nes-proj/cpu/msp430/f2xxx/msp430.c
2015-10-31 11:45:13 +05:30

298 lines
7.9 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.
*/
#include "contiki.h"
#include "dev/watchdog.h"
/* dco_required set to 1 will cause the CPU not to go into
* sleep modes where the DCO clock stopped */
int msp430_dco_required;
#if defined(__MSP430__) && defined(__GNUC__)
#define asmv(arg) __asm__ __volatile__ (arg)
#endif
/*---------------------------------------------------------------------------*/
#if defined(__MSP430__) && defined(__GNUC__) && MSP430_MEMCPY_WORKAROUND
void *
w_memcpy(void *out, const void *in, size_t n)
{
uint8_t *src, *dest;
src = (uint8_t *)in;
dest = (uint8_t *)out;
while(n-- > 0) {
*dest++ = *src++;
}
return out;
}
#endif /* __GNUC__ && __MSP430__ && MSP430_MEMCPY_WORKAROUND */
/*---------------------------------------------------------------------------*/
#if defined(__MSP430__) && defined(__GNUC__) && MSP430_MEMCPY_WORKAROUND
void *
w_memset(void *out, int value, size_t n)
{
uint8_t *dest;
dest = (uint8_t *)out;
while(n-- > 0) {
*dest++ = value & 0xff;
}
return out;
}
#endif /* __GNUC__ && __MSP430__ && MSP430_MEMCPY_WORKAROUND */
/*---------------------------------------------------------------------------*/
void
msp430_init_dco(void)
{
if(CALBC1_8MHZ != 0xFF) {
DCOCTL = 0x00;
BCSCTL1 = CALBC1_8MHZ; /*Set DCO to 8MHz */
DCOCTL = CALDCO_8MHZ;
} else { /*start using reasonable values at 8 Mhz */
DCOCTL = 0x00;
BCSCTL1 = 0x8D;
DCOCTL = 0x88;
}
/*BCSCTL1 |= XT2OFF; // Make sure XT2 is off */
/* BCSCTL2 = 0x00; // MCLK = DCOCLK/1 */
/* SMCLK = DCOCLK/1 */
/* DCO Internal Resistor */
}
/*---------------------------------------------------------------------------*/
static void
init_ports(void)
{
/* Turn everything off, device drivers enable what is needed. */
/* All configured for digital I/O */
#ifdef P1SEL
P1SEL = 0;
#endif
#ifdef P2SEL
P2SEL = 0;
#endif
#ifdef P3SEL
P3SEL = 0;
#endif
#ifdef P4SEL
P4SEL = 0;
#endif
#ifdef P5SEL
P5SEL = 0;
#endif
#ifdef P6SEL
P6SEL = 0;
#endif
/* All available inputs */
#ifdef P1DIR
P1DIR = 0;
P1OUT = 0;
#endif
#ifdef P2DIR
P2DIR = 0;
P2OUT = 0;
#endif
#ifdef P3DIR
P3DIR = 0;
P3OUT = 0;
#endif
#ifdef P4DIR
P4DIR = 0;
P4OUT = 0;
#endif
#ifdef P5DIR
P5DIR = 0;
P5OUT = 0;
#endif
#ifdef P6DIR
P6DIR = 0;
P6OUT = 0;
#endif
#ifdef P7DIR
P7DIR = 0;
P7OUT = 0;
#endif
#ifdef P8DIR
P8DIR = 0;
P8OUT = 0;
#endif
P1IE = 0;
P2IE = 0;
}
/*---------------------------------------------------------------------------*/
/* msp430-ld may align _end incorrectly. Workaround in cpu_init. */
#if defined(__MSP430__) && defined(__GNUC__)
extern int _end; /* Not in sys/unistd.h */
static char *cur_break = (char *)&_end;
#endif
/*---------------------------------------------------------------------------*/
/* add/remove_lpm_req - for requiring a specific LPM mode. currently Contiki */
/* jumps to LPM3 to save power, but DMA will not work if DCO is not clocked */
/* so some modules might need to enter their LPM requirements */
/* NOTE: currently only works with LPM1 (e.g. DCO) requirements. */
/*---------------------------------------------------------------------------*/
void
msp430_add_lpm_req(int req)
{
if(req <= MSP430_REQUIRE_LPM1) {
msp430_dco_required++;
}
}
void
msp430_remove_lpm_req(int req)
{
if(req <= MSP430_REQUIRE_LPM1) {
msp430_dco_required--;
}
}
void
msp430_cpu_init(void)
{
dint();
watchdog_init();
init_ports();
/* set DCO to a reasonable default value (8MHz) */
msp430_init_dco();
/* calibrate the DCO step-by-step */
msp430_sync_dco();
eint();
#if defined(__MSP430__) && defined(__GNUC__)
if((uintptr_t)cur_break & 1) { /* Workaround for msp430-ld bug! */
cur_break++;
}
#endif
msp430_dco_required = 0;
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/*
* Mask all interrupts that can be masked.
