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");