[linux-block.git] / drivers / iio / potentiometer / mcp4018.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Industrial I/O driver for Microchip digital potentiometers
 * Copyright (c) 2018  Axentia Technologies AB
 * Author: Peter Rosin <peda@axentia.se>
 *
 * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf
 *
 * DEVID	#Wipers	#Positions	Resistor Opts (kOhm)
 * mcp4017	1	128		5, 10, 50, 100
 * mcp4018	1	128		5, 10, 50, 100
 * mcp4019	1	128		5, 10, 50, 100
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>

#define MCP4018_WIPER_MAX 127

struct mcp4018_cfg {
	int kohms;
};

enum mcp4018_type {
	MCP4018_502,
	MCP4018_103,
	MCP4018_503,
	MCP4018_104,
};

static const struct mcp4018_cfg mcp4018_cfg[] = {
	[MCP4018_502] = { .kohms =   5, },
	[MCP4018_103] = { .kohms =  10, },
	[MCP4018_503] = { .kohms =  50, },
	[MCP4018_104] = { .kohms = 100, },
};

struct mcp4018_data {
	struct i2c_client *client;
	const struct mcp4018_cfg *cfg;
};

static const struct iio_chan_spec mcp4018_channel = {
	.type = IIO_RESISTANCE,
	.indexed = 1,
	.output = 1,
	.channel = 0,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
};

static int mcp4018_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct mcp4018_data *data = iio_priv(indio_dev);
	s32 ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = i2c_smbus_read_byte(data->client);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 1000 * data->cfg->kohms;
		*val2 = MCP4018_WIPER_MAX;
		return IIO_VAL_FRACTIONAL;
	}

	return -EINVAL;
}

static int mcp4018_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct mcp4018_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (val > MCP4018_WIPER_MAX || val < 0)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	return i2c_smbus_write_byte(data->client, val);
}

static const struct iio_info mcp4018_info = {
	.read_raw = mcp4018_read_raw,
	.write_raw = mcp4018_write_raw,
};

static const struct i2c_device_id mcp4018_id[] = {
	{ "mcp4017-502", MCP4018_502 },
	{ "mcp4017-103", MCP4018_103 },
	{ "mcp4017-503", MCP4018_503 },
	{ "mcp4017-104", MCP4018_104 },
	{ "mcp4018-502", MCP4018_502 },
	{ "mcp4018-103", MCP4018_103 },
	{ "mcp4018-503", MCP4018_503 },
	{ "mcp4018-104", MCP4018_104 },
	{ "mcp4019-502", MCP4018_502 },
	{ "mcp4019-103", MCP4018_103 },
	{ "mcp4019-503", MCP4018_503 },
	{ "mcp4019-104", MCP4018_104 },
	{}
};
MODULE_DEVICE_TABLE(i2c, mcp4018_id);

#ifdef CONFIG_OF

#define MCP4018_COMPATIBLE(of_compatible, cfg) {	\
	.compatible = of_compatible,			\
	.data = &mcp4018_cfg[cfg],			\
}

static const struct of_device_id mcp4018_of_match[] = {
	MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502),
	MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103),
	MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503),
	MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104),
	MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502),
	MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103),
	MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503),
	MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104),
	MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502),
	MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103),
	MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503),
	MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104),
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mcp4018_of_match);

#endif

static int mcp4018_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct mcp4018_data *data;
	struct iio_dev *indio_dev;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_BYTE)) {
		dev_err(dev, "SMBUS Byte transfers not supported\n");
		return -EOPNOTSUPP;
	}

	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->cfg = of_device_get_match_data(dev);
	if (!data->cfg)
		data->cfg = &mcp4018_cfg[i2c_match_id(mcp4018_id, client)->driver_data];

	indio_dev->dev.parent = dev;
	indio_dev->info = &mcp4018_info;
	indio_dev->channels = &mcp4018_channel;
	indio_dev->num_channels = 1;
	indio_dev->name = client->name;

	return devm_iio_device_register(dev, indio_dev);
}

static struct i2c_driver mcp4018_driver = {
	.driver = {
		.name	= "mcp4018",
		.of_match_table = of_match_ptr(mcp4018_of_match),
	},
	.probe_new	= mcp4018_probe,
	.id_table	= mcp4018_id,
};

module_i2c_driver(mcp4018_driver);

MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
MODULE_DESCRIPTION("MCP4018 digital potentiometer");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
5214ad6d PR	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Industrial I/O driver for Microchip digital potentiometers
	4	* Copyright (c) 2018 Axentia Technologies AB
	5	* Author: Peter Rosin <peda@axentia.se>
	6	*
	7	* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf
	8	*
	9	* DEVID #Wipers #Positions Resistor Opts (kOhm)
	10	* mcp4017 1 128 5, 10, 50, 100
	11	* mcp4018 1 128 5, 10, 50, 100
	12	* mcp4019 1 128 5, 10, 50, 100
	13	*/
	14
	15	#include <linux/err.h>
	16	#include <linux/i2c.h>
	17	#include <linux/iio/iio.h>
	18	#include <linux/module.h>
	19	#include <linux/of.h>
	20	#include <linux/of_device.h>
	21
	22	#define MCP4018_WIPER_MAX 127
	23
	24	struct mcp4018_cfg {
	25	int kohms;
	26	};
	27
	28	enum mcp4018_type {
	29	MCP4018_502,
	30	MCP4018_103,
	31	MCP4018_503,
	32	MCP4018_104,
	33	};
	34
	35	static const struct mcp4018_cfg mcp4018_cfg[] = {
	36	[MCP4018_502] = { .kohms = 5, },
	37	[MCP4018_103] = { .kohms = 10, },
	38	[MCP4018_503] = { .kohms = 50, },
	39	[MCP4018_104] = { .kohms = 100, },
	40	};
	41
	42	struct mcp4018_data {
	43	struct i2c_client *client;
	44	const struct mcp4018_cfg *cfg;
	45	};
	46
	47	static const struct iio_chan_spec mcp4018_channel = {
	48	.type = IIO_RESISTANCE,
	49	.indexed = 1,
	50	.output = 1,
	51	.channel = 0,
	52	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	53	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
	54	};
	55
	56	static int mcp4018_read_raw(struct iio_dev *indio_dev,
	57	struct iio_chan_spec const *chan,
	58	int val, int val2, long mask)
	59	{
	60	struct mcp4018_data *data = iio_priv(indio_dev);
	61	s32 ret;
	62
	63	switch (mask) {
	64	case IIO_CHAN_INFO_RAW:
65	ret = i2c_smbus_read_byte(data->client);
66	if (ret < 0)
67	return ret;
68	*val = ret;
69	return IIO_VAL_INT;
70	case IIO_CHAN_INFO_SCALE:
71	val = 1000 data->cfg->kohms;
72	*val2 = MCP4018_WIPER_MAX;
73	return IIO_VAL_FRACTIONAL;
74	}
75
76	return -EINVAL;
77	}
78
79	static int mcp4018_write_raw(struct iio_dev *indio_dev,
80	struct iio_chan_spec const *chan,
81	int val, int val2, long mask)
82	{
83	struct mcp4018_data *data = iio_priv(indio_dev);
84
85	switch (mask) {
86	case IIO_CHAN_INFO_RAW:
87	if (val > MCP4018_WIPER_MAX \|\| val < 0)
88	return -EINVAL;
89	break;
90	default:
91	return -EINVAL;
92	}
93
94	return i2c_smbus_write_byte(data->client, val);
95	}
96
97	static const struct iio_info mcp4018_info = {
98	.read_raw = mcp4018_read_raw,
99	.write_raw = mcp4018_write_raw,
100	};
101
0f6f400e PR	102	static const struct i2c_device_id mcp4018_id[] = {
	103	{ "mcp4017-502", MCP4018_502 },
	104	{ "mcp4017-103", MCP4018_103 },
	105	{ "mcp4017-503", MCP4018_503 },
	106	{ "mcp4017-104", MCP4018_104 },
	107	{ "mcp4018-502", MCP4018_502 },
	108	{ "mcp4018-103", MCP4018_103 },
	109	{ "mcp4018-503", MCP4018_503 },
	110	{ "mcp4018-104", MCP4018_104 },
	111	{ "mcp4019-502", MCP4018_502 },
	112	{ "mcp4019-103", MCP4018_103 },
	113	{ "mcp4019-503", MCP4018_503 },
	114	{ "mcp4019-104", MCP4018_104 },
	115	{}
	116	};
	117	MODULE_DEVICE_TABLE(i2c, mcp4018_id);
	118
5214ad6d PR	119	#ifdef CONFIG_OF
	120
	121	#define MCP4018_COMPATIBLE(of_compatible, cfg) { \
	122	.compatible = of_compatible, \
	123	.data = &mcp4018_cfg[cfg], \
	124	}
	125
	126	static const struct of_device_id mcp4018_of_match[] = {
	127	MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502),
	128	MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103),
	129	MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503),
	130	MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104),
	131	MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502),
	132	MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103),
	133	MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503),
	134	MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104),
	135	MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502),
	136	MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103),
	137	MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503),
	138	MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104),
	139	{ /* sentinel */ }
	140	};
	141	MODULE_DEVICE_TABLE(of, mcp4018_of_match);
	142
	143	#endif
	144
0f6f400e	145	static int mcp4018_probe(struct i2c_client *client)
5214ad6d PR	146	{
	147	struct device *dev = &client->dev;
	148	struct mcp4018_data *data;
	149	struct iio_dev *indio_dev;
5214ad6d PR	150
	151	if (!i2c_check_functionality(client->adapter,
	152	I2C_FUNC_SMBUS_BYTE)) {
	153	dev_err(dev, "SMBUS Byte transfers not supported\n");
	154	return -EOPNOTSUPP;
	155	}
	156
	157	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	158	if (!indio_dev)
	159	return -ENOMEM;
	160	data = iio_priv(indio_dev);
	161	i2c_set_clientdata(client, indio_dev);
	162	data->client = client;
	163
ce7c637a JL	164	data->cfg = of_device_get_match_data(dev);
ce7c637a JL	165	if (!data->cfg)
0f6f400e	166	data->cfg = &mcp4018_cfg[i2c_match_id(mcp4018_id, client)->driver_data];
5214ad6d PR	167
	168	indio_dev->dev.parent = dev;
	169	indio_dev->info = &mcp4018_info;
	170	indio_dev->channels = &mcp4018_channel;
	171	indio_dev->num_channels = 1;
	172	indio_dev->name = client->name;
	173
	174	return devm_iio_device_register(dev, indio_dev);
	175	}
	176
5214ad6d PR	177	static struct i2c_driver mcp4018_driver = {
	178	.driver = {
	179	.name = "mcp4018",
	180	.of_match_table = of_match_ptr(mcp4018_of_match),
	181	},
0f6f400e	182	.probe_new = mcp4018_probe,
5214ad6d PR	183	.id_table = mcp4018_id,
	184	};
	185
	186	module_i2c_driver(mcp4018_driver);
	187
	188	MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
	189	MODULE_DESCRIPTION("MCP4018 digital potentiometer");
b9ea8c31	190	MODULE_LICENSE("GPL v2");