contiki/platform/esb/dev/ctsrts-sensor.c

146 lines
4.7 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.
*
*/
/**
* 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 "dev/ctsrts-sensor.h"
#include "dev/irq.h"
#include "dev/hwconf.h"
const struct sensors_sensor ctsrts_sensor;
HWCONF_PIN(RS232RTS, 1, 7);
#define RS232CTS_IRQ() 6
HWCONF_PIN(RS232CTS, 1, RS232CTS_IRQ());
HWCONF_IRQ(RS232CTS, 1, RS232CTS_IRQ());
/*---------------------------------------------------------------------------*/
static int
irq(void)
{
/* 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;
}
/*---------------------------------------------------------------------------*/
static 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, int value)
{
switch(type) {
case SENSORS_HW_INIT:
RS232RTS_SELECT();
RS232RTS_MAKE_OUTPUT();
RS232RTS_CLEAR();
RS232CTS_SELECT();
RS232CTS_MAKE_INPUT();
return 1;
case SENSORS_ACTIVE:
if(value) {
if(!RS232CTS_IRQ_ENABLED()) {
/*
* 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();
}
irq_port1_activate(RS232CTS_IRQ(), irq);
RS232CTS_ENABLE_IRQ();
}
} else {
RS232CTS_DISABLE_IRQ();
irq_port1_deactivate(RS232CTS_IRQ());
}
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static int
status(int type)
{
switch(type) {
case SENSORS_ACTIVE:
case SENSORS_READY:
return RS232CTS_IRQ_ENABLED();
}
return 0;
}
/*---------------------------------------------------------------------------*/
/**
* 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();
}
/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(ctsrts_sensor, CTSRTS_SENSOR,
value, configure, status);