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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/hwmon-sysfs.h>
17#include <linux/iio/consumer.h>
18#include <linux/iio/types.h>
19
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22
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26
27
28struct iio_hwmon_state {
29 struct iio_channel *channels;
30 int num_channels;
31 struct device *hwmon_dev;
32 struct attribute_group attr_group;
33 struct attribute **attrs;
34};
35
36
37
38
39
40
41static ssize_t iio_hwmon_read_val(struct device *dev,
42 struct device_attribute *attr,
43 char *buf)
44{
45 int result;
46 int ret;
47 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
48 struct iio_hwmon_state *state = dev_get_drvdata(dev);
49
50 ret = iio_read_channel_processed(&state->channels[sattr->index],
51 &result);
52 if (ret < 0)
53 return ret;
54
55 return sprintf(buf, "%d\n", result);
56}
57
58static ssize_t show_name(struct device *dev, struct device_attribute *attr,
59 char *buf)
60{
61 return sprintf(buf, "iio_hwmon\n");
62}
63
64static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
65
66static int iio_hwmon_probe(struct platform_device *pdev)
67{
68 struct device *dev = &pdev->dev;
69 struct iio_hwmon_state *st;
70 struct sensor_device_attribute *a;
71 int ret, i;
72 int in_i = 1, temp_i = 1, curr_i = 1;
73 enum iio_chan_type type;
74 struct iio_channel *channels;
75
76 channels = iio_channel_get_all(dev);
77 if (IS_ERR(channels))
78 return PTR_ERR(channels);
79
80 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
81 if (st == NULL)
82 return -ENOMEM;
83
84 st->channels = channels;
85
86
87 while (st->channels[st->num_channels].indio_dev)
88 st->num_channels++;
89
90 st->attrs = devm_kzalloc(dev,
91 sizeof(*st->attrs) * (st->num_channels + 2),
92 GFP_KERNEL);
93 if (st->attrs == NULL) {
94 ret = -ENOMEM;
95 goto error_release_channels;
96 }
97
98 for (i = 0; i < st->num_channels; i++) {
99 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
100 if (a == NULL) {
101 ret = -ENOMEM;
102 goto error_release_channels;
103 }
104
105 sysfs_attr_init(&a->dev_attr.attr);
106 ret = iio_get_channel_type(&st->channels[i], &type);
107 if (ret < 0)
108 goto error_release_channels;
109
110 switch (type) {
111 case IIO_VOLTAGE:
112 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
113 "in%d_input",
114 in_i++);
115 break;
116 case IIO_TEMP:
117 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
118 "temp%d_input",
119 temp_i++);
120 break;
121 case IIO_CURRENT:
122 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
123 "curr%d_input",
124 curr_i++);
125 break;
126 default:
127 ret = -EINVAL;
128 goto error_release_channels;
129 }
130 if (a->dev_attr.attr.name == NULL) {
131 ret = -ENOMEM;
132 goto error_release_channels;
133 }
134 a->dev_attr.show = iio_hwmon_read_val;
135 a->dev_attr.attr.mode = S_IRUGO;
136 a->index = i;
137 st->attrs[i] = &a->dev_attr.attr;
138 }
139 st->attrs[st->num_channels] = &dev_attr_name.attr;
140 st->attr_group.attrs = st->attrs;
141 platform_set_drvdata(pdev, st);
142 ret = sysfs_create_group(&dev->kobj, &st->attr_group);
143 if (ret < 0)
144 goto error_release_channels;
145
146 st->hwmon_dev = hwmon_device_register(dev);
147 if (IS_ERR(st->hwmon_dev)) {
148 ret = PTR_ERR(st->hwmon_dev);
149 goto error_remove_group;
150 }
151 return 0;
152
153error_remove_group:
154 sysfs_remove_group(&dev->kobj, &st->attr_group);
155error_release_channels:
156 iio_channel_release_all(st->channels);
157 return ret;
158}
159
160static int iio_hwmon_remove(struct platform_device *pdev)
161{
162 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
163
164 hwmon_device_unregister(st->hwmon_dev);
165 sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
166 iio_channel_release_all(st->channels);
167
168 return 0;
169}
170
171static struct of_device_id iio_hwmon_of_match[] = {
172 { .compatible = "iio-hwmon", },
173 { }
174};
175
176static struct platform_driver __refdata iio_hwmon_driver = {
177 .driver = {
178 .name = "iio_hwmon",
179 .owner = THIS_MODULE,
180 .of_match_table = iio_hwmon_of_match,
181 },
182 .probe = iio_hwmon_probe,
183 .remove = iio_hwmon_remove,
184};
185
186module_platform_driver(iio_hwmon_driver);
187
188MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
189MODULE_DESCRIPTION("IIO to hwmon driver");
190MODULE_LICENSE("GPL v2");
191
