include/linux/iio/buffer.h

/* SPDX-License-Identifier: GPL-2.0-only */
/* The industrial I/O core - generic buffer interfaces.
 *
 * Copyright (c) 2008 Jonathan Cameron
 */

#ifndef _IIO_BUFFER_GENERIC_H_
#define _IIO_BUFFER_GENERIC_H_
#include <linux/sysfs.h>
#include <linux/iio/iio.h>

struct iio_buffer;

enum iio_buffer_direction {
	IIO_BUFFER_DIRECTION_IN,
	IIO_BUFFER_DIRECTION_OUT,
};

int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data);

int iio_pop_from_buffer(struct iio_buffer *buffer, void *data);

/**
 * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers
 * @indio_dev:		iio_dev structure for device.
 * @data:		sample data
 * @timestamp:		timestamp for the sample data
 *
 * DEPRECATED: Use iio_push_to_buffers_with_ts() instead.
 *
 * Returns 0 on success, a negative error code otherwise.
 */
static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev,
	void *data, int64_t timestamp)
{
	if (ACCESS_PRIVATE(indio_dev, scan_timestamp)) {
		size_t ts_offset = ACCESS_PRIVATE(indio_dev, scan_timestamp_offset);

		/*
		 * The size of indio_dev->scan_bytes is always aligned to the
		 * largest scan element's alignment (see iio_compute_scan_bytes()).
		 * So there may be padding after the timestamp. ts_offset contains
		 * the offset in bytes that was already computed for correctly
		 * aligning the timestamp.
		 */
		*(int64_t *)(data + ts_offset) = timestamp;
	}

	return iio_push_to_buffers(indio_dev, data);
}

/**
 * iio_push_to_buffers_with_ts() - push data and timestamp to buffers
 * @indio_dev:		iio_dev structure for device.
 * @data:		Pointer to sample data buffer.
 * @data_total_len:	The size of @data in bytes.
 * @timestamp:		Timestamp for the sample data.
 *
 * Pushes data to the IIO device's buffers. If timestamps are enabled for the
 * device the function will store the supplied timestamp as the last element in
 * the sample data buffer before pushing it to the device buffers. The sample
 * data buffer needs to be large enough to hold the additional timestamp
 * (usually the buffer should be at least indio->scan_bytes bytes large).
 *
 * Context: Any context.
 * Return: 0 on success, a negative error code otherwise.
 */
static inline int iio_push_to_buffers_with_ts(struct iio_dev *indio_dev,
					      void *data, size_t data_total_len,
					      s64 timestamp)
{
	if (unlikely(data_total_len < indio_dev->scan_bytes)) {
		dev_err(&indio_dev->dev, "Undersized storage pushed to buffer\n");
		return -ENOSPC;
	}

	return iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
}

int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev,
					  const void *data, size_t data_sz,
					  s64 timestamp);

bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
				   const unsigned long *mask);

int iio_device_attach_buffer(struct iio_dev *indio_dev,
			     struct iio_buffer *buffer);

#endif /* _IIO_BUFFER_GENERIC_H_ */