*/
int
splhigh_(void)
{
/* Clear the GIE (General Interrupt Enable) flag. */
int sr;
#ifdef __IAR_SYSTEMS_ICC__
sr = __get_SR_register();
__bic_SR_register(GIE);
#else
asmv("mov r2, %0" : "=r" (sr));
asmv("bic %0, r2" : : "i" (GIE));
#endif
return sr & GIE; /* Ignore other sr bits. */
}
/*---------------------------------------------------------------------------*/
/*
* Restore previous interrupt mask.
*/
/* void */
/* splx_(int sr) */
/* { */
/* #ifdef __IAR_SYSTEMS_ICC__ */
/* __bis_SR_register(sr); */
/* #else */
/* /\* If GIE was set, restore it. *\/ */
/* asmv("bis %0, r2" : : "r" (sr)); */
/* #endif */
/* } */
/*---------------------------------------------------------------------------*/
#ifdef __IAR_SYSTEMS_ICC__
int
__low_level_init(void)
{
/* turn off watchdog so that C-init will run */
WDTCTL = WDTPW + WDTHOLD;
/*
* Return value:
*
* 1 - Perform data segment initialization.
* 0 - Skip data segment initialization.
*/
return 1;
}
#endif
/*---------------------------------------------------------------------------*/
void
msp430_sync_dco(void)
{
uint16_t oldcapture;
int16_t diff;
/* DELTA_2 assumes an ACLK of 32768 Hz */
#define DELTA_2 ((MSP430_CPU_SPEED) / 32768)
/* Select SMCLK clock, and capture on ACLK for TBCCR6 */
TBCTL = TBSSEL1 | TBCLR;
TBCCTL6 = CCIS0 + CM0 + CAP;
/* start the timer */
TBCTL |= MC1;
while(1) {
/* wait for the next capture */
TBCCTL6 &= ~CCIFG;
while(!(TBCCTL6 & CCIFG));
oldcapture = TBCCR6;
/* wait for the next capture - and calculate difference */
TBCCTL6 &= ~CCIFG;
while(!(TBCCTL6 & CCIFG));
diff = TBCCR6 - oldcapture;
/* resynchronize the DCO speed if not at target */
if(DELTA_2 == diff) {
break; /* if equal, leave "while(1)" */
} else if(DELTA_2 < diff) { /* DCO is too fast, slow it down */
DCOCTL--;
if(DCOCTL == 0xFF) { /* Did DCO roll under? */
BCSCTL1--;
}
} else { /* -> Select next lower RSEL */
DCOCTL++;
if(DCOCTL == 0x00) { /* Did DCO roll over? */
BCSCTL1++;
}
/* -> Select next higher RSEL */
}
}
/* Stop the timer - conserves energy according to user guide */
TBCTL = 0;
}
/*---------------------------------------------------------------------------*/