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	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
 94error_free_scan_mask:
 95	bitmap_free(cb_buff->buffer.scan_mask);
 96error_release_channels:
 97	iio_channel_release_all(cb_buff->channels);
 98error_free_cb_buff:
 99	kfree(cb_buff);
100	return ERR_PTR(ret);
101}
102EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
103
104int 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}
113EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
114
115int 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}
120EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
121
122void 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}
126EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
127
128void 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}
133EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
134
135struct iio_channel
136*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
137{
138	return cb_buffer->channels;
139}
140EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
141
142struct iio_dev
143*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
144{
145	return cb_buffer->indio_dev;
146}
147EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
148
149MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
150MODULE_DESCRIPTION("Industrial I/O callback buffer");
151MODULE_LICENSE("GPL");