tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/* The industrial I/O callback buffer
3 */
4
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/slab.h>
8#include <linux/err.h>
9#include <linux/export.h>
10#include <linux/iio/iio.h>
11#include <linux/iio/buffer_impl.h>
12#include <linux/iio/consumer.h>
13
14struct iio_cb_buffer {
15 struct iio_buffer buffer;
16 /* Must be safe to call from any context (e.g. must not sleep). */
17 int (*cb)(const void *data, void *private);
18 void *private;
19 struct iio_channel *channels;
20 struct iio_dev *indio_dev;
21};
22
23static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
24{
25 return container_of(buffer, struct iio_cb_buffer, buffer);
26}
27
28static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
29{
30 struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
31 return cb_buff->cb(data, cb_buff->private);
32}
33
34static void iio_buffer_cb_release(struct iio_buffer *buffer)
35{
36 struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
37
38 bitmap_free(cb_buff->buffer.scan_mask);
39 kfree(cb_buff);
40}
41
42static const struct iio_buffer_access_funcs iio_cb_access = {
43 .store_to = &iio_buffer_cb_store_to,
44 .release = &iio_buffer_cb_release,
45
46 .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
47};
48
49struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
50 int (*cb)(const void *data,
51 void *private),
52 void *private)
53{
54 int ret;
55 struct iio_cb_buffer *cb_buff;
56 struct iio_channel *chan;
57
58 if (!cb) {
59 dev_err(dev, "Invalid arguments: A callback must be provided!\n");
60 return ERR_PTR(-EINVAL);
61 }
62
63 cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
64 if (cb_buff == NULL)
65 return ERR_PTR(-ENOMEM);
66
67 iio_buffer_init(&cb_buff->buffer);
68
69 cb_buff->private = private;
70 cb_buff->cb = cb;
71 cb_buff->buffer.access = &iio_cb_access;
72
73 cb_buff->channels = iio_channel_get_all(dev);
74 if (IS_ERR(cb_buff->channels)) {
75 ret = PTR_ERR(cb_buff->channels);
76 goto error_free_cb_buff;
77 }
78
79 cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
80 cb_buff->buffer.scan_mask = bitmap_zalloc(iio_get_masklength(cb_buff->indio_dev),
81 GFP_KERNEL);
82 if (cb_buff->buffer.scan_mask == NULL) {
83 ret = -ENOMEM;
84 goto error_release_channels;
85 }
86 chan = &cb_buff->channels[0];
87 while (chan->indio_dev) {
88 if (chan->indio_dev != cb_buff->indio_dev) {
89 ret = -EINVAL;
90 goto error_free_scan_mask;
91 }
92 set_bit(chan->channel->scan_index,
93 cb_buff->buffer.scan_mask);
94 chan++;
95 }
96
97 return cb_buff;
98
99error_free_scan_mask:
100 bitmap_free(cb_buff->buffer.scan_mask);
101error_release_channels:
102 iio_channel_release_all(cb_buff->channels);
103error_free_cb_buff:
104 kfree(cb_buff);
105 return ERR_PTR(ret);
106}
107EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
108
109int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
110 size_t watermark)
111{
112 if (!watermark)
113 return -EINVAL;
114 cb_buff->buffer.watermark = watermark;
115
116 return 0;
117}
118EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
119
120int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
121{
122 return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
123 NULL);
124}
125EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
126
127void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
128{
129 iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
130}
131EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
132
133void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
134{
135 iio_channel_release_all(cb_buff->channels);
136 iio_buffer_put(&cb_buff->buffer);
137}
138EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
139
140struct iio_channel
141*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
142{
143 return cb_buffer->channels;
144}
145EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
146
147struct iio_dev
148*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
149{
150 return cb_buffer->indio_dev;
151}
152EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
153
154MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
155MODULE_DESCRIPTION("Industrial I/O callback buffer");
156MODULE_LICENSE("GPL");