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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; | |
34 | struct attribute **attrs; | |
35 | }; | |
36 | ||
37 | /* | |
38 | * Assumes that IIO and hwmon operate in the same base units. | |
39 | * This is supposed to be true, but needs verification for | |
40 | * new channel types. | |
41 | */ | |
42 | static ssize_t iio_hwmon_read_val(struct device *dev, | |
43 | struct device_attribute *attr, | |
44 | char *buf) | |
45 | { | |
a0e545e0 LPC |
46 | int result; |
47 | int ret; | |
e0f8a24e JC |
48 | struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); |
49 | struct iio_hwmon_state *state = dev_get_drvdata(dev); | |
50 | ||
a0e545e0 LPC |
51 | ret = iio_read_channel_processed(&state->channels[sattr->index], |
52 | &result); | |
e0f8a24e JC |
53 | if (ret < 0) |
54 | return ret; | |
55 | ||
a0e545e0 | 56 | return sprintf(buf, "%d\n", result); |
e0f8a24e JC |
57 | } |
58 | ||
1daed9be GR |
59 | static ssize_t show_name(struct device *dev, struct device_attribute *attr, |
60 | char *buf) | |
61 | { | |
3465a224 GR |
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); | |
1daed9be GR |
68 | } |
69 | ||
70 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
71 | ||
4ae1c61f | 72 | static int iio_hwmon_probe(struct platform_device *pdev) |
e0f8a24e | 73 | { |
c4ac7b98 | 74 | struct device *dev = &pdev->dev; |
e0f8a24e JC |
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; | |
ca7d98db GR |
80 | struct iio_channel *channels; |
81 | ||
82 | channels = iio_channel_get_all(dev); | |
83 | if (IS_ERR(channels)) | |
84 | return PTR_ERR(channels); | |
e0f8a24e | 85 | |
c4ac7b98 | 86 | st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); |
4510d198 AL |
87 | if (st == NULL) { |
88 | ret = -ENOMEM; | |
89 | goto error_release_channels; | |
90 | } | |
e0f8a24e | 91 | |
ca7d98db | 92 | st->channels = channels; |
e0f8a24e JC |
93 | |
94 | /* count how many attributes we have */ | |
95 | while (st->channels[st->num_channels].indio_dev) | |
96 | st->num_channels++; | |
97 | ||
c4ac7b98 | 98 | st->attrs = devm_kzalloc(dev, |
1daed9be | 99 | sizeof(*st->attrs) * (st->num_channels + 2), |
c4ac7b98 | 100 | GFP_KERNEL); |
e0f8a24e JC |
101 | if (st->attrs == NULL) { |
102 | ret = -ENOMEM; | |
103 | goto error_release_channels; | |
104 | } | |
c4ac7b98 | 105 | |
e0f8a24e | 106 | for (i = 0; i < st->num_channels; i++) { |
c4ac7b98 | 107 | a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL); |
e0f8a24e JC |
108 | if (a == NULL) { |
109 | ret = -ENOMEM; | |
c4ac7b98 | 110 | goto error_release_channels; |
e0f8a24e JC |
111 | } |
112 | ||
113 | sysfs_attr_init(&a->dev_attr.attr); | |
314be14b | 114 | ret = iio_get_channel_type(&st->channels[i], &type); |
c4ac7b98 GR |
115 | if (ret < 0) |
116 | goto error_release_channels; | |
117 | ||
e0f8a24e JC |
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; | |
c4ac7b98 | 136 | goto error_release_channels; |
e0f8a24e JC |
137 | } |
138 | if (a->dev_attr.attr.name == NULL) { | |
e0f8a24e | 139 | ret = -ENOMEM; |
c4ac7b98 | 140 | goto error_release_channels; |
e0f8a24e JC |
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 | } | |
1daed9be | 147 | st->attrs[st->num_channels] = &dev_attr_name.attr; |
e0f8a24e JC |
148 | st->attr_group.attrs = st->attrs; |
149 | platform_set_drvdata(pdev, st); | |
c4ac7b98 | 150 | ret = sysfs_create_group(&dev->kobj, &st->attr_group); |
e0f8a24e | 151 | if (ret < 0) |
c4ac7b98 | 152 | goto error_release_channels; |
e0f8a24e | 153 | |
c4ac7b98 | 154 | st->hwmon_dev = hwmon_device_register(dev); |
e0f8a24e JC |
155 | if (IS_ERR(st->hwmon_dev)) { |
156 | ret = PTR_ERR(st->hwmon_dev); | |
157 | goto error_remove_group; | |
158 | } | |
159 | return 0; | |
160 | ||
161 | error_remove_group: | |
c4ac7b98 | 162 | sysfs_remove_group(&dev->kobj, &st->attr_group); |
e0f8a24e | 163 | error_release_channels: |
159c8cdd | 164 | iio_channel_release_all(channels); |
e0f8a24e JC |
165 | return ret; |
166 | } | |
167 | ||
447d4f29 | 168 | static int iio_hwmon_remove(struct platform_device *pdev) |
e0f8a24e JC |
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); | |
314be14b | 174 | iio_channel_release_all(st->channels); |
e0f8a24e JC |
175 | |
176 | return 0; | |
177 | } | |
178 | ||
a11e619b GR |
179 | static struct of_device_id iio_hwmon_of_match[] = { |
180 | { .compatible = "iio-hwmon", }, | |
181 | { } | |
182 | }; | |
2ec28196 | 183 | MODULE_DEVICE_TABLE(of, iio_hwmon_of_match); |
a11e619b | 184 | |
e0f8a24e JC |
185 | static struct platform_driver __refdata iio_hwmon_driver = { |
186 | .driver = { | |
187 | .name = "iio_hwmon", | |
188 | .owner = THIS_MODULE, | |
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"); |