cpu/avr/rtimer-arch.c

   1 /*
   2  * Copyright (c) 2007, Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is part of the Contiki operating system.
  30  *
  31  * $Id: rtimer-arch.c,v 1.7 2010/02/18 17:21:44 dak664 Exp $
  32  */
  33
  34 /**
  35  * \file
  36  *         AVR-specific rtimer code
  37  *         Currently only works on ATMEGAs that have Timer 3.
  38  * \author
  39  *         Fredrik Osterlind <fros@sics.se>
  40  *         Joakim Eriksson <joakime@sics.se>
  41  */
  42
  43 /* OBS: 8 seconds maximum time! */
  44
  45 #include <avr/io.h>
  46 #include <avr/interrupt.h>
  47 #include <stdio.h>
  48
  49 #include "sys/energest.h"
  50 #include "sys/rtimer.h"
  51 #include "rtimer-arch.h"
  52
  53 #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega1284P__)
  54 //#error FTH081029 test timer 3
  55 #define ETIMSK TIMSK3
  56 #define ETIFR TIFR3
  57 #define TICIE3 ICIE3
  58
  59 //Has no 'C', so we just set it to B. The code doesn't really use C so this
  60 //is safe to do but lets it compile
  61 #warning No OCIE3C in architecture, hopefully it will not be needed
  62 #define OCIE3C  OCIE3B
  63 #define OCF3C   OCF3B
  64 #endif
  65
  66 #if defined(__AVR_AT90USB1287__)
  67 #warning AT90USB1287 rtimers not tested
  68 #define ETIMSK TIMSK3
  69 #define ETIFR TIFR3
  70 #define TICIE3 ICIE3
  71 #endif
  72 uint8_t rtimerworks;
  73 /*---------------------------------------------------------------------------*/
  74 #ifdef TCNT3
  75 ISR (TIMER3_COMPA_vect) {
  76   ENERGEST_ON(ENERGEST_TYPE_IRQ);
  77
  78   ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
  79       (1 << TICIE3) | (1 << OCIE3C));
  80 rtimerworks++;
  81   /* Call rtimer callback */
  82   rtimer_run_next();
  83
  84   ENERGEST_OFF(ENERGEST_TYPE_IRQ);
  85 }
  86
  87 #else
  88 #error "No Timer3 in rtimer-arch.c"
  89
  90 #endif
  91 /*---------------------------------------------------------------------------*/
  92 void
  93 rtimer_arch_init(void)
  94 {
  95   /* Disable interrupts (store old state) */
  96   uint8_t sreg;
  97   sreg = SREG;
  98   cli ();
  99
 100 #ifdef TCNT3
 101 rtimerworks=240;
 102
 103   ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
 104       (1 << TICIE3) | (1 << OCIE3C));
 105   ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
 106   (1 << OCF3C);
 107
 108   /* Default timer behaviour */
 109   TCCR3A = 0;
 110   TCCR3B = 0;
 111   TCCR3C = 0;
 112
 113   /* Reset counter */
 114   TCNT3 = 0;
 115
 116   /* Maximum prescaler */
 117   TCCR3B |= 5;
 118
 119 #else
 120 #error "No Timer3 in rtimer-arch.c"
 121
 122 #endif
 123
 124   /* Restore interrupt state */
 125   SREG = sreg;
 126 }
 127 /*---------------------------------------------------------------------------*/
 128 void
 129 rtimer_arch_schedule(rtimer_clock_t t)
 130 {
 131   /* Disable interrupts (store old state) */
 132   uint8_t sreg;
 133   sreg = SREG;
 134   cli ();
 135
 136 #ifdef TCNT3
 137 rtimerworks=250;
 138   /* Set compare register */
 139   OCR3A = t;
 140   ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
 141   (1 << OCF3C);
 142   ETIMSK |= (1 << OCIE3A);
 143
 144 #else
 145 #error "No Timer3 in rtimer-arch.c"
 146
 147 #endif
 148
 149   /* Restore interrupt state */
 150   SREG = sreg;
 151   printf("rs%d",t);
 152 }