buffer.h

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/* The industrial I/O core - generic buffer interfaces.
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

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

#ifdef CONFIG_IIO_BUFFER

struct iio_buffer;

struct iio_buffer_access_funcs {
    int (*store_to)(struct iio_buffer *buffer, u8 *data);
    int (*read_first_n)(struct iio_buffer *buffer,
                size_t n,
                char __user *buf);

    int (*request_update)(struct iio_buffer *buffer);

    int (*get_bytes_per_datum)(struct iio_buffer *buffer);
    int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);
    int (*get_length)(struct iio_buffer *buffer);
    int (*set_length)(struct iio_buffer *buffer, int length);
};

struct iio_buffer {
    int                 length;
    int                 bytes_per_datum;
    struct attribute_group          *scan_el_attrs;
    long                    *scan_mask;
    bool                    scan_timestamp;
    const struct iio_buffer_access_funcs    *access;
    struct list_head            scan_el_dev_attr_list;
    struct attribute_group          scan_el_group;
    wait_queue_head_t           pollq;
    bool                    stufftoread;
    const struct attribute_group *attrs;
    struct list_head            demux_list;
    unsigned char               *demux_bounce;
};

void iio_buffer_init(struct iio_buffer *buffer);

static inline void __iio_update_buffer(struct iio_buffer *buffer,
                       int bytes_per_datum, int length)
{
    buffer->bytes_per_datum = bytes_per_datum;
    buffer->length = length;
}

int iio_scan_mask_query(struct iio_dev *indio_dev,
            struct iio_buffer *buffer, int bit);

int iio_scan_mask_set(struct iio_dev *indio_dev,
              struct iio_buffer *buffer, int bit);

int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data);

int iio_update_demux(struct iio_dev *indio_dev);

int iio_buffer_register(struct iio_dev *indio_dev,
            const struct iio_chan_spec *channels,
            int num_channels);

void iio_buffer_unregister(struct iio_dev *indio_dev);

ssize_t iio_buffer_read_length(struct device *dev,
                   struct device_attribute *attr,
                   char *buf);
ssize_t iio_buffer_write_length(struct device *dev,
                  struct device_attribute *attr,
                  const char *buf,
                  size_t len);
ssize_t iio_buffer_store_enable(struct device *dev,
                struct device_attribute *attr,
                const char *buf,
                size_t len);
ssize_t iio_buffer_show_enable(struct device *dev,
                   struct device_attribute *attr,
                   char *buf);
#define IIO_BUFFER_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR,   \
                       iio_buffer_read_length,  \
                       iio_buffer_write_length)

#define IIO_BUFFER_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,   \
                       iio_buffer_show_enable,  \
                       iio_buffer_store_enable)

int iio_sw_buffer_preenable(struct iio_dev *indio_dev);

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

#else /* CONFIG_IIO_BUFFER */

static inline int iio_buffer_register(struct iio_dev *indio_dev,
                       struct iio_chan_spec *channels,
                       int num_channels)
{
    return 0;
}

static inline void iio_buffer_unregister(struct iio_dev *indio_dev)
{}

#endif /* CONFIG_IIO_BUFFER */

#endif /* _IIO_BUFFER_GENERIC_H_ */