forked from Archive/PX4-Autopilot
124 lines
3.9 KiB
C
124 lines
3.9 KiB
C
/****************************************************************************
|
|
*
|
|
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name PX4 nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/**
|
|
* @file hx_stream.h
|
|
*
|
|
* A simple serial line framing protocol based on HDLC
|
|
* with 32-bit CRC protection.
|
|
*/
|
|
|
|
#ifndef _SYSTEMLIB_HX_STREAM_H
|
|
#define _SYSTEMLIB_HX_STREAM_H
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include "perf_counter.h"
|
|
|
|
struct hx_stream;
|
|
typedef struct hx_stream *hx_stream_t;
|
|
|
|
#define HX_STREAM_MAX_FRAME 64
|
|
|
|
typedef void (* hx_stream_rx_callback)(void *arg, const void *data, size_t length);
|
|
|
|
__BEGIN_DECLS
|
|
|
|
/**
|
|
* Allocate a new hx_stream object.
|
|
*
|
|
* @param fd The file handle over which the protocol will
|
|
* communicate.
|
|
* @param callback Called when a frame is received.
|
|
* @param callback_arg Passed to the callback.
|
|
* @return A handle to the stream, or NULL if memory could
|
|
* not be allocated.
|
|
*/
|
|
__EXPORT extern hx_stream_t hx_stream_init(int fd,
|
|
hx_stream_rx_callback callback,
|
|
void *arg);
|
|
|
|
/**
|
|
* Free a hx_stream object.
|
|
*
|
|
* @param stream A handle returned from hx_stream_init.
|
|
*/
|
|
__EXPORT extern void hx_stream_free(hx_stream_t stream);
|
|
|
|
/**
|
|
* Set performance counters for the stream.
|
|
*
|
|
* Any counter may be set to NULL to disable counting that datum.
|
|
*
|
|
* @param tx_frames Counter for transmitted frames.
|
|
* @param rx_frames Counter for received frames.
|
|
* @param rx_errors Counter for short and corrupt received frames.
|
|
*/
|
|
__EXPORT extern void hx_stream_set_counters(hx_stream_t stream,
|
|
perf_counter_t tx_frames,
|
|
perf_counter_t rx_frames,
|
|
perf_counter_t rx_errors);
|
|
|
|
/**
|
|
* Send a frame.
|
|
*
|
|
* This function will block until all frame bytes are sent if
|
|
* the descriptor passed to hx_stream_init is marked blocking,
|
|
* otherwise it will return -1 (but may transmit a
|
|
* runt frame at the same time).
|
|
*
|
|
* @todo Handling of non-blocking streams needs to be better.
|
|
*
|
|
* @param stream A handle returned from hx_stream_init.
|
|
* @param data Pointer to the data to send.
|
|
* @param count The number of bytes to send.
|
|
* @return Zero on success, nonzero with errno
|
|
* set on error.
|
|
*/
|
|
__EXPORT extern int hx_stream_send(hx_stream_t stream,
|
|
const void *data,
|
|
size_t count);
|
|
|
|
/**
|
|
* Handle a byte from the stream.
|
|
*
|
|
* @param stream A handle returned from hx_stream_init.
|
|
* @param c The character to process.
|
|
*/
|
|
__EXPORT extern void hx_stream_rx(hx_stream_t stream,
|
|
uint8_t c);
|
|
|
|
__END_DECLS
|
|
|
|
#endif
|