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
|
/* Hwmon client for industrial I/O devices
*
* Copyright (c) 2011 Jonathan Cameron
*
* 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/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/of.h>
#include <linux/hwmon-sysfs.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
/**
* struct iio_hwmon_state - device instance state
* @channels: filled with array of channels from iio
* @num_channels: number of channels in channels (saves counting twice)
* @hwmon_dev: associated hwmon device
* @attr_group: the group of attributes
* @attrs: null terminated array of attribute pointers.
*/
struct iio_hwmon_state {
struct iio_channel *channels;
int num_channels;
struct device *hwmon_dev;
struct attribute_group attr_group;
const struct attribute_group *groups[2];
struct attribute **attrs;
};
/*
* Assumes that IIO and hwmon operate in the same base units.
* This is supposed to be true, but needs verification for
* new channel types.
*/
static ssize_t iio_hwmon_read_val(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int result;
int ret;
struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
struct iio_hwmon_state *state = dev_get_drvdata(dev);
ret = iio_read_channel_processed(&state->channels[sattr->index],
&result);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", result);
}
static int iio_hwmon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct iio_hwmon_state *st;
struct sensor_device_attribute *a;
int ret, i;
int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1;
enum iio_chan_type type;
struct iio_channel *channels;
const char *name = "iio_hwmon";
char *sname;
if (dev->of_node && dev->of_node->name)
name = dev->of_node->name;
channels = iio_channel_get_all(dev);
if (IS_ERR(channels)) {
if (PTR_ERR(channels) == -ENODEV)
return -EPROBE_DEFER;
return PTR_ERR(channels);
}
st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
if (st == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
st->channels = channels;
/* count how many attributes we have */
while (st->channels[st->num_channels].indio_dev)
st->num_channels++;
st->attrs = devm_kzalloc(dev,
sizeof(*st->attrs) * (st->num_channels + 1),
GFP_KERNEL);
if (st->attrs == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
for (i = 0; i < st->num_channels; i++) {
a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
if (a == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
sysfs_attr_init(&a->dev_attr.attr);
ret = iio_get_channel_type(&st->channels[i], &type);
if (ret < 0)
goto error_release_channels;
switch (type) {
case IIO_VOLTAGE:
a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
"in%d_input",
in_i++);
break;
case IIO_TEMP:
a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
"temp%d_input",
temp_i++);
break;
case IIO_CURRENT:
a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
"curr%d_input",
curr_i++);
break;
case IIO_HUMIDITYRELATIVE:
a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
"humidity%d_input",
humidity_i++);
break;
default:
ret = -EINVAL;
goto error_release_channels;
}
if (a->dev_attr.attr.name == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
a->dev_attr.show = iio_hwmon_read_val;
a->dev_attr.attr.mode = S_IRUGO;
a->index = i;
st->attrs[i] = &a->dev_attr.attr;
}
st->attr_group.attrs = st->attrs;
st->groups[0] = &st->attr_group;
sname = devm_kstrdup(dev, name, GFP_KERNEL);
if (!sname) {
ret = -ENOMEM;
goto error_release_channels;
}
strreplace(sname, '-', '_');
st->hwmon_dev = hwmon_device_register_with_groups(dev, sname, st,
st->groups);
if (IS_ERR(st->hwmon_dev)) {
ret = PTR_ERR(st->hwmon_dev);
goto error_release_channels;
}
platform_set_drvdata(pdev, st);
return 0;
error_release_channels:
iio_channel_release_all(channels);
return ret;
}
static int iio_hwmon_remove(struct platform_device *pdev)
{
struct iio_hwmon_state *st = platform_get_drvdata(pdev);
hwmon_device_unregister(st->hwmon_dev);
iio_channel_release_all(st->channels);
return 0;
}
static const struct of_device_id iio_hwmon_of_match[] = {
{ .compatible = "iio-hwmon", },
{ }
};
MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
static struct platform_driver __refdata iio_hwmon_driver = {
.driver = {
.name = "iio_hwmon",
.of_match_table = iio_hwmon_of_match,
},
.probe = iio_hwmon_probe,
.remove = iio_hwmon_remove,
};
module_platform_driver(iio_hwmon_driver);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO to hwmon driver");
MODULE_LICENSE("GPL v2");
|
