Files
bacnet_stack/bacnet-stack/ports/rtos32/rs485.c
T
2005-05-06 21:11:36 +00:00

162 lines
4.5 KiB
C

/**************************************************************************
*
* Copyright (C) 2005 Steve Karg <skarg@users.sourceforge.net>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*********************************************************************/
#include <stdint.h>
#include <rtkernel.h>
#include <rtcom.h>
#include <itimer.h>
#include "mstp.h"
// note: use the RTKernel-C API so that it can use this library
#define RS485_IO_ENABLE(p) ModemControl(p,0,DTR);
#define RS485_TRANSMIT_ENABLE(p) ModemControl(p,1,RTS);
#define RS485_RECEIVE_ENABLE(p) ModemControl(p,0,RTS);
/* COM port number - COM1 = 0 */
static int RS485_Port = COM2;
/* baud rate */
static long RS485_Baud = 38400;
/* io base address */
static long RS485_Base = 0;
/* hardware IRQ number */
static long RS485_IRQ_Number = 0;
static void RS485_Standard_Port_Settings(long port, long *pIRQ, long *pBase)
{
switch (port)
{
case COM1:
*pBase = (long)0x3F8;
*pIRQ = 4L;
break;
case COM2:
*pBase = (long)0x2F8;
*pIRQ = 3L;
break;
case COM3:
*pBase = (long)0x3E8;
*pIRQ = 4L;
break;
case COM4:
*pBase = (long)0x2E8;
*pIRQ = 3L;
break;
default:
break;
}
}
static RS485_Open_Port(
int port, /* COM port number - COM1 = 0 */
long baud, /* baud rate */
unsigned base, /* io base address */
int irq) /* hardware IRQ number */
{
/* setup the COM IO */
SetIOBase(port, base);
SetIRQ(port, irq);
if (irq < 8)
RTKIRQTopPriority(irq,9);
InitPort(port, baud, PARITY_NONE, 1, 8);
if (HasFIFO(port))
EnableFIFO(port,8);
EnableCOMInterrupt(port, 1024*4);
/* enable the 485 via the DTR pin */
RS485_IO_ENABLE(port);
RS485_RECEIVE_ENABLE(port);
return;
}
void RS485_Initialize(void)
{
RS485_Standard_Port_Settings(RS485_Port, &RS485_IRQ_Number, &RS485_Base);
RS485_Open_Port(RS485_Port, RS485_Baud, RS485_Base, RS485_IRQ_Number);
}
void RS485_Send_Frame(
volatile struct mstp_port_struct_t *mstp_port, // port specific data
uint8_t *buffer, // frame to send (up to 501 bytes of data)
uint16_t nbytes) // number of bytes of data (up to 501)
{
bool status = true; // return value
(void)mstp_port;
RS485_TRANSMIT_ENABLE(RS485_Port);
SendBlock(RS485_Port, (char *)buffer, nbytes);
/* need to wait at least 9600 baud * 512 bytes = 54mS */
(void)WaitSendBufferEmpty(RS485_Port,MilliSecsToTicks(200));
while (!(LineStatus(RS485_Port) & TX_SHIFT_EMPTY))
RTKScheduler();
RS485_RECEIVE_ENABLE(RS485_Port);
return;
}
void RS485_Check_UART_Data(
volatile struct mstp_port_struct_t *mstp_port) // port specific data
{
COMData com_data = 0; /* byte from COM driver */
unsigned timeout = 10; // milliseconds to wait for a character
Duration ticks; /* duration to wait for data */
if (mstp_port->ReceiveError)
{
// wait for state machine to clear this
}
// wait for state machine to read from the DataRegister
else if (!mstp_port->DataAvailable)
{
// check for data
ticks = MilliSecsToTicks(timeout);
if (!ticks)
ticks = 1;
if (RTKGetTimed(ReceiveBuffer[RS485_Port],&com_data,ticks))
{
// if error,
if (com_data & (COM_OVERRUN << 8))
mstp_port->ReceiveError = true;
else if (com_data & (COM_FRAME << 8))
mstp_port->ReceiveError = true;
else
{
mstp_port->DataRegister = com_data & 0x00FF;
mstp_port->DataAvailable = true;
}
}
}
}
void RS485_Process_Tx_Message(void)
{
// nothing to do
}