avr/trutprofile.c

   1 /*
   2  * Copyright (C) 2007 Anton Blad
   3  * Copyright (C) 2007 Fredrik Kuivinen
   4  * Copyright (C) 2007 Jakob Rosén
   5  *
   6  * This file is licensed under GPL v2.
   7  */
   8
   9 #ifdef TRUT_PROFILE
  10
  11 #include "trutprofile.h"
  12
  13 #include <avr/io.h>
  14 #include <avr/interrupt.h>
  15
  16 static uint16_t profile_stamps[NPROFILE];
  17 static uint16_t profile_mwc[NPROFILE];
  18
  19 volatile static uint8_t timer0_high;
  20
  21 // Allocated measurements:
  22 // 0 - TIMER1_COMPA interrupt
  23 // 1 - TIMER1_OVF interrupt
  24 // 2 - TIMER1_CAPT interrupt
  25
  26 // Atomic read of timer stamp.
  27 static inline uint16_t profile_stamp()
  28 {
  29         // Save interrupt enable flag.
  30         uint8_t sreg = SREG;
  31         uint8_t low;
  32         uint8_t high;
  33
  34         cli();
  35
  36         low = TCNT0;
  37         if(low < 0xf0 && (TIFR0 & _BV(TOV0)))
  38                 high = timer0_high + 1;
  39         else
  40                 high = timer0_high;
  41
  42         // Reenable interrupts.
  43         SREG = sreg;
  44
  45         return (high << 8) | low;
  46 }
  47
  48 void profile_init()
  49 {
  50         uint8_t i;
  51
  52         for(i = 0; i < NPROFILE; i++)
  53         {
  54                 profile_stamps[i] = profile_mwc[i] = 0;
  55         }
  56
  57         timer0_high = 0;
  58
  59         TCCR0A = 0;
  60 #if PROFILE_PRESCALE == 1
  61         TCCR0B = _BV(CS00);
  62 #elif PROFILE_PRESCALE == 8
  63         TCCR0B = _BV(CS01);
  64 #elif PROFILE_PRESCALE == 64
  65         TCCR0B = _BV(CS00) | _BV(CS01);
  66 #elif PROFILE_PRESCALE == 256
  67         TCCR0B = _BV(CS02);
  68 #else
  69 #error Invalid PROFILE_PRESCALE value
  70 #endif
  71         TIMSK0 |= _BV(TOIE0);
  72 }
  73
  74 void profile_start(uint8_t m)
  75 {
  76         profile_stamps[m] = profile_stamp();
  77 }
  78
  79 void profile_stop(uint8_t m)
  80 {
  81         uint16_t len = profile_stamp() - profile_stamps[m];
  82
  83         if(len > profile_mwc[m])
  84                 profile_mwc[m] = len;
  85 }
  86
  87 uint16_t profile_wc(uint8_t m)
  88 {
  89         return profile_mwc[m];
  90 }
  91
  92 ISR(TIMER0_OVF_vect)
  93 {
  94         timer0_high++;
  95 }
  96
  97 #endif // TRUT_PROFILE