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
|
/*
* TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
*
* Copyright (C) 2012 Avionic Design GmbH
* Copyright (C) 2016 Intel
*
* 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.
*
* Datasheets:
* http://www.ti.com/lit/ds/symlink/adc081c021.pdf
* http://www.ti.com/lit/ds/symlink/adc101c021.pdf
* http://www.ti.com/lit/ds/symlink/adc121c021.pdf
*
* The devices have a very similar interface and differ mostly in the number of
* bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
* bits of value registers are reserved.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/iio/iio.h>
#include <linux/regulator/consumer.h>
struct adc081c {
struct i2c_client *i2c;
struct regulator *ref;
/* 8, 10 or 12 */
int bits;
};
#define REG_CONV_RES 0x00
static int adc081c_read_raw(struct iio_dev *iio,
struct iio_chan_spec const *channel, int *value,
int *shift, long mask)
{
struct adc081c *adc = iio_priv(iio);
int err;
switch (mask) {
case IIO_CHAN_INFO_RAW:
err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
if (err < 0)
return err;
*value = (err & 0xFFF) >> (12 - adc->bits);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
err = regulator_get_voltage(adc->ref);
if (err < 0)
return err;
*value = err / 1000;
*shift = adc->bits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static const struct iio_chan_spec adc081c_channel = {
.type = IIO_VOLTAGE,
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
};
struct adcxx1c_model {
int bits;
};
#define ADCxx1C_MODEL(_bits) \
{ \
.bits = (_bits), \
}
/* Model ids are indexes in _models array */
enum adcxx1c_model_id {
ADC081C = 0,
ADC101C = 1,
ADC121C = 2,
};
static struct adcxx1c_model adcxx1c_models[] = {
ADCxx1C_MODEL( 8),
ADCxx1C_MODEL(10),
ADCxx1C_MODEL(12),
};
static const struct iio_info adc081c_info = {
.read_raw = adc081c_read_raw,
.driver_module = THIS_MODULE,
};
static int adc081c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *iio;
struct adc081c *adc;
struct adcxx1c_model *model = &adcxx1c_models[id->driver_data];
int err;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -EOPNOTSUPP;
iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
if (!iio)
return -ENOMEM;
adc = iio_priv(iio);
adc->i2c = client;
adc->bits = model->bits;
adc->ref = devm_regulator_get(&client->dev, "vref");
if (IS_ERR(adc->ref))
return PTR_ERR(adc->ref);
err = regulator_enable(adc->ref);
if (err < 0)
return err;
iio->dev.parent = &client->dev;
iio->name = dev_name(&client->dev);
iio->modes = INDIO_DIRECT_MODE;
iio->info = &adc081c_info;
iio->channels = &adc081c_channel;
iio->num_channels = 1;
err = iio_device_register(iio);
if (err < 0)
goto regulator_disable;
i2c_set_clientdata(client, iio);
return 0;
regulator_disable:
regulator_disable(adc->ref);
return err;
}
static int adc081c_remove(struct i2c_client *client)
{
struct iio_dev *iio = i2c_get_clientdata(client);
struct adc081c *adc = iio_priv(iio);
iio_device_unregister(iio);
regulator_disable(adc->ref);
return 0;
}
static const struct i2c_device_id adc081c_id[] = {
{ "adc081c", ADC081C },
{ "adc101c", ADC101C },
{ "adc121c", ADC121C },
{ }
};
MODULE_DEVICE_TABLE(i2c, adc081c_id);
#ifdef CONFIG_OF
static const struct of_device_id adc081c_of_match[] = {
{ .compatible = "ti,adc081c" },
{ .compatible = "ti,adc101c" },
{ .compatible = "ti,adc121c" },
{ }
};
MODULE_DEVICE_TABLE(of, adc081c_of_match);
#endif
static struct i2c_driver adc081c_driver = {
.driver = {
.name = "adc081c",
.of_match_table = of_match_ptr(adc081c_of_match),
},
.probe = adc081c_probe,
.remove = adc081c_remove,
.id_table = adc081c_id,
};
module_i2c_driver(adc081c_driver);
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
MODULE_LICENSE("GPL v2");
|
