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>
17 #include <linux/hwmon-sysfs.h>
18 #include <linux/iio/consumer.h>
19 #include <linux/iio/types.h>
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.
29 struct iio_hwmon_state {
30 struct iio_channel *channels;
32 struct device *hwmon_dev;
33 struct attribute_group attr_group;
34 struct attribute **attrs;
38 * Assumes that IIO and hwmon operate in the same base units.
39 * This is supposed to be true, but needs verification for
42 static ssize_t iio_hwmon_read_val(struct device *dev,
43 struct device_attribute *attr,
48 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
49 struct iio_hwmon_state *state = dev_get_drvdata(dev);
51 ret = iio_read_channel_processed(&state->channels[sattr->index],
56 return sprintf(buf, "%d\n", result);
59 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
62 const char *name = "iio_hwmon";
64 if (dev->of_node && dev->of_node->name)
65 name = dev->of_node->name;
67 return sprintf(buf, "%s\n", name);
70 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
72 static int iio_hwmon_probe(struct platform_device *pdev)
74 struct device *dev = &pdev->dev;
75 struct iio_hwmon_state *st;
76 struct sensor_device_attribute *a;
78 int in_i = 1, temp_i = 1, curr_i = 1;
79 enum iio_chan_type type;
80 struct iio_channel *channels;
82 channels = iio_channel_get_all(dev);
84 return PTR_ERR(channels);
86 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
90 st->channels = channels;
92 /* count how many attributes we have */
93 while (st->channels[st->num_channels].indio_dev)
96 st->attrs = devm_kzalloc(dev,
97 sizeof(*st->attrs) * (st->num_channels + 2),
99 if (st->attrs == NULL) {
101 goto error_release_channels;
104 for (i = 0; i < st->num_channels; i++) {
105 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
108 goto error_release_channels;
111 sysfs_attr_init(&a->dev_attr.attr);
112 ret = iio_get_channel_type(&st->channels[i], &type);
114 goto error_release_channels;
118 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
123 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
128 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
134 goto error_release_channels;
136 if (a->dev_attr.attr.name == NULL) {
138 goto error_release_channels;
140 a->dev_attr.show = iio_hwmon_read_val;
141 a->dev_attr.attr.mode = S_IRUGO;
143 st->attrs[i] = &a->dev_attr.attr;
145 st->attrs[st->num_channels] = &dev_attr_name.attr;
146 st->attr_group.attrs = st->attrs;
147 platform_set_drvdata(pdev, st);
148 ret = sysfs_create_group(&dev->kobj, &st->attr_group);
150 goto error_release_channels;
152 st->hwmon_dev = hwmon_device_register(dev);
153 if (IS_ERR(st->hwmon_dev)) {
154 ret = PTR_ERR(st->hwmon_dev);
155 goto error_remove_group;
160 sysfs_remove_group(&dev->kobj, &st->attr_group);
161 error_release_channels:
162 iio_channel_release_all(st->channels);
166 static int iio_hwmon_remove(struct platform_device *pdev)
168 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
170 hwmon_device_unregister(st->hwmon_dev);
171 sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
172 iio_channel_release_all(st->channels);
177 static struct of_device_id iio_hwmon_of_match[] = {
178 { .compatible = "iio-hwmon", },
182 static struct platform_driver __refdata iio_hwmon_driver = {
185 .owner = THIS_MODULE,
186 .of_match_table = iio_hwmon_of_match,
188 .probe = iio_hwmon_probe,
189 .remove = iio_hwmon_remove,
192 module_platform_driver(iio_hwmon_driver);
194 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
195 MODULE_DESCRIPTION("IIO to hwmon driver");
196 MODULE_LICENSE("GPL v2");