nes-proj/drivers/cpu/msp430/f5xxx/uart0.c

122 lines
4.0 KiB
C

/*
* Copyright (c) 2011, 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.
*/
/*
* Yet another machine dependent MSP430X UART0 code.
* IF2, etc. can not be used here... need to abstract to some macros
* later.
*/
#include "contiki.h"
#include <stdlib.h>
#include "sys/energest.h"
#include "dev/uart0.h"
#include "dev/watchdog.h"
#include "isr_compat.h"
static int (*uart0_input_handler)(unsigned char c);
static volatile uint8_t transmitting;
/*---------------------------------------------------------------------------*/
uint8_t
uart0_active(void)
{
return (UCA0STAT & UCBUSY) | transmitting;
}
/*---------------------------------------------------------------------------*/
void
uart0_set_input(int (*input)(unsigned char c))
{
uart0_input_handler = input;
}
/*---------------------------------------------------------------------------*/
void
uart0_writeb(unsigned char c)
{
watchdog_periodic();
/* Loop until the transmission buffer is available. */
while((UCA0STAT & UCBUSY));
/* Transmit the data. */
UCA0TXBUF = c;
}
/*---------------------------------------------------------------------------*/
/**
* Initalize the RS232 port.
*
*/
void
uart0_init(unsigned long ubr)
{
/* RS232 */
UCA0CTL1 |= UCSWRST; /* Hold peripheral in reset state */
UCA0CTL1 |= UCSSEL_2; /* CLK = SMCLK */
ubr = (MSP430_CPU_SPEED / ubr);
UCA0BR0 = ubr & 0xff;
UCA0BR1 = (ubr >> 8) & 0xff;
UCA0MCTL = UCBRS_3; /* Modulation UCBRSx = 3 */
P3DIR &= ~0x20; /* P3.5 = USCI_A0 RXD as input */
P3DIR |= 0x10; /* P3.4 = USCI_A0 TXD as output */
P3SEL |= 0x30; /* P3.4,5 = USCI_A0 TXD/RXD */
/*UCA0CTL1 &= ~UCSWRST;*/ /* Initialize USCI state machine */
transmitting = 0;
/* XXX Clear pending interrupts before enable */
UCA0IE &= ~UCRXIFG;
UCA0IE &= ~UCTXIFG;
UCA0CTL1 &= ~UCSWRST; /* Initialize USCI state machine **before** enabling interrupts */
UCA0IE |= UCRXIE; /* Enable UCA0 RX interrupt */
}
/*---------------------------------------------------------------------------*/
ISR(USCI_A0, uart0_rx_interrupt)
{
uint8_t c;
ENERGEST_ON(ENERGEST_TYPE_IRQ);
if(UCA0IV == 2) {
if(UCA0STAT & UCRXERR) {
c = UCA0RXBUF; /* Clear error flags by forcing a dummy read. */
} else {
c = UCA0RXBUF;
if(uart0_input_handler != NULL) {
if(uart0_input_handler(c)) {
LPM4_EXIT;
}
}
}
}
ENERGEST_OFF(ENERGEST_TYPE_IRQ);
}
/*---------------------------------------------------------------------------*/