clock.c

/*
 * 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.
 *
 *
 */

#include <sys/clock.h>
#include <sys/cc.h>
#include <sys/etimer.h>
#include "dev/leds.h"

#include "contiki-conf.h"
#include "mc1322x.h"

#include "contiki-conf.h"

#define MAX_TICKS (~((clock_time_t)0) / 2)

static volatile clock_time_t current_clock = 0;

volatile unsigned long seconds = 0;

#define TCF  15
#define TCF1 4
#define TCF2 5

void
clock_init()
{
        /* timer setup */
        /* CTRL */
#define COUNT_MODE 1      /* use rising edge of primary source */
#define PRIME_SRC  0xf    /* Perip. clock with 128 prescale (for 24Mhz = 187500Hz)*/
#define SEC_SRC    0      /* don't need this */
#define ONCE       0      /* keep counting */
#define LEN        1      /* count until compare then reload with value in LOAD */
#define DIR        0      /* count up */
#define CO_INIT    0      /* other counters cannot force a re-initialization of this counter */
#define OUT_MODE   0      /* OFLAG is asserted while counter is active */

        *TMR_ENBL = 0;                     /* tmrs reset to enabled */
        *TMR0_SCTRL = 0;
        *TMR0_CSCTRL =0x0040;
        *TMR0_LOAD = 0;                    /* reload to zero */
        *TMR0_COMP_UP = 1875;             /* trigger a reload at the end */
        *TMR0_CMPLD1 = 1875;              /* compare 1 triggered reload level, 10HZ maybe? */
        *TMR0_CNTR = 0;                    /* reset count register */
        *TMR0_CTRL = (COUNT_MODE<<13) | (PRIME_SRC<<9) | (SEC_SRC<<7) | (ONCE<<6) | (LEN<<5) | (DIR<<4) | (CO_INIT<<3) | (OUT_MODE);
        *TMR_ENBL = 0xf;                   /* enable all the timers --- why not? */

        enable_irq(TMR);
/* Do startup scan of the ADC */
#if CLOCK_CONF_SAMPLEADC
        adc_reading[8]=0;
        adc_init();
        while (adc_reading[8]==0) adc_service();
#endif
}

void tmr0_isr(void) {
        if(bit_is_set(*TMR(0,CSCTRL),TCF1)) {
                current_clock++;
                if((current_clock % CLOCK_CONF_SECOND) == 0) {
                        seconds++;
#if BLINK_SECONDS
                        leds_toggle(LEDS_GREEN);
#endif
/* ADC can be serviced every tick or every second */
#if CLOCK_CONF_SAMPLEADC > 1
                        adc_service();
#endif
                }
#if CLOCK_CONF_SAMPLEADC == 1
                adc_service();
#endif
                if(etimer_pending() &&
                   (etimer_next_expiration_time() - current_clock - 1) > MAX_TICKS) {
                        etimer_request_poll();
                }


                /* clear the compare flags */
                clear_bit(*TMR(0,SCTRL),TCF);
                clear_bit(*TMR(0,CSCTRL),TCF1);
                clear_bit(*TMR(0,CSCTRL),TCF2);
                return;
        } else {
                /* this timer didn't create an interrupt condition */
                return;
        }
}

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;
}