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
|
/*
* ad2s90.c simple support for the ADI Resolver to Digital Converters: AD2S90
*
* Copyright (c) 2010-2010 Analog Devices Inc.
*
* 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/types.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include "../iio.h"
#include "../sysfs.h"
struct ad2s90_state {
struct mutex lock;
struct spi_device *sdev;
u8 rx[2] ____cacheline_aligned;
};
static int ad2s90_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad2s90_state *st = iio_priv(indio_dev);
mutex_lock(&st->lock);
ret = spi_read(st->sdev, st->rx, 2);
if (ret)
goto error_ret;
*val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
error_ret:
mutex_unlock(&st->lock);
return IIO_VAL_INT;
}
static const struct iio_info ad2s90_info = {
.read_raw = &ad2s90_read_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec ad2s90_chan = {
.type = IIO_ANGL,
.indexed = 1,
.channel = 0,
};
static int __devinit ad2s90_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad2s90_state *st;
int ret = 0;
indio_dev = iio_allocate_device(sizeof(*st));
if (indio_dev == NULL) {
ret = -ENOMEM;
goto error_ret;
}
st = iio_priv(indio_dev);
spi_set_drvdata(spi, indio_dev);
mutex_init(&st->lock);
st->sdev = spi;
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &ad2s90_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = &ad2s90_chan;
indio_dev->num_channels = 1;
indio_dev->name = spi_get_device_id(spi)->name;
ret = iio_device_register(indio_dev);
if (ret)
goto error_free_dev;
/* need 600ns between CS and the first falling edge of SCLK */
spi->max_speed_hz = 830000;
spi->mode = SPI_MODE_3;
spi_setup(spi);
return 0;
error_free_dev:
iio_free_device(indio_dev);
error_ret:
return ret;
}
static int __devexit ad2s90_remove(struct spi_device *spi)
{
iio_device_unregister(spi_get_drvdata(spi));
iio_free_device(spi_get_drvdata(spi));
return 0;
}
static const struct spi_device_id ad2s90_id[] = {
{ "ad2s90" },
{}
};
static struct spi_driver ad2s90_driver = {
.driver = {
.name = "ad2s90",
.owner = THIS_MODULE,
},
.probe = ad2s90_probe,
.remove = __devexit_p(ad2s90_remove),
.id_table = ad2s90_id,
};
static __init int ad2s90_spi_init(void)
{
return spi_register_driver(&ad2s90_driver);
}
module_init(ad2s90_spi_init);
static __exit void ad2s90_spi_exit(void)
{
spi_unregister_driver(&ad2s90_driver);
}
module_exit(ad2s90_spi_exit);
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver");
MODULE_LICENSE("GPL v2");
|
