summaryrefslogtreecommitdiff
path: root/drivers/iio/potentiometer/mcp4531.c
blob: a3f66874ee2e43058c36e05125c7370ff95e7161 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/*
 * 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");