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/iio.h>
14 #include <linux/iio/buffer_impl.h>
15 #include <linux/iio/consumer.h>
16
17 struct iio_cb_buffer {
18 struct iio_buffer buffer;
19 int (*cb)(const void *data, void *private);
20 void *private;
21 struct iio_channel *channels;
22 struct iio_dev *indio_dev;
23 };
24
buffer_to_cb_buffer(struct iio_buffer * buffer)25 static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
26 {
27 return container_of(buffer, struct iio_cb_buffer, buffer);
28 }
29
iio_buffer_cb_store_to(struct iio_buffer * buffer,const void * data)30 static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
31 {
32 struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
33 return cb_buff->cb(data, cb_buff->private);
34 }
35
iio_buffer_cb_release(struct iio_buffer * buffer)36 static void iio_buffer_cb_release(struct iio_buffer *buffer)
37 {
38 struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
39 kfree(cb_buff->buffer.scan_mask);
40 kfree(cb_buff);
41 }
42
43 static const struct iio_buffer_access_funcs iio_cb_access = {
44 .store_to = &iio_buffer_cb_store_to,
45 .release = &iio_buffer_cb_release,
46
47 .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
48 };
49
iio_channel_get_all_cb(struct device * dev,int (* cb)(const void * data,void * private),void * private)50 struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
51 int (*cb)(const void *data,
52 void *private),
53 void *private)
54 {
55 int ret;
56 struct iio_cb_buffer *cb_buff;
57 struct iio_channel *chan;
58
59 cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
60 if (cb_buff == NULL)
61 return ERR_PTR(-ENOMEM);
62
63 iio_buffer_init(&cb_buff->buffer);
64
65 cb_buff->private = private;
66 cb_buff->cb = cb;
67 cb_buff->buffer.access = &iio_cb_access;
68 INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
69
70 cb_buff->channels = iio_channel_get_all(dev);
71 if (IS_ERR(cb_buff->channels)) {
72 ret = PTR_ERR(cb_buff->channels);
73 goto error_free_cb_buff;
74 }
75
76 cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
77 cb_buff->buffer.scan_mask
78 = kcalloc(BITS_TO_LONGS(cb_buff->indio_dev->masklength),
79 sizeof(long), GFP_KERNEL);
80 if (cb_buff->buffer.scan_mask == NULL) {
81 ret = -ENOMEM;
82 goto error_release_channels;
83 }
84 chan = &cb_buff->channels[0];
85 while (chan->indio_dev) {
86 if (chan->indio_dev != cb_buff->indio_dev) {
87 ret = -EINVAL;
88 goto error_free_scan_mask;
89 }
90 set_bit(chan->channel->scan_index,
91 cb_buff->buffer.scan_mask);
92 chan++;
93 }
94
95 return cb_buff;
96
97 error_free_scan_mask:
98 kfree(cb_buff->buffer.scan_mask);
99 error_release_channels:
100 iio_channel_release_all(cb_buff->channels);
101 error_free_cb_buff:
102 kfree(cb_buff);
103 return ERR_PTR(ret);
104 }
105 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
106
iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer * cb_buff,size_t watermark)107 int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
108 size_t watermark)
109 {
110 if (!watermark)
111 return -EINVAL;
112 cb_buff->buffer.watermark = watermark;
113
114 return 0;
115 }
116 EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
117
iio_channel_start_all_cb(struct iio_cb_buffer * cb_buff)118 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
119 {
120 return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
121 NULL);
122 }
123 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
124
iio_channel_stop_all_cb(struct iio_cb_buffer * cb_buff)125 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
126 {
127 iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
128 }
129 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
130
iio_channel_release_all_cb(struct iio_cb_buffer * cb_buff)131 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
132 {
133 iio_channel_release_all(cb_buff->channels);
134 iio_buffer_put(&cb_buff->buffer);
135 }
136 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
137
138 struct iio_channel
iio_channel_cb_get_channels(const struct iio_cb_buffer * cb_buffer)139 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
140 {
141 return cb_buffer->channels;
142 }
143 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
144
145 struct iio_dev
iio_channel_cb_get_iio_dev(const struct iio_cb_buffer * cb_buffer)146 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
147 {
148 return cb_buffer->indio_dev;
149 }
150 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
151
152 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
153 MODULE_DESCRIPTION("Industrial I/O callback buffer");
154 MODULE_LICENSE("GPL");
155