_channels);
		if (ret < 0)
			return ret;

		*val = result[pot];
		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
		*val = 1000 * data->cfg->kohms;
		*val2 = DS1803_MAX_POS;
		return IIO_VAL_FRACTIONAL;
	}

	return -EINVAL;
}

static int ds1803_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct ds1803_data *data = iio_priv(indio_dev);
	int pot = chan->channel;

	if (val2 != 0)
		return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (val > DS1803_MAX_POS || val < 0)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	return i2c_smbus_write_byte_data(data->client, DS1803_WRITE(pot), val);
}

static const struct iio_info ds1803_info = {
	.read_raw = ds1803_read_raw,
	.write_raw = ds1803_write_raw,
	.driver_module = THIS_MODULE,
};

static int ds1803_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct ds1803_data *data;
	struct iio_dev *indio_dev;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	i2c_set_clientdata(client, indio_dev);

	data = iio_priv(indio_dev);
	data->client = client;
	data->cfg = &ds1803_cfg[id->driver_data];

	indio_dev->dev.parent = dev;
	indio_dev->info = &ds1803_info;
	indio_dev->channels = ds1803_channels;
	indio_dev->num_channels = ARRAY_SIZE(ds1803_channels);
	indio_dev->name = client->name;

	return devm_iio_device_register(dev, indio_dev);
}

#if defined(CONFIG_OF)
static const struct of_device_id ds1803_dt_ids[] = {
	{ .compatible = "maxim,ds1803-010", .data = &ds1803_cfg[DS1803_010] },
	{ .compatible = "maxim,ds1803-050", .data = &ds1803_cfg[DS1803_050] },
	{ .compatible = "maxim,ds1803-100", .data = &ds1803_cfg[DS1803_100] },
	{}
};
MODULE_DEVICE_TABLE(of, ds1803_dt_ids);
#endif /* CONFIG_OF */

static const struct i2c_device_id ds1803_id[] = {
	{ "ds1803-010", DS1803_010 },
	{ "ds1803-050", DS1803_050 },
	{ "ds1803-100", DS1803_100 },
	{}
};
MODULE_DEVICE_TABLE(i2c, ds1803_id);

static struct i2c_driver ds1803_driver = {
	.driver = {
		.name	= "ds1803",
		.of_match_table = of_match_ptr(ds1803_dt_ids),
	},
	.probe		= ds1803_probe,
	.id_table	= ds1803_id,
};

module_i2c_driver(ds1803_driver);

