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
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
// SPDX-License-Identifier: GPL-2.0+
/*
* ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC
*
* ADC Devices Supported:
* adc141s626 - 14-bit ADC
* adc161s626 - 16-bit ADC
*
* Copyright (C) 2016-2018
* Author: Matt Ranostay <matt.ranostay@konsulko.com>
*/
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regulator/consumer.h>
#define TI_ADC_DRV_NAME "ti-adc161s626"
enum {
TI_ADC141S626,
TI_ADC161S626,
};
static const struct iio_chan_spec ti_adc141s626_channels[] = {
{
.type = IIO_VOLTAGE,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 14,
.storagebits = 16,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
static const struct iio_chan_spec ti_adc161s626_channels[] = {
{
.type = IIO_VOLTAGE,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
struct ti_adc_data {
struct iio_dev *indio_dev;
struct spi_device *spi;
struct regulator *ref;
u8 read_size;
u8 shift;
u8 buffer[16] __aligned(IIO_DMA_MINALIGN);
};
static int ti_adc_read_measurement(struct ti_adc_data *data,
struct iio_chan_spec const *chan, int *val)
{
int ret;
switch (data->read_size) {
case 2: {
__be16 buf;
ret = spi_read(data->spi, (void *) &buf, 2);
if (ret)
return ret;
*val = be16_to_cpu(buf);
break;
}
case 3: {
__be32 buf;
ret = spi_read(data->spi, (void *) &buf, 3);
if (ret)
return ret;
*val = be32_to_cpu(buf) >> 8;
break;
}
default:
return -EINVAL;
}
*val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1);
return 0;
}
static irqreturn_t ti_adc_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
struct iio_dev *indio_dev = pf->indio_dev;
struct ti_adc_data *data = iio_priv(indio_dev);
int ret;
ret = ti_adc_read_measurement(data, &indio_dev->channels[0],
(int *) &data->buffer);
if (!ret)
iio_push_to_buffers_with_timestamp(indio_dev,
data->buffer,
iio_get_time_ns(indio_dev));
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ti_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ti_adc_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
ret = ti_adc_read_measurement(data, chan, val);
if (ret)
return ret;
return IIO_VAL_INT;
}
unreachable();
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(data->ref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
*val = 1 << (chan->scan_type.realbits - 1);
return IIO_VAL_INT;
}
return 0;
}
static const struct iio_info ti_adc_info = {
.read_raw = ti_adc_read_raw,
};
static void ti_adc_reg_disable(void *reg)
{
regulator_disable(reg);
}
static int ti_adc_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ti_adc_data *data;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
indio_dev->info = &ti_adc_info;
indio_dev->name = TI_ADC_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
data = iio_priv(indio_dev);
data->spi = spi;
switch (spi_get_device_id(spi)->driver_data) {
case TI_ADC141S626:
indio_dev->channels = ti_adc141s626_channels;
indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels);
data->shift = 0;
data->read_size = 2;
break;
case TI_ADC161S626:
indio_dev->channels = ti_adc161s626_channels;
indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels);
data->shift = 6;
data->read_size = 3;
break;
}
data->ref = devm_regulator_get(&spi->dev, "vdda");
if (IS_ERR(data->ref))
return PTR_ERR(data->ref);
ret = regulator_enable(data->ref);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(&spi->dev, ti_adc_reg_disable,
data->ref);
if (ret)
return ret;
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
ti_adc_trigger_handler, NULL);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id ti_adc_dt_ids[] = {
{ .compatible = "ti,adc141s626", },
{ .compatible = "ti,adc161s626", },
{ }
};
MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
static const struct spi_device_id ti_adc_id[] = {
{ "adc141s626", TI_ADC141S626 },
{ "adc161s626", TI_ADC161S626 },
{ }
};
MODULE_DEVICE_TABLE(spi, ti_adc_id);
static struct spi_driver ti_adc_driver = {
.driver = {
.name = TI_ADC_DRV_NAME,
.of_match_table = ti_adc_dt_ids,
},
.probe = ti_adc_probe,
.id_table = ti_adc_id,
};
module_spi_driver(ti_adc_driver);
MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
MODULE_LICENSE("GPL");
|
