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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
*
* Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip.
* Datasheets can be found here:
* https://www.ti.com/lit/ds/symlink/adc128s052.pdf
* https://www.ti.com/lit/ds/symlink/adc122s021.pdf
* https://www.ti.com/lit/ds/symlink/adc124s021.pdf
*/
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
struct adc128_configuration {
const struct iio_chan_spec *channels;
u8 num_channels;
};
struct adc128 {
struct spi_device *spi;
struct regulator *reg;
struct mutex lock;
u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
};
static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
{
int ret;
mutex_lock(&adc->lock);
adc->buffer[0] = channel << 3;
adc->buffer[1] = 0;
ret = spi_write(adc->spi, &adc->buffer, 2);
if (ret < 0) {
mutex_unlock(&adc->lock);
return ret;
}
ret = spi_read(adc->spi, &adc->buffer, 2);
mutex_unlock(&adc->lock);
if (ret < 0)
return ret;
return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
}
static int adc128_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct adc128 *adc = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = adc128_adc_conversion(adc, channel->channel);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(adc->reg);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
#define ADC128_VOLTAGE_CHANNEL(num) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (num), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
}
static const struct iio_chan_spec adc128s052_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
ADC128_VOLTAGE_CHANNEL(2),
ADC128_VOLTAGE_CHANNEL(3),
ADC128_VOLTAGE_CHANNEL(4),
ADC128_VOLTAGE_CHANNEL(5),
ADC128_VOLTAGE_CHANNEL(6),
ADC128_VOLTAGE_CHANNEL(7),
};
static const struct iio_chan_spec adc122s021_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
};
static const struct iio_chan_spec adc124s021_channels[] = {
ADC128_VOLTAGE_CHANNEL(0),
ADC128_VOLTAGE_CHANNEL(1),
ADC128_VOLTAGE_CHANNEL(2),
ADC128_VOLTAGE_CHANNEL(3),
};
static const struct adc128_configuration adc128_config[] = {
{ adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
{ adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
{ adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
};
static const struct iio_info adc128_info = {
.read_raw = adc128_read_raw,
};
static void adc128_disable_regulator(void *reg)
{
regulator_disable(reg);
}
static int adc128_probe(struct spi_device *spi)
{
const struct adc128_configuration *config;
struct iio_dev *indio_dev;
struct adc128 *adc;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
if (!indio_dev)
return -ENOMEM;
adc = iio_priv(indio_dev);
adc->spi = spi;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &adc128_info;
config = spi_get_device_match_data(spi);
indio_dev->channels = config->channels;
indio_dev->num_channels = config->num_channels;
adc->reg = devm_regulator_get(&spi->dev, "vref");
if (IS_ERR(adc->reg))
return PTR_ERR(adc->reg);
ret = regulator_enable(adc->reg);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
adc->reg);
if (ret)
return ret;
mutex_init(&adc->lock);
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id adc128_of_match[] = {
{ .compatible = "ti,adc128s052", .data = &adc128_config[0] },
{ .compatible = "ti,adc122s021", .data = &adc128_config[1] },
{ .compatible = "ti,adc122s051", .data = &adc128_config[1] },
{ .compatible = "ti,adc122s101", .data = &adc128_config[1] },
{ .compatible = "ti,adc124s021", .data = &adc128_config[2] },
{ .compatible = "ti,adc124s051", .data = &adc128_config[2] },
{ .compatible = "ti,adc124s101", .data = &adc128_config[2] },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, adc128_of_match);
static const struct spi_device_id adc128_id[] = {
{ "adc128s052", (kernel_ulong_t)&adc128_config[0] },
{ "adc122s021", (kernel_ulong_t)&adc128_config[1] },
{ "adc122s051", (kernel_ulong_t)&adc128_config[1] },
{ "adc122s101", (kernel_ulong_t)&adc128_config[1] },
{ "adc124s021", (kernel_ulong_t)&adc128_config[2] },
{ "adc124s051", (kernel_ulong_t)&adc128_config[2] },
{ "adc124s101", (kernel_ulong_t)&adc128_config[2] },
{ }
};
MODULE_DEVICE_TABLE(spi, adc128_id);
static const struct acpi_device_id adc128_acpi_match[] = {
{ "AANT1280", (kernel_ulong_t)&adc128_config[2] },
{ }
};
MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
static struct spi_driver adc128_driver = {
.driver = {
.name = "adc128s052",
.of_match_table = adc128_of_match,
.acpi_match_table = adc128_acpi_match,
},
.probe = adc128_probe,
.id_table = adc128_id,
};
module_spi_driver(adc128_driver);
MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
MODULE_DESCRIPTION("Texas Instruments ADC128S052");
MODULE_LICENSE("GPL v2");
|
