Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | /* Hwmon client for industrial I/O devices
*
* Copyright (c) 2011 Jonathan Cameron
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
/**
* struct iio_hwmon_state - device instance state
* @channels: filled with array of channels from iio
* @num_channels: number of channels in channels (saves counting twice)
* @hwmon_dev: associated hwmon device
* @attr_group: the group of attributes
* @attrs: null terminated array of attribute pointers.
*/
struct iio_hwmon_state {
struct iio_channel *channels;
int num_channels;
struct device *hwmon_dev;
struct attribute_group attr_group;
struct attribute **attrs;
};
/*
* Assumes that IIO and hwmon operate in the same base units.
* This is supposed to be true, but needs verification for
* new channel types.
*/
static ssize_t iio_hwmon_read_val(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int result;
int ret;
struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
struct iio_hwmon_state *state = dev_get_drvdata(dev);
ret = iio_read_channel_processed(&state->channels[sattr->index],
&result);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", result);
}
static void iio_hwmon_free_attrs(struct iio_hwmon_state *st)
{
int i;
struct sensor_device_attribute *a;
for (i = 0; i < st->num_channels; i++)
if (st->attrs[i]) {
a = to_sensor_dev_attr(
container_of(st->attrs[i],
struct device_attribute,
attr));
kfree(a);
}
}
static int iio_hwmon_probe(struct platform_device *pdev)
{
struct iio_hwmon_state *st;
struct sensor_device_attribute *a;
int ret, i;
int in_i = 1, temp_i = 1, curr_i = 1;
enum iio_chan_type type;
st = kzalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL) {
ret = -ENOMEM;
goto error_ret;
}
st->channels = iio_channel_get_all(dev_name(&pdev->dev));
if (IS_ERR(st->channels)) {
ret = PTR_ERR(st->channels);
goto error_free_state;
}
/* count how many attributes we have */
while (st->channels[st->num_channels].indio_dev)
st->num_channels++;
st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1),
GFP_KERNEL);
if (st->attrs == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
for (i = 0; i < st->num_channels; i++) {
a = kzalloc(sizeof(*a), GFP_KERNEL);
if (a == NULL) {
ret = -ENOMEM;
goto error_free_attrs;
}
sysfs_attr_init(&a->dev_attr.attr);
ret = iio_get_channel_type(&st->channels[i], &type);
if (ret < 0) {
kfree(a);
goto error_free_attrs;
}
switch (type) {
case IIO_VOLTAGE:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"in%d_input",
in_i++);
break;
case IIO_TEMP:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"temp%d_input",
temp_i++);
break;
case IIO_CURRENT:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"curr%d_input",
curr_i++);
break;
default:
ret = -EINVAL;
kfree(a);
goto error_free_attrs;
}
if (a->dev_attr.attr.name == NULL) {
kfree(a);
ret = -ENOMEM;
goto error_free_attrs;
}
a->dev_attr.show = iio_hwmon_read_val;
a->dev_attr.attr.mode = S_IRUGO;
a->index = i;
st->attrs[i] = &a->dev_attr.attr;
}
st->attr_group.attrs = st->attrs;
platform_set_drvdata(pdev, st);
ret = sysfs_create_group(&pdev->dev.kobj, &st->attr_group);
if (ret < 0)
goto error_free_attrs;
st->hwmon_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(st->hwmon_dev)) {
ret = PTR_ERR(st->hwmon_dev);
goto error_remove_group;
}
return 0;
error_remove_group:
sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
error_free_attrs:
iio_hwmon_free_attrs(st);
kfree(st->attrs);
error_release_channels:
iio_channel_release_all(st->channels);
error_free_state:
kfree(st);
error_ret:
return ret;
}
static int iio_hwmon_remove(struct platform_device *pdev)
{
struct iio_hwmon_state *st = platform_get_drvdata(pdev);
hwmon_device_unregister(st->hwmon_dev);
sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
iio_hwmon_free_attrs(st);
kfree(st->attrs);
iio_channel_release_all(st->channels);
return 0;
}
static struct platform_driver __refdata iio_hwmon_driver = {
.driver = {
.name = "iio_hwmon",
.owner = THIS_MODULE,
},
.probe = iio_hwmon_probe,
.remove = iio_hwmon_remove,
};
module_platform_driver(iio_hwmon_driver);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO to hwmon driver");
MODULE_LICENSE("GPL v2");
|