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qmk_firmware

custom branch of QMK firmware git clone https://anongit.hacktivis.me/git/qmk_firmware.git

timer.c (2998B)

    

  1. /*
  2. Copyright 2011 Jun Wako <wakojun@gmail.com>
  4. This program is free software: you can redistribute it and/or modify
  5. it under the terms of the GNU General Public License as published by
  6. the Free Software Foundation, either version 2 of the License, or
  7. (at your option) any later version.
  9. This program is distributed in the hope that it will be useful,
  10. but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12. GNU General Public License for more details.
  14. You should have received a copy of the GNU General Public License
  15. along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16. */
  18. #include <avr/io.h>
  19. #include <avr/interrupt.h>
  20. #include <util/atomic.h>
  21. #include <stdint.h>
  22. #include "timer_avr.h"
  23. #include "timer.h"
  25. // counter resolution 1ms
  26. // NOTE: union { uint32_t timer32; struct { uint16_t dummy; uint16_t timer16; }}
  27. volatile uint32_t timer_count;
  28. static uint32_t   saved_ms;
  30. /** \brief timer initialization
  31.  *
  32.  * FIXME: needs doc
  33.  */
  34. void timer_init(void) {
  35. #if TIMER_PRESCALER == 1
  36.     uint8_t prescaler = _BV(CS00);
  37. #elif TIMER_PRESCALER == 8
  38.     uint8_t prescaler = _BV(CS01);
  39. #elif TIMER_PRESCALER == 64
  40.     uint8_t prescaler = _BV(CS00) | _BV(CS01);
  41. #elif TIMER_PRESCALER == 256
  42.     uint8_t prescaler = _BV(CS02);
  43. #elif TIMER_PRESCALER == 1024
  44.     uint8_t prescaler = _BV(CS00) | _BV(CS02);
  45. #else
  46. #    error "Timer prescaler value is not valid"
  47. #endif
  49. #if defined(__AVR_ATmega32A__)
  50.     // Timer0 CTC mode
  51.     TCCR0 = _BV(WGM01) | prescaler;
  53.     OCR0  = TIMER_RAW_TOP;
  54.     TIMSK = _BV(OCIE0);
  55. #elif defined(__AVR_ATtiny85__)
  56.     // Timer0 CTC mode
  57.     TCCR0A = _BV(WGM01);
  58.     TCCR0B = prescaler;
  60.     OCR0A = TIMER_RAW_TOP;
  61.     TIMSK = _BV(OCIE0A);
  62. #else
  63.     // Timer0 CTC mode
  64.     TCCR0A = _BV(WGM01);
  65.     TCCR0B = prescaler;
  67.     OCR0A  = TIMER_RAW_TOP;
  68.     TIMSK0 = _BV(OCIE0A);
  69. #endif
  70. }
  72. /** \brief timer clear
  73.  *
  74.  * FIXME: needs doc
  75.  */
  76. inline void timer_clear(void) {
  77.     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  78.         timer_count = 0;
  79.     }
  80. }
  82. /** \brief timer save
  83.  *
  84.  * Set saved_ms to current time.
  85.  */
  86. void timer_save(void) {
  87.     saved_ms = timer_read32();
  88. }
  90. /** \brief timer restore
  91.  *
  92.  * Set timer_count to saved_ms
  93.  */
  94. void timer_restore(void) {
  95.     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  96.         timer_count = saved_ms;
  97.     }
  98. }
  100. /** \brief timer read
  101.  *
  102.  * FIXME: needs doc
  103.  */
  104. inline uint16_t timer_read(void) {
  105.     uint32_t t;
  107.     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  108.         t = timer_count;
  109.     }
  111.     return (t & 0xFFFF);
  112. }
  114. /** \brief timer read32
  115.  *
  116.  * FIXME: needs doc
  117.  */
  118. inline uint32_t timer_read32(void) {
  119.     uint32_t t;
  121.     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  122.         t = timer_count;
  123.     }
  125.     return t;
  126. }
  128. // excecuted once per 1ms.(excess for just timer count?)
  129. #ifndef __AVR_ATmega32A__
  130. #    define TIMER_INTERRUPT_VECTOR TIMER0_COMPA_vect
  131. #else
  132. #    define TIMER_INTERRUPT_VECTOR TIMER0_COMP_vect
  133. #endif
  134. ISR(TIMER_INTERRUPT_VECTOR, ISR_NOBLOCK) {
  135.     timer_count++;
  136. }