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
|
/*
* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
*
* Copyright 2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*
* Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk>
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
/*
* AD7314 power mode
*/
#define AD7314_PD 0x2000
/*
* AD7314 temperature masks
*/
#define AD7314_TEMP_SIGN 0x200
#define AD7314_TEMP_MASK 0x7FE0
#define AD7314_TEMP_OFFSET 5
/*
* ADT7301 and ADT7302 temperature masks
*/
#define ADT7301_TEMP_SIGN 0x2000
#define ADT7301_TEMP_MASK 0x3FFF
enum ad7314_variant {
adt7301,
adt7302,
ad7314,
};
struct ad7314_data {
struct spi_device *spi_dev;
struct device *hwmon_dev;
u16 rx ____cacheline_aligned;
};
static int ad7314_spi_read(struct ad7314_data *chip, s16 *data)
{
int ret;
ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));
if (ret < 0) {
dev_err(&chip->spi_dev->dev, "SPI read error\n");
return ret;
}
*data = be16_to_cpu(chip->rx);
return ret;
}
static ssize_t ad7314_show_temperature(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad7314_data *chip = dev_get_drvdata(dev);
s16 data;
int ret;
ret = ad7314_spi_read(chip, &data);
if (ret < 0)
return ret;
switch (spi_get_device_id(chip->spi_dev)->driver_data) {
case ad7314:
data = (data & AD7314_TEMP_MASK) >> AD7314_TEMP_OFFSET;
data = (data << 6) >> 6;
return sprintf(buf, "%d\n", 250 * data);
case adt7301:
case adt7302:
/*
* Documented as a 13 bit twos complement register
* with a sign bit - which is a 14 bit 2's complement
* register. 1lsb - 31.25 milli degrees centigrade
*/
data &= ADT7301_TEMP_MASK;
data = (data << 2) >> 2;
return sprintf(buf, "%d\n",
DIV_ROUND_CLOSEST(data * 3125, 100));
default:
return -EINVAL;
}
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
ad7314_show_temperature, NULL, 0);
static struct attribute *ad7314_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7314_group = {
.attrs = ad7314_attributes,
};
static int __devinit ad7314_probe(struct spi_device *spi_dev)
{
int ret;
struct ad7314_data *chip;
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL) {
ret = -ENOMEM;
goto error_ret;
}
dev_set_drvdata(&spi_dev->dev, chip);
ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
if (ret < 0)
goto error_free_chip;
chip->hwmon_dev = hwmon_device_register(&spi_dev->dev);
if (IS_ERR(chip->hwmon_dev)) {
ret = PTR_ERR(chip->hwmon_dev);
goto error_remove_group;
}
return 0;
error_remove_group:
sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
error_free_chip:
kfree(chip);
error_ret:
return ret;
}
static int __devexit ad7314_remove(struct spi_device *spi_dev)
{
struct ad7314_data *chip = dev_get_drvdata(&spi_dev->dev);
hwmon_device_unregister(chip->hwmon_dev);
sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
kfree(chip);
return 0;
}
static const struct spi_device_id ad7314_id[] = {
{ "adt7301", adt7301 },
{ "adt7302", adt7302 },
{ "ad7314", ad7314 },
{ }
};
MODULE_DEVICE_TABLE(spi, ad7314_id);
static struct spi_driver ad7314_driver = {
.driver = {
.name = "ad7314",
.owner = THIS_MODULE,
},
.probe = ad7314_probe,
.remove = __devexit_p(ad7314_remove),
.id_table = ad7314_id,
};
module_spi_driver(ad7314_driver);
MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"
" temperature sensor driver");
MODULE_LICENSE("GPL v2");
|
