avr/timer.c

   1 /*
   2  */
   3
   4
   5 #include "common.h"
   6
   7 #include <avr/interrupt.h>
   8 #include <util/atomic.h>
   9
  10 //#include <stdio.h>
  11
  12
  13 #include "timer.h"
  14
  15 /* timer interrupt/overflow counter */
  16 volatile uint32_t timestamp;
  17
  18
  19 /*---------------------------------------------------------*/
  20 /* 1000Hz timer interrupt generated by OC3A                */
  21 /*---------------------------------------------------------*/
  22
  23 ISR(TIMER3_COMPA_vect)
  24 {
  25         static int_fast8_t tick_10ms;
  26         int_fast8_t i;
  27
  28         extern void disk_timerproc(void);
  29
  30         timestamp++;
  31
  32         i = tick_10ms + 1;
  33         if (i == 10) {
  34                 i = 0;
  35                 Stat |= S_10MS_TO;
  36
  37                 /* Drive timer procedure of low level disk I/O module */
  38                 disk_timerproc();
  39         }
  40         tick_10ms = i;
  41
  42 }
  43
  44
  45
  46 /*--------------------------------------------------------------------------*/
  47
  48 #if 0
  49
  50 void do_10ms(void)
  51 {
  52                 if (to_counter)
  53                         to_counter--;
  54 }
  55
  56 #endif
  57
  58 /*--------------------------------------------------------------------------*/
  59
  60
  61 #if 0
  62 void timer_setup(void)
  63 {
  64
  65         /* Clock */
  66         CLKPR = _BV(CLKPCE);
  67         CLKPR = 0;
  68
  69         /* Timer */
  70
  71         OCR1A = F_CPU / 1000 - 1; // Timer1: 1000Hz interval (OC1A)
  72         TCCR1B = 0b00001001;
  73         TIMSK1 = _BV(OCIE1A); // Enable TC1.oca interrupt
  74 }
  75 #endif
  76
  77 uint32_t get_timer(uint32_t base)
  78 {
  79         uint32_t ret;
  80
  81         ATOMIC_BLOCK(ATOMIC_FORCEON)
  82         {
  83                 ret = timestamp;
  84         }
  85         return ret - base;
  86 }