update1

git-svn-id: http://svn.openzap.org/svn/openzap/trunk@216 a93c3328-9c30-0410-af19-c9cd2b2d52af

libs/freetdm/src/uart.c

@@ -0,0 +1,124 @@
+
+/*
+ *	uart.c
+ *
+ *	Copyright (c) 2005 Robert Krten.  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.
+ *
+ *	THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ *	This module contains a simple 8-bit UART, which performs a callback
+ *	with the decoded byte value.
+ *
+ *	2005 06 11	R. Krten		created
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "uart.h"
+
+/*
+ *	dsp_uart_attr_init
+ *
+ *	Initializes the attributes structure; this must be done before the
+ *	attributes structure is used.
+*/
+
+void dsp_uart_attr_init (dsp_uart_attr_t *attr)
+{
+	memset (attr, 0, sizeof (*attr));
+}
+
+/*
+ *	dsp_uart_attr_get_bytehandler
+ *	dsp_uart_attr_set_bytehandler
+ *
+ *	These functions get and set their respective elements from the
+ *	attributes structure.  If an error code is returned, it is just
+ *	zero == ok, -1 == fail.
+*/
+
+bytehandler_func_t dsp_uart_attr_get_bytehandler(dsp_uart_attr_t *attr, void **bytehandler_arg)
+{
+	*bytehandler_arg = attr->bytehandler_arg;
+	return attr->bytehandler;
+}
+
+void dsp_uart_attr_set_bytehandler(dsp_uart_attr_t *attr, bytehandler_func_t bytehandler, void *bytehandler_arg)
+{
+	attr->bytehandler = bytehandler;
+	attr->bytehandler_arg = bytehandler_arg;
+}
+
+dsp_uart_handle_t *dsp_uart_create(dsp_uart_attr_t *attr)
+{
+	dsp_uart_handle_t *handle;
+
+	handle = malloc(sizeof (*handle));
+	if (handle) {
+		memset(handle, 0, sizeof (handle));
+
+		/* fill the attributes member */
+		memcpy(&handle->attr, attr, sizeof (*attr));
+	}
+	return handle;
+}
+
+void dsp_uart_destroy(dsp_uart_handle_t **handle)
+{
+	if (*handle) {
+		free(*handle);
+		*handle = NULL;
+	}
+}
+
+
+void dsp_uart_bit_handler(void *x, int bit)
+{
+	dsp_uart_handle_t *handle = (dsp_uart_handle_t *) x;
+
+	if (!handle->have_start) {
+		if (bit) {
+			return;		/* waiting for start bit (0) */
+		}
+		handle->have_start = 1;
+		handle->data = 0;
+		handle->nbits = 0;
+		return;
+	}
+
+	handle->data >>= 1;
+	handle->data |= 0x80 * !!bit;
+	
+	handle->nbits++;
+	if (handle->nbits == 8) {
+		handle->attr.bytehandler(handle->attr.bytehandler_arg, handle->data);
+		handle->nbits = 0;
+		handle->data = 0;
+		handle->have_start = 0;
+	}
+/* might consider handling errors in the future... */
+}
+