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Jonathan Camerone0f8a242012-02-15 19:48:03 +00001/* 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>
Guenter Roeck3465a222013-03-20 15:52:00 +000016#include <linux/of.h>
Jonathan Camerone0f8a242012-02-15 19:48:03 +000017#include <linux/hwmon-sysfs.h>
Jonathan Cameron06458e22012-04-25 15:54:58 +010018#include <linux/iio/consumer.h>
19#include <linux/iio/types.h>
Jonathan Camerone0f8a242012-02-15 19:48:03 +000020
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 */
29struct iio_hwmon_state {
30 struct iio_channel *channels;
31 int num_channels;
32 struct device *hwmon_dev;
33 struct attribute_group attr_group;
Guenter Roeck4b49cca2013-12-01 19:33:16 -080034 const struct attribute_group *groups[2];
Jonathan Camerone0f8a242012-02-15 19:48:03 +000035 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 */
43static ssize_t iio_hwmon_read_val(struct device *dev,
44 struct device_attribute *attr,
45 char *buf)
46{
Lars-Peter Clausena0e545e2012-09-17 13:17:00 +010047 int result;
48 int ret;
Jonathan Camerone0f8a242012-02-15 19:48:03 +000049 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
50 struct iio_hwmon_state *state = dev_get_drvdata(dev);
51
Lars-Peter Clausena0e545e2012-09-17 13:17:00 +010052 ret = iio_read_channel_processed(&state->channels[sattr->index],
53 &result);
Jonathan Camerone0f8a242012-02-15 19:48:03 +000054 if (ret < 0)
55 return ret;
56
Lars-Peter Clausena0e545e2012-09-17 13:17:00 +010057 return sprintf(buf, "%d\n", result);
Jonathan Camerone0f8a242012-02-15 19:48:03 +000058}
59
Bill Pemberton4ae1c612012-11-19 13:21:57 -050060static int iio_hwmon_probe(struct platform_device *pdev)
Jonathan Camerone0f8a242012-02-15 19:48:03 +000061{
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000062 struct device *dev = &pdev->dev;
Jonathan Camerone0f8a242012-02-15 19:48:03 +000063 struct iio_hwmon_state *st;
64 struct sensor_device_attribute *a;
65 int ret, i;
66 int in_i = 1, temp_i = 1, curr_i = 1;
67 enum iio_chan_type type;
Guenter Roeckca7d98d2013-01-31 21:43:00 +000068 struct iio_channel *channels;
Guenter Roeck4b49cca2013-12-01 19:33:16 -080069 const char *name = "iio_hwmon";
70
71 if (dev->of_node && dev->of_node->name)
72 name = dev->of_node->name;
Guenter Roeckca7d98d2013-01-31 21:43:00 +000073
74 channels = iio_channel_get_all(dev);
75 if (IS_ERR(channels))
76 return PTR_ERR(channels);
Jonathan Camerone0f8a242012-02-15 19:48:03 +000077
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000078 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
Axel Lin4510d192013-04-23 17:06:43 +000079 if (st == NULL) {
80 ret = -ENOMEM;
81 goto error_release_channels;
82 }
Jonathan Camerone0f8a242012-02-15 19:48:03 +000083
Guenter Roeckca7d98d2013-01-31 21:43:00 +000084 st->channels = channels;
Jonathan Camerone0f8a242012-02-15 19:48:03 +000085
86 /* count how many attributes we have */
87 while (st->channels[st->num_channels].indio_dev)
88 st->num_channels++;
89
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000090 st->attrs = devm_kzalloc(dev,
Guenter Roeck4b49cca2013-12-01 19:33:16 -080091 sizeof(*st->attrs) * (st->num_channels + 1),
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000092 GFP_KERNEL);
Jonathan Camerone0f8a242012-02-15 19:48:03 +000093 if (st->attrs == NULL) {
94 ret = -ENOMEM;
95 goto error_release_channels;
96 }
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000097
Jonathan Camerone0f8a242012-02-15 19:48:03 +000098 for (i = 0; i < st->num_channels; i++) {
Guenter Roeckc4ac7b92013-01-31 21:42:00 +000099 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000100 if (a == NULL) {
101 ret = -ENOMEM;
Guenter Roeckc4ac7b92013-01-31 21:42:00 +0000102 goto error_release_channels;
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000103 }
104
