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e0f8a24e JC |
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> | |
3465a224 | 16 | #include <linux/of.h> |
e0f8a24e | 17 | #include <linux/hwmon-sysfs.h> |
06458e27 JC |
18 | #include <linux/iio/consumer.h> |
19 | #include <linux/iio/types.h> | |
e0f8a24e JC |
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 | */ | |
29 | struct iio_hwmon_state { | |
30 | struct iio_channel *channels; | |
31 | int num_channels; | |
32 | struct device *hwmon_dev; | |
33 | struct attribute_group attr_group; | |
4b49cca3 | 34 | const struct attribute_group *groups[2]; |
e0f8a24e JC |
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 | */ | |
43 | static ssize_t iio_hwmon_read_val(struct device *dev, | |
44 | struct device_attribute *attr, | |
45 | char *buf) | |
46 | { | |
a0e545e0 LPC |
47 | int result; |
48 | int ret; | |
e0f8a24e JC |
49 | struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); |
50 | struct iio_hwmon_state *state = dev_get_drvdata(dev); | |
51 | ||
a0e545e0 LPC |
52 | ret = iio_read_channel_processed(&state->channels[sattr->index], |
53 | &result); | |
e0f8a24e JC |
54 | if (ret < 0) |
55 | return ret; | |
56 | ||
a0e545e0 | 57 | return sprintf(buf, "%d\n", result); |
e0f8a24e JC |
58 | } |
59 | ||
4ae1c61f | 60 | static int iio_hwmon_probe(struct platform_device *pdev) |
e0f8a24e | 61 | { |
c4ac7b98 | 62 | struct device *dev = &pdev->dev; |
e0f8a24e JC |
63 | struct iio_hwmon_state *st; |
64 | struct sensor_device_attribute *a; | |
65 | int ret, i; | |
61bb53bc | 66 | int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1; |
e0f8a24e | 67 | enum iio_chan_type type; |
ca7d98db | 68 | struct iio_channel *channels; |
4b49cca3 | 69 | const char *name = "iio_hwmon"; |
b92fe9e3 | 70 | char *sname; |
4b49cca3 GR |
71 | |
72 | if (dev->of_node && dev->of_node->name) | |
73 | name = dev->of_node->name; | |
ca7d98db GR |
74 | |
75 | channels = iio_channel_get_all(dev); | |
76 | if (IS_ERR(channels)) | |
77 | return PTR_ERR(channels); | |
e0f8a24e | 78 | |
c4ac7b98 | 79 | st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); |
4510d198 AL |
80 | if (st == NULL) { |
81 | ret = -ENOMEM; | |
82 | goto error_release_channels; | |
83 | } | |
e0f8a24e | 84 | |
ca7d98db | 85 | st->channels = channels; |
e0f8a24e JC |
86 | |
87 | /* count how many attributes we have */ | |
88 | while (st->channels[st->num_channels].indio_dev) | |
89 | st->num_channels++; | |
90 | ||
c4ac7b98 | 91 | st->attrs = devm_kzalloc(dev, |
4b49cca3 | 92 | sizeof(*st->attrs) * (st->num_channels + 1), |
c4ac7b98 | 93 | GFP_KERNEL); |
e0f8a24e JC |
94 | if (st->attrs == NULL) { |
95 | ret = -ENOMEM; | |
96 | goto error_release_channels; | |
97 | } | |
c4ac7b98 | 98 | |
e0f8a24e | 99 | for (i = 0; i < st->num_channels; i++) { |
c4ac7b98 | 100 | a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL); |
e0f8a24e JC |
101 | if (a == NULL) { |
102 | ret = -ENOMEM; | |
c4ac7b98 | 103 | goto error_release_channels; |
e0f8a24e JC |
104 | } |
105 | ||
106 | sysfs_attr_init(&a->dev_attr.attr); | |
314be14b | 107 | ret = iio_get_channel_type(&st->channels[i], &type); |
c4ac7b98 GR |
108 | if (ret < 0) |
109 | goto error_release_channels; | |
110 | ||
e0f8a24e JC |
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; | |
61bb53bc GR |
127 | case IIO_HUMIDITYRELATIVE: |
128 | a->dev_attr.attr.name = kasprintf(GFP_KERNEL, | |
129 | "humidity%d_input", | |
130 | humidity_i++); | |
131 | break; | |
e0f8a24e JC |
132 | default: |
133 | ret = -EINVAL; | |
c4ac7b98 | 134 | goto error_release_channels; |
e0f8a24e JC |
135 | } |
136 | if (a->dev_attr.attr.name == NULL) { | |
e0f8a24e | 137 | ret = -ENOMEM; |
c4ac7b98 | 138 | goto error_release_channels; |
e0f8a24e JC |
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 | } | |
e0f8a24e | 145 | |
4b49cca3 GR |
146 | st->attr_group.attrs = st->attrs; |
147 | st->groups[0] = &st->attr_group; | |
b92fe9e3 SM |
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, | |
4b49cca3 | 157 | st->groups); |
e0f8a24e JC |
158 | if (IS_ERR(st->hwmon_dev)) { |
159 | ret = PTR_ERR(st->hwmon_dev); | |
4b49cca3 | 160 | goto error_release_channels; |
e0f8a24e | 161 | } |
4b49cca3 | 162 | platform_set_drvdata(pdev, st); |
e0f8a24e JC |
163 | return 0; |
164 | ||
e0f8a24e | 165 | error_release_channels: |
159c8cdd | 166 | iio_channel_release_all(channels); |
e0f8a24e JC |
167 | return ret; |
168 | } | |
169 | ||
447d4f29 | 170 | static int iio_hwmon_remove(struct platform_device *pdev) |
e0f8a24e JC |
171 | { |
172 | struct iio_hwmon_state *st = platform_get_drvdata(pdev); | |
173 | ||
174 | hwmon_device_unregister(st->hwmon_dev); | |
314be14b | 175 | iio_channel_release_all(st->channels); |
e0f8a24e JC |
176 | |
177 | return 0; | |
178 | } | |
179 | ||
cfe03d64 | 180 | static const struct of_device_id iio_hwmon_of_match[] = { |
a11e619b GR |
181 | { .compatible = "iio-hwmon", }, |
182 | { } | |
183 | }; | |
2ec28196 | 184 | MODULE_DEVICE_TABLE(of, iio_hwmon_of_match); |
a11e619b | 185 | |
e0f8a24e JC |
186 | static struct platform_driver __refdata iio_hwmon_driver = { |
187 | .driver = { | |
188 | .name = "iio_hwmon", | |
a11e619b | 189 | .of_match_table = iio_hwmon_of_match, |
e0f8a24e JC |
190 | }, |
191 | .probe = iio_hwmon_probe, | |
e543acf0 | 192 | .remove = iio_hwmon_remove, |
e0f8a24e JC |
193 | }; |
194 | ||
d16f6dbd | 195 | module_platform_driver(iio_hwmon_driver); |
e0f8a24e | 196 | |
0f8c9620 | 197 | MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); |
e0f8a24e JC |
198 | MODULE_DESCRIPTION("IIO to hwmon driver"); |
199 | MODULE_LICENSE("GPL v2"); |