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	int (*cb)(const void *data, void *private);
17	void *private;
18	struct iio_channel *channels;
19	struct iio_dev *indio_dev;
20};
21
22static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
23{
24	return container_of(buffer, struct iio_cb_buffer, buffer);
25}
26
27static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
28{
29	struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
30	return cb_buff->cb(data, cb_buff->private);
31}
32
33static void iio_buffer_cb_release(struct iio_buffer *buffer)
34{
35	struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
36
37	bitmap_free(cb_buff->buffer.scan_mask);
38	kfree(cb_buff);
39}
40
41static const struct iio_buffer_access_funcs iio_cb_access = {
42	.store_to = &iio_buffer_cb_store_to,
43	.release = &iio_buffer_cb_release,
44
45	.modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
46};
47
48struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
49					     int (*cb)(const void *data,
50						       void *private),
51					     void *private)
52{
53	int ret;
54	struct iio_cb_buffer *cb_buff;
55	struct iio_channel *chan;
56
57	if (!cb) {
58		dev_err(dev, "Invalid arguments: A callback must be provided!\n");
59		return ERR_PTR(-EINVAL);
60	}
61
62	cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
63	if (cb_buff == NULL)
64		return ERR_PTR(-ENOMEM);
65
66	iio_buffer_init(&cb_buff->buffer);
67
68	cb_buff->private = private;
69	cb_buff->cb = cb;
70	cb_buff->buffer.access = &iio_cb_access;
71	INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
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(cb_buff->indio_dev->masklength,
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");
157