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 
14 struct 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 
22 static 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 
27 static 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 
33 static 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 
41 static 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 
48 struct 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 	cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
58 	if (cb_buff == NULL)
59 		return ERR_PTR(-ENOMEM);
60 
61 	iio_buffer_init(&cb_buff->buffer);
62 
63 	cb_buff->private = private;
64 	cb_buff->cb = cb;
65 	cb_buff->buffer.access = &iio_cb_access;
66 	INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
67 
68 	cb_buff->channels = iio_channel_get_all(dev);
69 	if (IS_ERR(cb_buff->channels)) {
70 		ret = PTR_ERR(cb_buff->channels);
71 		goto error_free_cb_buff;
72 	}
73 
74 	cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
75 	cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
76 						  GFP_KERNEL);
77 	if (cb_buff->buffer.scan_mask == NULL) {
78 		ret = -ENOMEM;
79 		goto error_release_channels;
80 	}
81 	chan = &cb_buff->channels[0];
82 	while (chan->indio_dev) {
83 		if (chan->indio_dev != cb_buff->indio_dev) {
84 			ret = -EINVAL;
85 			goto error_free_scan_mask;
86 		}
87 		set_bit(chan->channel->scan_index,
88 			cb_buff->buffer.scan_mask);
89 		chan++;
90 	}
91 
92 	return cb_buff;
93 
94 error_free_scan_mask:
95 	bitmap_free(cb_buff->buffer.scan_mask);
96 error_release_channels:
97 	iio_channel_release_all(cb_buff->channels);
98 error_free_cb_buff:
99 	kfree(cb_buff);
100 	return ERR_PTR(ret);
101 }
102 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
103 
104 int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
105 					size_t watermark)
106 {
107 	if (!watermark)
108 		return -EINVAL;
109 	cb_buff->buffer.watermark = watermark;
110 
111 	return 0;
112 }
113 EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
114 
115 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
116 {
117 	return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
118 				  NULL);
119 }
120 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
121 
122 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
123 {
124 	iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
125 }
126 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
127 
128 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
129 {
130 	iio_channel_release_all(cb_buff->channels);
131 	iio_buffer_put(&cb_buff->buffer);
132 }
133 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
134 
135 struct iio_channel
136 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
137 {
138 	return cb_buffer->channels;
139 }
140 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
141 
142 struct iio_dev
143 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
144 {
145 	return cb_buffer->indio_dev;
146 }
147 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
148 
149 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
150 MODULE_DESCRIPTION("Industrial I/O callback buffer");
151 MODULE_LICENSE("GPL");
152