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1// SPDX-License-Identifier: GPL-2.0-only
2/* Hwmon client for industrial I/O devices
3 *
4 * Copyright (c) 2011 Jonathan Cameron
5 */
6
7#include <linux/kernel.h>
8#include <linux/slab.h>
9#include <linux/mod_devicetable.h>
10#include <linux/module.h>
11#include <linux/err.h>
12#include <linux/platform_device.h>
13#include <linux/property.h>
14
15#include <linux/hwmon.h>
16#include <linux/hwmon-sysfs.h>
17#include <linux/iio/consumer.h>
18#include <linux/iio/types.h>
19
20/**
21 * struct iio_hwmon_state - device instance state
22 * @channels: filled with array of channels from iio
23 * @num_channels: number of channels in channels (saves counting twice)
24 * @attr_group: the group of attributes
25 * @groups: null terminated array of attribute groups
26 * @attrs: null terminated array of attribute pointers.
27 */
28struct iio_hwmon_state {
29 struct iio_channel *channels;
30 int num_channels;
31 struct attribute_group attr_group;
32 const struct attribute_group *groups[2];
33 struct attribute **attrs;
34};
35
36/*
37 * Assumes that IIO and hwmon operate in the same base units.
38 * This is supposed to be true, but needs verification for
39 * new channel types.
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 struct iio_channel *chan = &state->channels[sattr->index];
50 enum iio_chan_type type;
51
52 ret = iio_read_channel_processed(chan, &result);
53 if (ret < 0)
54 return ret;
55
56 ret = iio_get_channel_type(chan, &type);
57 if (ret < 0)
58 return ret;
59
60 if (type == IIO_POWER)
61 result *= 1000; /* mili-Watts to micro-Watts conversion */
62
63 return sprintf(buf, "%d\n", result);
64}
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, humidity_i = 1, power_i = 1;
73 enum iio_chan_type type;
74 struct iio_channel *channels;
75 struct device *hwmon_dev;
76 char *sname;
77
78 channels = devm_iio_channel_get_all(dev);
79 if (IS_ERR(channels)) {
80 ret = PTR_ERR(channels);
81 if (ret == -ENODEV)
82 ret = -EPROBE_DEFER;
83 return dev_err_probe(dev, ret,
84 "Failed to get channels\n");
85 }
86
87 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
88 if (st == NULL)
89 return -ENOMEM;
90
91 st->channels = channels;
92
93 /* count how many attributes we have */
94 while (st->channels[st->num_channels].indio_dev)
95 st->num_channels++;
96
97 st->attrs = devm_kcalloc(dev,
98 st->num_channels + 1, sizeof(*st->attrs),
99 GFP_KERNEL);
100 if (st->attrs == NULL)
101 return -ENOMEM;
102
103 for (i = 0; i < st->num_channels; i++) {
104 const char *prefix;
105 int n;
106
107 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
108 if (a == NULL)
109 return -ENOMEM;
110
111 sysfs_attr_init(&a->dev_attr.attr);
112 ret = iio_get_channel_type(&st->channels[i], &type);
113 if (ret < 0)
114 return ret;
115
116 switch (type) {
117 case IIO_VOLTAGE:
118 n = in_i++;
119 prefix = "in";
120 break;
121 case IIO_TEMP:
122 n = temp_i++;
123 prefix = "temp";
124 break;
125 case IIO_CURRENT:
126 n = curr_i++;
127 prefix = "curr";
128 break;
129 case IIO_POWER:
130 n = power_i++;
131 prefix = "power";
132 break;
133 case IIO_HUMIDITYRELATIVE:
134 n = humidity_i++;
135 prefix = "humidity";
136 break;
137 default:
138 return -EINVAL;
139 }
140
141 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
142 "%s%d_input",
143 prefix, n);
144 if (a->dev_attr.attr.name == NULL)
145 return -ENOMEM;
146
147 a->dev_attr.show = iio_hwmon_read_val;
148 a->dev_attr.attr.mode = 0444;
149 a->index = i;
150 st->attrs[i] = &a->dev_attr.attr;
151 }
152
153 st->attr_group.attrs = st->attrs;
154 st->groups[0] = &st->attr_group;
155
156 if (dev_fwnode(dev)) {
157 sname = devm_kasprintf(dev, GFP_KERNEL, "%pfwP", dev_fwnode(dev));
158 if (!sname)
159 return -ENOMEM;
160 strreplace(sname, '-', '_');
161 } else {
162 sname = "iio_hwmon";
163 }
164
165 hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,
166 st->groups);
167 return PTR_ERR_OR_ZERO(hwmon_dev);
168}
169
170static const struct of_device_id iio_hwmon_of_match[] = {
171 { .compatible = "iio-hwmon", },
172 { }
173};
174MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
175
176static struct platform_driver iio_hwmon_driver = {
177 .driver = {
178 .name = "iio_hwmon",
179 .of_match_table = iio_hwmon_of_match,
180 },
181 .probe = iio_hwmon_probe,
182};
183
184module_platform_driver(iio_hwmon_driver);
185
186MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
187MODULE_DESCRIPTION("IIO to hwmon driver");
188MODULE_LICENSE("GPL v2");
1/* Hwmon client for industrial I/O devices
2 *
3 * Copyright (c) 2011 Jonathan Cameron
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
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 * struct iio_hwmon_state - device instance state
23 * @channels: filled with array of channels from iio
24 * @num_channels: number of channels in channels (saves counting twice)
25 * @hwmon_dev: associated hwmon device
26 * @attr_group: the group of attributes
27 * @attrs: null terminated array of attribute pointers.
