1 /* Hwmon client for industrial I/O devices
3 * Copyright (c) 2011 Jonathan Cameron
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.
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>
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.
28 struct iio_hwmon_state {
29 struct iio_channel *channels;
31 struct device *hwmon_dev;
32 struct attribute_group attr_group;
33 struct attribute **attrs;
37 * Assumes that IIO and hwmon operate in the same base units.
38 * This is supposed to be true, but needs verification for
41 static ssize_t iio_hwmon_read_val(struct device *dev,
42 struct device_attribute *attr,
47 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
48 struct iio_hwmon_state *state = dev_get_drvdata(dev);
50 ret = iio_read_channel_processed(&state->channels[sattr->index],
55 return sprintf(buf, "%d\n", result);
58 static void iio_hwmon_free_attrs(struct iio_hwmon_state *st)
61 struct sensor_device_attribute *a;
62 for (i = 0; i < st->num_channels; i++)
64 a = to_sensor_dev_attr(
65 container_of(st->attrs[i],
66 struct device_attribute,
72 static int iio_hwmon_probe(struct platform_device *pdev)
74 struct iio_hwmon_state *st;
75 struct sensor_device_attribute *a;
77 int in_i = 1, temp_i = 1, curr_i = 1;
78 enum iio_chan_type type;
80 st = kzalloc(sizeof(*st), GFP_KERNEL);
86 st->channels = iio_channel_get_all(dev_name(&pdev->dev));
87 if (IS_ERR(st->channels)) {
88 ret = PTR_ERR(st->channels);
89 goto error_free_state;
92 /* count how many attributes we have */
93 while (st->channels[st->num_channels].indio_dev)
96 st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1),
98 if (st->attrs == NULL) {
100 goto error_release_channels;
102 for (i = 0; i < st->num_channels; i++) {
103 a = kzalloc(sizeof(*a), GFP_KERNEL);
106 goto error_free_attrs;
109 sysfs_attr_init(&a->dev_attr.attr);
110 ret = iio_get_channel_type(&st->channels[i], &type);
113 goto error_free_attrs;
117 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
122 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
127 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
134 goto error_free_attrs;
136 if (a->dev_attr.attr.name == NULL) {
139 goto error_free_attrs;
141 a->dev_attr.show = iio_hwmon_read_val;
142 a->dev_attr.attr.mode = S_IRUGO;
144 st->attrs[i] = &a->dev_attr.attr;
147 st->attr_group.attrs = st->attrs;
148 platform_set_drvdata(pdev, st);
149 ret = sysfs_create_group(&pdev->dev.kobj, &st->attr_group);
151 goto error_free_attrs;
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;
161 sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
163 iio_hwmon_free_attrs(st);
165 error_release_channels:
166 iio_channel_release_all(st->channels);
173 static int iio_hwmon_remove(struct platform_device *pdev)
175 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
177 hwmon_device_unregister(st->hwmon_dev);
178 sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
179 iio_hwmon_free_attrs(st);
181 iio_channel_release_all(st->channels);
186 static struct platform_driver __refdata iio_hwmon_driver = {
189 .owner = THIS_MODULE,
191 .probe = iio_hwmon_probe,
192 .remove = iio_hwmon_remove,
195 module_platform_driver(iio_hwmon_driver);
197 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
198 MODULE_DESCRIPTION("IIO to hwmon driver");
199 MODULE_LICENSE("GPL v2");