contiki/platform/esb/dev/ctsrts-sensor.c
2006-06-18 07:49:33 +00:00

156 lines
4.8 KiB
C

/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* 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 of the Institute 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 INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: ctsrts-sensor.c,v 1.1 2006/06/18 07:49:33 adamdunkels Exp $
*/
/**
* RTS/CTS (Request to Send/Clear to Send) are the signals used for hardware
* flow control. By setting the RTS line to "ON" the host tells the connected
* device that it is ready to receive data. Hardware flow control is not
* implemented yet. This implementation is just so some application can use
* the pins, it would also be possible for rs232.c to use it for hardware
* handshake but as said, that is not implemented yet.
*/
#include "contiki-esb.h"
const struct sensors_sensor ctsrts_sensor;
HWCONF_PIN(RS232RTS, 1, 7);
HWCONF_PIN(RS232CTS, 1, 6);
HWCONF_IRQ(RS232CTS, 1, 6);
/*---------------------------------------------------------------------------*/
static void
init(void)
{
RS232RTS_SELECT();
RS232RTS_MAKE_OUTPUT();
RS232RTS_CLEAR();
RS232CTS_SELECT();
RS232CTS_MAKE_INPUT();
}
/**
* Indicate to host/client we are NOT ready to receive data. Sets the RTS pin
* to low.
*/
void ctsrts_rts_clear(void) {
RS232RTS_CLEAR();
}
/**
* Request host/client to send data. Sets the RTS pin to high.
*/
void ctsrts_rts_set(void) {
RS232RTS_SET();
}
/*---------------------------------------------------------------------------*/
static int
irq(void)
{
if(RS232CTS_CHECK_IRQ()) {
/* Change the flank triggering for the irq so we will detect next
shift. */
if(RS232CTS_READ()) {
RS232CTS_IRQ_EDGE_SELECTD();
} else {
RS232CTS_IRQ_EDGE_SELECTU();
}
sensors_changed(&ctsrts_sensor);
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static void
activate(void)
{
/*
* Check current status on the CTS pin and set IRQ flank so we will detect
* a shift.
*/
if(RS232CTS_READ()) {
RS232CTS_IRQ_EDGE_SELECTD();
} else {
RS232CTS_IRQ_EDGE_SELECTU();
}
sensors_add_irq(&ctsrts_sensor, RS232CTS_IRQ_PORT());
RS232CTS_ENABLE_IRQ();
}
/*---------------------------------------------------------------------------*/
static void
deactivate(void)
{
RS232CTS_DISABLE_IRQ();
sensors_remove_irq(&ctsrts_sensor, RS232CTS_IRQ_PORT());
}
/*---------------------------------------------------------------------------*/
static int
active(void)
{
return RS232CTS_IRQ_ENABLED();
}
/*---------------------------------------------------------------------------*/
static unsigned int
value(int type)
{
/*
* Invert the bit and return.
* This is strange, accordingly to the MSP430 manual section 9.2.1, Input
* Register PxIN the bit should be low when input is low. In RealTerm on
* the PC I set RTS which is coupled to the CTS on the esb and I read a 0.
* Maybe RTS is defined active LOW on the PC? //Kalle
*/
return RS232CTS_READ()?0:1;
}
/*---------------------------------------------------------------------------*/
static int
configure(int type, void *c)
{
return 0;
}
/*---------------------------------------------------------------------------*/
static void *
status(int type)
{
return NULL;
}
/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(ctsrts_sensor, CTSRTS_SENSOR,
init, irq, activate, deactivate, active,
value, configure, status);