1
2
3
4
5
6
7#include <linux/kernel.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/err.h>
11#include <linux/platform_device.h>
12#include <linux/hwmon.h>
13#include <linux/of.h>
14#include <linux/hwmon-sysfs.h>
15#include <linux/iio/consumer.h>
16#include <linux/iio/types.h>
17
18
19
20
21
22
23
24
25
26struct iio_hwmon_state {
27 struct iio_channel *channels;
28 int num_channels;
29 struct attribute_group attr_group;
30 const struct attribute_group *groups[2];
31 struct attribute **attrs;
32};
33
34
35
36
37
38
39static ssize_t iio_hwmon_read_val(struct device *dev,
40 struct device_attribute *attr,
41 char *buf)
42{
43 int result;
44 int ret;
45 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
46 struct iio_hwmon_state *state = dev_get_drvdata(dev);
47 struct iio_channel *chan = &state->channels[sattr->index];
48 enum iio_chan_type type;
49
50 ret = iio_read_channel_processed(chan, &result);
51 if (ret < 0)
52 return ret;
53
54 ret = iio_get_channel_type(chan, &type);
55 if (ret < 0)
56 return ret;
57
58 if (type == IIO_POWER)
59 result *= 1000;
60
61 return sprintf(buf, "%d\n", result);
62}
63
64static int iio_hwmon_probe(struct platform_device *pdev)
65{
66 struct device *dev = &pdev->dev;
67 struct iio_hwmon_state *st;
68 struct sensor_device_attribute *a;
69 int ret, i;
70 int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1, power_i = 1;
71 enum iio_chan_type type;
72 struct iio_channel *channels;
73 struct device *hwmon_dev;
74 char *sname;
75
76 channels = devm_iio_channel_get_all(dev);
77 if (IS_ERR(channels)) {
78 if (PTR_ERR(channels) == -ENODEV)
79 return -EPROBE_DEFER;
80 return PTR_ERR(channels);
81 }
82
83 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
84 if (st == NULL)
85 return -ENOMEM;
86
87 st->channels = channels;
88
89
90 while (st->channels[st->num_channels].indio_dev)
91 st->num_channels++;
92
93 st->attrs = devm_kcalloc(dev,
94 st->num_channels + 1, sizeof(*st->attrs),
95 GFP_KERNEL);
96 if (st->attrs == NULL)
97 return -ENOMEM;
98
99 for (i = 0; i < st->num_channels; i++) {
100 const char *prefix;
101 int n;
102
103 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
104 if (a == NULL)
105 return -ENOMEM;
106
107 sysfs_attr_init(&a->dev_attr.attr);
108 ret = iio_get_channel_type(&st->channels[i], &type);
109 if (ret < 0)
110 return ret;
111
112 switch (type) {
113 case IIO_VOLTAGE:
114 n = in_i++;
115 prefix = "in";
116 break;
117 case IIO_TEMP:
118 n = temp_i++;
119 prefix = "temp";
120 break;
121 case IIO_CURRENT:
122 n = curr_i++;
123 prefix = "curr";
124 break;
125 case IIO_POWER:
126 n = power_i++;
127 prefix = "power";
128 break;
129 case IIO_HUMIDITYRELATIVE:
130 n = humidity_i++;
131 prefix = "humidity";
132 break;
133 default:
134 return -EINVAL;
135 }
136
137 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
138 "%s%d_input",
139 prefix, n);
140 if (a->dev_attr.attr.name == NULL)
141 return -ENOMEM;
142
143 a->dev_attr.show = iio_hwmon_read_val;
144 a->dev_attr.attr.mode = 0444;
145 a->index = i;
146 st->attrs[i] = &a->dev_attr.attr;
147 }
148
149 st->attr_group.attrs = st->attrs;
150 st->groups[0] = &st->attr_group;
151
152 if (dev->of_node) {
153 sname = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
154 if (!sname)
155 return -ENOMEM;
156 strreplace(sname, '-', '_');
157 } else {
158 sname = "iio_hwmon";
159 }
160
161 hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,
162 st->groups);
163 return PTR_ERR_OR_ZERO(hwmon_dev);
164}
165
166static const struct of_device_id iio_hwmon_of_match[] = {
167 { .compatible = "iio-hwmon", },
168 { }
169};
170MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
171
172static struct platform_driver iio_hwmon_driver = {
173 .driver = {
174 .name = "iio_hwmon",
175 .of_match_table = iio_hwmon_of_match,
176 },
177 .probe = iio_hwmon_probe,
178};
179
180module_platform_driver(iio_hwmon_driver);
181
182MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
183MODULE_DESCRIPTION("IIO to hwmon driver");
184MODULE_LICENSE("GPL v2");
185
