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
|
/*
* AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
*
* Copyright 2012 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/bitrev.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
struct ad8366_state {
struct spi_device *spi;
struct regulator *reg;
unsigned char ch[2];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
unsigned char data[2] ____cacheline_aligned;
};
static int ad8366_write(struct iio_dev *indio_dev,
unsigned char ch_a, char unsigned ch_b)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
ch_a = bitrev8(ch_a & 0x3F);
ch_b = bitrev8(ch_b & 0x3F);
st->data[0] = ch_b >> 4;
st->data[1] = (ch_b << 4) | (ch_a >> 2);
ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
if (ret < 0)
dev_err(&indio_dev->dev, "write failed (%d)", ret);
return ret;
}
static int ad8366_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
unsigned code;
mutex_lock(&indio_dev->mlock);
switch (m) {
case IIO_CHAN_INFO_HARDWAREGAIN:
code = st->ch[chan->channel];
/* Values in dB */
code = code * 253 + 4500;
*val = code / 1000;
*val2 = (code % 1000) * 1000;
ret = IIO_VAL_INT_PLUS_MICRO_DB;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return ret;
};
static int ad8366_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad8366_state *st = iio_priv(indio_dev);
unsigned code;
int ret;
if (val < 0 || val2 < 0)
return -EINVAL;
/* Values in dB */
code = (((u8)val * 1000) + ((u32)val2 / 1000));
if (code > 20500 || code < 4500)
return -EINVAL;
code = (code - 4500) / 253;
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_HARDWAREGAIN:
st->ch[chan->channel] = code;
ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
break;
default:
ret = -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return ret;
}
static const struct iio_info ad8366_info = {
.read_raw = &ad8366_read_raw,
.write_raw = &ad8366_write_raw,
.driver_module = THIS_MODULE,
};
#define AD8366_CHAN(_channel) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.indexed = 1, \
.channel = _channel, \
.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
}
static const struct iio_chan_spec ad8366_channels[] = {
AD8366_CHAN(0),
AD8366_CHAN(1),
};
static int ad8366_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad8366_state *st;
int ret;
indio_dev = iio_device_alloc(sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
st->reg = regulator_get(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
goto error_put_reg;
}
spi_set_drvdata(spi, indio_dev);
st->spi = spi;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad8366_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ad8366_channels;
indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
ad8366_write(indio_dev, 0 , 0);
return 0;
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
error_put_reg:
if (!IS_ERR(st->reg))
regulator_put(st->reg);
iio_device_free(indio_dev);
return ret;
}
static int ad8366_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad8366_state *st = iio_priv(indio_dev);
struct regulator *reg = st->reg;
iio_device_unregister(indio_dev);
if (!IS_ERR(reg)) {
regulator_disable(reg);
regulator_put(reg);
}
iio_device_free(indio_dev);
return 0;
}
static const struct spi_device_id ad8366_id[] = {
{"ad8366", 0},
{}
};
static struct spi_driver ad8366_driver = {
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
},
.probe = ad8366_probe,
.remove = ad8366_remove,
.id_table = ad8366_id,
};
module_spi_driver(ad8366_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
MODULE_LICENSE("GPL v2");
|
