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	if (!cb) {
 58		dev_err(dev, "Invalid arguments: A callback must be provided!\n");
 59		return ERR_PTR(-EINVAL);
 60	}
 61
 62	cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
 63	if (cb_buff == NULL)
 64		return ERR_PTR(-ENOMEM);
 65
 66	iio_buffer_init(&cb_buff->buffer);
 67
 68	cb_buff->private = private;
 69	cb_buff->cb = cb;
 70	cb_buff->buffer.access = &iio_cb_access;
 71	INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
 72
 73	cb_buff->channels = iio_channel_get_all(dev);
 74	if (IS_ERR(cb_buff->channels)) {
 75		ret = PTR_ERR(cb_buff->channels);
 76		goto error_free_cb_buff;
 77	}
 78
 79	cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
 80	cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
 81						  GFP_KERNEL);
 82	if (cb_buff->buffer.scan_mask == NULL) {
 83		ret = -ENOMEM;
 84		goto error_release_channels;
 85	}
 86	chan = &cb_buff->channels[0];
 87	while (chan->indio_dev) {
 88		if (chan->indio_dev != cb_buff->indio_dev) {
 89			ret = -EINVAL;
 90			goto error_free_scan_mask;
 91		}
 92		set_bit(chan->channel->scan_index,
 93			cb_buff->buffer.scan_mask);
 94		chan++;
 95	}
 96
 97	return cb_buff;
 98
 99error_free_scan_mask:
100	bitmap_free(cb_buff->buffer.scan_mask);
101error_release_channels:
102	iio_channel_release_all(cb_buff->channels);
103error_free_cb_buff:
104	kfree(cb_buff);
105	return ERR_PTR(ret);
106}
107EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
108
109int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
110					size_t watermark)
111{
112	if (!watermark)
113		return -EINVAL;
114	cb_buff->buffer.watermark = watermark;
115
116	return 0;
117}
118EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
119
120int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
121{
122	return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
123				  NULL);
124}
125EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
126
127void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
128{
129	iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
130}
131EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
132
133void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
134{
135	iio_channel_release_all(cb_buff->channels);
136	iio_buffer_put(&cb_buff->buffer);
137}
138EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
139
140struct iio_channel
141*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
142{
143	return cb_buffer->channels;
144}
145EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
146
147struct iio_dev
148*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
149{
150	return cb_buffer->indio_dev;
151}
152EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
153
154MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
155MODULE_DESCRIPTION("Industrial I/O callback buffer");
156MODULE_LICENSE("GPL");