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 * Assumes that IIO and hwmon operate in the same base units.
40 * This is supposed to be true, but needs verification for
41 * new channel types.
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 return PTR_ERR(channels);
78
79 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
80 if (st == NULL) {
81 ret = -ENOMEM;
82 goto error_release_channels;
83 }
84
85 st->channels = channels;
86
87 /* count how many attributes we have */
88 while (st->channels[st->num_channels].indio_dev)
89 st->num_channels++;
90
91 st->attrs = devm_kzalloc(dev,
92 sizeof(*st->attrs) * (st->num_channels + 1),
93 GFP_KERNEL);
94 if (st->attrs == NULL) {
95 ret = -ENOMEM;
96 goto error_release_channels;
97 }
98
99 for (i = 0; i < st->num_channels; i++) {
100 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
101 if (a == NULL) {
102 ret = -ENOMEM;
103 goto error_release_channels;
104 }
105
106 sysfs_attr_init(&a->dev_attr.attr);
107 ret = iio_get_channel_type(&st->channels[i], &type);
108 if (ret < 0)
109 goto error_release_channels;
110
111 switch (type) {
112 case IIO_VOLTAGE:
113 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
114 "in%d_input",
115 in_i++);
116 break;
117 case IIO_TEMP:
118 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
119 "temp%d_input",
120 temp_i++);
121 break;
122 case IIO_CURRENT:
123 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
124 "curr%d_input",
125 curr_i++);
126 break;
127 case IIO_HUMIDITYRELATIVE:
128 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
129 "humidity%d_input",
130 humidity_i++);
131 break;
132 default:
133 ret = -EINVAL;
134 goto error_release_channels;
135 }
136 if (a->dev_attr.attr.name == NULL) {
137 ret = -ENOMEM;
138 goto error_release_channels;
139 }
140 a->dev_attr.show = iio_hwmon_read_val;
141 a->dev_attr.attr.mode = S_IRUGO;
142 a->index = i;
143 st->attrs[i] = &a->dev_attr.attr;
144 }
145
146 st->attr_group.attrs = st->attrs;
147 st->groups[0] = &st->attr_group;
148
149 sname = devm_kstrdup(dev, name, GFP_KERNEL);
150 if (!sname) {
151 ret = -ENOMEM;
152 goto error_release_channels;
153 }
154
155 strreplace(sname, '-', '_');
156 st->hwmon_dev = hwmon_device_register_with_groups(dev, sname, st,
157 st->groups);
158 if (IS_ERR(st->hwmon_dev)) {
159 ret = PTR_ERR(st->hwmon_dev);
160 goto error_release_channels;
161 }
162 platform_set_drvdata(pdev, st);
163 return 0;
164
165error_release_channels:
166 iio_channel_release_all(channels);
167 return ret;
168}
169
170static int iio_hwmon_remove(struct platform_device *pdev)
171{
172 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
173
174 hwmon_device_unregister(st->hwmon_dev);
175 iio_channel_release_all(st->channels);
176
177 return 0;
178}
179
180static const struct of_device_id iio_hwmon_of_match[] = {
181 { .compatible = "iio-hwmon", },
182 { }
183};
184MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
185
186static struct platform_driver __refdata iio_hwmon_driver = {
187 .driver = {
188 .name = "iio_hwmon",
189 .of_match_table = iio_hwmon_of_match,
190 },
191 .probe = iio_hwmon_probe,
192 .remove = iio_hwmon_remove,
193};
194
195module_platform_driver(iio_hwmon_driver);
196
197MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
198MODULE_DESCRIPTION("IIO to hwmon driver");
199MODULE_LICENSE("GPL v2");