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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
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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 struct attribute **attrs;
35};
36
37
38
39
40
41
42static ssize_t iio_hwmon_read_val(struct device *dev,
43 struct device_attribute *attr,
44 char *buf)
45{
46 int result;
47 int ret;
48 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
49 struct iio_hwmon_state *state = dev_get_drvdata(dev);
50
51 ret = iio_read_channel_processed(&state->channels[sattr->index],
52 &result);
53 if (ret < 0)
54 return ret;
55
56 return sprintf(buf, "%d\n", result);
57}
58
59static ssize_t show_name(struct device *dev, struct device_attribute *attr,
60 char *buf)
61{
62 const char *name = "iio_hwmon";
63
64 if (dev->of_node && dev->of_node->name)
65 name = dev->of_node->name;
66
67 return sprintf(buf, "%s\n", name);
68}
69
70static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
71
72static int iio_hwmon_probe(struct platform_device *pdev)
73{
74 struct device *dev = &pdev->dev;
75 struct iio_hwmon_state *st;
76 struct sensor_device_attribute *a;
77 int ret, i;
78 int in_i = 1, temp_i = 1, curr_i = 1;
79 enum iio_chan_type type;
80 struct iio_channel *channels;
81
82 channels = iio_channel_get_all(dev);
83 if (IS_ERR(channels))
84 return PTR_ERR(channels);
85
86 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
87 if (st == NULL) {
88 ret = -ENOMEM;
89 goto error_release_channels;
90 }
91
92 st->channels = channels;
93
94
95 while (st->channels[st->num_channels].indio_dev)
96 st->num_channels++;
97
98 st->attrs = devm_kzalloc(dev,
99 sizeof(*st->attrs) * (st->num_channels + 2),
100 GFP_KERNEL);
101 if (st->attrs == NULL) {
102 ret = -ENOMEM;
103 goto error_release_channels;
104 }
105
106 for (i = 0; i < st->num_channels; i++) {
107 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
108 if (a == NULL) {
109 ret = -ENOMEM;
110 goto error_release_channels;
111 }
112
113 sysfs_attr_init(&a->dev_attr.attr);
114 ret = iio_get_channel_type(&st->channels[i], &type);
115 if (ret < 0)
116 goto error_release_channels;
117
118 switch (type) {
119 case IIO_VOLTAGE:
120 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
121 "in%d_input",
122 in_i++);
123 break;
124 case IIO_TEMP:
125 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
126 "temp%d_input",
127 temp_i++);
128 break;
129 case IIO_CURRENT:
130 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
131 "curr%d_input",
132 curr_i++);
133 break;
134 default:
135 ret = -EINVAL;
136 goto error_release_channels;
137 }
138 if (a->dev_attr.attr.name == NULL) {
139 ret = -ENOMEM;
140 goto error_release_channels;
141 }
142 a->dev_attr.show = iio_hwmon_read_val;
143 a->dev_attr.attr.mode = S_IRUGO;
144 a->index = i;
145 st->attrs[i] = &a->dev_attr.attr;
146 }
147 st->attrs[st->num_channels] = &dev_attr_name.attr;
148 st->attr_group.attrs = st->attrs;
149 platform_set_drvdata(pdev, st);
150 ret = sysfs_create_group(&dev->kobj, &st->attr_group);
151 if (ret < 0)
152 goto error_release_channels;
153
154 st->hwmon_dev = hwmon_device_register(dev);
155 if (IS_ERR(st->hwmon_dev)) {
156 ret = PTR_ERR(st->hwmon_dev);
157 goto error_remove_group;
158 }
159 return 0;
160
161error_remove_group:
162 sysfs_remove_group(&dev->kobj, &st->attr_group);
163error_release_channels:
164 iio_channel_release_all(channels);
165 return ret;
166}
167
168static int iio_hwmon_remove(struct platform_device *pdev)
169{
170 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
171
172 hwmon_device_unregister(st->hwmon_dev);
173 sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
174 iio_channel_release_all(st->channels);
175
176 return 0;
177}
178
179static struct of_device_id iio_hwmon_of_match[] = {
180 { .compatible = "iio-hwmon", },
181 { }
182};
183
184static struct platform_driver __refdata iio_hwmon_driver = {
185 .driver = {
186 .name = "iio_hwmon",
187 .owner = THIS_MODULE,
188 .of_match_table = iio_hwmon_of_match,
189 },
190 .probe = iio_hwmon_probe,
191 .remove = iio_hwmon_remove,
192};
193
194module_platform_driver(iio_hwmon_driver);
195
196MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
197MODULE_DESCRIPTION("IIO to hwmon driver");
198MODULE_LICENSE("GPL v2");
199
