nes-proj/cpu/mc1322x/clock.c

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/*
* Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
* to the MC1322x project (http://mc1322x.devl.org) and Contiki.
*
* 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 OS.
*
2011-02-13 22:12:33 +00:00
*
*/
#include <sys/clock.h>
#include <sys/cc.h>
#include <sys/etimer.h>
#include <sys/rtimer.h>
#include "contiki-conf.h"
#include "mc1322x.h"
#define MAX_TICKS (~((clock_time_t)0) / 2)
static volatile clock_time_t current_clock = 0;
volatile unsigned long seconds = 0;
static struct rtimer rt_clock;
/* the typical clock things like incrementing current_clock and etimer checks */
/* are performed as a periodically scheduled rtimer */
void
rt_do_clock(struct rtimer *t, void *ptr)
{
rtimer_set(t, RTIMER_TIME(t) + (rtc_freq/CLOCK_CONF_SECOND) , 1,
(rtimer_callback_t)rt_do_clock, ptr);
current_clock++;
if((current_clock % CLOCK_CONF_SECOND) == 0) {
seconds++;
}
if(etimer_pending() &&
(etimer_next_expiration_time() - current_clock - 1) > MAX_TICKS) {
etimer_request_poll();
}
}
/* RTC MUST have been already setup by mc1322x init */
void
clock_init(void)
{
rtimer_set(&rt_clock, RTIMER_NOW() + rtc_freq/CLOCK_CONF_SECOND, 1, (rtimer_callback_t)rt_do_clock, NULL);
}
clock_time_t
clock_time(void)
{
return current_clock;
}
unsigned long
clock_seconds(void)
{
return seconds;
}
void
clock_wait(clock_time_t t)
{
clock_time_t endticks = current_clock + t;
while ((signed long)(current_clock - endticks) < 0) {;}
}
/*---------------------------------------------------------------------------*/
/**
* Delay the CPU for up to 65535 microseconds.
* Use the 250KHz MACA clock for longer delays to avoid interrupt effects.
* However that can't be used if the radio is being power cycled!
*/
void
clock_delay_usec(uint16_t howlong)
{
if(howlong<2) return;
#if 0
if(howlong>400) {
volatile register uint32_t i=*MACA_CLK+howlong/4;
while (i > *MACA_CLK) ;
return;
}
#endif
/* These numbers at 25MHz, gcc -Os */
volatile register uint32_t i=4000*howlong/2301;
while(--i);
}
/*---------------------------------------------------------------------------*/
/**
* Delay the CPU for up to 65535 milliseconds. The watchdog is NOT disabled.
*/
void
clock_delay_msec(uint16_t howlong)
{
while(howlong--) clock_delay_usec(1000);
}
/*---------------------------------------------------------------------------*/
/**
* Legacy delay. The original clock_delay for the msp430 used a granularity
* of 2.83 usec. This approximates that delay for values up to 1456 usec.
* (The largest core call in leds.c uses 400).
*/
void
clock_delay(unsigned int howlong)
{
if(howlong--) return;
clock_delay_usec((283*howlong)/100);
}
/*---------------------------------------------------------------------------*/
/**
* Adjust clock ticks after a cpu sleep.
*/
void clock_adjust_ticks(clock_time_t howmany) {
/* Add seconds */
seconds+=howmany/CLOCK_CONF_SECOND;
/* Handle tick overflow */
if(((current_clock % CLOCK_CONF_SECOND) + (howmany % CLOCK_CONF_SECOND)) >= CLOCK_CONF_SECOND) seconds++;
/* Add ticks */
current_clock+=howmany;
}