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
 16struct 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};
 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	kfree(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_dev *indio_dev;
 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	indio_dev = cb_buff->channels[0].indio_dev;
 76	cb_buff->buffer.scan_mask
 77		= kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
 78			  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 != 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
 96error_free_scan_mask:
 97	kfree(cb_buff->buffer.scan_mask);
 98error_release_channels:
 99	iio_channel_release_all(cb_buff->channels);
100error_free_cb_buff:
101	kfree(cb_buff);
102	return ERR_PTR(ret);
103}
104EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
105
106int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
107{
108	return iio_update_buffers(cb_buff->channels[0].indio_dev,
109				  &cb_buff->buffer,
110				  NULL);
111}
112EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
113
114void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
115{
116	iio_update_buffers(cb_buff->channels[0].indio_dev,
117			   NULL,
118			   &cb_buff->buffer);
119}
120EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
121
122void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
123{
124	iio_channel_release_all(cb_buff->channels);
125	iio_buffer_put(&cb_buff->buffer);
126}
127EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
128
129struct iio_channel
130*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
131{
132	return cb_buffer->channels;
133}
134EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
135
136MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
137MODULE_DESCRIPTION("Industrial I/O callback buffer");
138MODULE_LICENSE("GPL");