MODULE_AUTHOR("Slawomir Stepien <sst@poczta.fm>");
MODULE_DESCRIPTION("DS1803 digital potentiometer");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
fbbc5e70 SS	1	/*
	2	* Maxim Integrated DS1803 digital potentiometer driver
	3	* Copyright (c) 2016 Slawomir Stepien
	4	*
	5	* Datasheet: https://datasheets.maximintegrated.com/en/ds/DS1803.pdf
	6	*
	7	* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
	8	* ds1803 2 256 10, 50, 100 0101xxx
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License version 2 as published by
	12	* the Free Software Foundation.
	13	*/
	14
	15	#include <linux/err.h>
	16	#include <linux/export.h>
	17	#include <linux/i2c.h>
	18	#include <linux/iio/iio.h>
	19	#include <linux/module.h>
	20	#include <linux/of.h>
	21
	22	#define DS1803_MAX_POS 255
	23	#define DS1803_WRITE(chan) (0xa8 \| ((chan) + 1))
	24
	25	enum ds1803_type {
	26	DS1803_010,
	27	DS1803_050,
	28	DS1803_100,
	29	};
	30
	31	struct ds1803_cfg {
	32	int kohms;
	33	};
	34
	35	static const struct ds1803_cfg ds1803_cfg[] = {
	36	[DS1803_010] = { .kohms = 10, },
	37	[DS1803_050] = { .kohms = 50, },
	38	[DS1803_100] = { .kohms = 100, },
	39	};
	40
	41	struct ds1803_data {
	42	struct i2c_client *client;
	43	const struct ds1803_cfg *cfg;
	44	};
	45
	46	#define DS1803_CHANNEL(ch) { \
	47	.type = IIO_RESISTANCE, \
	48	.indexed = 1, \
	49	.output = 1, \
	50	.channel = (ch), \
	51	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	52	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	53	}
	54
	55	static const struct iio_chan_spec ds1803_channels[] = {
	56	DS1803_CHANNEL(0),
	57	DS1803_CHANNEL(1),
	58	};
	59
	60	static int ds1803_read_raw(struct iio_dev *indio_dev,
	61	struct iio_chan_spec const *chan,
	62	int val, int val2, long mask)
	63	{
	64	struct ds1803_data *data = iio_priv(indio_dev);
65	int pot = chan->channel;
66	int ret;
67	u8 result[indio_dev->num_channels];
68
69	switch (mask) {
70	case IIO_CHAN_INFO_RAW:
71	ret = i2c_master_recv(data->client, result,
72	indio_dev->num_channels);
73	if (ret < 0)
74	return ret;
75
76	*val = result[pot];
77	return IIO_VAL_INT;
78
79	case IIO_CHAN_INFO_SCALE:
80	val = 1000 data->cfg->kohms;
81	*val2 = DS1803_MAX_POS;
82	return IIO_VAL_FRACTIONAL;
83	}
84
85	return -EINVAL;
86	}
87
88	static int ds1803_write_raw(struct iio_dev *indio_dev,
89	struct iio_chan_spec const *chan,
90	int val, int val2, long mask)
91	{
92	struct ds1803_data *data = iio_priv(indio_dev);
93	int pot = chan->channel;
94
95	if (val2 != 0)
96	return -EINVAL;
97
98	switch (mask) {
99	case IIO_CHAN_INFO_RAW:
100	if (val > DS1803_MAX_POS \|\| val < 0)
101	return -EINVAL;
102	break;
103	default:
104	return -EINVAL;
105	}
106
107	return i2c_smbus_write_byte_data(data->client, DS1803_WRITE(pot), val);
108	}
109
110	static const struct iio_info ds1803_info = {
111	.read_raw = ds1803_read_raw,
112	.write_raw = ds1803_write_raw,
113	.driver_module = THIS_MODULE,
114	};
115
116	static int ds1803_probe(struct i2c_client *client,
117	const struct i2c_device_id *id)
118	{
119	struct device *dev = &client->dev;
120	struct ds1803_data *data;
121	struct iio_dev *indio_dev;
122
123	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
124	if (!indio_dev)
125	return -ENOMEM;
126
127	i2c_set_clientdata(client, indio_dev);
128
129	data = iio_priv(indio_dev);
130	data->client = client;
131	data->cfg = &ds1803_cfg[id->driver_data];
132
133	indio_dev->dev.parent = dev;
134	indio_dev->info = &ds1803_info;
135	indio_dev->channels = ds1803_channels;
136	indio_dev->num_channels = ARRAY_SIZE(ds1803_channels);
137	indio_dev->name = client->name;
138
139	return devm_iio_device_register(dev, indio_dev);
140	}
141
142	#if defined(CONFIG_OF)
143	static const struct of_device_id ds1803_dt_ids[] = {
144	{ .compatible = "maxim,ds1803-010", .data = &ds1803_cfg[DS1803_010] },
145	{ .compatible = "maxim,ds1803-050", .data = &ds1803_cfg[DS1803_050] },
146	{ .compatible = "maxim,ds1803-100", .data = &ds1803_cfg[DS1803_100] },
147	{}
148	};
149	MODULE_DEVICE_TABLE(of, ds1803_dt_ids);
150	#endif /* CONFIG_OF */
151
152	static const struct i2c_device_id ds1803_id[] = {
153	{ "ds1803-010", DS1803_010 },
154	{ "ds1803-050", DS1803_050 },
155	{ "ds1803-100", DS1803_100 },
156	{}
157	};
158	MODULE_DEVICE_TABLE(i2c, ds1803_id);
159
160	static struct i2c_driver ds1803_driver = {
161	.driver = {
162	.name = "ds1803",
163	.of_match_table = of_match_ptr(ds1803_dt_ids),
164	},
165	.probe = ds1803_probe,
166	.id_table = ds1803_id,
167	};
168
169	module_i2c_driver(ds1803_driver);
170
171	MODULE_AUTHOR("Slawomir Stepien <sst@poczta.fm>");
172	MODULE_DESCRIPTION("DS1803 digital potentiometer");
173	MODULE_LICENSE("GPL v2");