1 files changed, 128 insertions, 0 deletions
diff --git a/tmk_core/common/avr/timer.c b/tmk_core/common/avr/timer.c
new file mode 100644
index 0000000000..369015200d
--- /dev/null
+++ b/tmk_core/common/avr/timer.c
@@ -0,0 +1,128 @@
+/*
+Copyright 2011 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/atomic.h>
+#include <stdint.h>
+#include "timer_avr.h"
+#include "timer.h"
+
+
+// counter resolution 1ms
+// NOTE: union { uint32_t timer32; struct { uint16_t dummy; uint16_t timer16; }}
+volatile uint32_t timer_count;
+
+void timer_init(void)
+{
+#if TIMER_PRESCALER == 1
+    uint8_t prescaler = 0x01;
+#elif TIMER_PRESCALER == 8
+    uint8_t prescaler = 0x02;
+#elif TIMER_PRESCALER == 64
+    uint8_t prescaler = 0x03;
+#elif TIMER_PRESCALER == 256
+    uint8_t prescaler = 0x04;
+#elif TIMER_PRESCALER == 1024
+    uint8_t prescaler = 0x05;
+#else
+#   error "Timer prescaler value is NOT vaild."
+#endif
+
+#ifndef __AVR_ATmega32A__
+    // Timer0 CTC mode
+    TCCR0A = 0x02;
+
+    TCCR0B = prescaler;
+
+    OCR0A = TIMER_RAW_TOP;
+    TIMSK0 = (1<<OCIE0A);
+#else
+    // Timer0 CTC mode
+    TCCR0 = (1 << WGM01) | prescaler;
+
+    OCR0 = TIMER_RAW_TOP;
+    TIMSK = (1 << OCIE0);
+#endif
+}
+
+inline
+void timer_clear(void)
+{
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    timer_count = 0;
+  }
+}
+
+inline
+uint16_t timer_read(void)
+{
+    uint32_t t;
+
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+      t = timer_count;
+    }
+
+    return (t & 0xFFFF);
+}
+
+inline
+uint32_t timer_read32(void)
+{
+    uint32_t t;
+
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+      t = timer_count;
+    }
+
+    return t;
+}
+
+inline
+uint16_t timer_elapsed(uint16_t last)
+{
+    uint32_t t;
+
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+      t = timer_count;
+    }
+
+    return TIMER_DIFF_16((t & 0xFFFF), last);
+}
+
+inline
+uint32_t timer_elapsed32(uint32_t last)
+{
+    uint32_t t;
+
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+      t = timer_count;
+    }
+
+    return TIMER_DIFF_32(t, last);
+}
+
+// excecuted once per 1ms.(excess for just timer count?)
+#ifndef __AVR_ATmega32A__
+#define TIMER_INTERRUPT_VECTOR TIMER0_COMPA_vect
+#else
+#define TIMER_INTERRUPT_VECTOR TIMER0_COMP_vect
+#endif
+ISR(TIMER_INTERRUPT_VECTOR, ISR_NOBLOCK)
+{
+    timer_count++;
+}