105 sysfs_attr_init(&a->dev_attr.attr);
Jonathan Cameron314be142012-05-01 21:04:24 +0100106 ret = iio_get_channel_type(&st->channels[i], &type);
Guenter Roeckc4ac7b92013-01-31 21:42:00 +0000107 if (ret < 0)
108 goto error_release_channels;
109
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000110 switch (type) {
111 case IIO_VOLTAGE:
112 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
113 "in%d_input",
114 in_i++);
115 break;
116 case IIO_TEMP:
117 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
118 "temp%d_input",
119 temp_i++);
120 break;
121 case IIO_CURRENT:
122 a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
123 "curr%d_input",
124 curr_i++);
125 break;
126 default:
127 ret = -EINVAL;
Guenter Roeckc4ac7b92013-01-31 21:42:00 +0000128 goto error_release_channels;
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000129 }
130 if (a->dev_attr.attr.name == NULL) {
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000131 ret = -ENOMEM;
Guenter Roeckc4ac7b92013-01-31 21:42:00 +0000132 goto error_release_channels;
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000133 }
134 a->dev_attr.show = iio_hwmon_read_val;
135 a->dev_attr.attr.mode = S_IRUGO;
136 a->index = i;
137 st->attrs[i] = &a->dev_attr.attr;
138 }
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000139
Guenter Roeck4b49cca2013-12-01 19:33:16 -0800140 st->attr_group.attrs = st->attrs;
141 st->groups[0] = &st->attr_group;
142 st->hwmon_dev = hwmon_device_register_with_groups(dev, name, st,
143 st->groups);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000144 if (IS_ERR(st->hwmon_dev)) {
145 ret = PTR_ERR(st->hwmon_dev);
Guenter Roeck4b49cca2013-12-01 19:33:16 -0800146 goto error_release_channels;
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000147 }
Guenter Roeck4b49cca2013-12-01 19:33:16 -0800148 platform_set_drvdata(pdev, st);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000149 return 0;
150
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000151error_release_channels:
Axel Lin159c8cd2013-05-13 21:37:26 +0800152 iio_channel_release_all(channels);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000153 return ret;
154}
155
Bill Pemberton447d4f22012-11-19 13:26:37 -0500156static int iio_hwmon_remove(struct platform_device *pdev)
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000157{
158 struct iio_hwmon_state *st = platform_get_drvdata(pdev);
159
160 hwmon_device_unregister(st->hwmon_dev);
Jonathan Cameron314be142012-05-01 21:04:24 +0100161 iio_channel_release_all(st->channels);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000162
163 return 0;
164}
165
Guenter Roecka11e6192013-01-31 21:43:00 +0000166static struct of_device_id iio_hwmon_of_match[] = {
167 { .compatible = "iio-hwmon", },
168 { }
169};
Sebastian Andrzej Siewior2ec28192013-06-10 17:47:45 +0200170MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
Guenter Roecka11e6192013-01-31 21:43:00 +0000171
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000172static struct platform_driver __refdata iio_hwmon_driver = {
173 .driver = {
174 .name = "iio_hwmon",
175 .owner = THIS_MODULE,
Guenter Roecka11e6192013-01-31 21:43:00 +0000176 .of_match_table = iio_hwmon_of_match,
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000177 },
178 .probe = iio_hwmon_probe,
Bill Pembertone543acf2012-11-19 13:21:38 -0500179 .remove = iio_hwmon_remove,
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000180};
181
Devendra Nagad16f6db2012-07-21 09:54:00 +0100182module_platform_driver(iio_hwmon_driver);
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000183
Jonathan Cameron0f8c9622012-09-02 21:34:59 +0100184MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
Jonathan Camerone0f8a242012-02-15 19:48:03 +0000185MODULE_DESCRIPTION("IIO to hwmon driver");
186MODULE_LICENSE("GPL v2");