1
2
3
4
5
6
7
8
9
10#include <linux/kernel.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13#include <linux/err.h>
14#include <linux/platform_device.h>
15#include <linux/hwmon.h>
16#include <linux/of.h>
17#include <linux/hwmon-sysfs.h>
18#include <linux/iio/consumer.h>
19#include <linux/iio/types.h>
20
21
22
23
24
25
26
27
28
29struct iio_hwmon_state {
30 struct iio_channel *channels;
31 int num_channels;
32 struct device *hwmon_dev;
33 struct attribute_group attr_group;
34 const struct attribute_group *groups[2];
35 struct attribute **attrs;
36};
37
38
39
40
41
42
43static ssize_t iio_hwmon_read_val(struct device *dev,
44 struct device_attribute *attr,
45 char *buf)
46{
47 int result;
48 int ret;
49 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
50 struct iio_hwmon_state *state = dev_get_drvdata(dev);
51
52 ret = iio_read_channel_processed(&state->channels[sattr->index],
53 &result);
54 if (ret < 0)
55 return ret;
56
57 return sprintf(buf, "%d\n", result);
58}
59
60static int iio_hwmon_probe(struct platform_device *pdev)
61{
62 struct device *dev = &pdev->dev;
63 struct iio_hwmon_state *st;
64 struct sensor_device_attribute *a;
65 int ret, i;
66 int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1;
67 enum iio_chan_type type;
68 struct iio_channel *channels;
69 const char *name = "iio_hwmon";
70 char *sname;
71
72 if (dev->of_node && dev->of_node->name)
73 name = dev->of_node->name;
74
75 channels = iio_channel_get_all(dev);
76 if (IS_ERR(channels)) {
77 if (PTR_ERR(channels) == -ENODEV)
78 return -EPROBE_DEFER;
79 return PTR_ERR(channels);
80 }
81
82 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
83 if (st == NULL) {
84 ret = -ENOMEM;
85 goto error_release_channels;
86 }
87
88 st->channels = channels;
89
90
91 while (st->channels[st->num_channels].indio_dev)
92 st->num_channels++;
93
94 st->attrs = devm_kzalloc(dev,
95 sizeof(*st->attrs) * (st->num_channels + 1),
96 GFP_KERNEL);
97 if (st->attrs == NULL) {
98 ret = -ENOMEM;
99 goto error_release_channels;
100 }
101
102 for (i = 0; i < st->num_channels; i++) {
103 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
104 if (a == NULL) {
105 ret = -ENOMEM;
106 goto error_release_channels;
107 }
108
109 sysfs_attr_init(&a->dev_attr.attr);
110 ret = iio_get_channel_type(&st->channels[i], &type);
111 if (ret < 0)
112 goto error_release_channels;
113
114 switch (type) {
115 case IIO_VOLTAGE:
116 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
117 "in%d_input",
118 in_i++);
119 break;
120 case IIO_TEMP:
121 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
122 "temp%d_input",
123 temp_i++);
124 break;
125 case IIO_CURRENT:
126 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
127 "curr%d_input",
128 curr_i++);
129 break;
130 case IIO_HUMIDITYRELATIVE:
131 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
132 "humidity%d_input",
133 humidity_i++);
134 break;
135 default:
136 ret = -EINVAL;
137 goto error_release_channels;
138 }
139 if (a->dev_attr.attr.name == NULL) {
140 ret = -ENOMEM;
141 goto error_release_channels;
142 }
143 a->dev_attr.show = iio_hwmon_read_val;
144 a->dev_attr.attr.mode = S_IRUGO;
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 sname = devm_kstrdup(dev, name, GFP_KERNEL);
153 if (!sname) {
154 ret = -ENOMEM;
155 goto error_release_channels;
156 }
157
158 strreplace(sname, '-', '_');
159 st->hwmon_dev = hwmon_device_register_with_groups(dev, sname, st,
160 st->groups);
161 if (IS_ERR(st->hwmon_dev)) {
162 ret = PTR_ERR(st->hwmon_dev);
163 goto error_release_channels;
164 }
165 platform_set_drvdata(pdev, st);
166 return 0;
167
168error_release_channels:
169 iio_channel_release_all(channels);
170 return ret;
171}
172
173static int iio_hwmon_remove(struct platform_device *pdev)
174{
175 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
176
177 hwmon_device_unregister(st->hwmon_dev);
178 iio_channel_release_all(st->channels);
179
180 return 0;
181}
182
183static const struct of_device_id iio_hwmon_of_match[] = {
184 { .compatible = "iio-hwmon", },
185 { }
186};
187MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
188
189static struct platform_driver __refdata iio_hwmon_driver = {
190 .driver = {
191 .name = "iio_hwmon",
192 .of_match_table = iio_hwmon_of_match,
193 },
194 .probe = iio_hwmon_probe,
195 .remove = iio_hwmon_remove,
196};
197
198module_platform_driver(iio_hwmon_driver);
199
200MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
201MODULE_DESCRIPTION("IIO to hwmon driver");
202MODULE_LICENSE("GPL v2");
203
