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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> | |
16 | #include <linux/hwmon-sysfs.h> | |
06458e27 JC |
17 | #include <linux/iio/consumer.h> |
18 | #include <linux/iio/types.h> | |
e0f8a24e JC |
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 | * @hwmon_dev: associated hwmon device | |
25 | * @attr_group: the group of attributes | |
26 | * @attrs: null terminated array of attribute pointers. | |
27 | */ | |
28 | struct 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 | * 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 | */ | |
41 | static ssize_t iio_hwmon_read_val(struct device *dev, | |
42 | struct device_attribute *attr, | |
43 | char *buf) | |
44 | { | |
a0e545e0 LPC |
45 | int result; |
46 | int ret; | |
e0f8a24e JC |
47 | struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); |
48 | struct iio_hwmon_state *state = dev_get_drvdata(dev); | |
49 | ||
a0e545e0 LPC |
50 | ret = iio_read_channel_processed(&state->channels[sattr->index], |
51 | &result); | |
e0f8a24e JC |
52 | if (ret < 0) |
53 | return ret; | |
54 | ||
a0e545e0 | 55 | return sprintf(buf, "%d\n", result); |
e0f8a24e JC |
56 | } |
57 | ||
58 | static void iio_hwmon_free_attrs(struct iio_hwmon_state *st) | |
59 | { | |
60 | int i; | |
61 | struct sensor_device_attribute *a; | |
62 | for (i = 0; i < st->num_channels; i++) | |
63 | if (st->attrs[i]) { | |
64 | a = to_sensor_dev_attr( | |
65 | container_of(st->attrs[i], | |
66 | struct device_attribute, | |
67 | attr)); | |
68 | kfree(a); | |
69 | } | |
70 | } | |
71 | ||
72 | static int __devinit iio_hwmon_probe(struct platform_device *pdev) | |
73 | { | |
74 | struct iio_hwmon_state *st; | |
75 | struct sensor_device_attribute *a; | |
76 | int ret, i; | |
77 | int in_i = 1, temp_i = 1, curr_i = 1; | |
78 | enum iio_chan_type type; | |
79 | ||
80 | st = kzalloc(sizeof(*st), GFP_KERNEL); | |
81 | if (st == NULL) { | |
82 | ret = -ENOMEM; | |
83 | goto error_ret; | |
84 | } | |
85 | ||
314be14b | 86 | st->channels = iio_channel_get_all(dev_name(&pdev->dev)); |
e0f8a24e JC |
87 | if (IS_ERR(st->channels)) { |
88 | ret = PTR_ERR(st->channels); | |
89 | goto error_free_state; | |
90 | } | |
91 | ||
92 | /* count how many attributes we have */ | |
93 | while (st->channels[st->num_channels].indio_dev) | |
94 | st->num_channels++; | |
95 | ||
96 | st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1), | |
97 | GFP_KERNEL); | |
98 | if (st->attrs == NULL) { | |
99 | ret = -ENOMEM; | |
100 | goto error_release_channels; | |
101 | } | |
102 | for (i = 0; i < st->num_channels; i++) { | |
103 | a = kzalloc(sizeof(*a), GFP_KERNEL); | |
104 | if (a == NULL) { | |
105 | ret = -ENOMEM; | |
106 | goto error_free_attrs; | |
107 | } | |
108 | ||
109 | sysfs_attr_init(&a->dev_attr.attr); | |
314be14b | 110 | ret = iio_get_channel_type(&st->channels[i], &type); |
e0f8a24e JC |
111 | if (ret < 0) { |
112 | kfree(a); | |
113 | goto error_free_attrs; | |
114 | } | |
115 | switch (type) { | |
116 | case IIO_VOLTAGE: | |
117 | a->dev_attr.attr.name = kasprintf(GFP_KERNEL, | |
118 | "in%d_input", | |
119 | in_i++); | |
120 | break; | |
121 | case IIO_TEMP: | |
122 | a->dev_attr.attr.name = kasprintf(GFP_KERNEL, | |
123 | "temp%d_input", | |
124 | temp_i++); | |
125 | break; | |
126 | case IIO_CURRENT: | |
127 | a->dev_attr.attr.name = kasprintf(GFP_KERNEL, | |
128 | "curr%d_input", | |
129 | curr_i++); | |
130 | break; | |
131 | default: | |
132 | ret = -EINVAL; | |
133 | kfree(a); | |
134 | goto error_free_attrs; | |
135 | } | |
136 | if (a->dev_attr.attr.name == NULL) { | |
137 | kfree(a); | |
138 | ret = -ENOMEM; | |
139 | goto error_free_attrs; | |
140 | } | |
141 | a->dev_attr.show = iio_hwmon_read_val; | |
142 | a->dev_attr.attr.mode = S_IRUGO; | |
143 | a->index = i; | |
144 | st->attrs[i] = &a->dev_attr.attr; | |
145 | } | |
146 | ||
147 | st->attr_group.attrs = st->attrs; | |
148 | platform_set_drvdata(pdev, st); | |
149 | ret = sysfs_create_group(&pdev->dev.kobj, &st->attr_group); | |
150 | if (ret < 0) | |
151 | goto error_free_attrs; | |
152 | ||
153 | st->hwmon_dev = hwmon_device_register(&pdev->dev); | |
154 | if (IS_ERR(st->hwmon_dev)) { | |
155 | ret = PTR_ERR(st->hwmon_dev); | |
156 | goto error_remove_group; | |
157 | } | |
158 | return 0; | |
159 | ||
160 | error_remove_group: | |
161 | sysfs_remove_group(&pdev->dev.kobj, &st->attr_group); | |
162 | error_free_attrs: | |
163 | iio_hwmon_free_attrs(st); | |
164 | kfree(st->attrs); | |
165 | error_release_channels: | |
314be14b | 166 | iio_channel_release_all(st->channels); |
e0f8a24e JC |
167 | error_free_state: |
168 | kfree(st); | |
169 | error_ret: | |
170 | return ret; | |
171 | } | |
172 | ||
173 | static int __devexit iio_hwmon_remove(struct platform_device *pdev) | |
174 | { | |
175 | struct iio_hwmon_state *st = platform_get_drvdata(pdev); | |
176 | ||
177 | hwmon_device_unregister(st->hwmon_dev); | |
178 | sysfs_remove_group(&pdev->dev.kobj, &st->attr_group); | |
179 | iio_hwmon_free_attrs(st); | |
180 | kfree(st->attrs); | |
314be14b | 181 | iio_channel_release_all(st->channels); |
e0f8a24e JC |
182 | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static struct platform_driver __refdata iio_hwmon_driver = { | |
187 | .driver = { | |
188 | .name = "iio_hwmon", | |
189 | .owner = THIS_MODULE, | |
190 | }, | |
191 | .probe = iio_hwmon_probe, | |
192 | .remove = __devexit_p(iio_hwmon_remove), | |
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"); |