1 /* The industrial I/O callback buffer
2  *
3  * This program is free software; you can redistribute it and/or modify it
4  * under the terms of the GNU General Public License version 2 as published by
5  * the Free Software Foundation.
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/err.h>
12 #include <linux/export.h>
13 #include <linux/iio/buffer.h>
14 #include <linux/iio/consumer.h>
15 
16 struct iio_cb_buffer {
17 	struct iio_buffer buffer;
18 	int (*cb)(const void *data, void *private);
19 	void *private;
20 	struct iio_channel *channels;
21 	struct iio_dev *indio_dev;
22 };
23 
24 static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
25 {
26 	return container_of(buffer, struct iio_cb_buffer, buffer);
27 }
28 
29 static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
30 {
31 	struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
32 	return cb_buff->cb(data, cb_buff->private);
33 }
34 
35 static void iio_buffer_cb_release(struct iio_buffer *buffer)
36 {
37 	struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
38 	kfree(cb_buff->buffer.scan_mask);
39 	kfree(cb_buff);
40 }
41 
42 static 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 
49 struct 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 	cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
59 	if (cb_buff == NULL)
60 		return ERR_PTR(-ENOMEM);
61 
62 	iio_buffer_init(&cb_buff->buffer);
63 
64 	cb_buff->private = private;
65 	cb_buff->cb = cb;
66 	cb_buff->buffer.access = &iio_cb_access;
67 	INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
68 
69 	cb_buff->channels = iio_channel_get_all(dev);
70 	if (IS_ERR(cb_buff->channels)) {
71 		ret = PTR_ERR(cb_buff->channels);
72 		goto error_free_cb_buff;
73 	}
74 
75 	cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
76 	cb_buff->buffer.scan_mask
77 		= kcalloc(BITS_TO_LONGS(cb_buff->indio_dev->masklength),
78 			  sizeof(long), GFP_KERNEL);
79 	if (cb_buff->buffer.scan_mask == NULL) {
80 		ret = -ENOMEM;
81 		goto error_release_channels;
82 	}
83 	chan = &cb_buff->channels[0];
84 	while (chan->indio_dev) {
85 		if (chan->indio_dev != cb_buff->indio_dev) {
86 			ret = -EINVAL;
87 			goto error_free_scan_mask;
88 		}
89 		set_bit(chan->channel->scan_index,
90 			cb_buff->buffer.scan_mask);
91 		chan++;
92 	}
93 
94 	return cb_buff;
95 
96 error_free_scan_mask:
97 	kfree(cb_buff->buffer.scan_mask);
98 error_release_channels:
99 	iio_channel_release_all(cb_buff->channels);
100 error_free_cb_buff:
101 	kfree(cb_buff);
102 	return ERR_PTR(ret);
103 }
104 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
105 
106 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
107 {
108 	return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
109 				  NULL);
110 }
111 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
112 
113 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
114 {
115 	iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
116 }
117 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
118 
119 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
120 {
121 	iio_channel_release_all(cb_buff->channels);
122 	iio_buffer_put(&cb_buff->buffer);
123 }
124 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
125 
126 struct iio_channel
127 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
128 {
129 	return cb_buffer->channels;
130 }
131 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
132 
133 struct iio_dev
134 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
135 {
136 	return cb_buffer->indio_dev;
137 }
138 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
139 
140 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
141 MODULE_DESCRIPTION("Industrial I/O callback buffer");
142 MODULE_LICENSE("GPL");
143