Fresh import of the PX4 firmware sources.

1 files changed, 121 insertions, 0 deletions

diff --git a/apps/systemlib/hx_stream.h b/apps/systemlib/hx_stream.h
new file mode 100644
index 000000000..591bb1291
--- /dev/null
+++ b/apps/systemlib/hx_stream.h
@@ -0,0 +1,121 @@
+/****************************************************************************
+ *
+ *   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	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